i2c: MPC8349E-mITX Power Management and GPIO expander driver (d6c3db83) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/i2c/chips/Kconfig

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		@@ -172,4 +172,15 @@ config MENELAUS
		and other features that are often used in portable devices like
		cell phones and PDAs.

		config MCU_MPC8349EMITX
		tristate "MPC8349E-mITX MCU driver"
		depends on I2C && PPC_83xx
		select GENERIC_GPIO
		select ARCH_REQUIRE_GPIOLIB
		help
		Say Y here to enable soft power-off functionality on the Freescale
		boards with the MPC8349E-mITX-compatible MCU chips. This driver will
		also register MCU GPIOs with the generic GPIO API, so you'll able
		to use MCU pins as GPIOs.

		endmenu

drivers/i2c/chips/Makefile

+1 −0

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		@@ -21,6 +21,7 @@ obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o
		obj-$(CONFIG_TPS65010) += tps65010.o
		obj-$(CONFIG_MENELAUS) += menelaus.o
		obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
		obj-$(CONFIG_MCU_MPC8349EMITX) += mcu_mpc8349emitx.o

		ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
		EXTRA_CFLAGS += -DDEBUG

drivers/i2c/chips/mcu_mpc8349emitx.c

0 → 100644

+209 −0

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		/*
		* Power Management and GPIO expander driver for MPC8349E-mITX-compatible MCU
		*
		* Copyright (c) 2008 MontaVista Software, Inc.
		*
		* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/

		#include <linux/init.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/device.h>
		#include <linux/mutex.h>
		#include <linux/i2c.h>
		#include <linux/gpio.h>
		#include <linux/of.h>
		#include <linux/of_gpio.h>
		#include <asm/prom.h>
		#include <asm/machdep.h>

		/*
		* I don't have specifications for the MCU firmware, I found this register
		* and bits positions by the trial&error method.
		*/
		#define MCU_REG_CTRL 0x20
		#define MCU_CTRL_POFF 0x40

		#define MCU_NUM_GPIO 2

		struct mcu {
		struct mutex lock;
		struct device_node *np;
		struct i2c_client *client;
		struct of_gpio_chip of_gc;
		u8 reg_ctrl;
		};

		static struct mcu *glob_mcu;

		static void mcu_power_off(void)
		{
		struct mcu *mcu = glob_mcu;

		pr_info("Sending power-off request to the MCU...\n");
		mutex_lock(&mcu->lock);
		i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
		mcu->reg_ctrl \| MCU_CTRL_POFF);
		mutex_unlock(&mcu->lock);
		}

		static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
		{
		struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
		struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
		u8 bit = 1 << (4 + gpio);

		mutex_lock(&mcu->lock);
		if (val)
		mcu->reg_ctrl &= ~bit;
		else
		mcu->reg_ctrl \|= bit;

		i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
		mutex_unlock(&mcu->lock);
		}

		static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
		{
		mcu_gpio_set(gc, gpio, val);
		return 0;
		}

		static int mcu_gpiochip_add(struct mcu *mcu)
		{
		struct device_node *np;
		struct of_gpio_chip *of_gc = &mcu->of_gc;
		struct gpio_chip *gc = &of_gc->gc;
		int ret;

		np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
		if (!np)
		return -ENODEV;

		gc->owner = THIS_MODULE;
		gc->label = np->full_name;
		gc->can_sleep = 1;
		gc->ngpio = MCU_NUM_GPIO;
		gc->base = -1;
		gc->set = mcu_gpio_set;
		gc->direction_output = mcu_gpio_dir_out;
		of_gc->gpio_cells = 2;
		of_gc->xlate = of_gpio_simple_xlate;

		np->data = of_gc;
		mcu->np = np;

		/*
		* We don't want to lose the node, its ->data and ->full_name...
		* So, if succeeded, we don't put the node here.
		*/
		ret = gpiochip_add(gc);
		if (ret)
		of_node_put(np);
		return ret;
		}

		static int mcu_gpiochip_remove(struct mcu *mcu)
		{
		int ret;

		ret = gpiochip_remove(&mcu->of_gc.gc);
		if (ret)
		return ret;
		of_node_put(mcu->np);

		return 0;
		}

		static int __devinit mcu_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct mcu *mcu;
		int ret;

		mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
		if (!mcu)
		return -ENOMEM;

		mutex_init(&mcu->lock);
		mcu->client = client;
		i2c_set_clientdata(client, mcu);

		ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
		if (ret < 0)
		goto err;
		mcu->reg_ctrl = ret;

		ret = mcu_gpiochip_add(mcu);
		if (ret)
		goto err;

		/* XXX: this is potentially racy, but there is no lock for ppc_md */
		if (!ppc_md.power_off) {
		glob_mcu = mcu;
		ppc_md.power_off = mcu_power_off;
		dev_info(&client->dev, "will provide power-off service\n");
		}

		return 0;
		err:
		kfree(mcu);
		return ret;
		}

		static int __devexit mcu_remove(struct i2c_client *client)
		{
		struct mcu *mcu = i2c_get_clientdata(client);
		int ret;

		if (glob_mcu == mcu) {
		ppc_md.power_off = NULL;
		glob_mcu = NULL;
		}

		ret = mcu_gpiochip_remove(mcu);
		if (ret)
		return ret;
		i2c_set_clientdata(client, NULL);
		kfree(mcu);
		return 0;
		}

		static const struct i2c_device_id mcu_ids[] = {
		{ "mcu-mpc8349emitx", },
		{},
		};
		MODULE_DEVICE_TABLE(i2c, mcu_ids);

		static struct i2c_driver mcu_driver = {
		.driver = {
		.name = "mcu-mpc8349emitx",
		.owner = THIS_MODULE,
		},
		.probe = mcu_probe,
		.remove = __devexit_p(mcu_remove),
		.id_table = mcu_ids,
		};

		static int __init mcu_init(void)
		{
		return i2c_add_driver(&mcu_driver);
		}
		module_init(mcu_init);

		static void __exit mcu_exit(void)
		{
		i2c_del_driver(&mcu_driver);
		}
		module_exit(mcu_exit);

		MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
		"MPC8349E-mITX-compatible MCU");
		MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
		MODULE_LICENSE("GPL");