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-rw-r--r--drivers/i2c/i2c-core-base.c2530
1 files changed, 2530 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
new file mode 100644
index 000000000..5e3976ba5
--- /dev/null
+++ b/drivers/i2c/i2c-core-base.c
@@ -0,0 +1,2530 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux I2C core
+ *
+ * Copyright (C) 1995-99 Simon G. Vogl
+ * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
+ * Mux support by Rodolfo Giometti <giometti@enneenne.com> and
+ * Michael Lawnick <michael.lawnick.ext@nsn.com>
+ *
+ * Copyright (C) 2013-2017 Wolfram Sang <wsa@kernel.org>
+ */
+
+#define pr_fmt(fmt) "i2c-core: " fmt
+
+#include <dt-bindings/i2c/i2c.h>
+#include <linux/acpi.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqflags.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/property.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+
+#include "i2c-core.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/i2c.h>
+
+#define I2C_ADDR_OFFSET_TEN_BIT 0xa000
+#define I2C_ADDR_OFFSET_SLAVE 0x1000
+
+#define I2C_ADDR_7BITS_MAX 0x77
+#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
+
+#define I2C_ADDR_DEVICE_ID 0x7c
+
+/*
+ * core_lock protects i2c_adapter_idr, and guarantees that device detection,
+ * deletion of detected devices are serialized
+ */
+static DEFINE_MUTEX(core_lock);
+static DEFINE_IDR(i2c_adapter_idr);
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
+
+static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
+static bool is_registered;
+
+int i2c_transfer_trace_reg(void)
+{
+ static_branch_inc(&i2c_trace_msg_key);
+ return 0;
+}
+
+void i2c_transfer_trace_unreg(void)
+{
+ static_branch_dec(&i2c_trace_msg_key);
+}
+
+const char *i2c_freq_mode_string(u32 bus_freq_hz)
+{
+ switch (bus_freq_hz) {
+ case I2C_MAX_STANDARD_MODE_FREQ:
+ return "Standard Mode (100 kHz)";
+ case I2C_MAX_FAST_MODE_FREQ:
+ return "Fast Mode (400 kHz)";
+ case I2C_MAX_FAST_MODE_PLUS_FREQ:
+ return "Fast Mode Plus (1.0 MHz)";
+ case I2C_MAX_TURBO_MODE_FREQ:
+ return "Turbo Mode (1.4 MHz)";
+ case I2C_MAX_HIGH_SPEED_MODE_FREQ:
+ return "High Speed Mode (3.4 MHz)";
+ case I2C_MAX_ULTRA_FAST_MODE_FREQ:
+ return "Ultra Fast Mode (5.0 MHz)";
+ default:
+ return "Unknown Mode";
+ }
+}
+EXPORT_SYMBOL_GPL(i2c_freq_mode_string);
+
+const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+ const struct i2c_client *client)
+{
+ if (!(id && client))
+ return NULL;
+
+ while (id->name[0]) {
+ if (strcmp(client->name, id->name) == 0)
+ return id;
+ id++;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(i2c_match_id);
+
+static int i2c_device_match(struct device *dev, struct device_driver *drv)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+
+
+ /* Attempt an OF style match */
+ if (i2c_of_match_device(drv->of_match_table, client))
+ return 1;
+
+ /* Then ACPI style match */
+ if (acpi_driver_match_device(dev, drv))
+ return 1;
+
+ driver = to_i2c_driver(drv);
+
+ /* Finally an I2C match */
+ if (i2c_match_id(driver->id_table, client))
+ return 1;
+
+ return 0;
+}
+
+static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int rc;
+
+ rc = of_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
+ rc = acpi_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
+ return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
+}
+
+/* i2c bus recovery routines */
+static int get_scl_gpio_value(struct i2c_adapter *adap)
+{
+ return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
+}
+
+static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
+{
+ gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
+}
+
+static int get_sda_gpio_value(struct i2c_adapter *adap)
+{
+ return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
+}
+
+static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
+{
+ gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
+}
+
+static int i2c_generic_bus_free(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ int ret = -EOPNOTSUPP;
+
+ if (bri->get_bus_free)
+ ret = bri->get_bus_free(adap);
+ else if (bri->get_sda)
+ ret = bri->get_sda(adap);
+
+ if (ret < 0)
+ return ret;
+
+ return ret ? 0 : -EBUSY;
+}
+
+/*
+ * We are generating clock pulses. ndelay() determines durating of clk pulses.
+ * We will generate clock with rate 100 KHz and so duration of both clock levels
+ * is: delay in ns = (10^6 / 100) / 2
+ */
+#define RECOVERY_NDELAY 5000
+#define RECOVERY_CLK_CNT 9
+
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ int i = 0, scl = 1, ret = 0;
+
+ if (bri->prepare_recovery)
+ bri->prepare_recovery(adap);
+ if (bri->pinctrl)
+ pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
+
+ /*
+ * If we can set SDA, we will always create a STOP to ensure additional
+ * pulses will do no harm. This is achieved by letting SDA follow SCL
+ * half a cycle later. Check the 'incomplete_write_byte' fault injector
+ * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
+ * here for simplicity.
+ */
+ bri->set_scl(adap, scl);
+ ndelay(RECOVERY_NDELAY);
+ if (bri->set_sda)
+ bri->set_sda(adap, scl);
+ ndelay(RECOVERY_NDELAY / 2);
+
+ /*
+ * By this time SCL is high, as we need to give 9 falling-rising edges
+ */
+ while (i++ < RECOVERY_CLK_CNT * 2) {
+ if (scl) {
+ /* SCL shouldn't be low here */
+ if (!bri->get_scl(adap)) {
+ dev_err(&adap->dev,
+ "SCL is stuck low, exit recovery\n");
+ ret = -EBUSY;
+ break;
+ }
+ }
+
+ scl = !scl;
+ bri->set_scl(adap, scl);
+ /* Creating STOP again, see above */
+ if (scl) {
+ /* Honour minimum tsu:sto */
+ ndelay(RECOVERY_NDELAY);
+ } else {
+ /* Honour minimum tf and thd:dat */
+ ndelay(RECOVERY_NDELAY / 2);
+ }
+ if (bri->set_sda)
+ bri->set_sda(adap, scl);
+ ndelay(RECOVERY_NDELAY / 2);
+
+ if (scl) {
+ ret = i2c_generic_bus_free(adap);
+ if (ret == 0)
+ break;
+ }
+ }
+
+ /* If we can't check bus status, assume recovery worked */
+ if (ret == -EOPNOTSUPP)
+ ret = 0;
+
+ if (bri->unprepare_recovery)
+ bri->unprepare_recovery(adap);
+ if (bri->pinctrl)
+ pinctrl_select_state(bri->pinctrl, bri->pins_default);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
+
+int i2c_recover_bus(struct i2c_adapter *adap)
+{
+ if (!adap->bus_recovery_info)
+ return -EBUSY;
+
+ dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
+ return adap->bus_recovery_info->recover_bus(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_recover_bus);
+
+static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ struct device *dev = &adap->dev;
+ struct pinctrl *p = bri->pinctrl;
+
+ /*
+ * we can't change states without pinctrl, so remove the states if
+ * populated
+ */
+ if (!p) {
+ bri->pins_default = NULL;
+ bri->pins_gpio = NULL;
+ return;
+ }
+
+ if (!bri->pins_default) {
+ bri->pins_default = pinctrl_lookup_state(p,
+ PINCTRL_STATE_DEFAULT);
+ if (IS_ERR(bri->pins_default)) {
+ dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n");
+ bri->pins_default = NULL;
+ }
+ }
+ if (!bri->pins_gpio) {
+ bri->pins_gpio = pinctrl_lookup_state(p, "gpio");
+ if (IS_ERR(bri->pins_gpio))
+ bri->pins_gpio = pinctrl_lookup_state(p, "recovery");
+
+ if (IS_ERR(bri->pins_gpio)) {
+ dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n");
+ bri->pins_gpio = NULL;
+ }
+ }
+
+ /* for pinctrl state changes, we need all the information */
+ if (bri->pins_default && bri->pins_gpio) {
+ dev_info(dev, "using pinctrl states for GPIO recovery");
+ } else {
+ bri->pinctrl = NULL;
+ bri->pins_default = NULL;
+ bri->pins_gpio = NULL;
+ }
+}
+
+static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ struct device *dev = &adap->dev;
+ struct gpio_desc *gpiod;
+ int ret = 0;
+
+ /*
+ * don't touch the recovery information if the driver is not using
+ * generic SCL recovery
+ */
+ if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)
+ return 0;
+
+ /*
+ * pins might be taken as GPIO, so we should inform pinctrl about
+ * this and move the state to GPIO
+ */
+ if (bri->pinctrl)
+ pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
+
+ /*
+ * if there is incomplete or no recovery information, see if generic
+ * GPIO recovery is available
+ */
+ if (!bri->scl_gpiod) {
+ gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
+ if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto cleanup_pinctrl_state;
+ }
+ if (!IS_ERR(gpiod)) {
+ bri->scl_gpiod = gpiod;
+ bri->recover_bus = i2c_generic_scl_recovery;
+ dev_info(dev, "using generic GPIOs for recovery\n");
+ }
+ }
+
+ /* SDA GPIOD line is optional, so we care about DEFER only */
+ if (!bri->sda_gpiod) {
+ /*
+ * We have SCL. Pull SCL low and wait a bit so that SDA glitches
+ * have no effect.
