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-rw-r--r--drivers/i2c/muxes/Kconfig122
-rw-r--r--drivers/i2c/muxes/Makefile18
-rw-r--r--drivers/i2c/muxes/i2c-arb-gpio-challenge.c205
-rw-r--r--drivers/i2c/muxes/i2c-demux-pinctrl.c324
-rw-r--r--drivers/i2c/muxes/i2c-mux-gpio.c258
-rw-r--r--drivers/i2c/muxes/i2c-mux-gpmux.c165
-rw-r--r--drivers/i2c/muxes/i2c-mux-ltc4306.c317
-rw-r--r--drivers/i2c/muxes/i2c-mux-mlxcpld.c193
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca9541.c348
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c647
-rw-r--r--drivers/i2c/muxes/i2c-mux-pinctrl.c196
-rw-r--r--drivers/i2c/muxes/i2c-mux-reg.c264
12 files changed, 3057 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
new file mode 100644
index 0000000000..db1b905761
--- /dev/null
+++ b/drivers/i2c/muxes/Kconfig
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Multiplexer I2C chip drivers configuration
+#
+
+menu "Multiplexer I2C Chip support"
+ depends on I2C_MUX
+
+config I2C_ARB_GPIO_CHALLENGE
+ tristate "GPIO-based I2C arbitration"
+ depends on GPIOLIB || COMPILE_TEST
+ depends on OF
+ help
+ If you say yes to this option, support will be included for an
+ I2C multimaster arbitration scheme using GPIOs and a challenge &
+ response mechanism where masters have to claim the bus by asserting
+ a GPIO.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-arb-gpio-challenge.
+
+config I2C_MUX_GPIO
+ tristate "GPIO-based I2C multiplexer"
+ depends on GPIOLIB
+ help
+ If you say yes to this option, support will be included for a
+ GPIO based I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ through GPIO pins.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-gpio.
+
+config I2C_MUX_GPMUX
+ tristate "General Purpose I2C multiplexer"
+ select MULTIPLEXER
+ depends on OF
+ help
+ If you say yes to this option, support will be included for a
+ general purpose I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which in turn is controlled
+ by a MUX-controller from the MUX subsystem.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-gpmux.
+
+config I2C_MUX_LTC4306
+ tristate "LTC LTC4306/5 I2C multiplexer"
+ select GPIOLIB
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for the Analog Devices
+ LTC4306 or LTC4305 I2C mux/switch devices.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-ltc4306.
+
+config I2C_MUX_PCA9541
+ tristate "NXP PCA9541 I2C Master Selector"
+ help
+ If you say yes here you get support for the NXP PCA9541
+ I2C Master Selector.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-pca9541.
+
+config I2C_MUX_PCA954x
+ tristate "NXP PCA954x/PCA984x and Maxim MAX735x/MAX736x I2C Mux/switches"
+ depends on GPIOLIB || COMPILE_TEST
+ help
+ If you say yes here you get support for NXP PCA954x/PCA984x
+ and Maxim MAX735x/MAX736x I2C mux/switch devices.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-pca954x.
+
+config I2C_MUX_PINCTRL
+ tristate "pinctrl-based I2C multiplexer"
+ depends on PINCTRL
+ depends on OF
+ help
+ If you say yes to this option, support will be included for an I2C
+ multiplexer that uses the pinctrl subsystem, i.e. pin multiplexing.
+ This is useful for SoCs whose I2C module's signals can be routed to
+ different sets of pins at run-time.
+
+ This driver can also be built as a module. If so, the module will be
+ called i2c-mux-pinctrl.
+
+config I2C_MUX_REG
+ tristate "Register-based I2C multiplexer"
+ depends on HAS_IOMEM
+ help
+ If you say yes to this option, support will be included for a
+ register based I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ by a single register.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-reg.
+
+config I2C_DEMUX_PINCTRL
+ tristate "pinctrl-based I2C demultiplexer"
+ depends on PINCTRL && OF
+ select OF_DYNAMIC
+ help
+ If you say yes to this option, support will be included for an I2C
+ demultiplexer that uses the pinctrl subsystem. This is useful if you
+ want to change the I2C master at run-time depending on features.
+
+config I2C_MUX_MLXCPLD
+ tristate "Mellanox CPLD based I2C multiplexer"
+ help
+ If you say yes to this option, support will be included for a
+ CPLD based I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ by a CPLD register.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-mlxcpld.
+
+endmenu
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
new file mode 100644
index 0000000000..6d9d865e85
--- /dev/null
+++ b/drivers/i2c/muxes/Makefile
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for multiplexer I2C chip drivers.
+
+obj-$(CONFIG_I2C_ARB_GPIO_CHALLENGE) += i2c-arb-gpio-challenge.o
+
+obj-$(CONFIG_I2C_DEMUX_PINCTRL) += i2c-demux-pinctrl.o
+
+obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o
+obj-$(CONFIG_I2C_MUX_GPMUX) += i2c-mux-gpmux.o
+obj-$(CONFIG_I2C_MUX_LTC4306) += i2c-mux-ltc4306.o
+obj-$(CONFIG_I2C_MUX_MLXCPLD) += i2c-mux-mlxcpld.o
+obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o
+obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o
+obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o
+obj-$(CONFIG_I2C_MUX_REG) += i2c-mux-reg.o
+
+ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
new file mode 100644
index 0000000000..24168e9f7d
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO-based I2C Arbitration Using a Challenge & Response Mechanism
+ *
+ * Copyright (C) 2012 Google, Inc
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+
+/**
+ * struct i2c_arbitrator_data - Driver data for I2C arbitrator
+ *
+ * @our_gpio: GPIO descriptor we'll use to claim.
+ * @their_gpio: GPIO descriptor that the other side will use to claim.
+ * @slew_delay_us: microseconds to wait for a GPIO to go high.
+ * @wait_retry_us: we'll attempt another claim after this many microseconds.
+ * @wait_free_us: we'll give up after this many microseconds.
+ */
+
+struct i2c_arbitrator_data {
+ struct gpio_desc *our_gpio;
+ struct gpio_desc *their_gpio;
+ unsigned int slew_delay_us;
+ unsigned int wait_retry_us;
+ unsigned int wait_free_us;
+};
+
+
+/*
+ * i2c_arbitrator_select - claim the I2C bus
+ *
+ * Use the GPIO-based signalling protocol; return -EBUSY if we fail.
+ */
+static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);
+ unsigned long stop_retry, stop_time;
+
+ /* Start a round of trying to claim the bus */
+ stop_time = jiffies + usecs_to_jiffies(arb->wait_free_us) + 1;
+ do {
+ /* Indicate that we want to claim the bus */
+ gpiod_set_value(arb->our_gpio, 1);
+ udelay(arb->slew_delay_us);
+
+ /* Wait for the other master to release it */
+ stop_retry = jiffies + usecs_to_jiffies(arb->wait_retry_us) + 1;
+ while (time_before(jiffies, stop_retry)) {
+ int gpio_val = gpiod_get_value(arb->their_gpio);
+
+ if (!gpio_val) {
+ /* We got it, so return */
+ return 0;
+ }
+
+ usleep_range(50, 200);
+ }
+
+ /* It didn't release, so give up, wait, and try again */
+ gpiod_set_value(arb->our_gpio, 0);
+
+ usleep_range(arb->wait_retry_us, arb->wait_retry_us * 2);
+ } while (time_before(jiffies, stop_time));
+
+ /* Give up, release our claim */
+ gpiod_set_value(arb->our_gpio, 0);
+ udelay(arb->slew_delay_us);
+ dev_err(muxc->dev, "Could not claim bus, timeout\n");
+ return -EBUSY;
+}
+
+/*
+ * i2c_arbitrator_deselect - release the I2C bus
+ *
+ * Release the I2C bus using the GPIO-based signalling protocol.
+ */
+static int i2c_arbitrator_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);
+
+ /* Release the bus and wait for the other master to notice */
+ gpiod_set_value(arb->our_gpio, 0);
+ udelay(arb->slew_delay_us);
+
+ return 0;
+}
+
+static int i2c_arbitrator_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_mux_core *muxc;
+ struct i2c_arbitrator_data *arb;
+ struct gpio_desc *dummy;
+ int ret;
+
+ /* We only support probing from device tree; no platform_data */
+ if (!np) {
+ dev_err(dev, "Cannot find device tree node\n");
+ return -ENODEV;
+ }
+ if (dev_get_platdata(dev)) {
+ dev_err(dev, "Platform data is not supported\n");
+ return -EINVAL;
+ }
+
+ muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), I2C_MUX_ARBITRATOR,
+ i2c_arbitrator_select, i2c_arbitrator_deselect);
+ if (!muxc)
+ return -ENOMEM;
+ arb = i2c_mux_priv(muxc);
+
+ platform_set_drvdata(pdev, muxc);
+
+ /* Request GPIOs, our GPIO as unclaimed to begin with */
+ arb->our_gpio = devm_gpiod_get(dev, "our-claim", GPIOD_OUT_LOW);
+ if (IS_ERR(arb->our_gpio)) {
+ dev_err(dev, "could not get \"our-claim\" GPIO (%ld)\n",
+ PTR_ERR(arb->our_gpio));
+ return PTR_ERR(arb->our_gpio);
+ }
+
+ arb->their_gpio = devm_gpiod_get(dev, "their-claim", GPIOD_IN);
+ if (IS_ERR(arb->their_gpio)) {
+ dev_err(dev, "could not get \"their-claim\" GPIO (%ld)\n",
+ PTR_ERR(arb->their_gpio));
+ return PTR_ERR(arb->their_gpio);
+ }
+
+ /* At the moment we only support a single two master (us + 1 other) */
+ dummy = devm_gpiod_get_index(dev, "their-claim", 1, GPIOD_IN);
+ if (!IS_ERR(dummy)) {
+ dev_err(dev, "Only one other master is supported\n");
+ return -EINVAL;
+ } else if (PTR_ERR(dummy) == -EPROBE_DEFER) {
+ return -EPROBE_DEFER;
+ }
+
+ /* Arbitration parameters */
+ if (of_property_read_u32(np, "slew-delay-us", &arb->slew_delay_us))
+ arb->slew_delay_us = 10;
+ if (of_property_read_u32(np, "wait-retry-us", &arb->wait_retry_us))
+ arb->wait_retry_us = 3000;
+ if (of_property_read_u32(np, "wait-free-us", &arb->wait_free_us))
+ arb->wait_free_us = 50000;
+
+ /* Find our parent */
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return -EINVAL;
+ }
+ muxc->parent = of_get_i2c_adapter_by_node(parent_np);
+ of_node_put(parent_np);
+ if (!muxc->parent) {
+ dev_err(dev, "Cannot find parent bus\n");
+ return -EPROBE_DEFER;
+ }
+
+ /* Actually add the mux adapter */
+ ret = i2c_mux_add_adapter(muxc, 0, 0, 0);
+ if (ret)
+ i2c_put_adapter(muxc->parent);
+
+ return ret;
+}
+
+static void i2c_arbitrator_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+}
+
+static const struct of_device_id i2c_arbitrator_of_match[] = {
+ { .compatible = "i2c-arb-gpio-challenge", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_arbitrator_of_match);
+
+static struct platform_driver i2c_arbitrator_driver = {
+ .probe = i2c_arbitrator_probe,
+ .remove_new = i2c_arbitrator_remove,
+ .driver = {
+ .name = "i2c-arb-gpio-challenge",
+ .of_match_table = i2c_arbitrator_of_match,
+ },
+};
+
+module_platform_driver(i2c_arbitrator_driver);
+
+MODULE_DESCRIPTION("GPIO-based I2C Arbitration");
+MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-arb-gpio-challenge");
diff --git a/drivers/i2c/muxes/i2c-demux-pinctrl.c b/drivers/i2c/muxes/i2c-demux-pinctrl.c
new file mode 100644
index 0000000000..9f2e4aa281
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Pinctrl based I2C DeMultiplexer
+ *
+ * Copyright (C) 2015-16 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ * Copyright (C) 2015-16 by Renesas Electronics Corporation
+ *
+ * See the bindings doc for DTS setup and the sysfs doc for usage information.
