diff options
Diffstat (limited to 'drivers/mux')
| -rw-r--r-- | drivers/mux/Kconfig | 61 | ||||
| -rw-r--r-- | drivers/mux/Makefile | 16 | ||||
| -rw-r--r-- | drivers/mux/adg792a.c | 153 | ||||
| -rw-r--r-- | drivers/mux/adgs1408.c | 131 | ||||
| -rw-r--r-- | drivers/mux/core.c | 760 | ||||
| -rw-r--r-- | drivers/mux/gpio.c | 106 | ||||
| -rw-r--r-- | drivers/mux/mmio.c | 142 |
7 files changed, 1369 insertions, 0 deletions
diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig new file mode 100644 index 0000000000..80f015cf6e --- /dev/null +++ b/drivers/mux/Kconfig @@ -0,0 +1,61 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Multiplexer devices +# + +config MULTIPLEXER + tristate + +menu "Multiplexer drivers" + depends on MULTIPLEXER + +config MUX_ADG792A + tristate "Analog Devices ADG792A/ADG792G Multiplexers" + depends on I2C + help + ADG792A and ADG792G Wide Bandwidth Triple 4:1 Multiplexers + + The driver supports both operating the three multiplexers in + parallel and operating them independently. + + To compile the driver as a module, choose M here: the module will + be called mux-adg792a. + +config MUX_ADGS1408 + tristate "Analog Devices ADGS1408/ADGS1409 Multiplexers" + depends on SPI + help + ADGS1408 8:1 multiplexer and ADGS1409 double 4:1 multiplexer + switches. + + To compile the driver as a module, choose M here: the module will + be called mux-adgs1408. + +config MUX_GPIO + tristate "GPIO-controlled Multiplexer" + depends on GPIOLIB || COMPILE_TEST + help + GPIO-controlled Multiplexer controller. + + The driver builds a single multiplexer controller using a number + of gpio pins. For N pins, there will be 2^N possible multiplexer + states. The GPIO pins can be connected (by the hardware) to several + multiplexers, which in that case will be operated in parallel. + + To compile the driver as a module, choose M here: the module will + be called mux-gpio. + +config MUX_MMIO + tristate "MMIO/Regmap register bitfield-controlled Multiplexer" + depends on OF + help + MMIO/Regmap register bitfield-controlled Multiplexer controller. + + The driver builds multiplexer controllers for bitfields in either + a syscon register or a driver regmap register. For N bit wide + bitfields, there will be 2^N possible multiplexer states. + + To compile the driver as a module, choose M here: the module will + be called mux-mmio. + +endmenu diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile new file mode 100644 index 0000000000..6e9fa47daf --- /dev/null +++ b/drivers/mux/Makefile @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for multiplexer devices. +# + +mux-core-objs := core.o +mux-adg792a-objs := adg792a.o +mux-adgs1408-objs := adgs1408.o +mux-gpio-objs := gpio.o +mux-mmio-objs := mmio.o + +obj-$(CONFIG_MULTIPLEXER) += mux-core.o +obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o +obj-$(CONFIG_MUX_ADGS1408) += mux-adgs1408.o +obj-$(CONFIG_MUX_GPIO) += mux-gpio.o +obj-$(CONFIG_MUX_MMIO) += mux-mmio.o diff --git a/drivers/mux/adg792a.c b/drivers/mux/adg792a.c new file mode 100644 index 0000000000..4da5aecb9f --- /dev/null +++ b/drivers/mux/adg792a.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux + * + * Copyright (C) 2017 Axentia Technologies AB + * + * Author: Peter Rosin <peda@axentia.se> + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mux/driver.h> +#include <linux/property.h> + +#define ADG792A_LDSW BIT(0) +#define ADG792A_RESETB BIT(1) +#define ADG792A_DISABLE(mux) (0x50 | (mux)) +#define ADG792A_DISABLE_ALL (0x5f) +#define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state)) +#define ADG792A_MUX_ALL(state) (0xc0 | (state)) + +static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset) +{ + u8 data = ADG792A_RESETB | ADG792A_LDSW; + + /* ADG792A_RESETB is active low, the chip resets when it is zero. */ + if (reset) + data &= ~ADG792A_RESETB; + + return i2c_smbus_write_byte_data(i2c, cmd, data); +} + +static int adg792a_set(struct mux_control *mux, int state) +{ + struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent); + u8 cmd; + + if (mux->chip->controllers == 1) { + /* parallel mux controller operation */ + if (state == MUX_IDLE_DISCONNECT) + cmd = ADG792A_DISABLE_ALL; + else + cmd = ADG792A_MUX_ALL(state); + } else { + unsigned int controller = mux_control_get_index(mux); + + if (state == MUX_IDLE_DISCONNECT) + cmd = ADG792A_DISABLE(controller); + else + cmd = ADG792A_MUX(controller, state); + } + + return adg792a_write_cmd(i2c, cmd, 0); +} + +static const struct mux_control_ops adg792a_ops = { + .set = adg792a_set, +}; + +static int adg792a_probe(struct i2c_client *i2c) +{ + struct device *dev = &i2c->dev; + struct mux_chip *mux_chip; + s32 idle_state[3]; + u32 cells; + int ret; + int i; + + if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -ENODEV; + + ret = device_property_read_u32(dev, "#mux-control-cells", &cells); + if (ret < 0) + return ret; + if (cells >= 2) + return -EINVAL; + + mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0); + if (IS_ERR(mux_chip)) + return PTR_ERR(mux_chip); + + mux_chip->ops = &adg792a_ops; + + ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1); + if (ret < 0) + return ret; + + ret = device_property_read_u32_array(dev, "idle-state", + (u32 *)idle_state, + mux_chip->controllers); + if (ret < 0) { + idle_state[0] = MUX_IDLE_AS_IS; + idle_state[1] = MUX_IDLE_AS_IS; + idle_state[2] = MUX_IDLE_AS_IS; + } + + for (i = 0; i < mux_chip->controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + mux->states = 4; + + switch (idle_state[i]) { + case MUX_IDLE_DISCONNECT: + case MUX_IDLE_AS_IS: + case 0 ... 4: + mux->idle_state = idle_state[i]; + break; + default: + dev_err(dev, "invalid idle-state %d\n", idle_state[i]); + return -EINVAL; + } + } + + ret = devm_mux_chip_register(dev, mux_chip); + if (ret < 0) + return ret; + + if (cells) + dev_info(dev, "3x single pole quadruple throw muxes registered\n"); + else + dev_info(dev, "triple pole quadruple throw mux registered\n"); + + return 0; +} + +static const struct i2c_device_id adg792a_id[] = { + { .name = "adg792a", }, + { .name = "adg792g", }, + { } +}; +MODULE_DEVICE_TABLE(i2c, adg792a_id); + +static const struct of_device_id adg792a_of_match[] = { + { .compatible = "adi,adg792a", }, + { .compatible = "adi,adg792g", }, + { } +}; +MODULE_DEVICE_TABLE(of, adg792a_of_match); + +static struct i2c_driver adg792a_driver = { + .driver = { + .name = "adg792a", + .of_match_table = of_match_ptr(adg792a_of_match), + }, + .probe = adg792a_probe, + .id_table = adg792a_id, +}; +module_i2c_driver(adg792a_driver); + +MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver"); +MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/mux/adgs1408.c b/drivers/mux/adgs1408.c new file mode 100644 index 0000000000..22ed051eb1 --- /dev/null +++ b/drivers/mux/adgs1408.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ADGS1408/ADGS1409 SPI MUX driver + * + * Copyright 2018 Analog Devices Inc. + */ + +#include <linux/err.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mux/driver.h> +#include <linux/property.h> +#include <linux/spi/spi.h> + +#define ADGS1408_SW_DATA (0x01) +#define ADGS1408_REG_READ(reg) ((reg) | 0x80) +#define ADGS1408_DISABLE (0x00) +#define ADGS1408_MUX(state) (((state) << 1) | 1) + +enum adgs1408_chip_id { + ADGS1408 = 1, + ADGS1409, +}; + +static int adgs1408_spi_reg_write(struct spi_device *spi, + u8 reg_addr, u8 reg_data) +{ + u8 tx_buf[2]; + + tx_buf[0] = reg_addr; + tx_buf[1] = reg_data; + + return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0); +} + +static int adgs1408_set(struct mux_control *mux, int state) +{ + struct spi_device *spi = to_spi_device(mux->chip->dev.parent); + u8 reg; + + if (state == MUX_IDLE_DISCONNECT) + reg = ADGS1408_DISABLE; + else + reg = ADGS1408_MUX(state); + + return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg); +} + +static const struct mux_control_ops adgs1408_ops = { + .set = adgs1408_set, +}; + +static int adgs1408_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + enum adgs1408_chip_id chip_id; + struct mux_chip *mux_chip; + struct mux_control *mux; + s32 idle_state; + int ret; + + chip_id = (enum adgs1408_chip_id)device_get_match_data(dev); + if (!chip_id) + chip_id = spi_get_device_id(spi)->driver_data; + + mux_chip = devm_mux_chip_alloc(dev, 1, 0); + if (IS_ERR(mux_chip)) + return PTR_ERR(mux_chip); + + mux_chip->ops = &adgs1408_ops; + + ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE); + if (ret < 0) + return ret; + + ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); + if (ret < 0) + idle_state = MUX_IDLE_AS_IS; + + mux = mux_chip->mux; + + if (chip_id == ADGS1408) + mux->states = 8; + else + mux->states = 4; + + switch (idle_state) { + case MUX_IDLE_DISCONNECT: + case MUX_IDLE_AS_IS: + case 0 ... 