+ */
+ gpiod_direction_output(bri->scl_gpiod, 0);
+ udelay(10);
+ gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN);
+
+ /* Wait a bit in case of a SDA glitch, and then release SCL. */
+ udelay(10);
+ gpiod_direction_output(bri->scl_gpiod, 1);
+
+ if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto cleanup_pinctrl_state;
+ }
+ if (!IS_ERR(gpiod))
+ bri->sda_gpiod = gpiod;
+ }
+
+cleanup_pinctrl_state:
+ /* change the state of the pins back to their default state */
+ if (bri->pinctrl)
+ pinctrl_select_state(bri->pinctrl, bri->pins_default);
+
+ return ret;
+}
+
+static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
+{
+ i2c_gpio_init_pinctrl_recovery(adap);
+ return i2c_gpio_init_generic_recovery(adap);
+}
+
+static int i2c_init_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ bool is_error_level = true;
+ char *err_str;
+
+ if (!bri)
+ return 0;
+
+ if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ if (!bri->recover_bus) {
+ err_str = "no suitable method provided";
+ is_error_level = false;
+ goto err;
+ }
+
+ if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
+ bri->get_scl = get_scl_gpio_value;
+ bri->set_scl = set_scl_gpio_value;
+ if (bri->sda_gpiod) {
+ bri->get_sda = get_sda_gpio_value;
+ /* FIXME: add proper flag instead of '0' once available */
+ if (gpiod_get_direction(bri->sda_gpiod) == 0)
+ bri->set_sda = set_sda_gpio_value;
+ }
+ } else if (bri->recover_bus == i2c_generic_scl_recovery) {
+ /* Generic SCL recovery */
+ if (!bri->set_scl || !bri->get_scl) {
+ err_str = "no {get|set}_scl() found";
+ goto err;
+ }
+ if (!bri->set_sda && !bri->get_sda) {
+ err_str = "either get_sda() or set_sda() needed";
+ goto err;
+ }
+ }
+
+ return 0;
+ err:
+ if (is_error_level)
+ dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
+ else
+ dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);
+ adap->bus_recovery_info = NULL;
+
+ return -EINVAL;
+}
+
+static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
+{
+ struct i2c_adapter *adap = client->adapter;
+ unsigned int irq;
+
+ if (!adap->host_notify_domain)
+ return -ENXIO;
+
+ if (client->flags & I2C_CLIENT_TEN)
+ return -EINVAL;
+
+ irq = irq_create_mapping(adap->host_notify_domain, client->addr);
+
+ return irq > 0 ? irq : -ENXIO;
+}
+
+static int i2c_device_probe(struct device *dev)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+ bool do_power_on;
+ int status;
+
+ if (!client)
+ return 0;
+
+ client->irq = client->init_irq;
+
+ if (!client->irq) {
+ int irq = -ENOENT;
+
+ if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
+ dev_dbg(dev, "Using Host Notify IRQ\n");
+ /* Keep adapter active when Host Notify is required */
+ pm_runtime_get_sync(&client->adapter->dev);
+ irq = i2c_smbus_host_notify_to_irq(client);
+ } else if (dev->of_node) {
+ irq = of_irq_get_byname(dev->of_node, "irq");
+ if (irq == -EINVAL || irq == -ENODATA)
+ irq = of_irq_get(dev->of_node, 0);
+ } else if (ACPI_COMPANION(dev)) {
+ bool wake_capable;
+
+ irq = i2c_acpi_get_irq(client, &wake_capable);
+ if (irq > 0 && wake_capable)
+ client->flags |= I2C_CLIENT_WAKE;
+ }
+ if (irq == -EPROBE_DEFER) {
+ status = irq;
+ goto put_sync_adapter;
+ }
+
+ if (irq < 0)
+ irq = 0;
+
+ client->irq = irq;
+ }
+
+ driver = to_i2c_driver(dev->driver);
+
+ /*
+ * An I2C ID table is not mandatory, if and only if, a suitable OF
+ * or ACPI ID table is supplied for the probing device.
+ */
+ if (!driver->id_table &&
+ !acpi_driver_match_device(dev, dev->driver) &&
+ !i2c_of_match_device(dev->driver->of_match_table, client)) {
+ status = -ENODEV;
+ goto put_sync_adapter;
+ }
+
+ if (client->flags & I2C_CLIENT_WAKE) {
+ int wakeirq;
+
+ wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
+ if (wakeirq == -EPROBE_DEFER) {
+ status = wakeirq;
+ goto put_sync_adapter;
+ }
+
+ device_init_wakeup(&client->dev, true);
+
+ if (wakeirq > 0 && wakeirq != client->irq)
+ status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
+ else if (client->irq > 0)
+ status = dev_pm_set_wake_irq(dev, client->irq);
+ else
+ status = 0;
+
+ if (status)
+ dev_warn(&client->dev, "failed to set up wakeup irq\n");
+ }
+
+ dev_dbg(dev, "probe\n");
+
+ status = of_clk_set_defaults(dev->of_node, false);
+ if (status < 0)
+ goto err_clear_wakeup_irq;
+
+ do_power_on = !i2c_acpi_waive_d0_probe(dev);
+ status = dev_pm_domain_attach(&client->dev, do_power_on);
+ if (status)
+ goto err_clear_wakeup_irq;
+
+ client->devres_group_id = devres_open_group(&client->dev, NULL,
+ GFP_KERNEL);
+ if (!client->devres_group_id) {
+ status = -ENOMEM;
+ goto err_detach_pm_domain;
+ }
+
+ /*
+ * When there are no more users of probe(),
+ * rename probe_new to probe.
+ */
+ if (driver->probe_new)
+ status = driver->probe_new(client);
+ else if (driver->probe)
+ status = driver->probe(client,
+ i2c_match_id(driver->id_table, client));
+ else
+ status = -EINVAL;
+
+ /*
+ * Note that we are not closing the devres group opened above so
+ * even resources that were attached to the device after probe is
+ * run are released when i2c_device_remove() is executed. This is
+ * needed as some drivers would allocate additional resources,
+ * for example when updating firmware.