+ * (look for filenames containing 'i2c-demux-pinctrl' in Documentation/)
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+struct i2c_demux_pinctrl_chan {
+ struct device_node *parent_np;
+ struct i2c_adapter *parent_adap;
+ struct of_changeset chgset;
+};
+
+struct i2c_demux_pinctrl_priv {
+ int cur_chan;
+ int num_chan;
+ struct device *dev;
+ const char *bus_name;
+ struct i2c_adapter cur_adap;
+ struct i2c_algorithm algo;
+ struct i2c_demux_pinctrl_chan chan[];
+};
+
+static int i2c_demux_master_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ struct i2c_demux_pinctrl_priv *priv = adap->algo_data;
+ struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;
+
+ return __i2c_transfer(parent, msgs, num);
+}
+
+static u32 i2c_demux_functionality(struct i2c_adapter *adap)
+{
+ struct i2c_demux_pinctrl_priv *priv = adap->algo_data;
+ struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;
+
+ return parent->algo->functionality(parent);
+}
+
+static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 new_chan)
+{
+ struct i2c_adapter *adap;
+ struct pinctrl *p;
+ int ret;
+
+ ret = of_changeset_apply(&priv->chan[new_chan].chgset);
+ if (ret)
+ goto err;
+
+ adap = of_get_i2c_adapter_by_node(priv->chan[new_chan].parent_np);
+ if (!adap) {
+ ret = -ENODEV;
+ goto err_with_revert;
+ }
+
+ /*
+ * Check if there are pinctrl states at all. Note: we cant' use
+ * devm_pinctrl_get_select() because we need to distinguish between
+ * the -ENODEV from devm_pinctrl_get() and pinctrl_lookup_state().
+ */
+ p = devm_pinctrl_get(adap->dev.parent);
+ if (IS_ERR(p)) {
+ ret = PTR_ERR(p);
+ /* continue if just no pinctrl states (e.g. i2c-gpio), otherwise exit */
+ if (ret != -ENODEV)
+ goto err_with_put;
+ } else {
+ /* there are states. check and use them */
+ struct pinctrl_state *s = pinctrl_lookup_state(p, priv->bus_name);
+
+ if (IS_ERR(s)) {
+ ret = PTR_ERR(s);
+ goto err_with_put;
+ }
+ ret = pinctrl_select_state(p, s);
+ if (ret < 0)
+ goto err_with_put;
+ }
+
+ priv->chan[new_chan].parent_adap = adap;
+ priv->cur_chan = new_chan;
+
+ /* Now fill out current adapter structure. cur_chan must be up to date */
+ priv->algo.master_xfer = i2c_demux_master_xfer;
+ if (adap->algo->master_xfer_atomic)
+ priv->algo.master_xfer_atomic = i2c_demux_master_xfer;
+ priv->algo.functionality = i2c_demux_functionality;
+
+ snprintf(priv->cur_adap.name, sizeof(priv->cur_adap.name),
+ "i2c-demux (master i2c-%d)", i2c_adapter_id(adap));
+ priv->cur_adap.owner = THIS_MODULE;
+ priv->cur_adap.algo = &priv->algo;
+ priv->cur_adap.algo_data = priv;
+ priv->cur_adap.dev.parent = &adap->dev;
+ priv->cur_adap.class = adap->class;
+ priv->cur_adap.retries = adap->retries;
+ priv->cur_adap.timeout = adap->timeout;
+ priv->cur_adap.quirks = adap->quirks;
+ priv->cur_adap.dev.of_node = priv->dev->of_node;
+ ret = i2c_add_adapter(&priv->cur_adap);
+ if (ret < 0)
+ goto err_with_put;
+
+ return 0;
+
+ err_with_put:
+ i2c_put_adapter(adap);
+ err_with_revert:
+ of_changeset_revert(&priv->chan[new_chan].chgset);
+ err:
+ dev_err(priv->dev, "failed to setup demux-adapter %d (%d)\n", new_chan, ret);
+ priv->cur_chan = -EINVAL;
+ return ret;
+}
+
+static int i2c_demux_deactivate_master(struct i2c_demux_pinctrl_priv *priv)
+{
+ int ret, cur = priv->cur_chan;
+
+ if (cur < 0)
+ return 0;
+
+ i2c_del_adapter(&priv->cur_adap);
+ i2c_put_adapter(priv->chan[cur].parent_adap);
+
+ ret = of_changeset_revert(&priv->chan[cur].chgset);
+
+ priv->chan[cur].parent_adap = NULL;
+ priv->cur_chan = -EINVAL;
+
+ return ret;
+}
+
+static int i2c_demux_change_master(struct i2c_demux_pinctrl_priv *priv, u32 new_chan)
+{
+ int ret;
+
+ if (new_chan == priv->cur_chan)
+ return 0;
+
+ ret = i2c_demux_deactivate_master(priv);
+ if (ret)
+ return ret;
+
+ return i2c_demux_activate_master(priv, new_chan);
+}
+
+static ssize_t available_masters_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
+ int count = 0, i;
+
+ for (i = 0; i < priv->num_chan && count < PAGE_SIZE; i++)
+ count += scnprintf(buf + count, PAGE_SIZE - count, "%d:%pOF%c",
+ i, priv->chan[i].parent_np,
+ i == priv->num_chan - 1 ? '\n' : ' ');
+
+ return count;
+}
+static DEVICE_ATTR_RO(available_masters);
+
+static ssize_t current_master_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", priv->cur_chan);
+}
+
+static ssize_t current_master_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+
+ if (val >= priv->num_chan)
+ return -EINVAL;
+
+ ret = i2c_demux_change_master(priv, val);
+
+ return ret < 0 ? ret : count;
+}
+static DEVICE_ATTR_RW(current_master);
+
+static int i2c_demux_pinctrl_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct i2c_demux_pinctrl_priv *priv;
+ struct property *props;
+ int num_chan, i, j, err;
+
+ num_chan = of_count_phandle_with_args(np, "i2c-parent", NULL);
+ if (num_chan < 2) {
+ dev_err(&pdev->dev, "Need at least two I2C masters to switch\n");
+ return -EINVAL;
+ }
+
+ priv = devm_kzalloc(&pdev->dev, struct_size(priv, chan, num_chan),
+ GFP_KERNEL);
+
+ props = devm_kcalloc(&pdev->dev, num_chan, sizeof(*props), GFP_KERNEL);
+
+ if (!priv || !props)
+ return -ENOMEM;
+
+ err = of_property_read_string(np, "i2c-bus-name", &priv->bus_name);
+ if (err)
+ return err;
+
+ for (i = 0; i < num_chan; i++) {
+ struct device_node *adap_np;
+
+ adap_np = of_parse_phandle(np, "i2c-parent", i);
+ if (!adap_np) {
+ dev_err(&pdev->dev, "can't get phandle for parent %d\n", i);
+ err = -ENOENT;
+ goto err_rollback;
+ }
+ priv->chan[i].parent_np = adap_np;
+
+ props[i].name = devm_kstrdup(&pdev->dev, "status", GFP_KERNEL);
+ props[i].value = devm_kstrdup(&pdev->dev, "ok", GFP_KERNEL);
+ if (!props[i].name || !props[i].value) {
+ err = -ENOMEM;
+ goto err_rollback;
+ }
+ props[i].length = 3;
+
+ of_changeset_init(&priv->chan[i].chgset);
+ of_changeset_update_property(&priv->chan[i].chgset, adap_np, &props[i]);
+ }
+
+ priv->num_chan = num_chan;
+ priv->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, priv);
+
+ pm_runtime_no_callbacks(&pdev->dev);
+
+ /* switch to first parent as active master */
+ i2c_demux_activate_master(priv, 0);
+
+ err = device_create_file(&pdev->dev, &dev_attr_available_masters);
+ if (err)
+ goto err_rollback_activation;
+
+ err = device_create_file(&pdev->dev, &dev_attr_current_master);
+ if (err)
+ goto err_rollback_available;
+
+ return 0;
+
+err_rollback_available:
+ device_remove_file(&pdev->dev, &dev_attr_available_masters);
+err_rollback_activation:
+ i2c_demux_deactivate_master(priv);
+err_rollback:
+ for (j = 0; j < i; j++) {
+ of_node_put(priv->chan[j].parent_np);
+ of_changeset_destroy(&priv->chan[j].chgset);
+ }
+
+ return err;
+}
+
+static void i2c_demux_pinctrl_remove(struct platform_device *pdev)
+{
+ struct i2c_demux_pinctrl_priv *priv = platform_get_drvdata(pdev);
+ int i;
+
+ device_remove_file(&pdev->dev, &dev_attr_current_master);
+ device_remove_file(&pdev->dev, &dev_attr_available_masters);
+
+ i2c_demux_deactivate_master(priv);
+
+ for (i = 0; i < priv->num_chan; i++) {
+ of_node_put(priv->chan[i].parent_np);
+ of_changeset_destroy(&priv->chan[i].chgset);
+ }
+}
+
+static const struct of_device_id i2c_demux_pinctrl_of_match[] = {
+ { .compatible = "i2c-demux-pinctrl", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_demux_pinctrl_of_match);
+
+static struct platform_driver i2c_demux_pinctrl_driver = {
+ .driver = {
+ .name = "i2c-demux-pinctrl",
+ .of_match_table = i2c_demux_pinctrl_of_match,
+ },
+ .probe = i2c_demux_pinctrl_probe,
+ .remove_new = i2c_demux_pinctrl_remove,
+};
+module_platform_driver(i2c_demux_pinctrl_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C demux driver");
+MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-demux-pinctrl");
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
new file mode 100644
index 0000000000..5ca03bd34c
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C multiplexer using GPIO API
+ *
+ * Peter Korsgaard <peter.korsgaard@barco.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/overflow.h>
+#include <linux/platform_data/i2c-mux-gpio.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/bits.h>
+#include <linux/gpio/consumer.h>
+/* FIXME: stop poking around inside gpiolib */
+#include "../../gpio/gpiolib.h"
+
+struct gpiomux {
+ struct i2c_mux_gpio_platform_data data;
+ int ngpios;
+ struct gpio_desc **gpios;
+};
+
+static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
+{
+ DECLARE_BITMAP(values, BITS_PER_TYPE(val));
+
+ values[0] = val;
+
+ gpiod_set_array_value_cansleep(mux->ngpios, mux->gpios, NULL, values);
+}
+
+static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct gpiomux *mux = i2c_mux_priv(muxc);
+
+ i2c_mux_gpio_set(mux, chan);
+
+ return 0;
+}
+
+static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct gpiomux *mux = i2c_mux_priv(muxc);
+
+ i2c_mux_gpio_set(mux, mux->data.idle);
+
+ return 0;
+}
+
+static int i2c_mux_gpio_probe_fw(struct gpiomux *mux,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct fwnode_handle *fwnode = dev_fwnode(dev);
+ struct device_node *np = dev->of_node;
+ struct device_node *adapter_np;
+ struct i2c_adapter *adapter = NULL;
+ struct fwnode_handle *child;
+ unsigned *values;
+ int rc, i = 0;
+
+ if (is_of_node(fwnode)) {
+ if (!np)
+ return -ENODEV;
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ of_node_put(adapter_np);
+
+ } else if (is_acpi_node(fwnode)) {
+ /*
+ * In ACPI land the mux should be a direct child of the i2c
+ * bus it muxes.