7: + /* adgs1409 supports only 4 states */ + if (idle_state < mux->states) { + mux->idle_state = idle_state; + break; + } + fallthrough; + default: + dev_err(dev, "invalid idle-state %d\n", idle_state); + return -EINVAL; + } + + return devm_mux_chip_register(dev, mux_chip); +} + +static const struct spi_device_id adgs1408_spi_id[] = { + { "adgs1408", ADGS1408 }, + { "adgs1409", ADGS1409 }, + { } +}; +MODULE_DEVICE_TABLE(spi, adgs1408_spi_id); + +static const struct of_device_id adgs1408_of_match[] = { + { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, }, + { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, }, + { } +}; +MODULE_DEVICE_TABLE(of, adgs1408_of_match); + +static struct spi_driver adgs1408_driver = { + .driver = { + .name = "adgs1408", + .of_match_table = adgs1408_of_match, + }, + .probe = adgs1408_probe, + .id_table = adgs1408_spi_id, +}; +module_spi_driver(adgs1408_driver); + +MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>"); +MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/mux/core.c b/drivers/mux/core.c new file mode 100644 index 0000000000..7758161129 --- /dev/null +++ b/drivers/mux/core.c @@ -0,0 +1,760 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Multiplexer subsystem + * + * Copyright (C) 2017 Axentia Technologies AB + * + * Author: Peter Rosin <peda@axentia.se> + */ + +#define pr_fmt(fmt) "mux-core: " fmt + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/idr.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mux/consumer.h> +#include <linux/mux/driver.h> +#include <linux/of.h> +#include <linux/slab.h> + +/* + * The idle-as-is "state" is not an actual state that may be selected, it + * only implies that the state should not be changed. So, use that state + * as indication that the cached state of the multiplexer is unknown. + */ +#define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS + +/** + * struct mux_state - Represents a mux controller state specific to a given + * consumer. + * @mux: Pointer to a mux controller. + * @state: State of the mux to be selected. + * + * This structure is specific to the consumer that acquires it and has + * information specific to that consumer. + */ +struct mux_state { + struct mux_control *mux; + unsigned int state; +}; + +static struct class mux_class = { + .name = "mux", +}; + +static DEFINE_IDA(mux_ida); + +static int __init mux_init(void) +{ + ida_init(&mux_ida); + return class_register(&mux_class); +} + +static void __exit mux_exit(void) +{ + class_unregister(&mux_class); + ida_destroy(&mux_ida); +} + +static void mux_chip_release(struct device *dev) +{ + struct mux_chip *mux_chip = to_mux_chip(dev); + + ida_simple_remove(&mux_ida, mux_chip->id); + kfree(mux_chip); +} + +static const struct device_type mux_type = { + .name = "mux-chip", + .release = mux_chip_release, +}; + +/** + * mux_chip_alloc() - Allocate a mux-chip. + * @dev: The parent device implementing the mux interface. + * @controllers: The number of mux controllers to allocate for this chip. + * @sizeof_priv: Size of extra memory area for private use by the caller. + * + * After allocating the mux-chip with the desired number of mux controllers + * but before registering the chip, the mux driver is required to configure + * the number of valid mux states in the mux_chip->mux[N].states members and + * the desired idle state in the returned mux_chip->mux[N].idle_state members. + * The default idle state is MUX_IDLE_AS_IS. The mux driver also needs to + * provide a pointer to the operations struct in the mux_chip->ops member + * before registering the mux-chip with mux_chip_register. + * + * Return: A pointer to the new mux-chip, or an ERR_PTR with a negative errno. + */ +struct mux_chip *mux_chip_alloc(struct device *dev, + unsigned int controllers, size_t sizeof_priv) +{ + struct mux_chip *mux_chip; + int i; + + if (WARN_ON(!dev || !controllers)) + return ERR_PTR(-EINVAL); + + mux_chip = kzalloc(sizeof(*mux_chip) + + controllers * sizeof(*mux_chip->mux) + + sizeof_priv, GFP_KERNEL); + if (!mux_chip) + return ERR_PTR(-ENOMEM); + + mux_chip->mux = (struct mux_control *)(mux_chip + 1); + mux_chip->dev.class = &mux_class; + mux_chip->dev.type = &mux_type; + mux_chip->dev.parent = dev; + mux_chip->dev.of_node = dev->of_node; + dev_set_drvdata(&mux_chip->dev, mux_chip); + + mux_chip->id = ida_simple_get(&mux_ida, 0, 0, GFP_KERNEL); + if (mux_chip->id < 0) { + int err = mux_chip->id; + + pr_err("muxchipX failed to get a device id\n"); + kfree(mux_chip); + return ERR_PTR(err); + } + dev_set_name(&mux_chip->dev, "muxchip%d", mux_chip->id); + + mux_chip->controllers = controllers; + for (i = 0; i < controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + mux->chip = mux_chip; + sema_init(&mux->lock, 1); + mux->cached_state = MUX_CACHE_UNKNOWN; + mux->idle_state = MUX_IDLE_AS_IS; + mux->last_change = ktime_get(); + } + + device_initialize(&mux_chip->dev); + + return mux_chip; +} +EXPORT_SYMBOL_GPL(mux_chip_alloc); + +static int mux_control_set(struct mux_control *mux, int state) +{ + int ret = mux->chip->ops->set(mux, state); + + mux->cached_state = ret < 0 ? MUX_CACHE_UNKNOWN : state; + if (ret >= 0) + mux->last_change = ktime_get(); + + return ret; +} + +/** + * mux_chip_register() - Register a mux-chip, thus readying the controllers + * for use. + * @mux_chip: The mux-chip to register. + * + * Do not retry registration of the same mux-chip on failure. You should + * instead put it away with mux_chip_free() and allocate a new one, if you + * for some reason would like to retry registration. + * + * Return: Zero on success or a negative errno on error. + */ +int mux_chip_register(struct mux_chip *mux_chip) +{ + int i; + int ret; + + for (i = 0; i < mux_chip->controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + if (mux->idle_state == mux->cached_state) + continue; + + ret = mux_control_set(mux, mux->idle_state); + if (ret < 0) { + dev_err(&mux_chip->dev, "unable to set idle state\n"); + return ret; + } + } + + ret = device_add(&mux_chip->dev); + if (ret < 0) + dev_err(&mux_chip->dev, + "device_add failed in %s: %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(mux_chip_register); + +/** + * mux_chip_unregister() - Take the mux-chip off-line. + * @mux_chip: The mux-chip to unregister. + * + * mux_chip_unregister() reverses the effects of mux_chip_register(). + * But not completely, you should not try to call mux_chip_register() + * on a mux-chip that has been registered before. + */ +void mux_chip_unregister(struct mux_chip *mux_chip) +{ + device_del(&mux_chip->dev); +} +EXPORT_SYMBOL_GPL(mux_chip_unregister); + +/** + * mux_chip_free() - Free the mux-chip for good. + * @mux_chip: The mux-chip to free. + * + * mux_chip_free() reverses the effects of mux_chip_alloc(). + */ +void mux_chip_free(struct mux_chip *mux_chip) +{ + if (!mux_chip) + return; + + put_device(&mux_chip->dev); +} +EXPORT_SYMBOL_GPL(mux_chip_free); + +static void devm_mux_chip_release(struct device *dev, void *res) +{ + struct mux_chip *mux_chip = *(struct mux_chip **)res; + + mux_chip_free(mux_chip); +} + +/** + * devm_mux_chip_alloc() - Resource-managed version of mux_chip_alloc(). + * @dev: The parent device implementing the mux interface. + * @controllers: The number of mux controllers to allocate for this chip. + * @sizeof_priv: Size of extra memory area for private use by the caller. + * + * See mux_chip_alloc() for more details. + * + * Return: A pointer to the new mux-chip, or an ERR_PTR with a negative errno. + */ +struct mux_chip *devm_mux_chip_alloc(struct device *dev, + unsigned int controllers, + size_t sizeof_priv) +{ + struct mux_chip **ptr, *mux_chip; + + ptr = devres_alloc(devm_mux_chip_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + mux_chip = mux_chip_alloc(dev, controllers, sizeof_priv); + if (IS_ERR(mux_chip)) { + devres_free(ptr); + return mux_chip; + } + + *ptr = mux_chip; + devres_add(dev, ptr); + + return mux_chip; +} +EXPORT_SYMBOL_GPL(devm_mux_chip_alloc); + +static void devm_mux_chip_reg_release(struct device *dev, void *res) +{ + struct mux_chip *mux_chip = *(struct mux_chip **)res; + + mux_chip_unregister(mux_chip); +} + +/** + * devm_mux_chip_register() - Resource-managed version mux_chip_register(). + * @dev: The parent device implementing the mux interface. + * @mux_chip: The mux-chip to register. + * + * See mux_chip_register() for more details. + * + * Return: Zero on success or a negative errno on error. + */ +int devm_mux_chip_register(struct device *dev, + struct mux_chip *mux_chip) +{ + struct mux_chip **ptr; + int res; + + ptr = devres_alloc(devm_mux_chip_reg_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + res = mux_chip_register(mux_chip); + if (res) { + devres_free(ptr); + return res; + } + + *ptr = mux_chip; + devres_add(dev, ptr); + + return res; +} +EXPORT_SYMBOL_GPL(devm_mux_chip_register); + +/** + * mux_control_states() - Query the number of multiplexer states. + * @mux: The mux-control to query. + * + * Return: The number of multiplexer states. + */ +unsigned int mux_control_states(struct mux_control *mux) +{ + return mux->states; +} +EXPORT_SYMBOL_GPL(mux_control_states); + +/* + * The mux->lock must be down when calling this function. + */ +static int __mux_control_select(struct mux_control *mux, int state) +{ + int ret; + + if (WARN_ON(state < 0 || state >= mux->states)) + return -EINVAL; + + if (mux->cached_state == state) + return 