+ */
+
+ if (status)
+ goto err_release_driver_resources;
+
+ return 0;
+
+err_release_driver_resources:
+ devres_release_group(&client->dev, client->devres_group_id);
+err_detach_pm_domain:
+ dev_pm_domain_detach(&client->dev, do_power_on);
+err_clear_wakeup_irq:
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
+put_sync_adapter:
+ if (client->flags & I2C_CLIENT_HOST_NOTIFY)
+ pm_runtime_put_sync(&client->adapter->dev);
+
+ return status;
+}
+
+static void i2c_device_remove(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_driver *driver;
+
+ driver = to_i2c_driver(dev->driver);
+ if (driver->remove) {
+ dev_dbg(dev, "remove\n");
+
+ driver->remove(client);
+ }
+
+ devres_release_group(&client->dev, client->devres_group_id);
+
+ dev_pm_domain_detach(&client->dev, true);
+
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
+
+ client->irq = 0;
+ if (client->flags & I2C_CLIENT_HOST_NOTIFY)
+ pm_runtime_put(&client->adapter->dev);
+}
+
+static void i2c_device_shutdown(struct device *dev)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+
+ if (!client || !dev->driver)
+ return;
+ driver = to_i2c_driver(dev->driver);
+ if (driver->shutdown)
+ driver->shutdown(client);
+ else if (client->irq > 0)
+ disable_irq(client->irq);
+}
+
+static void i2c_client_dev_release(struct device *dev)
+{
+ kfree(to_i2c_client(dev));
+}
+
+static ssize_t
+name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
+ to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t
+modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int len;
+
+ len = of_device_modalias(dev, buf, PAGE_SIZE);
+ if (len != -ENODEV)
+ return len;
+
+ len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+ if (len != -ENODEV)
+ return len;
+
+ return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *i2c_dev_attrs[] = {
+ &dev_attr_name.attr,
+ /* modalias helps coldplug: modprobe $(cat .../modalias) */
+ &dev_attr_modalias.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(i2c_dev);
+
+struct bus_type i2c_bus_type = {
+ .name = "i2c",
+ .match = i2c_device_match,
+ .probe = i2c_device_probe,
+ .remove = i2c_device_remove,
+ .shutdown = i2c_device_shutdown,
+};
+EXPORT_SYMBOL_GPL(i2c_bus_type);
+
+struct device_type i2c_client_type = {
+ .groups = i2c_dev_groups,
+ .uevent = i2c_device_uevent,
+ .release = i2c_client_dev_release,
+};
+EXPORT_SYMBOL_GPL(i2c_client_type);
+
+
+/**
+ * i2c_verify_client - return parameter as i2c_client, or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find. Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_client.
+ */
+struct i2c_client *i2c_verify_client(struct device *dev)
+{
+ return (dev->type == &i2c_client_type)
+ ? to_i2c_client(dev)
+ : NULL;
+}
+EXPORT_SYMBOL(i2c_verify_client);
+
+
+/* Return a unique address which takes the flags of the client into account */
+static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
+{
+ unsigned short addr = client->addr;
+
+ /* For some client flags, add an arbitrary offset to avoid collisions */
+ if (client->flags & I2C_CLIENT_TEN)
+ addr |= I2C_ADDR_OFFSET_TEN_BIT;
+
+ if (client->flags & I2C_CLIENT_SLAVE)
+ addr |= I2C_ADDR_OFFSET_SLAVE;
+
+ return addr;
+}
+
+/* This is a permissive address validity check, I2C address map constraints
+ * are purposely not enforced, except for the general call address. */
+static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
+{
+ if (flags & I2C_CLIENT_TEN) {
+ /* 10-bit address, all values are valid */
+ if (addr > 0x3ff)
+ return -EINVAL;
+ } else {
+ /* 7-bit address, reject the general call address */
+ if (addr == 0x00 || addr > 0x7f)
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* And this is a strict address validity check, used when probing. If a
+ * device uses a reserved address, then it shouldn't be probed. 7-bit
+ * addressing is assumed, 10-bit address devices are rare and should be
+ * explicitly enumerated. */
+int i2c_check_7bit_addr_validity_strict(unsigned short addr)
+{
+ /*
+ * Reserved addresses per I2C specification:
+ * 0x00 General call address / START byte
+ * 0x01 CBUS address
+ * 0x02 Reserved for different bus format
+ * 0x03 Reserved for future purposes
+ * 0x04-0x07 Hs-mode master code
+ * 0x78-0x7b 10-bit slave addressing
+ * 0x7c-0x7f Reserved for future purposes
+ */
+ if (addr < 0x08 || addr > 0x77)
+ return -EINVAL;
+ return 0;
+}
+
+static int __i2c_check_addr_busy(struct device *dev, void *addrp)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ int addr = *(int *)addrp;
+
+ if (client && i2c_encode_flags_to_addr(client) == addr)
+ return -EBUSY;
+ return 0;
+}
+
+/* walk up mux tree */
+static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+ int result;
+
+ result = device_for_each_child(&adapter->dev, &addr,
+ __i2c_check_addr_busy);
+
+ if (!result && parent)
+ result = i2c_check_mux_parents(parent, addr);
+
+ return result;
+}
+
+/* recurse down mux tree */
+static int i2c_check_mux_children(struct device *dev, void *addrp)
+{
+ int result;
+
+ if (dev->type == &i2c_adapter_type)
+ result = device_for_each_child(dev, addrp,
+ i2c_check_mux_children);
+ else
+ result = __i2c_check_addr_busy(dev, addrp);
+
+ return result;
+}
+
+static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
+{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+ int result = 0;
+
+ if (parent)
+ result = i2c_check_mux_parents(parent, addr);
+
+ if (!result)
+ result = device_for_each_child(&adapter->dev, &addr,
+ i2c_check_mux_children);
+
+ return result;
+}
+
+/**
+ * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
+ * locks only this branch in the adapter tree
+ */
+static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
+}
+
+/**
+ * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
+ * trylocks only this branch in the adapter tree
+ */
+static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ return rt_mutex_trylock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
+ * unlocks only this branch in the adapter tree
+ */
+static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ rt_mutex_unlock(&adapter->bus_lock);
+}
+
+static void i2c_dev_set_name(struct i2c_adapter *adap,
+ struct i2c_client *client,
+ struct i2c_board_info const *info)
+{
+ struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+
+ if (info && info->dev_name) {
+ dev_set_name(&client->dev, "i2c-%s", info->dev_name);
+ return;
+ }
+
+ if (adev) {
+ dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
+ return;
+ }
+
+ dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
+ i2c_encode_flags_to_addr(client));
+}
+
+int i2c_dev_irq_from_resources(const struct resource *resources,
+ unsigned int num_resources)
+{
+ struct irq_data *irqd;
+ int i;
+
+ for (i = 0; i < num_resources; i++) {
+ const struct resource *r = &resources[i];
+
+ if (resource_type(r) != IORESOURCE_IRQ)
+ continue;
+
+ if (r->flags & IORESOURCE_BITS) {
+ irqd = irq_get_irq_data(r->start);
+ if (!irqd)
+ break;
+
+ irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
+ }
+
+ return r->start;
+ }
+
+ return 0;
+}
+
+/**
+ * i2c_new_client_device - instantiate an i2c device
+ * @adap: the adapter managing the device
+ * @info: describes one I2C device; bus_num is ignored
+ * Context: can sleep
+ *
+ * Create an i2c device. Binding is handled through driver model
+ * probe()/remove() methods. A driver may be bound to this device when we
+ * return from this function, or any later moment (e.g. maybe hotplugging will
+ * load the driver module). This call is not appropriate for use by mainboard
+ * initialization logic, which usually runs during an arch_initcall() long
+ * before any i2c_adapter could exist.
+ *
+ * This returns the new i2c client, which may be saved for later use with
+ * i2c_unregister_device(); or an ERR_PTR to describe the error.