+ */
+ acpi_handle dev_handle = ACPI_HANDLE(dev->parent);
+
+ adapter = i2c_acpi_find_adapter_by_handle(dev_handle);
+ }
+
+ if (!adapter)
+ return -EPROBE_DEFER;
+
+ mux->data.parent = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ mux->data.n_values = device_get_child_node_count(dev);
+ values = devm_kcalloc(dev,
+ mux->data.n_values, sizeof(*mux->data.values),
+ GFP_KERNEL);
+ if (!values) {
+ dev_err(dev, "Cannot allocate values array");
+ return -ENOMEM;
+ }
+
+ device_for_each_child_node(dev, child) {
+ if (is_of_node(child)) {
+ fwnode_property_read_u32(child, "reg", values + i);
+
+ } else if (is_acpi_node(child)) {
+ rc = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), values + i);
+ if (rc) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, rc, "Cannot get address\n");
+ }
+ }
+
+ i++;
+ }
+ mux->data.values = values;
+
+ if (device_property_read_u32(dev, "idle-state", &mux->data.idle))
+ mux->data.idle = I2C_MUX_GPIO_NO_IDLE;
+
+ return 0;
+}
+
+static int i2c_mux_gpio_probe(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc;
+ struct gpiomux *mux;
+ struct i2c_adapter *parent;
+ struct i2c_adapter *root;
+ unsigned initial_state;
+ int i, ngpios, ret;
+
+ mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ if (!dev_get_platdata(&pdev->dev)) {
+ ret = i2c_mux_gpio_probe_fw(mux, pdev);
+ if (ret < 0)
+ return ret;
+ } else {
+ memcpy(&mux->data, dev_get_platdata(&pdev->dev),
+ sizeof(mux->data));
+ }
+
+ ngpios = gpiod_count(&pdev->dev, "mux");
+ if (ngpios <= 0) {
+ dev_err(&pdev->dev, "no valid gpios provided\n");
+ return ngpios ?: -EINVAL;
+ }
+ mux->ngpios = ngpios;
+
+ parent = i2c_get_adapter(mux->data.parent);
+ if (!parent)
+ return -EPROBE_DEFER;
+
+ muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values,
+ array_size(ngpios, sizeof(*mux->gpios)), 0,
+ i2c_mux_gpio_select, NULL);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto alloc_failed;
+ }
+ mux->gpios = muxc->priv;
+ muxc->priv = mux;
+
+ platform_set_drvdata(pdev, muxc);
+
+ root = i2c_root_adapter(&parent->dev);
+
+ muxc->mux_locked = true;
+
+ if (mux->data.idle != I2C_MUX_GPIO_NO_IDLE) {
+ initial_state = mux->data.idle;
+ muxc->deselect = i2c_mux_gpio_deselect;
+ } else {
+ initial_state = mux->data.values[0];
+ }
+
+ for (i = 0; i < ngpios; i++) {
+ struct device *gpio_dev;
+ struct gpio_desc *gpiod;
+ enum gpiod_flags flag;
+
+ if (initial_state & BIT(i))
+ flag = GPIOD_OUT_HIGH;
+ else
+ flag = GPIOD_OUT_LOW;
+ gpiod = devm_gpiod_get_index(&pdev->dev, "mux", i, flag);
+ if (IS_ERR(gpiod)) {
+ ret = PTR_ERR(gpiod);
+ goto alloc_failed;
+ }
+
+ mux->gpios[i] = gpiod;
+
+ if (!muxc->mux_locked)
+ continue;
+
+ /* FIXME: find a proper way to access the GPIO device */
+ gpio_dev = &gpiod->gdev->dev;
+ muxc->mux_locked = i2c_root_adapter(gpio_dev) == root;
+ }
+
+ if (muxc->mux_locked)
+ dev_info(&pdev->dev, "mux-locked i2c mux\n");
+
+ for (i = 0; i < mux->data.n_values; i++) {
+ u32 nr = mux->data.base_nr ? (mux->data.base_nr + i) : 0;
+ unsigned int class = mux->data.classes ? mux->data.classes[i] : 0;
+
+ ret = i2c_mux_add_adapter(muxc, nr, mux->data.values[i], class);
+ if (ret)
+ goto add_adapter_failed;
+ }
+
+ dev_info(&pdev->dev, "%d port mux on %s adapter\n",
+ mux->data.n_values, parent->name);
+
+ return 0;
+
+add_adapter_failed:
+ i2c_mux_del_adapters(muxc);
+alloc_failed:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static void i2c_mux_gpio_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+}
+
+static const struct of_device_id i2c_mux_gpio_of_match[] = {
+ { .compatible = "i2c-mux-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_gpio_of_match);
+
+static struct platform_driver i2c_mux_gpio_driver = {
+ .probe = i2c_mux_gpio_probe,
+ .remove_new = i2c_mux_gpio_remove,
+ .driver = {
+ .name = "i2c-mux-gpio",
+ .of_match_table = i2c_mux_gpio_of_match,
+ },
+};
+
+module_platform_driver(i2c_mux_gpio_driver);
+
+MODULE_DESCRIPTION("GPIO-based I2C multiplexer driver");
+MODULE_AUTHOR("Peter Korsgaard <peter.korsgaard@barco.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c-mux-gpio");
diff --git a/drivers/i2c/muxes/i2c-mux-gpmux.c b/drivers/i2c/muxes/i2c-mux-gpmux.c
new file mode 100644
index 0000000000..8305661e12
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-gpmux.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * General Purpose I2C multiplexer
+ *
+ * Copyright (C) 2017 Axentia Technologies AB
+ *
+ * Author: Peter Rosin <peda@axentia.se>
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/mux/consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+struct mux {
+ struct mux_control *control;
+
+ bool do_not_deselect;
+};
+
+static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+ int ret;
+
+ ret = mux_control_select(mux->control, chan);
+ mux->do_not_deselect = ret < 0;
+
+ return ret;
+}
+
+static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+
+ if (mux->do_not_deselect)
+ return 0;
+
+ return mux_control_deselect(mux->control);
+}
+
+static struct i2c_adapter *mux_parent_adapter(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_adapter *parent;
+
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return ERR_PTR(-ENODEV);
+ }
+ parent = of_get_i2c_adapter_by_node(parent_np);
+ of_node_put(parent_np);
+ if (!parent)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return parent;
+}
+
+static const struct of_device_id i2c_mux_of_match[] = {
+ { .compatible = "i2c-mux", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
+
+static int i2c_mux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *child;
+ struct i2c_mux_core *muxc;
+ struct mux *mux;
+ struct i2c_adapter *parent;
+ int children;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ mux->control = devm_mux_control_get(dev, NULL);
+ if (IS_ERR(mux->control))
+ return dev_err_probe(dev, PTR_ERR(mux->control),
+ "failed to get control-mux\n");
+
+ parent = mux_parent_adapter(dev);
+ if (IS_ERR(parent))
+ return dev_err_probe(dev, PTR_ERR(parent),
+ "failed to get i2c-parent adapter\n");
+
+ children = of_get_child_count(np);
+
+ muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
+ i2c_mux_select, i2c_mux_deselect);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err_parent;
+ }
+ muxc->priv = mux;
+
+ platform_set_drvdata(pdev, muxc);
+
+ muxc->mux_locked = of_property_read_bool(np, "mux-locked");
+
+ for_each_child_of_node(np, child) {
+ u32 chan;
+
+ ret = of_property_read_u32(child, "reg", &chan);
+ if (ret < 0) {
+ dev_err(dev, "no reg property for node '%pOFn'\n",
+ child);
+ goto err_children;
+ }
+
+ if (chan >= mux_control_states(mux->control)) {
+ dev_err(dev, "invalid reg %u\n", chan);
+ ret = -EINVAL;
+ goto err_children;
+ }
+
+ ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
+ if (ret)
+ goto err_children;
+ }
+
+ dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
+
+ return 0;
+
+err_children:
+ of_node_put(child);
+ i2c_mux_del_adapters(muxc);
+err_parent:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static void i2c_mux_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+}
+
+static struct platform_driver i2c_mux_driver = {
+ .probe = i2c_mux_probe,
+ .remove_new = i2c_mux_remove,
+ .driver = {
+ .name = "i2c-mux-gpmux",
+ .of_match_table = i2c_mux_of_match,
+ },
+};
+module_platform_driver(i2c_mux_driver);
+
+MODULE_DESCRIPTION("General Purpose I2C multiplexer driver");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-ltc4306.c b/drivers/i2c/muxes/i2c-mux-ltc4306.c
new file mode 100644
index 0000000000..23766d853e
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-ltc4306.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Linear Technology LTC4306 and LTC4305 I2C multiplexer/switch
+ *
+ * Copyright (C) 2017 Analog Devices Inc.