0; + + ret = mux_control_set(mux, state); + if (ret >= 0) + return 0; + + /* The mux update failed, try to revert if appropriate... */ + if (mux->idle_state != MUX_IDLE_AS_IS) + mux_control_set(mux, mux->idle_state); + + return ret; +} + +static void mux_control_delay(struct mux_control *mux, unsigned int delay_us) +{ + ktime_t delayend; + s64 remaining; + + if (!delay_us) + return; + + delayend = ktime_add_us(mux->last_change, delay_us); + remaining = ktime_us_delta(delayend, ktime_get()); + if (remaining > 0) + fsleep(remaining); +} + +/** + * mux_control_select_delay() - Select the given multiplexer state. + * @mux: The mux-control to request a change of state from. + * @state: The new requested state. + * @delay_us: The time to delay (in microseconds) if the mux state is changed. + * + * On successfully selecting the mux-control state, it will be locked until + * there is a call to mux_control_deselect(). If the mux-control is already + * selected when mux_control_select() is called, the caller will be blocked + * until mux_control_deselect() or mux_state_deselect() is called (by someone + * else). + * + * Therefore, make sure to call mux_control_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_control_deselect() if mux_control_select() fails. + * + * Return: 0 when the mux-control state has the requested state or a negative + * errno on error. + */ +int mux_control_select_delay(struct mux_control *mux, unsigned int state, + unsigned int delay_us) +{ + int ret; + + ret = down_killable(&mux->lock); + if (ret < 0) + return ret; + + ret = __mux_control_select(mux, state); + if (ret >= 0) + mux_control_delay(mux, delay_us); + + if (ret < 0) + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_select_delay); + +/** + * mux_state_select_delay() - Select the given multiplexer state. + * @mstate: The mux-state to select. + * @delay_us: The time to delay (in microseconds) if the mux state is changed. + * + * On successfully selecting the mux-state, its mux-control will be locked + * until there is a call to mux_state_deselect(). If the mux-control is already + * selected when mux_state_select() is called, the caller will be blocked + * until mux_state_deselect() or mux_control_deselect() is called (by someone + * else). + * + * Therefore, make sure to call mux_state_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_state_deselect() if mux_state_select() fails. + * + * Return: 0 when the mux-state has been selected or a negative + * errno on error. + */ +int mux_state_select_delay(struct mux_state *mstate, unsigned int delay_us) +{ + return mux_control_select_delay(mstate->mux, mstate->state, delay_us); +} +EXPORT_SYMBOL_GPL(mux_state_select_delay); + +/** + * mux_control_try_select_delay() - Try to select the given multiplexer state. + * @mux: The mux-control to request a change of state from. + * @state: The new requested state. + * @delay_us: The time to delay (in microseconds) if the mux state is changed. + * + * On successfully selecting the mux-control state, it will be locked until + * mux_control_deselect() is called. + * + * Therefore, make sure to call mux_control_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_control_deselect() if mux_control_try_select() fails. + * + * Return: 0 when the mux-control state has the requested state or a negative + * errno on error. Specifically -EBUSY if the mux-control is contended. + */ +int mux_control_try_select_delay(struct mux_control *mux, unsigned int state, + unsigned int delay_us) +{ + int ret; + + if (down_trylock(&mux->lock)) + return -EBUSY; + + ret = __mux_control_select(mux, state); + if (ret >= 0) + mux_control_delay(mux, delay_us); + + if (ret < 0) + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_try_select_delay); + +/** + * mux_state_try_select_delay() - Try to select the given multiplexer state. + * @mstate: The mux-state to select. + * @delay_us: The time to delay (in microseconds) if the mux state is changed. + * + * On successfully selecting the mux-state, its mux-control will be locked + * until mux_state_deselect() is called. + * + * Therefore, make sure to call mux_state_deselect() when the operation is + * complete and the mux-control is free for others to use, but do not call + * mux_state_deselect() if mux_state_try_select() fails. + * + * Return: 0 when the mux-state has been selected or a negative errno on + * error. Specifically -EBUSY if the mux-control is contended. + */ +int mux_state_try_select_delay(struct mux_state *mstate, unsigned int delay_us) +{ + return