+ */
+struct i2c_client *
+i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
+{
+ struct i2c_client *client;
+ bool need_put = false;
+ int status;
+
+ client = kzalloc(sizeof *client, GFP_KERNEL);
+ if (!client)
+ return ERR_PTR(-ENOMEM);
+
+ client->adapter = adap;
+
+ client->dev.platform_data = info->platform_data;
+ client->flags = info->flags;
+ client->addr = info->addr;
+
+ client->init_irq = info->irq;
+ if (!client->init_irq)
+ client->init_irq = i2c_dev_irq_from_resources(info->resources,
+ info->num_resources);
+
+ strscpy(client->name, info->type, sizeof(client->name));
+
+ status = i2c_check_addr_validity(client->addr, client->flags);
+ if (status) {
+ dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
+ client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
+ goto out_err_silent;
+ }
+
+ /* Check for address business */
+ status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
+ if (status)
+ goto out_err;
+
+ client->dev.parent = &client->adapter->dev;
+ client->dev.bus = &i2c_bus_type;
+ client->dev.type = &i2c_client_type;
+ client->dev.of_node = of_node_get(info->of_node);
+ client->dev.fwnode = info->fwnode;
+
+ device_enable_async_suspend(&client->dev);
+
+ if (info->swnode) {
+ status = device_add_software_node(&client->dev, info->swnode);
+ if (status) {
+ dev_err(&adap->dev,
+ "Failed to add software node to client %s: %d\n",
+ client->name, status);
+ goto out_err_put_of_node;
+ }
+ }
+
+ i2c_dev_set_name(adap, client, info);
+ status = device_register(&client->dev);
+ if (status)
+ goto out_remove_swnode;
+
+ dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
+ client->name, dev_name(&client->dev));
+
+ return client;
+
+out_remove_swnode:
+ device_remove_software_node(&client->dev);
+ need_put = true;
+out_err_put_of_node:
+ of_node_put(info->of_node);
+out_err:
+ dev_err(&adap->dev,
+ "Failed to register i2c client %s at 0x%02x (%d)\n",
+ client->name, client->addr, status);
+out_err_silent:
+ if (need_put)
+ put_device(&client->dev);
+ else
+ kfree(client);
+ return ERR_PTR(status);
+}
+EXPORT_SYMBOL_GPL(i2c_new_client_device);
+
+/**
+ * i2c_unregister_device - reverse effect of i2c_new_*_device()
+ * @client: value returned from i2c_new_*_device()
+ * Context: can sleep
+ */
+void i2c_unregister_device(struct i2c_client *client)
+{
+ if (IS_ERR_OR_NULL(client))
+ return;
+
+ if (client->dev.of_node) {
+ of_node_clear_flag(client->dev.of_node, OF_POPULATED);
+ of_node_put(client->dev.of_node);
+ }
+
+ if (ACPI_COMPANION(&client->dev))
+ acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
+ device_remove_software_node(&client->dev);
+ device_unregister(&client->dev);
+}
+EXPORT_SYMBOL_GPL(i2c_unregister_device);
+
+
+static const struct i2c_device_id dummy_id[] = {
+ { "dummy", 0 },
+ { },
+};
+
+static int dummy_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ return 0;
+}
+
+static struct i2c_driver dummy_driver = {
+ .driver.name = "dummy",
+ .probe = dummy_probe,
+ .id_table = dummy_id,
+};
+
+/**
+ * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This returns an I2C client bound to the "dummy" driver, intended for use
+ * with devices that consume multiple addresses. Examples of such chips
+ * include various EEPROMS (like 24c04 and 24c08 models).
+ *
+ * These dummy devices have two main uses. First, most I2C and SMBus calls
+ * except i2c_transfer() need a client handle; the dummy will be that handle.
+ * And second, this prevents the specified address from being bound to a
+ * different driver.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or an ERR_PTR to describe the error.
+ */
+struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
+{
+ struct i2c_board_info info = {
+ I2C_BOARD_INFO("dummy", address),
+ };
+
+ return i2c_new_client_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
+
+static void devm_i2c_release_dummy(void *client)
+{
+ i2c_unregister_device(client);
+}
+
+/**
+ * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
+ * @dev: device the managed resource is bound to
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This is the device-managed version of @i2c_new_dummy_device. It returns the
+ * new i2c client or an ERR_PTR in case of an error.
+ */
+struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
+ struct i2c_adapter *adapter,
+ u16 address)
+{
+ struct i2c_client *client;
+ int ret;
+
+ client = i2c_new_dummy_device(adapter, address);
+ if (IS_ERR(client))
+ return client;
+
+ ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return client;
+}
+EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
+
+/**
+ * i2c_new_ancillary_device - Helper to get the instantiated secondary address
+ * and create the associated device
+ * @client: Handle to the primary client
+ * @name: Handle to specify which secondary address to get
+ * @default_addr: Used as a fallback if no secondary address was specified
+ * Context: can sleep
+ *
+ * I2C clients can be composed of multiple I2C slaves bound together in a single
+ * component. The I2C client driver then binds to the master I2C slave and needs
+ * to create I2C dummy clients to communicate with all the other slaves.
+ *
+ * This function creates and returns an I2C dummy client whose I2C address is
+ * retrieved from the platform firmware based on the given slave name. If no
+ * address is specified by the firmware default_addr is used.
+ *
+ * On DT-based platforms the address is retrieved from the "reg" property entry
+ * cell whose "reg-names" value matches the slave name.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or an ERR_PTR to describe the error.
+ */
+struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
+ const char *name,
+ u16 default_addr)
+{
+ struct device_node *np = client->dev.of_node;
+ u32 addr = default_addr;
+ int i;
+
+ if (np) {
+ i = of_property_match_string(np, "reg-names", name);
+ if (i >= 0)
+ of_property_read_u32_index(np, "reg", i, &addr);
+ }
+
+ dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
+ return i2c_new_dummy_device(client->adapter, addr);
+}
+EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
+
+/* ------------------------------------------------------------------------- */
+
+/* I2C bus adapters -- one roots each I2C or SMBUS segment */
+
+static void i2c_adapter_dev_release(struct device *dev)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ complete(&adap->dev_released);
+}
+
+unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
+{
+ unsigned int depth = 0;
+
+ while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
+ depth++;
+
+ WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
+ "adapter depth exceeds lockdep subclass limit\n");
+
+ return depth;
+}
+EXPORT_SYMBOL_GPL(i2c_adapter_depth);
+
+/*
+ * Let users instantiate I2C devices through sysfs. This can be used when
+ * platform initialization code doesn't contain the proper data for
+ * whatever reason. Also useful for drivers that do device detection and
+ * detection fails, either because the device uses an unexpected address,
+ * or this is a compatible device with different ID register values.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to provide incorrect parameters.
+ */
+static ssize_t
+new_device_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ struct i2c_board_info info;
+ struct i2c_client *client;
+ char *blank, end;
+ int res;
+
+ memset(&info, 0, sizeof(struct i2c_board_info));
+
+ blank = strchr(buf, ' ');
+ if (!blank) {
+ dev_err(dev, "%s: Missing parameters\n", "new_device");
+ return -EINVAL;
+ }
+ if (blank - buf > I2C_NAME_SIZE - 1) {
+ dev_err(dev, "%s: Invalid device name\n", "new_device");
+ return -EINVAL;
+ }
+ memcpy(info.type, buf, blank - buf);
+
+ /* Parse remaining parameters, reject extra parameters */
+ res = sscanf(++blank, "%hi%c", &info.addr, &end);
+ if (res < 1) {
+ dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
+ return -EINVAL;
+ }
+ if (res > 1 && end != '\n') {
+ dev_err(dev, "%s: Extra parameters\n", "new_device");
+ return -EINVAL;
+ }
+
+ if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
+ info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
+ info.flags |= I2C_CLIENT_TEN;
+ }
+
+ if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
+ info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
+ info.flags |= I2C_CLIENT_SLAVE;
+ }
+
+ client = i2c_new_client_device(adap, &info);
+ if (IS_ERR(client))
+ return PTR_ERR(client);
+
+ /* Keep track of the added device */
+ mutex_lock(&adap->userspace_clients_lock);
+ list_add_tail(&client->detected, &adap->userspace_clients);
+ mutex_unlock(&adap->userspace_clients_lock);
+ dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
+ info.type, info.addr);
+
+ return count;
+}
+static DEVICE_ATTR_WO(new_device);
+
+/*
+ * And of course let the users delete the devices they instantiated, if
+ * they got it wrong. This interface can only be used to delete devices
+ * instantiated by i2c_sysfs_new_device above. This guarantees that we
+ * don't delete devices to which some kernel code still has references.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to delete the wrong device.
+ */
+static ssize_t
+delete_device_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ struct i2c_client *client, *next;
+ unsigned short addr;
+ char end;
+ int res;
+
+ /* Parse parameters, reject extra parameters */
+ res = sscanf(buf, "%hi%c", &addr, &end);
+ if (res < 1) {
+ dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
+ return -EINVAL;
+ }
+ if (res > 1 && end != '\n') {
+ dev_err(dev, "%s: Extra parameters\n", "delete_device");
+ return -EINVAL;
+ }
+
+ /* Make sure the device was added through sysfs */
+ res = -ENOENT;
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
+ list_for_each_entry_safe(client, next, &adap->userspace_clients,
+ detected) {
+ if (i2c_encode_flags_to_addr(client) == addr) {
+ dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
+ "delete_device", client->name, client->addr);
+
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ res = count;
+ break;
+ }
+ }
+ mutex_unlock(&adap->userspace_clients_lock);
+
+ if (res < 0)
+ dev_err(dev, "%s: Can't find device in list\n",
+ "delete_device");
+ return res;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
+ delete_device_store);
+
+static struct attribute *i2c_adapter_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_new_device.attr,
+ &dev_attr_delete_device.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(i2c_adapter);
+
+struct device_type i2c_adapter_type = {
+ .groups = i2c_adapter_groups,
+ .release = i2c_adapter_dev_release,
+};
+EXPORT_SYMBOL_GPL(i2c_adapter_type);
+
+/**
+ * i2c_verify_adapter - return parameter as i2c_adapter or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find. Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_adapter.