+ *
+ * Based on: i2c-mux-pca954x.c
+ *
+ * Datasheet: http://cds.linear.com/docs/en/datasheet/4306.pdf
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c-mux.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define LTC4305_MAX_NCHANS 2
+#define LTC4306_MAX_NCHANS 4
+
+#define LTC_REG_STATUS 0x0
+#define LTC_REG_CONFIG 0x1
+#define LTC_REG_MODE 0x2
+#define LTC_REG_SWITCH 0x3
+
+#define LTC_DOWNSTREAM_ACCL_EN BIT(6)
+#define LTC_UPSTREAM_ACCL_EN BIT(7)
+
+#define LTC_GPIO_ALL_INPUT 0xC0
+#define LTC_SWITCH_MASK 0xF0
+
+enum ltc_type {
+ ltc_4305,
+ ltc_4306,
+};
+
+struct chip_desc {
+ u8 nchans;
+ u8 num_gpios;
+};
+
+struct ltc4306 {
+ struct regmap *regmap;
+ struct gpio_chip gpiochip;
+ const struct chip_desc *chip;
+};
+
+static const struct chip_desc chips[] = {
+ [ltc_4305] = {
+ .nchans = LTC4305_MAX_NCHANS,
+ },
+ [ltc_4306] = {
+ .nchans = LTC4306_MAX_NCHANS,
+ .num_gpios = 2,
+ },
+};
+
+static bool ltc4306_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+ return reg == LTC_REG_CONFIG;
+}
+
+static const struct regmap_config ltc4306_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = LTC_REG_SWITCH,
+ .volatile_reg = ltc4306_is_volatile_reg,
+ .cache_type = REGCACHE_FLAT,
+};
+
+static int ltc4306_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(data->regmap, LTC_REG_CONFIG, &val);
+ if (ret < 0)
+ return ret;
+
+ return !!(val & BIT(1 - offset));
+}
+
+static void ltc4306_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+
+ regmap_update_bits(data->regmap, LTC_REG_CONFIG, BIT(5 - offset),
+ value ? BIT(5 - offset) : 0);
+}
+
+static int ltc4306_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(data->regmap, LTC_REG_MODE, &val);
+ if (ret < 0)
+ return ret;
+
+ return !!(val & BIT(7 - offset));
+}
+
+static int ltc4306_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+
+ return regmap_update_bits(data->regmap, LTC_REG_MODE,
+ BIT(7 - offset), BIT(7 - offset));
+}
+
+static int ltc4306_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+
+ ltc4306_gpio_set(chip, offset, value);
+ return regmap_update_bits(data->regmap, LTC_REG_MODE,
+ BIT(7 - offset), 0);
+}
+
+static int ltc4306_gpio_set_config(struct gpio_chip *chip,
+ unsigned int offset, unsigned long config)
+{
+ struct ltc4306 *data = gpiochip_get_data(chip);
+ unsigned int val;
+
+ switch (pinconf_to_config_param(config)) {
+ case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ val = 0;
+ break;
+ case PIN_CONFIG_DRIVE_PUSH_PULL:
+ val = BIT(4 - offset);
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ return regmap_update_bits(data->regmap, LTC_REG_MODE,
+ BIT(4 - offset), val);
+}
+
+static int ltc4306_gpio_init(struct ltc4306 *data)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+
+ if (!data->chip->num_gpios)
+ return 0;
+
+ data->gpiochip.label = dev_name(dev);
+ data->gpiochip.base = -1;
+ data->gpiochip.ngpio = data->chip->num_gpios;
+ data->gpiochip.parent = dev;
+ data->gpiochip.can_sleep = true;
+ data->gpiochip.get_direction = ltc4306_gpio_get_direction;
+ data->gpiochip.direction_input = ltc4306_gpio_direction_input;
+ data->gpiochip.direction_output = ltc4306_gpio_direction_output;
+ data->gpiochip.get = ltc4306_gpio_get;
+ data->gpiochip.set = ltc4306_gpio_set;
+ data->gpiochip.set_config = ltc4306_gpio_set_config;
+ data->gpiochip.owner = THIS_MODULE;
+
+ /* gpiolib assumes all GPIOs default input */
+ regmap_write(data->regmap, LTC_REG_MODE, LTC_GPIO_ALL_INPUT);
+
+ return devm_gpiochip_add_data(dev, &data->gpiochip, data);
+}
+
+static int ltc4306_select_mux(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct ltc4306 *data = i2c_mux_priv(muxc);
+
+ return regmap_update_bits(data->regmap, LTC_REG_SWITCH,
+ LTC_SWITCH_MASK, BIT(7 - chan));
+}
+
+static int ltc4306_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct ltc4306 *data = i2c_mux_priv(muxc);
+
+ return regmap_update_bits(data->regmap, LTC_REG_SWITCH,
+ LTC_SWITCH_MASK, 0);
+}
+
+static const struct i2c_device_id ltc4306_id[] = {
+ { "ltc4305", ltc_4305 },
+ { "ltc4306", ltc_4306 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltc4306_id);
+
+static const struct of_device_id ltc4306_of_match[] = {
+ { .compatible = "lltc,ltc4305", .data = &chips[ltc_4305] },
+ { .compatible = "lltc,ltc4306", .data = &chips[ltc_4306] },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ltc4306_of_match);
+
+static int ltc4306_probe(struct i2c_client *client)
+{
+ struct i2c_adapter *adap = client->adapter;
+ const struct chip_desc *chip;
+ struct i2c_mux_core *muxc;
+ struct ltc4306 *data;
+ struct gpio_desc *gpio;
+ bool idle_disc;
+ unsigned int val = 0;
+ int num, ret;
+
+ chip = of_device_get_match_data(&client->dev);
+
+ if (!chip)
+ chip = &chips[i2c_match_id(ltc4306_id, client)->driver_data];
+
+ idle_disc = device_property_read_bool(&client->dev,
+ "i2c-mux-idle-disconnect");
+
+ muxc = i2c_mux_alloc(adap, &client->dev,
+ chip->nchans, sizeof(*data),
+ I2C_MUX_LOCKED, ltc4306_select_mux,
+ idle_disc ? ltc4306_deselect_mux : NULL);
+ if (!muxc)
+ return -ENOMEM;
+ data = i2c_mux_priv(muxc);
+ data->chip = chip;
+
+ i2c_set_clientdata(client, muxc);
+
+ data->regmap = devm_regmap_init_i2c(client, &ltc4306_regmap_config);
+ if (IS_ERR(data->regmap)) {
+ ret = PTR_ERR(data->regmap);
+ dev_err(&client->dev, "Failed to allocate register map: %d\n",
+ ret);
+ return ret;
+ }
+
+ /* Reset and enable the mux if an enable GPIO is specified. */
+ gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_LOW);
+ if (IS_ERR(gpio))
+ return PTR_ERR(gpio);
+
+ if (gpio) {
+ udelay(1);
+ gpiod_set_value(gpio, 1);
+ }
+
+ /*
+ * Write the mux register at addr to verify
+ * that the mux is in fact present. This also
+ * initializes the mux to disconnected state.
+ */
+ if (regmap_write(data->regmap, LTC_REG_SWITCH, 0) < 0) {
+ dev_warn(&client->dev, "probe failed\n");
+ return -ENODEV;
+ }
+
+ if (device_property_read_bool(&client->dev,
+ "ltc,downstream-accelerators-enable"))
+ val |= LTC_DOWNSTREAM_ACCL_EN;
+
+ if (device_property_read_bool(&client->dev,
+ "ltc,upstream-accelerators-enable"))
+ val |= LTC_UPSTREAM_ACCL_EN;
+
+ if (regmap_write(data->regmap, LTC_REG_CONFIG, val) < 0)
+ return -ENODEV;
+
+ ret = ltc4306_gpio_init(data);
+ if (ret < 0)
+ return ret;
+
+ /* Now create an adapter for each channel */
+ for (num = 0; num < chip->nchans; num++) {
+ ret = i2c_mux_add_adapter(muxc, 0, num, 0);
+ if (ret) {
+ i2c_mux_del_adapters(muxc);
+ return ret;
+ }
+ }
+
+ dev_info(&client->dev,
+ "registered %d multiplexed busses for I2C switch %s\n",
+ num, client->name);
+
+ return 0;
+}
+
+static void ltc4306_remove(struct i2c_client *client)
+{
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+
+ i2c_mux_del_adapters(muxc);
+}
+
+static struct i2c_driver ltc4306_driver = {
+ .driver = {
+ .name = "ltc4306",
+ .of_match_table = of_match_ptr(ltc4306_of_match),
+ },
+ .probe = ltc4306_probe,
+ .remove = ltc4306_remove,
+ .id_table = ltc4306_id,
+};
+
+module_i2c_driver(ltc4306_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Linear Technology LTC4306, LTC4305 I2C mux/switch driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-mlxcpld.c b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
new file mode 100644
index 0000000000..3dda00f1df
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*
+ * Mellanox i2c mux driver
+ *
+ * Copyright (C) 2016-2020 Mellanox Technologies
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_data/mlxcpld.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* mlxcpld_mux - mux control structure:
+ * @last_val - last selected register value or -1 if mux deselected
+ * @client - I2C device client
+ * @pdata: platform data
+ */
+struct mlxcpld_mux {
+ int last_val;
+ struct i2c_client *client;
+ struct mlxcpld_mux_plat_data pdata;
+};
+
+/* MUX logic description.