mux_control_try_select_delay(mstate->mux, mstate->state, delay_us); +} +EXPORT_SYMBOL_GPL(mux_state_try_select_delay); + +/** + * mux_control_deselect() - Deselect the previously selected multiplexer state. + * @mux: The mux-control to deselect. + * + * It is required that a single call is made to mux_control_deselect() for + * each and every successful call made to either of mux_control_select() or + * mux_control_try_select(). + * + * Return: 0 on success and a negative errno on error. An error can only + * occur if the mux has an idle state. Note that even if an error occurs, the + * mux-control is unlocked and is thus free for the next access. + */ +int mux_control_deselect(struct mux_control *mux) +{ + int ret = 0; + + if (mux->idle_state != MUX_IDLE_AS_IS && + mux->idle_state != mux->cached_state) + ret = mux_control_set(mux, mux->idle_state); + + up(&mux->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mux_control_deselect); + +/** + * mux_state_deselect() - Deselect the previously selected multiplexer state. + * @mstate: The mux-state to deselect. + * + * It is required that a single call is made to mux_state_deselect() for + * each and every successful call made to either of mux_state_select() or + * mux_state_try_select(). + * + * Return: 0 on success and a negative errno on error. An error can only + * occur if the mux has an idle state. Note that even if an error occurs, the + * mux-control is unlocked and is thus free for the next access. + */ +int mux_state_deselect(struct mux_state *mstate) +{ + return mux_control_deselect(mstate->mux); +} +EXPORT_SYMBOL_GPL(mux_state_deselect); + +/* Note this function returns a reference to the mux_chip dev. */ +static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np) +{ + struct device *dev; + + dev = class_find_device_by_of_node(&mux_class, np); + + return dev ? to_mux_chip(dev) : NULL; +} + +/* + * mux_get() - Get the mux-control for a device. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * @state: Pointer to where the requested state is returned, or NULL when + * the required multiplexer states are handled by other means. + * + * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +static struct mux_control *mux_get(struct device *dev, const char *mux_name, + unsigned int *state) +{ + struct device_node *np = dev->of_node; + struct of_phandle_args args; + struct mux_chip *mux_chip; + unsigned int controller; + int index = 0; + int ret; + + if (mux_name) { + if (state) + index = of_property_match_string(np, "mux-state-names", + mux_name); + else + index = of_property_match_string(np, "mux-control-names", + mux_name); + if (index < 0) { + dev_err(dev, "mux controller '%s' not found\n", + mux_name); + return ERR_PTR(index); + } + } + + if (state) + ret = of_parse_phandle_with_args(np, + "mux-states", "#mux-state-cells", + index, &args); + else + ret = of_parse_phandle_with_args(np, + "mux-controls", "#mux-control-cells", + index, &args); + if (ret) { + dev_err(dev, "%pOF: failed to get mux-%s %s(%i)\n", + np, state ? "state" : "control", mux_name ?: "", index); + return ERR_PTR(ret); + } + + mux_chip = of_find_mux_chip_by_node(args.np); + of_node_put(args.np); + if (!mux_chip) + return ERR_PTR(-EPROBE_DEFER); + + controller = 0; + if (state) { + if (args.args_count > 2 || args.args_count == 0 || + (args.args_count < 2 && mux_chip->controllers > 1)) { + dev_err(dev, "%pOF: wrong #mux-state-cells for %pOF\n", + np, args.np); + put_device(&mux_chip->dev); + return ERR_PTR(-EINVAL); + } + + if (args.args_count == 2) { + controller = args.args[0]; + *state = args.args[1]; + } else { + *state = args.args[0]; + } + + } else { + if (args.args_count > 1 || + (!args.args_count && mux_chip->controllers > 1)) { + dev_err(dev, "%pOF: wrong #mux-control-cells for %pOF\n", + np, args.np); + put_device(&mux_chip->dev); + return ERR_PTR(-EINVAL); + } + + if (args.args_count) + controller = args.args[0]; + } + + if (controller >= mux_chip->controllers) { + dev_err(dev, "%pOF: bad mux controller %u specified in %pOF\n", + np, controller, args.np); + put_device(&mux_chip->dev); + return ERR_PTR(-EINVAL); + } + + return &mux_chip->mux[controller]; +} + +/** + * mux_control_get() - Get the mux-control for a device. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control *mux_control_get(struct device *dev, const char *mux_name) +{ + return mux_get(dev, mux_name, NULL); +} +EXPORT_SYMBOL_GPL(mux_control_get); + +/** + * mux_control_put() - Put away the mux-control for good. + * @mux: The mux-control to put away. + * + * mux_control_put() reverses the effects of mux_control_get(). + */ +void mux_control_put(struct mux_control *mux) +{ + put_device(&mux->chip->dev); +} +EXPORT_SYMBOL_GPL(mux_control_put); + +static void devm_mux_control_release(struct device *dev, void *res) +{ + struct mux_control *mux = *(struct mux_control **)res; + + mux_control_put(mux); +} + +/** + * devm_mux_control_get() - Get the mux-control for a device, with resource + * management. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control *devm_mux_control_get(struct device *dev, + const char *mux_name) +{ + struct mux_control **ptr, *mux; + + ptr = devres_alloc(devm_mux_control_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + mux = mux_control_get(dev, mux_name); + if (IS_ERR(mux)) { + devres_free(ptr); + return mux; + } + + *ptr = mux; + devres_add(dev, ptr); + + return mux; +} +EXPORT_SYMBOL_GPL(devm_mux_control_get); + +/* + * mux_state_get() - Get the mux-state for a device. + * @dev: The device that needs a mux-state. + * @mux_name: The name identifying the mux-state. + * + * Return: A pointer to the mux-state, or an ERR_PTR with a negative errno. + */ +static struct mux_state *mux_state_get(struct device *dev, const char *mux_name) +{ + struct mux_state *mstate; + + mstate = kzalloc(sizeof(*mstate), GFP_KERNEL); + if (!mstate) + return ERR_PTR(-ENOMEM); + + mstate->mux = mux_get(dev, mux_name, &mstate->state); + if (IS_ERR(mstate->mux)) { + int err = PTR_ERR(mstate->mux); + + kfree(mstate); + return ERR_PTR(err); + } + + return mstate; +} + +/* + * mux_state_put() - Put away the mux-state for good. + * @mstate: The mux-state to put away. + * + * mux_state_put() reverses the effects of mux_state_get(). + */ +static void mux_state_put(struct mux_state *mstate) +{ + mux_control_put(mstate->mux); + kfree(mstate); +} + +static void devm_mux_state_release(struct device *dev, void *res) +{ + struct mux_state *mstate = *(struct mux_state **)res; + + mux_state_put(mstate); +} + +/** + * devm_mux_state_get() - Get the mux-state for a device, with resource + * management. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno. + */ +struct mux_state *devm_mux_state_get(struct device *dev, + const char *mux_name) +{ + struct mux_state **ptr, *mstate; + + ptr = devres_alloc(devm_mux_state_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + mstate = mux_state_get(dev, mux_name); + if (IS_ERR(mstate)) { + devres_free(ptr); + return mstate; + } + + *ptr = mstate; + devres_add(dev, ptr); + + return mstate; +} +EXPORT_SYMBOL_GPL(devm_mux_state_get); + +/* + * Using subsys_initcall instead of module_init here to try to ensure - for + * the non-modular case - that the subsystem is initialized when mux consumers + * and mux controllers start to use it. + * For the modular case, the ordering is ensured with module dependencies. + */ +subsys_initcall(mux_init); +module_exit(mux_exit); + +MODULE_DESCRIPTION("Multiplexer subsystem"); +MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/mux/gpio.c b/drivers/mux/gpio.c new file mode 100644 index 0000000000..cc5f2c1861 --- /dev/null +++ b/drivers/mux/gpio.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPIO-controlled multiplexer driver + * + * Copyright (C) 2017 Axentia Technologies AB + * + * Author: Peter Rosin <peda@axentia.se> + */ + +#include <linux/bitmap.h> +#include <linux/err.h> +#include <linux/gpio/consumer.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mux/driver.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +struct mux_gpio { + struct gpio_descs *gpios; +}; + +static int mux_gpio_set(struct mux_control *mux, int state) +{ + struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip); + DECLARE_BITMAP(values, BITS_PER_TYPE(state)); + u32 value = state; + + bitmap_from_arr32(values, &value, BITS_PER_TYPE(value)); + + gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs, + mux_gpio->gpios->desc, + mux_gpio->gpios->info, values); + + return 0; +} + +static const struct mux_control_ops mux_gpio_ops = { + .set = mux_gpio_set, +}; + +static const struct of_device_id mux_gpio_dt_ids[] = { + { .compatible = "gpio-mux", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids); + +static int mux_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mux_chip *mux_chip; + struct mux_gpio *mux_gpio; + int pins; + s32 idle_state; + int ret; + + pins = gpiod_count(dev, "mux"); + if (pins < 0) + return pins; + + mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio)); + if (IS_ERR(mux_chip)) + return PTR_ERR(mux_chip); + + mux_gpio = mux_chip_priv(mux_chip); + mux_chip->ops = &mux_gpio_ops; + + mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW); + if (IS_ERR(mux_gpio->gpios)) + return dev_err_probe(dev, PTR_ERR(mux_gpio->gpios), + "failed to get gpios\n"); + WARN_ON(pins != mux_gpio->gpios->ndescs); + mux_chip->mux->states = BIT(pins); + + ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); + if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) { + if (idle_state < 0 || idle_state >= mux_chip->mux->states) { + dev_err(dev, "invalid idle-state %u\n", idle_state); + return -EINVAL; + } + + mux_chip->mux->idle_state = idle_state; + } + + ret = devm_mux_chip_register(dev, mux_chip); + if (ret < 0) + return ret; + + dev_info(dev, "%u-way mux-controller registered\n", + mux_chip->mux->states); + + return 0; +} + +static struct platform_driver mux_gpio_driver = { + .driver = { + .name = "gpio-mux", + .of_match_table = mux_gpio_dt_ids, + }, + .probe = mux_gpio_probe, +}; +module_platform_driver(mux_gpio_driver); + +MODULE_DESCRIPTION("GPIO-controlled multiplexer driver"); +MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c new file mode 100644 index 0000000000..fd1d121a58 --- /dev/null +++ b/drivers/mux/mmio.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MMIO register bitfield-controlled multiplexer driver + * + * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de> + */ + +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/mux/driver.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/regmap.h> + +static int mux_mmio_set(struct mux_control *mux, int state) +{ + struct regmap_field **fields = mux_chip_priv(mux->chip); + + return regmap_field_write(fields[mux_control_get_index(mux)], state); +} + +static const struct mux_control_ops mux_mmio_ops = { + .set = mux_mmio_set, +}; + +static const struct of_device_id mux_mmio_dt_ids[] = { + { .compatible = "mmio-mux", }, + { .compatible = "reg-mux", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mux_mmio_dt_ids); + +static int mux_mmio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct regmap_field **fields; + struct mux_chip *mux_chip; + struct regmap *regmap; + int num_fields; + int ret; + int i; + + if (of_device_is_compatible(np, "mmio-mux")) + regmap = syscon_node_to_regmap(np->parent); + else + regmap = dev_get_regmap(dev->parent, NULL) ?: ERR_PTR(-ENODEV); + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(dev, "failed to get regmap: %d\n", ret); + return ret; + } + + ret = of_property_count_u32_elems(np, "mux-reg-masks"); + if (ret == 0 || ret % 2) + ret = -EINVAL; + if (ret < 0) { + dev_err(dev, "mux-reg-masks property missing or invalid: %d\n", + ret); + return ret; + } + num_fields = ret / 2; + + mux_chip = devm_mux_chip_alloc(dev, num_fields, num_fields * + sizeof(*fields)); + if (IS_ERR(mux_chip)) + return PTR_ERR(mux_chip); + + fields = mux_chip_priv(mux_chip); + + for (i = 0; i < num_fields; i++) { + struct mux_control *mux = &mux_chip->mux[i]; + struct reg_field field; + s32 idle_state = MUX_IDLE_AS_IS; + u32 reg, mask; + int bits; + + ret = of_property_read_u32_index(np, "mux-reg-masks", + 2 * i, ®); + if (!ret) + ret = of_property_read_u32_index(np, "mux-reg-masks", + 2 * i + 1, &mask); + if (ret < 0) { + dev_err(dev, "bitfield %d: failed to read mux-reg-masks property: %d\n", + i, ret); + return ret; + } + + field.reg = reg; + field.msb = fls(mask) - 1; + field.lsb = ffs(mask) - 1; + + if (mask != GENMASK(field.msb, field.lsb)) { + dev_err(dev, "bitfield %d: invalid mask 0x%x\n", + i, mask); + return -EINVAL; + } + + fields[i] = devm_regmap_field_alloc(dev, regmap, field); + if (IS_ERR(fields[i])) { + ret = PTR_ERR(fields[i]); + dev_err(dev, "bitfield %d: failed allocate: %d\n", + i, ret); + return ret; + } + + bits = 1 + field.msb - field.lsb; + mux->states = 1 << bits; + + of_property_read_u32_index(np, "idle-states", i, + (u32 *)&idle_state); + if (idle_state != MUX_IDLE_AS_IS) { + if (idle_state < 0 || idle_state >= mux->states) { + dev_err(dev, "bitfield: %d: out of range idle state %d\n", + i, idle_state); + return -EINVAL; + } + + mux->idle_state = idle_state; + } + } + + mux_chip->ops = &mux_mmio_ops; + + return devm_mux_chip_register(dev, mux_chip); +} + +static struct platform_driver mux_mmio_driver = { + .driver = { + .name = "mmio-mux", + .of_match_table = mux_mmio_dt_ids, + }, + .probe = mux_mmio_probe, +}; +module_platform_driver(mux_mmio_driver); + +MODULE_DESCRIPTION("MMIO register bitfield-controlled multiplexer driver"); +MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>"); +MODULE_LICENSE("GPL v2"); |