+ */
+struct i2c_adapter *i2c_verify_adapter(struct device *dev)
+{
+ return (dev->type == &i2c_adapter_type)
+ ? to_i2c_adapter(dev)
+ : NULL;
+}
+EXPORT_SYMBOL(i2c_verify_adapter);
+
+#ifdef CONFIG_I2C_COMPAT
+static struct class_compat *i2c_adapter_compat_class;
+#endif
+
+static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
+{
+ struct i2c_devinfo *devinfo;
+
+ down_read(&__i2c_board_lock);
+ list_for_each_entry(devinfo, &__i2c_board_list, list) {
+ if (devinfo->busnum == adapter->nr &&
+ IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))
+ dev_err(&adapter->dev,
+ "Can't create device at 0x%02x\n",
+ devinfo->board_info.addr);
+ }
+ up_read(&__i2c_board_lock);
+}
+
+static int i2c_do_add_adapter(struct i2c_driver *driver,
+ struct i2c_adapter *adap)
+{
+ /* Detect supported devices on that bus, and instantiate them */
+ i2c_detect(adap, driver);
+
+ return 0;
+}
+
+static int __process_new_adapter(struct device_driver *d, void *data)
+{
+ return i2c_do_add_adapter(to_i2c_driver(d), data);
+}
+
+static const struct i2c_lock_operations i2c_adapter_lock_ops = {
+ .lock_bus = i2c_adapter_lock_bus,
+ .trylock_bus = i2c_adapter_trylock_bus,
+ .unlock_bus = i2c_adapter_unlock_bus,
+};
+
+static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
+{
+ struct irq_domain *domain = adap->host_notify_domain;
+ irq_hw_number_t hwirq;
+
+ if (!domain)
+ return;
+
+ for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
+ irq_dispose_mapping(irq_find_mapping(domain, hwirq));
+
+ irq_domain_remove(domain);
+ adap->host_notify_domain = NULL;
+}
+
+static int i2c_host_notify_irq_map(struct irq_domain *h,
+ unsigned int virq,
+ irq_hw_number_t hw_irq_num)
+{
+ irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops i2c_host_notify_irq_ops = {
+ .map = i2c_host_notify_irq_map,
+};
+
+static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
+{
+ struct irq_domain *domain;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
+ return 0;
+
+ domain = irq_domain_create_linear(adap->dev.parent->fwnode,
+ I2C_ADDR_7BITS_COUNT,
+ &i2c_host_notify_irq_ops, adap);
+ if (!domain)
+ return -ENOMEM;
+
+ adap->host_notify_domain = domain;
+
+ return 0;
+}
+
+/**
+ * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
+ * I2C client.
+ * @adap: the adapter
+ * @addr: the I2C address of the notifying device
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the Host Notify IRQ.
+ */
+int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
+{
+ int irq;
+
+ if (!adap)
+ return -EINVAL;
+
+ irq = irq_find_mapping(adap->host_notify_domain, addr);
+ if (irq <= 0)
+ return -ENXIO;
+
+ generic_handle_irq_safe(irq);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
+
+static int i2c_register_adapter(struct i2c_adapter *adap)
+{
+ int res = -EINVAL;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!is_registered)) {
+ res = -EAGAIN;
+ goto out_list;
+ }
+
+ /* Sanity checks */
+ if (WARN(!adap->name[0], "i2c adapter has no name"))
+ goto out_list;
+
+ if (!adap->algo) {
+ pr_err("adapter '%s': no algo supplied!\n", adap->name);
+ goto out_list;
+ }
+
+ if (!adap->lock_ops)
+ adap->lock_ops = &i2c_adapter_lock_ops;
+
+ adap->locked_flags = 0;
+ rt_mutex_init(&adap->bus_lock);
+ rt_mutex_init(&adap->mux_lock);
+ mutex_init(&adap->userspace_clients_lock);
+ INIT_LIST_HEAD(&adap->userspace_clients);
+
+ /* Set default timeout to 1 second if not already set */
+ if (adap->timeout == 0)
+ adap->timeout = HZ;
+
+ /* register soft irqs for Host Notify */
+ res = i2c_setup_host_notify_irq_domain(adap);
+ if (res) {
+ pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
+ adap->name, res);
+ goto out_list;
+ }
+
+ dev_set_name(&adap->dev, "i2c-%d", adap->nr);
+ adap->dev.bus = &i2c_bus_type;
+ adap->dev.type = &i2c_adapter_type;
+ res = device_register(&adap->dev);
+ if (res) {
+ pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
+ goto out_list;
+ }
+
+ res = i2c_setup_smbus_alert(adap);
+ if (res)
+ goto out_reg;
+
+ device_enable_async_suspend(&adap->dev);
+ pm_runtime_no_callbacks(&adap->dev);
+ pm_suspend_ignore_children(&adap->dev, true);
+ pm_runtime_enable(&adap->dev);
+
+ res = i2c_init_recovery(adap);
+ if (res == -EPROBE_DEFER)
+ goto out_reg;
+
+ dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
+
+#ifdef CONFIG_I2C_COMPAT
+ res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
+ adap->dev.parent);
+ if (res)
+ dev_warn(&adap->dev,
+ "Failed to create compatibility class link\n");
+#endif
+
+ /* create pre-declared device nodes */
+ of_i2c_register_devices(adap);
+ i2c_acpi_install_space_handler(adap);
+ i2c_acpi_register_devices(adap);
+
+ if (adap->nr < __i2c_first_dynamic_bus_num)
+ i2c_scan_static_board_info(adap);
+
+ /* Notify drivers */
+ mutex_lock(&core_lock);
+ bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
+ mutex_unlock(&core_lock);
+
+ return 0;
+
+out_reg:
+ init_completion(&adap->dev_released);
+ device_unregister(&adap->dev);
+ wait_for_completion(&adap->dev_released);
+out_list:
+ mutex_lock(&core_lock);
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+ return res;
+}
+
+/**
+ * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
+ * @adap: the adapter to register (with adap->nr initialized)
+ * Context: can sleep
+ *
+ * See i2c_add_numbered_adapter() for details.
+ */
+static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ int id;
+
+ mutex_lock(&core_lock);
+ id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
+ mutex_unlock(&core_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id == -ENOSPC ? -EBUSY : id;
+
+ return i2c_register_adapter(adap);
+}
+
+/**
+ * i2c_add_adapter - declare i2c adapter, use dynamic bus number
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * doesn't matter or when its bus number is specified by an dt alias.
+ * Examples of bases when the bus number doesn't matter: I2C adapters
+ * dynamically added by USB links or PCI plugin cards.
+ *
+ * When this returns zero, a new bus number was allocated and stored
+ * in adap->nr, and the specified adapter became available for clients.
+ * Otherwise, a negative errno value is returned.
+ */
+int i2c_add_adapter(struct i2c_adapter *adapter)
+{
+ struct device *dev = &adapter->dev;
+ int id;
+
+ if (dev->of_node) {
+ id = of_alias_get_id(dev->of_node, "i2c");
+ if (id >= 0) {
+ adapter->nr = id;
+ return __i2c_add_numbered_adapter(adapter);
+ }
+ }
+
+ mutex_lock(&core_lock);
+ id = idr_alloc(&i2c_adapter_idr, adapter,
+ __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
+ mutex_unlock(&core_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id;
+
+ adapter->nr = id;
+
+ return i2c_register_adapter(adapter);
+}
+EXPORT_SYMBOL(i2c_add_adapter);
+
+/**
+ * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
+ * @adap: the adapter to register (with adap->nr initialized)
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * matters. For example, use it for I2C adapters from system-on-chip CPUs,
+ * or otherwise built in to the system's mainboard, and where i2c_board_info
+ * is used to properly configure I2C devices.