+ * Driver can support different mux control logic, according to CPLD
+ * implementation.
+ *
+ * Connectivity schema.
+ *
+ * i2c-mlxcpld Digital Analog
+ * driver
+ * *--------* * -> mux1 (virt bus2) -> mux -> |
+ * | I2CLPC | i2c physical * -> mux2 (virt bus3) -> mux -> |
+ * | bridge | bus 1 *---------* |
+ * | logic |---------------------> * mux reg * |
+ * | in CPLD| *---------* |
+ * *--------* i2c-mux-mlxpcld ^ * -> muxn (virt busn) -> mux -> |
+ * | driver | |
+ * | *---------------* | Devices
+ * | * CPLD (i2c bus)* select |
+ * | * registers for *--------*
+ * | * mux selection * deselect
+ * | *---------------*
+ * | |
+ * <--------> <----------->
+ * i2c cntrl Board cntrl reg
+ * reg space space (mux select,
+ * IO, LED, WD, info)
+ *
+ */
+
+/* Write to mux register. Don't use i2c_transfer() and i2c_smbus_xfer()
+ * for this as they will try to lock adapter a second time.
+ */
+static int mlxcpld_mux_reg_write(struct i2c_adapter *adap,
+ struct mlxcpld_mux *mux, u32 val)
+{
+ struct i2c_client *client = mux->client;
+ union i2c_smbus_data data;
+ struct i2c_msg msg;
+ u8 buf[3];
+
+ switch (mux->pdata.reg_size) {
+ case 1:
+ data.byte = val;
+ return __i2c_smbus_xfer(adap, client->addr, client->flags,
+ I2C_SMBUS_WRITE, mux->pdata.sel_reg_addr,
+ I2C_SMBUS_BYTE_DATA, &data);
+ case 2:
+ buf[0] = mux->pdata.sel_reg_addr >> 8;
+ buf[1] = mux->pdata.sel_reg_addr;
+ buf[2] = val;
+ msg.addr = client->addr;
+ msg.buf = buf;
+ msg.len = mux->pdata.reg_size + 1;
+ msg.flags = 0;
+ return __i2c_transfer(adap, &msg, 1);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mlxcpld_mux *mux = i2c_mux_priv(muxc);
+ u32 regval = chan;
+ int err = 0;
+
+ if (mux->pdata.reg_size == 1)
+ regval += 1;
+
+ /* Only select the channel if its different from the last channel */
+ if (mux->last_val != regval) {
+ err = mlxcpld_mux_reg_write(muxc->parent, mux, regval);
+ mux->last_val = err < 0 ? -1 : regval;
+ }
+
+ return err;
+}
+
+static int mlxcpld_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mlxcpld_mux *mux = i2c_mux_priv(muxc);
+
+ /* Deselect active channel */
+ mux->last_val = -1;
+
+ return mlxcpld_mux_reg_write(muxc->parent, mux, 0);
+}
+
+/* Probe/reomove functions */
+static int mlxcpld_mux_probe(struct platform_device *pdev)
+{
+ struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct i2c_client *client = to_i2c_client(pdev->dev.parent);
+ struct i2c_mux_core *muxc;
+ struct mlxcpld_mux *data;
+ int num, err;
+ u32 func;
+
+ if (!pdata)
+ return -EINVAL;
+
+ switch (pdata->reg_size) {
+ case 1:
+ func = I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
+ break;
+ case 2:
+ func = I2C_FUNC_I2C;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!i2c_check_functionality(client->adapter, func))
+ return -ENODEV;
+
+ muxc = i2c_mux_alloc(client->adapter, &pdev->dev, pdata->num_adaps,
+ sizeof(*data), 0, mlxcpld_mux_select_chan,
+ mlxcpld_mux_deselect);
+ if (!muxc)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, muxc);
+ data = i2c_mux_priv(muxc);
+ data->client = client;
+ memcpy(&data->pdata, pdata, sizeof(*pdata));
+ data->last_val = -1; /* force the first selection */
+
+ /* Create an adapter for each channel. */
+ for (num = 0; num < pdata->num_adaps; num++) {
+ err = i2c_mux_add_adapter(muxc, 0, pdata->chan_ids[num], 0);
+ if (err)
+ goto virt_reg_failed;
+ }
+
+ /* Notify caller when all channels' adapters are created. */
+ if (pdata->completion_notify)
+ pdata->completion_notify(pdata->handle, muxc->parent, muxc->adapter);
+
+ return 0;
+
+virt_reg_failed:
+ i2c_mux_del_adapters(muxc);
+ return err;
+}
+
+static void mlxcpld_mux_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+}
+
+static struct platform_driver mlxcpld_mux_driver = {
+ .driver = {
+ .name = "i2c-mux-mlxcpld",
+ },
+ .probe = mlxcpld_mux_probe,
+ .remove_new = mlxcpld_mux_remove,
+};
+
+module_platform_driver(mlxcpld_mux_driver);
+
+MODULE_AUTHOR("Michael Shych (michaels@mellanox.com)");
+MODULE_DESCRIPTION("Mellanox I2C-CPLD-MUX driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:i2c-mux-mlxcpld");
diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c
new file mode 100644
index 0000000000..ce0fb69249
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pca9541.c
@@ -0,0 +1,348 @@
+/*
+ * I2C multiplexer driver for PCA9541 bus master selector
+ *
+ * Copyright (c) 2010 Ericsson AB.
+ *
+ * Author: Guenter Roeck <linux@roeck-us.net>
+ *
+ * Derived from:
+ * pca954x.c
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/*
+ * The PCA9541 is a bus master selector. It supports two I2C masters connected
+ * to a single slave bus.
+ *
+ * Before each bus transaction, a master has to acquire bus ownership. After the
+ * transaction is complete, bus ownership has to be released. This fits well
+ * into the I2C multiplexer framework, which provides select and release
+ * functions for this purpose. For this reason, this driver is modeled as
+ * single-channel I2C bus multiplexer.
+ *
+ * This driver assumes that the two bus masters are controlled by two different
+ * hosts. If a single host controls both masters, platform code has to ensure
+ * that only one of the masters is instantiated at any given time.
+ */
+
+#define PCA9541_CONTROL 0x01
+#define PCA9541_ISTAT 0x02
+
+#define PCA9541_CTL_MYBUS BIT(0)
+#define PCA9541_CTL_NMYBUS BIT(1)
+#define PCA9541_CTL_BUSON BIT(2)
+#define PCA9541_CTL_NBUSON BIT(3)
+#define PCA9541_CTL_BUSINIT BIT(4)
+#define PCA9541_CTL_TESTON BIT(6)
+#define PCA9541_CTL_NTESTON BIT(7)
+
+#define PCA9541_ISTAT_INTIN BIT(0)
+#define PCA9541_ISTAT_BUSINIT BIT(1)
+#define PCA9541_ISTAT_BUSOK BIT(2)
+#define PCA9541_ISTAT_BUSLOST BIT(3)
+#define PCA9541_ISTAT_MYTEST BIT(6)
+#define PCA9541_ISTAT_NMYTEST BIT(7)
+
+#define BUSON (PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
+#define MYBUS (PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)
+#define mybus(x) (!((x) & MYBUS) || ((x) & MYBUS) == MYBUS)
+#define busoff(x) (!((x) & BUSON) || ((x) & BUSON) == BUSON)
+
+/* arbitration timeouts, in jiffies */
+#define ARB_TIMEOUT (HZ / 8) /* 125 ms until forcing bus ownership */
+#define ARB2_TIMEOUT (HZ / 4) /* 250 ms until acquisition failure */
+
+/* arbitration retry delays, in us */
+#define SELECT_DELAY_SHORT 50
+#define SELECT_DELAY_LONG 1000
+
+struct pca9541 {
+ struct i2c_client *client;
+ unsigned long select_timeout;
+ unsigned long arb_timeout;
+};
+
+static const struct i2c_device_id pca9541_id[] = {
+ {"pca9541", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, pca9541_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pca9541_of_match[] = {
+ { .compatible = "nxp,pca9541" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pca9541_of_match);
+#endif
+
+/*
+ * Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ * as they will try to lock the adapter a second time.
+ */
+static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
+{
+ struct i2c_adapter *adap = client->adapter;
+ union i2c_smbus_data data = { .byte = val };
+
+ return __i2c_smbus_xfer(adap, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+}
+
+/*
+ * Read from chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ * as they will try to lock adapter a second time.
+ */
+static int pca9541_reg_read(struct i2c_client *client, u8 command)
+{
+ struct i2c_adapter *adap = client->adapter;
+ union i2c_smbus_data data;
+ int ret;
+
+ ret = __i2c_smbus_xfer(adap, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+
+ return ret ?: data.byte;
+}
+
+/*
+ * Arbitration management functions
+ */
+
+/* Release bus. Also reset NTESTON and BUSINIT if it was set. */
+static void pca9541_release_bus(struct i2c_client *client)
+{
+ int reg;
+
+ reg = pca9541_reg_read(client, PCA9541_CONTROL);
+ if (reg >= 0 && !busoff(reg) && mybus(reg))
+ pca9541_reg_write(client, PCA9541_CONTROL,
+ (reg & PCA9541_CTL_NBUSON) >> 1);
+}
+
+/*
+ * Arbitration is defined as a two-step process. A bus master can only activate
+ * the slave bus if it owns it; otherwise it has to request ownership first.
+ * This multi-step process ensures that access contention is resolved
+ * gracefully.
+ *
+ * Bus Ownership Other master Action
+ * state requested access
+ * ----------------------------------------------------
+ * off - yes wait for arbitration timeout or
+ * for other master to drop request
+ * off no no take ownership
+ * off yes no turn on bus
+ * on yes - done
+ * on no - wait for arbitration timeout or
+ * for other master to release bus
+ *
+ * The main contention point occurs if the slave bus is off and both masters
+ * request ownership at the same time. In this case, one master will turn on
+ * the slave bus, believing that it owns it. The other master will request
+ * bus ownership. Result is that the bus is turned on, and master which did
+ * _not_ own the slave bus before ends up owning it.
