On 04/01/17 12:16, Peter Rosin wrote:
> Analog Devices ADG792A/G is a triple 4:1 mux.
>
> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <jic23@xxxxxxxxxx>
A nice little driver. Hopefully this example will do the job of
convincing people a subsystem makes sense!
Jonathan
> ---
> drivers/mux/Kconfig | 12 ++++
> drivers/mux/Makefile | 1 +
> drivers/mux/mux-adg792a.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 182 insertions(+)
> create mode 100644 drivers/mux/mux-adg792a.c
>
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index de5a35ffe7af..39b06e19aa96 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -16,6 +16,18 @@ menuconfig MULTIPLEXER
>
> if 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_GPIO
> tristate "GPIO-controlled Multiplexer"
> depends on OF && GPIOLIB
> diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> index facc43da3648..fddbb073fc77 100644
> --- a/drivers/mux/Makefile
> +++ b/drivers/mux/Makefile
> @@ -3,4 +3,5 @@
> #
>
> obj-$(CONFIG_MULTIPLEXER) += mux-core.o
> +obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o
> obj-$(CONFIG_MUX_GPIO) += mux-gpio.o
> diff --git a/drivers/mux/mux-adg792a.c b/drivers/mux/mux-adg792a.c
> new file mode 100644
> index 000000000000..c6d5c4571e7c
> --- /dev/null
> +++ b/drivers/mux/mux-adg792a.c
> @@ -0,0 +1,169 @@
> +/*
> + * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux
> + *
> + * Copyright (C) 2016 Axentia Technologies AB
> + *
> + * Author: Peter Rosin <peda@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/mux.h>
> +
> +#define ADG792A_LDSW BIT(0)
> +#define ADG792A_RESET 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))
> +
> +#define ADG792A_DISABLE_STATE (4)
> +
> +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 == ADG792A_DISABLE_STATE)
> + cmd = ADG792A_DISABLE_ALL;
> + else
> + cmd = ADG792A_MUX_ALL(state);
> + } else {
> + unsigned int controller = mux_control_get_index(mux);
> +
> + if (state == ADG792A_DISABLE_STATE)
> + cmd = ADG792A_DISABLE(controller);
> + else
> + cmd = ADG792A_MUX(controller, state);
> + }
> +
> + return i2c_smbus_write_byte_data(i2c, cmd, ADG792A_LDSW);
> +}
> +
> +static const struct mux_control_ops adg792a_ops = {
> + .set = adg792a_set,
> +};
> +
> +static int adg792a_probe(struct i2c_client *i2c,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &i2c->dev;
> + struct mux_chip *mux_chip;
> + bool parallel;
> + int count;
> + int ret;
> + int i;
> +
> + parallel = of_property_read_bool(i2c->dev.of_node, "adi,parallel");
> +
> + mux_chip = devm_mux_chip_alloc(dev, parallel ? 1 : 3, 0);
> + if (!mux_chip)
> + return -ENOMEM;
> +
> + mux_chip->ops = &adg792a_ops;
> +
> + ret = i2c_smbus_write_byte_data(i2c, ADG792A_DISABLE_ALL,
> + ADG792A_RESET | ADG792A_LDSW);
> + if (ret < 0)
> + return ret;
> +
> + for (i = 0; i < mux_chip->controllers; ++i) {
> + struct mux_control *mux = &mux_chip->mux[i];
> +
> + mux->states = 4;
> + }
> +
> + count = of_property_count_u32_elems(dev->of_node, "adi,idle-state");
> + for (i = 0; i < count; i += 2) {
> + u32 index;
> + u32 idle_state;
> +
> + ret = of_property_read_u32_index(dev->of_node,
> + "adi,idle-state", i,
> + &index);
> + if (ret < 0)
> + return ret;
> + if (index >= mux_chip->controllers) {
> + dev_err(dev, "invalid mux %u\n", index);
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32_index(dev->of_node,
> + "adi,idle-state", i + 1,
> + &idle_state);
> + if (ret < 0)
> + return ret;
> + if (idle_state >= ADG792A_DISABLE_STATE) {
> + dev_err(dev, "invalid idle-state %u for mux %u\n",
> + idle_state, index);
> + return -EINVAL;
> + }
> + mux_chip->mux[index].idle_state = idle_state;
> + }
> +
> + count = of_property_count_u32_elems(dev->of_node,
> + "adi,idle-high-impedance");
> + for (i = 0; i < count; ++i) {
> + u32 index;
> +
> + ret = of_property_read_u32_index(dev->of_node,
> + "adi,idle-high-impedance", i,
> + &index);
> + if (ret < 0)
> + return ret;
> + if (index >= mux_chip->controllers) {
> + dev_err(dev, "invalid mux %u\n", index);
> + return -EINVAL;
> + }
> +
> + mux_chip->mux[index].idle_state = ADG792A_DISABLE_STATE;
> + }
> +
> + ret = devm_mux_chip_register(dev, mux_chip);
> + if (ret < 0) {
> + dev_err(dev, "failed to register mux-chip\n");
> + return ret;
> + }
> +
> + if (parallel)
> + dev_info(dev, "triple pole quadruple throw mux registered\n");
> + else
> + dev_info(dev, "3x single pole quadruple throw muxes 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@xxxxxxxxxx");
> +MODULE_LICENSE("GPL v2");
>
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