+ *
+ * If the requested bus number is set to -1, then this function will behave
+ * identically to i2c_add_adapter, and will dynamically assign a bus number.
+ *
+ * If no devices have pre-been declared for this bus, then be sure to
+ * register the adapter before any dynamically allocated ones. Otherwise
+ * the required bus ID may not be available.
+ *
+ * When this returns zero, the specified adapter became available for
+ * clients using the bus number provided in adap->nr. Also, the table
+ * of I2C devices pre-declared using i2c_register_board_info() is scanned,
+ * and the appropriate driver model device nodes are created. Otherwise, a
+ * negative errno value is returned.
+ */
+int i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ if (adap->nr == -1) /* -1 means dynamically assign bus id */
+ return i2c_add_adapter(adap);
+
+ return __i2c_add_numbered_adapter(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
+
+static void i2c_do_del_adapter(struct i2c_driver *driver,
+ struct i2c_adapter *adapter)
+{
+ struct i2c_client *client, *_n;
+
+ /* Remove the devices we created ourselves as the result of hardware
+ * probing (using a driver's detect method) */
+ list_for_each_entry_safe(client, _n, &driver->clients, detected) {
+ if (client->adapter == adapter) {
+ dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
+ client->name, client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ }
+}
+
+static int __unregister_client(struct device *dev, void *dummy)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ if (client && strcmp(client->name, "dummy"))
+ i2c_unregister_device(client);
+ return 0;
+}
+
+static int __unregister_dummy(struct device *dev, void *dummy)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ i2c_unregister_device(client);
+ return 0;
+}
+
+static int __process_removed_adapter(struct device_driver *d, void *data)
+{
+ i2c_do_del_adapter(to_i2c_driver(d), data);
+ return 0;
+}
+
+/**
+ * i2c_del_adapter - unregister I2C adapter
+ * @adap: the adapter being unregistered
+ * Context: can sleep
+ *
+ * This unregisters an I2C adapter which was previously registered
+ * by @i2c_add_adapter or @i2c_add_numbered_adapter.
+ */
+void i2c_del_adapter(struct i2c_adapter *adap)
+{
+ struct i2c_adapter *found;
+ struct i2c_client *client, *next;
+
+ /* First make sure that this adapter was ever added */
+ mutex_lock(&core_lock);
+ found = idr_find(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+ if (found != adap) {
+ pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
+ return;
+ }
+
+ i2c_acpi_remove_space_handler(adap);
+ /* Tell drivers about this removal */
+ mutex_lock(&core_lock);
+ bus_for_each_drv(&i2c_bus_type, NULL, adap,
+ __process_removed_adapter);
+ mutex_unlock(&core_lock);
+
+ /* Remove devices instantiated from sysfs */
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
+ list_for_each_entry_safe(client, next, &adap->userspace_clients,
+ detected) {
+ dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
+ client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ mutex_unlock(&adap->userspace_clients_lock);
+
+ /* Detach any active clients. This can't fail, thus we do not
+ * check the returned value. This is a two-pass process, because
+ * we can't remove the dummy devices during the first pass: they
+ * could have been instantiated by real devices wishing to clean
+ * them up properly, so we give them a chance to do that first. */
+ device_for_each_child(&adap->dev, NULL, __unregister_client);
+ device_for_each_child(&adap->dev, NULL, __unregister_dummy);
+
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
+ adap->dev.parent);
+#endif
+
+ /* device name is gone after device_unregister */
+ dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
+
+ pm_runtime_disable(&adap->dev);
+
+ i2c_host_notify_irq_teardown(adap);
+
+ /* wait until all references to the device are gone
+ *
+ * FIXME: This is old code and should ideally be replaced by an
+ * alternative which results in decoupling the lifetime of the struct
+ * device from the i2c_adapter, like spi or netdev do. Any solution
+ * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
+ */
+ init_completion(&adap->dev_released);
+ device_unregister(&adap->dev);
+ wait_for_completion(&adap->dev_released);
+
+ /* free bus id */
+ mutex_lock(&core_lock);
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+
+ /* Clear the device structure in case this adapter is ever going to be
+ added again */
+ memset(&adap->dev, 0, sizeof(adap->dev));
+}
+EXPORT_SYMBOL(i2c_del_adapter);
+
+static void devm_i2c_del_adapter(void *adapter)
+{
+ i2c_del_adapter(adapter);
+}
+
+/**
+ * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
+ * @dev: managing device for adding this I2C adapter
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * Add adapter with dynamic bus number, same with i2c_add_adapter()
+ * but the adapter will be auto deleted on driver detach.
+ */
+int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
+{
+ int ret;
+
+ ret = i2c_add_adapter(adapter);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);
+}
+EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);
+
+static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,
+ u32 def_val, bool use_def)
+{
+ int ret;
+
+ ret = device_property_read_u32(dev, prop_name, cur_val_p);
+ if (ret && use_def)
+ *cur_val_p = def_val;
+
+ dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p);
+}
+
+/**
+ * i2c_parse_fw_timings - get I2C related timing parameters from firmware
+ * @dev: The device to scan for I2C timing properties
+ * @t: the i2c_timings struct to be filled with values
+ * @use_defaults: bool to use sane defaults derived from the I2C specification
+ * when properties are not found, otherwise don't update
+ *
+ * Scan the device for the generic I2C properties describing timing parameters
+ * for the signal and fill the given struct with the results. If a property was
+ * not found and use_defaults was true, then maximum timings are assumed which
+ * are derived from the I2C specification. If use_defaults is not used, the
+ * results will be as before, so drivers can apply their own defaults before
+ * calling this helper. The latter is mainly intended for avoiding regressions
+ * of existing drivers which want to switch to this function. New drivers
+ * almost always should use the defaults.
+ */
+void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
+{
+ bool u = use_defaults;
+ u32 d;
+
+ i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz,
+ I2C_MAX_STANDARD_MODE_FREQ, u);
+
+ d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 :
+ t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
+ i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u);
+
+ d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
+ i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u);
+
+ i2c_parse_timing(dev, "i2c-scl-internal-delay-ns",
+ &t->scl_int_delay_ns, 0, u);
+ i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns,
+ t->scl_fall_ns, u);
+ i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u);
+ i2c_parse_timing(dev, "i2c-digital-filter-width-ns",
+ &t->digital_filter_width_ns, 0, u);
+ i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency",
+ &t->analog_filter_cutoff_freq_hz, 0, u);
+}
+EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
+
+/* ------------------------------------------------------------------------- */
+
+int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
+{
+ int res;
+
+ mutex_lock(&core_lock);
+ res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
+ mutex_unlock(&core_lock);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(i2c_for_each_dev);
+
+static int __process_new_driver(struct device *dev, void *data)
+{
+ if (dev->type != &i2c_adapter_type)
+ return 0;
+ return i2c_do_add_adapter(data, to_i2c_adapter(dev));
+}
+
+/*
+ * An i2c_driver is used with one or more i2c_client (device) nodes to access
+ * i2c slave chips, on a bus instance associated with some i2c_adapter.
+ */
+
+int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
+{
+ int res;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!is_registered))
+ return -EAGAIN;
+
+ /* add the driver to the list of i2c drivers in the driver core */
+ driver->driver.owner = owner;
+ driver->driver.bus = &i2c_bus_type;
+ INIT_LIST_HEAD(&driver->clients);
+
+ /* When registration returns, the driver core
+ * will have called probe() for all matching-but-unbound devices.