+ */
+
+/* Control commands per PCA9541 datasheet */
+static const u8 pca9541_control[16] = {
+ 4, 0, 1, 5, 4, 4, 5, 5, 0, 0, 1, 1, 0, 4, 5, 1
+};
+
+/*
+ * Channel arbitration
+ *
+ * Return values:
+ * <0: error
+ * 0 : bus not acquired
+ * 1 : bus acquired
+ */
+static int pca9541_arbitrate(struct i2c_client *client)
+{
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+ struct pca9541 *data = i2c_mux_priv(muxc);
+ int reg;
+
+ reg = pca9541_reg_read(client, PCA9541_CONTROL);
+ if (reg < 0)
+ return reg;
+
+ if (busoff(reg)) {
+ int istat;
+ /*
+ * Bus is off. Request ownership or turn it on unless
+ * other master requested ownership.
+ */
+ istat = pca9541_reg_read(client, PCA9541_ISTAT);
+ if (!(istat & PCA9541_ISTAT_NMYTEST)
+ || time_is_before_eq_jiffies(data->arb_timeout)) {
+ /*
+ * Other master did not request ownership,
+ * or arbitration timeout expired. Take the bus.
+ */
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ pca9541_control[reg & 0x0f]
+ | PCA9541_CTL_NTESTON);
+ data->select_timeout = SELECT_DELAY_SHORT;
+ } else {
+ /*
+ * Other master requested ownership.
+ * Set extra long timeout to give it time to acquire it.
+ */
+ data->select_timeout = SELECT_DELAY_LONG * 2;
+ }
+ } else if (mybus(reg)) {
+ /*
+ * Bus is on, and we own it. We are done with acquisition.
+ * Reset NTESTON and BUSINIT, then return success.
+ */
+ if (reg & (PCA9541_CTL_NTESTON | PCA9541_CTL_BUSINIT))
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ reg & ~(PCA9541_CTL_NTESTON
+ | PCA9541_CTL_BUSINIT));
+ return 1;
+ } else {
+ /*
+ * Other master owns the bus.
+ * If arbitration timeout has expired, force ownership.
+ * Otherwise request it.
+ */
+ data->select_timeout = SELECT_DELAY_LONG;
+ if (time_is_before_eq_jiffies(data->arb_timeout)) {
+ /* Time is up, take the bus and reset it. */
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ pca9541_control[reg & 0x0f]
+ | PCA9541_CTL_BUSINIT
+ | PCA9541_CTL_NTESTON);
+ } else {
+ /* Request bus ownership if needed */
+ if (!(reg & PCA9541_CTL_NTESTON))
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ reg | PCA9541_CTL_NTESTON);
+ }
+ }
+ return 0;
+}
+
+static int pca9541_select_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct pca9541 *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+ int ret;
+ unsigned long timeout = jiffies + ARB2_TIMEOUT;
+ /* give up after this time */
+
+ data->arb_timeout = jiffies + ARB_TIMEOUT;
+ /* force bus ownership after this time */
+
+ do {
+ ret = pca9541_arbitrate(client);
+ if (ret)
+ return ret < 0 ? ret : 0;
+
+ if (data->select_timeout == SELECT_DELAY_SHORT)
+ udelay(data->select_timeout);
+ else
+ msleep(data->select_timeout / 1000);
+ } while (time_is_after_eq_jiffies(timeout));
+
+ return -ETIMEDOUT;
+}
+
+static int pca9541_release_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct pca9541 *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+
+ pca9541_release_bus(client);
+ return 0;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+static int pca9541_probe(struct i2c_client *client)
+{
+ struct i2c_adapter *adap = client->adapter;
+ struct i2c_mux_core *muxc;
+ struct pca9541 *data;
+ int ret;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ /*
+ * I2C accesses are unprotected here.
+ * We have to lock the I2C segment before releasing the bus.
+ */
+ i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
+ pca9541_release_bus(client);
+ i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
+
+ /* Create mux adapter */
+
+ muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data),
+ I2C_MUX_ARBITRATOR,
+ pca9541_select_chan, pca9541_release_chan);
+ if (!muxc)
+ return -ENOMEM;
+
+ data = i2c_mux_priv(muxc);
+ data->client = client;
+
+ i2c_set_clientdata(client, muxc);
+
+ ret = i2c_mux_add_adapter(muxc, 0, 0, 0);
+ if (ret)
+ return ret;
+
+ dev_info(&client->dev, "registered master selector for I2C %s\n",
+ client->name);
+
+ return 0;
+}
+
+static void pca9541_remove(struct i2c_client *client)
+{
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+
+ i2c_mux_del_adapters(muxc);
+}
+
+static struct i2c_driver pca9541_driver = {
+ .driver = {
+ .name = "pca9541",
+ .of_match_table = of_match_ptr(pca9541_of_match),
+ },
+ .probe = pca9541_probe,
+ .remove = pca9541_remove,
+ .id_table = pca9541_id,
+};
+
+module_i2c_driver(pca9541_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("PCA9541 I2C master selector driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
new file mode 100644
index 0000000000..2219062104
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -0,0 +1,647 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * I2C multiplexer
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This module supports the PCA954x and PCA984x series of I2C multiplexer/switch
+ * chips made by NXP Semiconductors.
+ * This includes the:
+ * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547,
+ * PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849.
+ *
+ * It's also compatible to Maxims MAX735x I2C switch chips, which are controlled
+ * as the NXP PCA9548 and the MAX736x chips that act like the PCA9544.
+ *
+ * This includes the:
+ * MAX7356, MAX7357, MAX7358, MAX7367, MAX7368 and MAX7369
+ *
+ * These chips are all controlled via the I2C bus itself, and all have a
+ * single 8-bit register. The upstream "parent" bus fans out to two,
+ * four, or eight downstream busses or channels; which of these
+ * are selected is determined by the chip type and register contents. A
+ * mux can select only one sub-bus at a time; a switch can select any
+ * combination simultaneously.
+ *
+ * Based on:
+ * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
+ * Copyright (C) 2006
+ *
+ * Based on:
+ * pca954x.c from Ken Harrenstien
+ * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
+ *
+ * Based on:
+ * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
+ * and
+ * pca9540.c from Jean Delvare <jdelvare@suse.de>.
+ */
+
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <dt-bindings/mux/mux.h>
+
+#define PCA954X_MAX_NCHANS 8
+
+#define PCA954X_IRQ_OFFSET 4
+
+enum pca_type {
+ max_7356,
+ max_7357,
+ max_7358,
+ max_7367,
+ max_7368,
+ max_7369,
+ pca_9540,
+ pca_9542,
+ pca_9543,
+ pca_9544,
+ pca_9545,
+ pca_9546,
+ pca_9547,
+ pca_9548,
+ pca_9846,
+ pca_9847,
+ pca_9848,
+ pca_9849,
+};
+
+struct chip_desc {
+ u8 nchans;
+ u8 enable; /* used for muxes only */
+ u8 has_irq;
+ enum muxtype {
+ pca954x_ismux = 0,
+ pca954x_isswi
+ } muxtype;
+ struct i2c_device_identity id;
+};
+
+struct pca954x {
+ const struct chip_desc *chip;
+
+ u8 last_chan; /* last register value */
+ /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
+ s32 idle_state;
+
+ struct i2c_client *client;
+
+ struct irq_domain *irq;
+ unsigned int irq_mask;
+ raw_spinlock_t lock;
+ struct regulator *supply;
+};
+
+/* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */
+static const struct chip_desc chips[] = {
+ [max_7356] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [max_7357] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ /*
+ * No interrupt controller support. The interrupt
+ * provides information about stuck channels.
+ */
+ },
+ [max_7358] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ /*
+ * No interrupt controller support. The interrupt
+ * provides information about stuck channels.
+ */
+ },
+ [max_7367] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ .has_irq = 1,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [max_7368] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [max_7369] = {
+ .nchans = 4,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ .has_irq = 1,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9540] = {
+ .nchans = 2,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9542] = {
+ .nchans = 2,
+ .enable = 0x4,
+ .has_irq = 1,
+ .muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9543] = {
+ .nchans = 2,
+ .has_irq = 1,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9544] = {
+ .nchans = 4,
+ .enable = 0x4,
+ .has_irq = 1,
+ .muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9545] = {
+ .nchans = 4,
+ .has_irq = 1,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9546] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9547] = {
+ .nchans = 8,
+ .enable = 0x8,
+ .muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9548] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
+ },
+ [pca_9846] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x10b,
+ },
+ },
+ [pca_9847] = {
+ .nchans = 8,
+ .enable = 0x8,
+ .muxtype = pca954x_ismux,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x108,
+ },
+ },
+ [pca_9848] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x10a,
+ },
+ },
+ [pca_9849] = {
+ .nchans = 4,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x109,
+ },
+ },
+};
+
+static const struct i2c_device_id pca954x_id[] = {
+ { "max7356", max_7356 },
+ { "max7357", max_7357 },
+ { "max7358", max_7358 },
+ { "max7367", max_7367 },
+ { "max7368", max_7368 },
+ { "max7369", max_7369 },
+ { "pca9540", pca_9540 },
+ { "pca9542", pca_9542 },
+ { "pca9543", pca_9543 },
+ { "pca9544", pca_9544 },
+ { "pca9545", pca_9545 },
+ { "pca9546", pca_9546 },
+ { "pca9547", pca_9547 },
+ { "pca9548", pca_9548 },
+ { "pca9846", pca_9846 },
+ { "pca9847", pca_9847 },
+ { "pca9848", pca_9848 },
+ { "pca9849", pca_9849 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pca954x_id);
+
+static const struct of_device_id pca954x_of_match[] = {
+ { .compatible = "maxim,max7356", .data = &chips[max_7356] },
+ { .compatible = "maxim,max7357", .data = &chips[max_7357] },
+ { .compatible = "maxim,max7358", .data = &chips[max_7358] },
+ { .compatible = "maxim,max7367", .data = &chips[max_7367] },
+ { .compatible = "maxim,max7368", .data = &chips[max_7368] },
+ { .compatible = "maxim,max7369", .data = &chips[max_7369] },
+ { .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
+ { .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
+ { .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
+ { .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
+ { .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
+ { .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
+ { .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
+ { .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
+ { .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
+ { .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
+ { .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
+ { .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pca954x_of_match);
+
+/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ for this as they will try to lock adapter a second time */
+static int pca954x_reg_write(struct i2c_adapter *adap,
+ struct i2c_client *client, u8 val)
+{
+ union i2c_smbus_data dummy;
+
+ return __i2c_smbus_xfer(adap, client->addr, client->flags,
+ I2C_SMBUS_WRITE, val,
+ I2C_SMBUS_BYTE, &dummy);
+}
+
+static u8 pca954x_regval(struct pca954x *data, u8 chan)
+{
+ /* We make switches look like muxes, not sure how to be smarter. */
+ if (data->chip->muxtype == pca954x_ismux)
+ return chan | data->chip->enable;
+ else
+ return 1 << chan;
+}
+
+static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct pca954x *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+ u8 regval;
+ int ret = 0;
+
+ regval = pca954x_regval(data, chan);
+ /* Only select the channel if its different from the last channel */
+ if (data->last_chan != regval) {
+ ret = pca954x_reg_write(muxc->parent, client, regval);
+ data->last_chan = ret < 0 ? 0 : regval;
+ }
+
+ return ret;
+}
+
+static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct pca954x *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+ s32 idle_state;
+
+ idle_state = READ_ONCE(data->idle_state);
+ if (idle_state >= 0)
+ /* Set the mux back to a predetermined channel */
+ return pca954x_select_chan(muxc, idle_state);
+
+ if (idle_state == MUX_IDLE_DISCONNECT) {
+ /* Deselect active channel */
+ data->last_chan = 0;
+ return pca954x_reg_write(muxc->parent, client,
+ data->last_chan);
+ }
+
+ /* otherwise leave as-is */
+
+ return 0;
+}
+
+static ssize_t idle_state_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+ struct pca954x *data = i2c_mux_priv(muxc);
+
+ return sprintf(buf, "%d\n", READ_ONCE(data->idle_state));
+}
+
+static ssize_t idle_state_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+ struct pca954x *data = i2c_mux_priv(muxc);
+ int val;
+ int ret;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+
+ if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT &&
+ (val < 0 || val >= data->chip->nchans))
+ return -EINVAL;
+
+ i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT);
+
+ WRITE_ONCE(data->idle_state, val);
+ /*
+ * Set the mux into a state consistent with the new
+ * idle_state.
