mux: adg792a: add mux controller driver for ADG792A/G (afda08c4) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/mux/Kconfig

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		@@ -17,6 +17,18 @@ menuconfig MULTIPLEXER

		if MULTIPLEXER

		config MUX_ADG792A
		tristate "Analog Devices ADG792A/ADG792G Multiplexers"
		depends on I2C \|\| COMPILE_TEST
		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 GPIOLIB \|\| COMPILE_TEST

drivers/mux/Makefile

+1 −0

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		@@ -3,4 +3,5 @@
		#

		obj-$(CONFIG_MULTIPLEXER) += mux-core.o
		obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o
		obj-$(CONFIG_MUX_GPIO) += mux-gpio.o

drivers/mux/mux-adg792a.c

0 → 100644

+157 −0

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		/*
		* Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux
		*
		* Copyright (C) 2017 Axentia Technologies AB
		*
		* Author: Peter Rosin <peda@axentia.se>
		*
		* 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/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,
		const struct i2c_device_id *id)
		{
		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");