+ */
+ res = driver_register(&driver->driver);
+ if (res)
+ return res;
+
+ pr_debug("driver [%s] registered\n", driver->driver.name);
+
+ /* Walk the adapters that are already present */
+ i2c_for_each_dev(driver, __process_new_driver);
+
+ return 0;
+}
+EXPORT_SYMBOL(i2c_register_driver);
+
+static int __process_removed_driver(struct device *dev, void *data)
+{
+ if (dev->type == &i2c_adapter_type)
+ i2c_do_del_adapter(data, to_i2c_adapter(dev));
+ return 0;
+}
+
+/**
+ * i2c_del_driver - unregister I2C driver
+ * @driver: the driver being unregistered
+ * Context: can sleep
+ */
+void i2c_del_driver(struct i2c_driver *driver)
+{
+ i2c_for_each_dev(driver, __process_removed_driver);
+
+ driver_unregister(&driver->driver);
+ pr_debug("driver [%s] unregistered\n", driver->driver.name);
+}
+EXPORT_SYMBOL(i2c_del_driver);
+
+/* ------------------------------------------------------------------------- */
+
+struct i2c_cmd_arg {
+ unsigned cmd;
+ void *arg;
+};
+
+static int i2c_cmd(struct device *dev, void *_arg)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_cmd_arg *arg = _arg;
+ struct i2c_driver *driver;
+
+ if (!client || !client->dev.driver)
+ return 0;
+
+ driver = to_i2c_driver(client->dev.driver);
+ if (driver->command)
+ driver->command(client, arg->cmd, arg->arg);
+ return 0;
+}
+
+void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
+{
+ struct i2c_cmd_arg cmd_arg;
+
+ cmd_arg.cmd = cmd;
+ cmd_arg.arg = arg;
+ device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
+}
+EXPORT_SYMBOL(i2c_clients_command);
+
+static int __init i2c_init(void)
+{
+ int retval;
+
+ retval = of_alias_get_highest_id("i2c");
+
+ down_write(&__i2c_board_lock);
+ if (retval >= __i2c_first_dynamic_bus_num)
+ __i2c_first_dynamic_bus_num = retval + 1;
+ up_write(&__i2c_board_lock);
+
+ retval = bus_register(&i2c_bus_type);
+ if (retval)
+ return retval;
+
+ is_registered = true;
+
+#ifdef CONFIG_I2C_COMPAT
+ i2c_adapter_compat_class = class_compat_register("i2c-adapter");
+ if (!i2c_adapter_compat_class) {
+ retval = -ENOMEM;
+ goto bus_err;
+ }
+#endif
+ retval = i2c_add_driver(&dummy_driver);
+ if (retval)
+ goto class_err;
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
+
+ return 0;
+
+class_err:
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_unregister(i2c_adapter_compat_class);
+bus_err:
+#endif
+ is_registered = false;
+ bus_unregister(&i2c_bus_type);
+ return retval;
+}
+
+static void __exit i2c_exit(void)
+{
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
+ i2c_del_driver(&dummy_driver);
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_unregister(i2c_adapter_compat_class);
+#endif
+ bus_unregister(&i2c_bus_type);
+ tracepoint_synchronize_unregister();
+}
+
+/* We must initialize early, because some subsystems register i2c drivers
+ * in subsys_initcall() code, but are linked (and initialized) before i2c.
+ */
+postcore_initcall(i2c_init);
+module_exit(i2c_exit);
+
+/* ----------------------------------------------------
+ * the functional interface to the i2c busses.
+ * ----------------------------------------------------
+ */
+
+/* Check if val is exceeding the quirk IFF quirk is non 0 */
+#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
+
+static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
+{
+ dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
+ err_msg, msg->addr, msg->len,
+ msg->flags & I2C_M_RD ? "read" : "write");
+ return -EOPNOTSUPP;
+}
+
+static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ const struct i2c_adapter_quirks *q = adap->quirks;
+ int max_num = q->max_num_msgs, i;
+ bool do_len_check = true;
+
+ if (q->flags & I2C_AQ_COMB) {
+ max_num = 2;
+
+ /* special checks for combined messages */
+ if (num == 2) {
+ if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
+ return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
+
+ if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
+ return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
+
+ if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
+ return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
+
+ if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
+ return i2c_quirk_error(adap, &msgs[0], "msg too long");
+
+ if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
+ return i2c_quirk_error(adap, &msgs[1], "msg too long");
+
+ do_len_check = false;
+ }
+ }
+
+ if (i2c_quirk_exceeded(num, max_num))
+ return i2c_quirk_error(adap, &msgs[0], "too many messages");
+
+ for (i = 0; i < num; i++) {
+ u16 len = msgs[i].len;
+
+ if (msgs[i].flags & I2C_M_RD) {
+ if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+
+ if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
+ return i2c_quirk_error(adap, &msgs[i], "no zero length");
+ } else {
+ if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+
+ if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
+ return i2c_quirk_error(adap, &msgs[i], "no zero length");
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * __i2c_transfer - unlocked flavor of i2c_transfer
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ * terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Adapter lock must be held when calling this function. No debug logging
+ * takes place. adap->algo->master_xfer existence isn't checked.
+ */
+int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ unsigned long orig_jiffies;
+ int ret, try;
+
+ if (WARN_ON(!msgs || num < 1))
+ return -EINVAL;
+
+ ret = __i2c_check_suspended(adap);
+ if (ret)
+ return ret;
+
+ if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
+ return -EOPNOTSUPP;
+
+ /*
+ * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
+ * enabled. This is an efficient way of keeping the for-loop from
+ * being executed when not needed.
+ */
+ if (static_branch_unlikely(&i2c_trace_msg_key)) {
+ int i;
+ for (i = 0; i < num; i++)
+ if (msgs[i].flags & I2C_M_RD)
+ trace_i2c_read(adap, &msgs[i], i);
+ else
+ trace_i2c_write(adap, &msgs[i], i);
+ }
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (ret = 0, try = 0; try <= adap->retries; try++) {
+ if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
+ ret = adap->algo->master_xfer_atomic(adap, msgs, num);
+ else
+ ret = adap->algo->master_xfer(adap, msgs, num);
+
+ if (ret != -EAGAIN)
+ break;
+ if (time_after(jiffies, orig_jiffies + adap->timeout))
+ break;
+ }
+
+ if (static_branch_unlikely(&i2c_trace_msg_key)) {
+ int i;
+ for (i = 0; i < ret; i++)
+ if (msgs[i].flags & I2C_M_RD)
+ trace_i2c_reply(adap, &msgs[i], i);
+ trace_i2c_result(adap, num, ret);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(__i2c_transfer);
+
+/**
+ * i2c_transfer - execute a single or combined I2C message
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ * terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Note that there is no requirement that each message be sent to
+ * the same slave address, although that is the most common model.
+ */
+int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ int ret;
+
+ if (!adap->algo->master_xfer) {
+ dev_dbg(&adap->dev, "I2C level transfers not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* REVISIT the fault reporting model here is weak:
+ *
+ * - When we get an error after receiving N bytes from a slave,
+ * there is no way to report "N".
+ *
+ * - When we get a NAK after transmitting N bytes to a slave,
+ * there is no way to report "N" ... or to let the master
+ * continue executing the rest of this combined message, if
+ * that's the appropriate response.
+ *
+ * - When for example "num" is two and we successfully complete
+ * the first message but get an error part way through the
+ * second, it's unclear whether that should be reported as
+ * one (discarding status on the second message) or errno
+ * (discarding status on the first one).
+ */
+ ret = __i2c_lock_bus_helper(adap);
+ if (ret)
+ return ret;
+
+ ret = __i2c_transfer(adap, msgs, num);
+ i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
+
+ return ret;
+}
+EXPORT_SYMBOL(i2c_transfer);
+
+/**
+ * i2c_transfer_buffer_flags - issue a single I2C message transferring data
+ * to/from a buffer
+ * @client: Handle to slave device
+ * @buf: Where the data is stored
+ * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
+ * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
+ *
+ * Returns negative errno, or else the number of bytes transferred.
+ */
+int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
+ int count, u16 flags)
+{
+ int ret;
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = flags | (client->flags & I2C_M_TEN),
+ .len = count,
+ .buf = buf,
+ };
+
+ ret = i2c_transfer(client->adapter, &msg, 1);
+
+ /*
+ * If everything went ok (i.e. 1 msg transferred), return #bytes
+ * transferred, else error code.
+ */
+ return (ret == 1) ? count : ret;
+}
+EXPORT_SYMBOL(i2c_transfer_buffer_flags);
+
+/**
+ * i2c_get_device_id - get manufacturer, part id and die revision of a device
+ * @client: The device to query
+ * @id: The queried information
+ *
+ * Returns negative errno on error, zero on success.