+ */
+ if (data->last_chan || val != MUX_IDLE_DISCONNECT)
+ ret = pca954x_deselect_mux(muxc, 0);
+
+ i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT);
+
+ return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR_RW(idle_state);
+
+static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
+{
+ struct pca954x *data = dev_id;
+ unsigned long pending;
+ int ret, i;
+
+ ret = i2c_smbus_read_byte(data->client);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ pending = (ret >> PCA954X_IRQ_OFFSET) & (BIT(data->chip->nchans) - 1);
+ for_each_set_bit(i, &pending, data->chip->nchans)
+ handle_nested_irq(irq_linear_revmap(data->irq, i));
+
+ return IRQ_RETVAL(pending);
+}
+
+static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
+{
+ if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
+ return -EINVAL;
+ return 0;
+}
+
+static struct irq_chip pca954x_irq_chip = {
+ .name = "i2c-mux-pca954x",
+ .irq_set_type = pca954x_irq_set_type,
+};
+
+static int pca954x_irq_setup(struct i2c_mux_core *muxc)
+{
+ struct pca954x *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+ int c, irq;
+
+ if (!data->chip->has_irq || client->irq <= 0)
+ return 0;
+
+ raw_spin_lock_init(&data->lock);
+
+ data->irq = irq_domain_add_linear(client->dev.of_node,
+ data->chip->nchans,
+ &irq_domain_simple_ops, data);
+ if (!data->irq)
+ return -ENODEV;
+
+ for (c = 0; c < data->chip->nchans; c++) {
+ irq = irq_create_mapping(data->irq, c);
+ if (!irq) {
+ dev_err(&client->dev, "failed irq create map\n");
+ return -EINVAL;
+ }
+ irq_set_chip_data(irq, data);
+ irq_set_chip_and_handler(irq, &pca954x_irq_chip,
+ handle_simple_irq);
+ }
+
+ return 0;
+}
+
+static void pca954x_cleanup(struct i2c_mux_core *muxc)
+{
+ struct pca954x *data = i2c_mux_priv(muxc);
+ int c, irq;
+
+ regulator_disable(data->supply);
+
+ if (data->irq) {
+ for (c = 0; c < data->chip->nchans; c++) {
+ irq = irq_find_mapping(data->irq, c);
+ irq_dispose_mapping(irq);
+ }
+ irq_domain_remove(data->irq);
+ }
+ i2c_mux_del_adapters(muxc);
+}
+
+static int pca954x_init(struct i2c_client *client, struct pca954x *data)
+{
+ int ret;
+
+ if (data->idle_state >= 0)
+ data->last_chan = pca954x_regval(data, data->idle_state);
+ else
+ data->last_chan = 0; /* Disconnect multiplexer */
+
+ ret = i2c_smbus_write_byte(client, data->last_chan);
+ if (ret < 0)
+ data->last_chan = 0;
+
+ return ret;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+static int pca954x_probe(struct i2c_client *client)
+{
+ const struct i2c_device_id *id = i2c_client_get_device_id(client);
+ struct i2c_adapter *adap = client->adapter;
+ struct device *dev = &client->dev;
+ struct gpio_desc *gpio;
+ struct i2c_mux_core *muxc;
+ struct pca954x *data;
+ int num;
+ int ret;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
+ return -ENODEV;
+
+ muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0,
+ pca954x_select_chan, pca954x_deselect_mux);
+ if (!muxc)
+ return -ENOMEM;
+ data = i2c_mux_priv(muxc);
+
+ i2c_set_clientdata(client, muxc);
+ data->client = client;
+
+ data->supply = devm_regulator_get(dev, "vdd");
+ if (IS_ERR(data->supply))
+ return dev_err_probe(dev, PTR_ERR(data->supply),
+ "Failed to request regulator\n");
+
+ ret = regulator_enable(data->supply);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to enable vdd supply\n");
+
+ /* Reset the mux if a reset GPIO is specified. */
+ gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(gpio)) {
+ ret = PTR_ERR(gpio);
+ goto fail_cleanup;
+ }
+ if (gpio) {
+ udelay(1);
+ gpiod_set_value_cansleep(gpio, 0);
+ /* Give the chip some time to recover. */
+ udelay(1);
+ }
+
+ data->chip = device_get_match_data(dev);
+ if (!data->chip)
+ data->chip = &chips[id->driver_data];
+
+ if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
+ struct i2c_device_identity id;
+
+ ret = i2c_get_device_id(client, &id);
+ if (ret && ret != -EOPNOTSUPP)
+ goto fail_cleanup;
+
+ if (!ret &&
+ (id.manufacturer_id != data->chip->id.manufacturer_id ||
+ id.part_id != data->chip->id.part_id)) {
+ dev_warn(dev, "unexpected device id %03x-%03x-%x\n",
+ id.manufacturer_id, id.part_id,
+ id.die_revision);
+ ret = -ENODEV;
+ goto fail_cleanup;
+ }
+ }
+
+ data->idle_state = MUX_IDLE_AS_IS;
+ if (device_property_read_u32(dev, "idle-state", &data->idle_state)) {
+ if (device_property_read_bool(dev, "i2c-mux-idle-disconnect"))
+ data->idle_state = MUX_IDLE_DISCONNECT;
+ }
+
+ /*
+ * Write the mux register at addr to verify
+ * that the mux is in fact present. This also
+ * initializes the mux to a channel
+ * or disconnected state.
+ */
+ ret = pca954x_init(client, data);
+ if (ret < 0) {
+ dev_warn(dev, "probe failed\n");
+ ret = -ENODEV;
+ goto fail_cleanup;
+ }
+
+ ret = pca954x_irq_setup(muxc);
+ if (ret)
+ goto fail_cleanup;
+
+ /* Now create an adapter for each channel */
+ for (num = 0; num < data->chip->nchans; num++) {
+ ret = i2c_mux_add_adapter(muxc, 0, num, 0);
+ if (ret)
+ goto fail_cleanup;
+ }
+
+ if (data->irq) {
+ ret = devm_request_threaded_irq(dev, data->client->irq,
+ NULL, pca954x_irq_handler,
+ IRQF_ONESHOT | IRQF_SHARED,
+ "pca954x", data);
+ if (ret)
+ goto fail_cleanup;
+ }
+
+ /*
+ * The attr probably isn't going to be needed in most cases,
+ * so don't fail completely on error.