+ */
+int i2c_get_device_id(const struct i2c_client *client,
+ struct i2c_device_identity *id)
+{
+ struct i2c_adapter *adap = client->adapter;
+ union i2c_smbus_data raw_id;
+ int ret;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return -EOPNOTSUPP;
+
+ raw_id.block[0] = 3;
+ ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
+ I2C_SMBUS_READ, client->addr << 1,
+ I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
+ if (ret)
+ return ret;
+
+ id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
+ id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
+ id->die_revision = raw_id.block[3] & 0x7;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_get_device_id);
+
+/* ----------------------------------------------------
+ * the i2c address scanning function
+ * Will not work for 10-bit addresses!
+ * ----------------------------------------------------
+ */
+
+/*
+ * Legacy default probe function, mostly relevant for SMBus. The default
+ * probe method is a quick write, but it is known to corrupt the 24RF08
+ * EEPROMs due to a state machine bug, and could also irreversibly
+ * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
+ * we use a short byte read instead. Also, some bus drivers don't implement
+ * quick write, so we fallback to a byte read in that case too.
+ * On x86, there is another special case for FSC hardware monitoring chips,
+ * which want regular byte reads (address 0x73.) Fortunately, these are the
+ * only known chips using this I2C address on PC hardware.
+ * Returns 1 if probe succeeded, 0 if not.
+ */
+static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
+{
+ int err;
+ union i2c_smbus_data dummy;
+
+#ifdef CONFIG_X86
+ if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE_DATA, &dummy);
+ else
+#endif
+ if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
+ I2C_SMBUS_QUICK, NULL);
+ else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &dummy);
+ else {
+ dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
+ addr);
+ err = -EOPNOTSUPP;
+ }
+
+ return err >= 0;
+}
+
+static int i2c_detect_address(struct i2c_client *temp_client,
+ struct i2c_driver *driver)
+{
+ struct i2c_board_info info;
+ struct i2c_adapter *adapter = temp_client->adapter;
+ int addr = temp_client->addr;
+ int err;
+
+ /* Make sure the address is valid */
+ err = i2c_check_7bit_addr_validity_strict(addr);
+ if (err) {
+ dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
+ addr);
+ return err;
+ }
+
+ /* Skip if already in use (7 bit, no need to encode flags) */
+ if (i2c_check_addr_busy(adapter, addr))
+ return 0;
+
+ /* Make sure there is something at this address */
+ if (!i2c_default_probe(adapter, addr))
+ return 0;
+
+ /* Finally call the custom detection function */
+ memset(&info, 0, sizeof(struct i2c_board_info));
+ info.addr = addr;
+ err = driver->detect(temp_client, &info);
+ if (err) {
+ /* -ENODEV is returned if the detection fails. We catch it
+ here as this isn't an error. */
+ return err == -ENODEV ? 0 : err;
+ }
+
+ /* Consistency check */
+ if (info.type[0] == '\0') {
+ dev_err(&adapter->dev,
+ "%s detection function provided no name for 0x%x\n",
+ driver->driver.name, addr);
+ } else {
+ struct i2c_client *client;
+
+ /* Detection succeeded, instantiate the device */
+ if (adapter->class & I2C_CLASS_DEPRECATED)
+ dev_warn(&adapter->dev,
+ "This adapter will soon drop class based instantiation of devices. "
+ "Please make sure client 0x%02x gets instantiated by other means. "
+ "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
+ info.addr);
+
+ dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
+ info.type, info.addr);
+ client = i2c_new_client_device(adapter, &info);
+ if (!IS_ERR(client))
+ list_add_tail(&client->detected, &driver->clients);
+ else
+ dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
+ info.type, info.addr);
+ }
+ return 0;
+}
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
+{
+ const unsigned short *address_list;
+ struct i2c_client *temp_client;
+ int i, err = 0;
+
+ address_list = driver->address_list;
+ if (!driver->detect || !address_list)
+ return 0;
+
+ /* Warn that the adapter lost class based instantiation */
+ if (adapter->class == I2C_CLASS_DEPRECATED) {
+ dev_dbg(&adapter->dev,
+ "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
+ "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
+ driver->driver.name);
+ return 0;
+ }
+
+ /* Stop here if the classes do not match */
+ if (!(adapter->class & driver->class))
+ return 0;
+
+ /* Set up a temporary client to help detect callback */
+ temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+ if (!temp_client)
+ return -ENOMEM;
+ temp_client->adapter = adapter;
+
+ for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
+ dev_dbg(&adapter->dev,
+ "found normal entry for adapter %d, addr 0x%02x\n",
+ i2c_adapter_id(adapter), address_list[i]);
+ temp_client->addr = address_list[i];
+ err = i2c_detect_address(temp_client, driver);
+ if (unlikely(err))
+ break;
+ }
+
+ kfree(temp_client);
+ return err;
+}
+
+int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
+{
+ return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_QUICK, NULL) >= 0;
+}
+EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
+
+struct i2c_client *
+i2c_new_scanned_device(struct i2c_adapter *adap,
+ struct i2c_board_info *info,
+ unsigned short const *addr_list,
+ int (*probe)(struct i2c_adapter *adap, unsigned short addr))
+{
+ int i;
+
+ if (!probe)
+ probe = i2c_default_probe;
+
+ for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
+ /* Check address validity */
+ if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
+ dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
+ addr_list[i]);
+ continue;
+ }
+
+ /* Check address availability (7 bit, no need to encode flags) */
+ if (i2c_check_addr_busy(adap, addr_list[i])) {
+ dev_dbg(&adap->dev,
+ "Address 0x%02x already in use, not probing\n",
+ addr_list[i]);
+ continue;
+ }
+
+ /* Test address responsiveness */
+ if (probe(adap, addr_list[i]))
+ break;
+ }
+
+ if (addr_list[i] == I2C_CLIENT_END) {
+ dev_dbg(&adap->dev, "Probing failed, no device found\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ info->addr = addr_list[i];
+ return i2c_new_client_device(adap, info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_scanned_device);
+
+struct i2c_adapter *i2c_get_adapter(int nr)
+{
+ struct i2c_adapter *adapter;
+
+ mutex_lock(&core_lock);
+ adapter = idr_find(&i2c_adapter_idr, nr);
+ if (!adapter)
+ goto exit;
+
+ if (try_module_get(adapter->owner))
+ get_device(&adapter->dev);
+ else
+ adapter = NULL;
+
+ exit:
+ mutex_unlock(&core_lock);
+ return adapter;
+}
+EXPORT_SYMBOL(i2c_get_adapter);
+
+void i2c_put_adapter(struct i2c_adapter *adap)
+{
+ if (!adap)
+ return;
+
+ module_put(adap->owner);
+ /* Should be last, otherwise we risk use-after-free with 'adap' */
+ put_device(&adap->dev);
+}
+EXPORT_SYMBOL(i2c_put_adapter);
+
+/**
+ * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
+ * @msg: the message to be checked
+ * @threshold: the minimum number of bytes for which using DMA makes sense.
+ * Should at least be 1.
+ *
+ * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
+ * Or a valid pointer to be used with DMA. After use, release it by
+ * calling i2c_put_dma_safe_msg_buf().
+ *
+ * This function must only be called from process context!
+ */
+u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
+{
+ /* also skip 0-length msgs for bogus thresholds of 0 */
+ if (!threshold)
+ pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
+ msg->addr);
+ if (msg->len < threshold || msg->len == 0)
+ return NULL;
+
+ if (msg->flags & I2C_M_DMA_SAFE)
+ return msg->buf;
+
+ pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
+ msg->addr, msg->len);
+
+ if (msg->flags & I2C_M_RD)
+ return kzalloc(msg->len, GFP_KERNEL);
+ else
+ return kmemdup(msg->buf, msg->len, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
+
+/**
+ * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
+ * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
+ * @msg: the message which the buffer corresponds to
+ * @xferred: bool saying if the message was transferred
+ */
+void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
+{
+ if (!buf || buf == msg->buf)
+ return;
+
+ if (xferred && msg->flags & I2C_M_RD)
+ memcpy(msg->buf, buf, msg->len);
+
+ kfree(buf);
+}
+EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
+
+MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C-Bus main module");
+MODULE_LICENSE("GPL");