+ */
+ device_create_file(dev, &dev_attr_idle_state);
+
+ dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
+ num, data->chip->muxtype == pca954x_ismux
+ ? "mux" : "switch", client->name);
+
+ return 0;
+
+fail_cleanup:
+ pca954x_cleanup(muxc);
+ return ret;
+}
+
+static void pca954x_remove(struct i2c_client *client)
+{
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+
+ device_remove_file(&client->dev, &dev_attr_idle_state);
+
+ pca954x_cleanup(muxc);
+}
+
+static int pca954x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+ struct pca954x *data = i2c_mux_priv(muxc);
+ int ret;
+
+ ret = pca954x_init(client, data);
+ if (ret < 0)
+ dev_err(&client->dev, "failed to verify mux presence\n");
+
+ return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
+
+static struct i2c_driver pca954x_driver = {
+ .driver = {
+ .name = "pca954x",
+ .pm = pm_sleep_ptr(&pca954x_pm),
+ .of_match_table = pca954x_of_match,
+ },
+ .probe = pca954x_probe,
+ .remove = pca954x_remove,
+ .id_table = pca954x_id,
+};
+
+module_i2c_driver(pca954x_driver);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c
new file mode 100644
index 0000000000..6ebca7bfd8
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C multiplexer using pinctrl API
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include "../../pinctrl/core.h"
+
+struct i2c_mux_pinctrl {
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *states[];
+};
+
+static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
+
+ return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
+}
+
+static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ return i2c_mux_pinctrl_select(muxc, muxc->num_adapters);
+}
+
+static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
+ struct pinctrl_state *state)
+{
+ struct i2c_adapter *root = NULL;
+ struct pinctrl_setting *setting;
+ struct i2c_adapter *pin_root;
+
+ list_for_each_entry(setting, &state->settings, node) {
+ pin_root = i2c_root_adapter(setting->pctldev->dev);
+ if (!pin_root)
+ return NULL;
+ if (!root)
+ root = pin_root;
+ else if (root != pin_root)
+ return NULL;
+ }
+
+ return root;
+}
+
+static struct i2c_adapter *i2c_mux_pinctrl_parent_adapter(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_adapter *parent;
+
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return ERR_PTR(-ENODEV);
+ }
+ parent = of_get_i2c_adapter_by_node(parent_np);
+ of_node_put(parent_np);
+ if (!parent)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return parent;
+}
+
+static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct i2c_mux_core *muxc;
+ struct i2c_mux_pinctrl *mux;
+ struct i2c_adapter *parent;
+ struct i2c_adapter *root;
+ int num_names, i, ret;
+ const char *name;
+
+ num_names = of_property_count_strings(np, "pinctrl-names");
+ if (num_names < 0) {
+ dev_err(dev, "Cannot parse pinctrl-names: %d\n",
+ num_names);
+ return num_names;
+ }
+
+ parent = i2c_mux_pinctrl_parent_adapter(dev);
+ if (IS_ERR(parent))
+ return PTR_ERR(parent);
+
+ muxc = i2c_mux_alloc(parent, dev, num_names,
+ struct_size(mux, states, num_names),
+ 0, i2c_mux_pinctrl_select, NULL);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err_put_parent;
+ }
+ mux = i2c_mux_priv(muxc);
+
+ platform_set_drvdata(pdev, muxc);
+
+ mux->pinctrl = devm_pinctrl_get(dev);
+ if (IS_ERR(mux->pinctrl)) {
+ ret = PTR_ERR(mux->pinctrl);
+ dev_err(dev, "Cannot get pinctrl: %d\n", ret);
+ goto err_put_parent;
+ }
+
+ for (i = 0; i < num_names; i++) {
+ ret = of_property_read_string_index(np, "pinctrl-names", i,
+ &name);
+ if (ret < 0) {
+ dev_err(dev, "Cannot parse pinctrl-names: %d\n", ret);
+ goto err_put_parent;
+ }
+
+ mux->states[i] = pinctrl_lookup_state(mux->pinctrl, name);
+ if (IS_ERR(mux->states[i])) {
+ ret = PTR_ERR(mux->states[i]);
+ dev_err(dev, "Cannot look up pinctrl state %s: %d\n",
+ name, ret);
+ goto err_put_parent;
+ }
+
+ if (strcmp(name, "idle"))
+ continue;
+
+ if (i != num_names - 1) {
+ dev_err(dev, "idle state must be last\n");
+ ret = -EINVAL;
+ goto err_put_parent;
+ }
+ muxc->deselect = i2c_mux_pinctrl_deselect;
+ }
+
+ root = i2c_root_adapter(&muxc->parent->dev);
+
+ muxc->mux_locked = true;
+ for (i = 0; i < num_names; i++) {
+ if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
+ muxc->mux_locked = false;
+ break;
+ }
+ }
+ if (muxc->mux_locked)
+ dev_info(dev, "mux-locked i2c mux\n");
+
+ /* Do not add any adapter for the idle state (if it's there at all). */
+ for (i = 0; i < num_names - !!muxc->deselect; i++) {
+ ret = i2c_mux_add_adapter(muxc, 0, i, 0);
+ if (ret)
+ goto err_del_adapter;
+ }
+
+ return 0;
+
+err_del_adapter:
+ i2c_mux_del_adapters(muxc);
+err_put_parent:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static void i2c_mux_pinctrl_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+}
+
+static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
+ { .compatible = "i2c-mux-pinctrl", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
+
+static struct platform_driver i2c_mux_pinctrl_driver = {
+ .driver = {
+ .name = "i2c-mux-pinctrl",
+ .of_match_table = i2c_mux_pinctrl_of_match,
+ },
+ .probe = i2c_mux_pinctrl_probe,
+ .remove_new = i2c_mux_pinctrl_remove,
+};
+module_platform_driver(i2c_mux_pinctrl_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-mux-pinctrl");
diff --git a/drivers/i2c/muxes/i2c-mux-reg.c b/drivers/i2c/muxes/i2c-mux-reg.c
new file mode 100644
index 0000000000..9efc1ed015
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-reg.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * I2C multiplexer using a single register
+ *
+ * Copyright 2015 Freescale Semiconductor
+ * York Sun <yorksun@freescale.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_data/i2c-mux-reg.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct regmux {
+ struct i2c_mux_reg_platform_data data;
+};
+
+static int i2c_mux_reg_set(const struct regmux *mux, unsigned int chan_id)
+{
+ if (!mux->data.reg)
+ return -EINVAL;
+
+ /*
+ * Write to the register, followed by a read to ensure the write is
+ * completed on a "posted" bus, for example PCI or write buffers.
+ * The endianness of reading doesn't matter and the return data
+ * is not used.
+ */
+ switch (mux->data.reg_size) {
+ case 4:
+ if (mux->data.little_endian)
+ iowrite32(chan_id, mux->data.reg);
+ else
+ iowrite32be(chan_id, mux->data.reg);
+ if (!mux->data.write_only)
+ ioread32(mux->data.reg);
+ break;
+ case 2:
+ if (mux->data.little_endian)
+ iowrite16(chan_id, mux->data.reg);
+ else
+ iowrite16be(chan_id, mux->data.reg);
+ if (!mux->data.write_only)
+ ioread16(mux->data.reg);
+ break;
+ case 1:
+ iowrite8(chan_id, mux->data.reg);
+ if (!mux->data.write_only)
+ ioread8(mux->data.reg);
+ break;
+ }
+
+ return 0;
+}
+
+static int i2c_mux_reg_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct regmux *mux = i2c_mux_priv(muxc);
+
+ return i2c_mux_reg_set(mux, chan);
+}
+
+static int i2c_mux_reg_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct regmux *mux = i2c_mux_priv(muxc);
+
+ if (mux->data.idle_in_use)
+ return i2c_mux_reg_set(mux, mux->data.idle);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static int i2c_mux_reg_probe_dt(struct regmux *mux,
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *adapter_np, *child;
+ struct i2c_adapter *adapter;
+ struct resource res;
+ unsigned *values;
+ int i = 0;
+
+ if (!np)
+ return -ENODEV;
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ of_node_put(adapter_np);
+ if (!adapter)
+ return -EPROBE_DEFER;
+
+ mux->data.parent = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ mux->data.n_values = of_get_child_count(np);
+ if (of_property_read_bool(np, "little-endian")) {
+ mux->data.little_endian = true;
+ } else if (of_property_read_bool(np, "big-endian")) {
+ mux->data.little_endian = false;
+ } else {
+#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : \
+ defined(__LITTLE_ENDIAN)
+ mux->data.little_endian = true;
+#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : \
+ defined(__BIG_ENDIAN)
+ mux->data.little_endian = false;
+#else
+#error Endianness not defined?
+#endif
+ }
+ mux->data.write_only = of_property_read_bool(np, "write-only");
+
+ values = devm_kcalloc(&pdev->dev,
+ mux->data.n_values, sizeof(*mux->data.values),
+ GFP_KERNEL);
+ if (!values)
+ return -ENOMEM;
+
+ for_each_child_of_node(np, child) {
+ of_property_read_u32(child, "reg", values + i);
+ i++;
+ }
+ mux->data.values = values;
+
+ if (!of_property_read_u32(np, "idle-state", &mux->data.idle))
+ mux->data.idle_in_use = true;
+
+ /* map address from "reg" if exists */
+ if (of_address_to_resource(np, 0, &res) == 0) {
+ mux->data.reg_size = resource_size(&res);
+ mux->data.reg = devm_ioremap_resource(&pdev->dev, &res);
+ if (IS_ERR(mux->data.reg))
+ return PTR_ERR(mux->data.reg);
+ }
+
+ return 0;
+}
+#else
+static int i2c_mux_reg_probe_dt(struct regmux *mux,
+ struct platform_device *pdev)
+{
+ return 0;
+}
+#endif
+
+static int i2c_mux_reg_probe(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc;
+ struct regmux *mux;
+ struct i2c_adapter *parent;
+ struct resource *res;
+ unsigned int class;
+ int i, ret, nr;
+
+ mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ if (dev_get_platdata(&pdev->dev)) {
+ memcpy(&mux->data, dev_get_platdata(&pdev->dev),
+ sizeof(mux->data));
+ } else {
+ ret = i2c_mux_reg_probe_dt(mux, pdev);
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, ret,
+ "Error parsing device tree");
+ }
+
+ parent = i2c_get_adapter(mux->data.parent);
+ if (!parent)
+ return -EPROBE_DEFER;
+
+ if (!mux->data.reg) {
+ dev_info(&pdev->dev,
+ "Register not set, using platform resource\n");
+ mux->data.reg = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(mux->data.reg)) {
+ ret = PTR_ERR(mux->data.reg);
+ goto err_put_parent;
+ }
+ mux->data.reg_size = resource_size(res);
+ }
+
+ if (mux->data.reg_size != 4 && mux->data.reg_size != 2 &&
+ mux->data.reg_size != 1) {
+ dev_err(&pdev->dev, "Invalid register size\n");
+ ret = -EINVAL;
+ goto err_put_parent;
+ }
+
+ muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values, 0, 0,
+ i2c_mux_reg_select, NULL);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err_put_parent;
+ }
+ muxc->priv = mux;
+
+ platform_set_drvdata(pdev, muxc);
+
+ if (mux->data.idle_in_use)
+ muxc->deselect = i2c_mux_reg_deselect;
+
+ for (i = 0; i < mux->data.n_values; i++) {
+ nr = mux->data.base_nr ? (mux->data.base_nr + i) : 0;
+ class = mux->data.classes ? mux->data.classes[i] : 0;
+
+ ret = i2c_mux_add_adapter(muxc, nr, mux->data.values[i], class);
+ if (ret)
+ goto err_del_mux_adapters;
+ }
+
+ dev_dbg(&pdev->dev, "%d port mux on %s adapter\n",
+ mux->data.n_values, muxc->parent->name);
+
+ return 0;
+
+err_del_mux_adapters:
+ i2c_mux_del_adapters(muxc);
+err_put_parent:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static void i2c_mux_reg_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+}
+
+static const struct of_device_id i2c_mux_reg_of_match[] = {
+ { .compatible = "i2c-mux-reg", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_reg_of_match);
+
+static struct platform_driver i2c_mux_reg_driver = {
+ .probe = i2c_mux_reg_probe,
+ .remove_new = i2c_mux_reg_remove,
+ .driver = {
+ .name = "i2c-mux-reg",
+ .of_match_table = of_match_ptr(i2c_mux_reg_of_match),
+ },
+};
+
+module_platform_driver(i2c_mux_reg_driver);
+
+MODULE_DESCRIPTION("Register-based I2C multiplexer driver");
+MODULE_AUTHOR("York Sun <yorksun@freescale.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c-mux-reg");