[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / platforms / 83xx / mcu_mpc8349emitx.c

/*
 * 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 <linux/slab.h>
#include <linux/kthread.h>
#include <linux/reboot.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_CTRL_BTN	0x80

#define MCU_NUM_GPIO	2

struct mcu {
	struct mutex lock;
	struct i2c_client *client;
	struct gpio_chip gc;
	u8 reg_ctrl;
};

static struct mcu *glob_mcu;

struct task_struct *shutdown_thread;
static int shutdown_thread_fn(void *data)
{
	int ret;
	struct mcu *mcu = glob_mcu;

	while (!kthread_should_stop()) {
		ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
		if (ret < 0)
			pr_err("MCU status reg read failed.\n");
		mcu->reg_ctrl = ret;


		if (mcu->reg_ctrl & MCU_CTRL_BTN) {
			i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
						  mcu->reg_ctrl & ~MCU_CTRL_BTN);

			ctrl_alt_del();
		}

		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(HZ);
	}

	return 0;
}

static ssize_t show_status(struct device *d,
			   struct device_attribute *attr, char *buf)
{
	int ret;
	struct mcu *mcu = glob_mcu;

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

	return sprintf(buf, "%02x\n", ret);
}
static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);

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(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 mcu *mcu = container_of(gc, struct mcu, 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 gpio_chip *gc = &mcu->gc;

	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;
	gc->of_node = np;

	return gpiochip_add(gc);
}

static int mcu_gpiochip_remove(struct mcu *mcu)
{
	return gpiochip_remove(&mcu->gc);
}

static int 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");
	}

	if (device_create_file(&client->dev, &dev_attr_status))
		dev_err(&client->dev,
			"couldn't create device file for status\n");

	shutdown_thread = kthread_run(shutdown_thread_fn, NULL,
				      "mcu-i2c-shdn");

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

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

	kthread_stop(shutdown_thread);

	device_remove_file(&client->dev, &dev_attr_status);

	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 of_device_id mcu_of_match_table[] = {
	{ .compatible = "fsl,mcu-mpc8349emitx", },
	{ },
};

static struct i2c_driver mcu_driver = {
	.driver = {
		.name = "mcu-mpc8349emitx",
		.owner = THIS_MODULE,
		.of_match_table = mcu_of_match_table,
	},
	.probe = mcu_probe,
	.remove	= 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");
Commit	Line	Data
d6c3db83 AV	1	/*
	2	* Power Management and GPIO expander driver for MPC8349E-mITX-compatible MCU
	3	*
	4	* Copyright (c) 2008 MontaVista Software, Inc.
	5	*
	6	* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*/
	13
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/device.h>
	18	#include <linux/mutex.h>
	19	#include <linux/i2c.h>
	20	#include <linux/gpio.h>
	21	#include <linux/of.h>
	22	#include <linux/of_gpio.h>
5a0e3ad6	23	#include <linux/slab.h>
6ca6ca5d FB	24	#include <linux/kthread.h>
6ca6ca5d FB	25	#include <linux/reboot.h>
d6c3db83 AV	26	#include <asm/prom.h>
	27	#include <asm/machdep.h>
	28
	29	/*
	30	* I don't have specifications for the MCU firmware, I found this register
	31	* and bits positions by the trial&error method.
	32	*/
	33	#define MCU_REG_CTRL 0x20
	34	#define MCU_CTRL_POFF 0x40
6ca6ca5d	35	#define MCU_CTRL_BTN 0x80
d6c3db83 AV	36
	37	#define MCU_NUM_GPIO 2
	38
	39	struct mcu {
	40	struct mutex lock;
d6c3db83	41	struct i2c_client *client;
a19e3da5	42	struct gpio_chip gc;
d6c3db83 AV	43	u8 reg_ctrl;
	44	};
	45
	46	static struct mcu *glob_mcu;
	47
6ca6ca5d FB	48	struct task_struct *shutdown_thread;
	49	static int shutdown_thread_fn(void *data)
	50	{
	51	int ret;
	52	struct mcu *mcu = glob_mcu;
	53
	54	while (!kthread_should_stop()) {
	55	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
	56	if (ret < 0)
	57	pr_err("MCU status reg read failed.\n");
	58	mcu->reg_ctrl = ret;
	59
	60
	61	if (mcu->reg_ctrl & MCU_CTRL_BTN) {
	62	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
	63	mcu->reg_ctrl & ~MCU_CTRL_BTN);
	64
	65	ctrl_alt_del();
	66	}
	67
	68	set_current_state(TASK_INTERRUPTIBLE);
	69	schedule_timeout(HZ);
	70	}
	71
	72	return 0;
	73	}
	74
	75	static ssize_t show_status(struct device *d,
	76	struct device_attribute attr, char buf)
	77	{
	78	int ret;
	79	struct mcu *mcu = glob_mcu;
	80
	81	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
	82	if (ret < 0)
	83	return -ENODEV;
	84	mcu->reg_ctrl = ret;
	85
	86	return sprintf(buf, "%02x\n", ret);
	87	}
	88	static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
	89
d6c3db83 AV	90	static void mcu_power_off(void)
	91	{
	92	struct mcu *mcu = glob_mcu;
	93
	94	pr_info("Sending power-off request to the MCU...\n");
	95	mutex_lock(&mcu->lock);
6ca6ca5d	96	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
d6c3db83 AV	97	mcu->reg_ctrl \| MCU_CTRL_POFF);
	98	mutex_unlock(&mcu->lock);
	99	}
	100
	101	static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	102	{
a19e3da5	103	struct mcu *mcu = container_of(gc, struct mcu, gc);
d6c3db83 AV	104	u8 bit = 1 << (4 + gpio);
	105
	106	mutex_lock(&mcu->lock);
	107	if (val)
	108	mcu->reg_ctrl &= ~bit;
	109	else
	110	mcu->reg_ctrl \|= bit;
	111
	112	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
	113	mutex_unlock(&mcu->lock);
	114	}
	115
	116	static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	117	{
	118	mcu_gpio_set(gc, gpio, val);
	119	return 0;
	120	}
	121
	122	static int mcu_gpiochip_add(struct mcu *mcu)
	123	{
	124	struct device_node *np;
a19e3da5	125	struct gpio_chip *gc = &mcu->gc;
d6c3db83 AV	126
	127	np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
	128	if (!np)
	129	return -ENODEV;
	130
	131	gc->owner = THIS_MODULE;
	132	gc->label = np->full_name;
	133	gc->can_sleep = 1;
	134	gc->ngpio = MCU_NUM_GPIO;
	135	gc->base = -1;
	136	gc->set = mcu_gpio_set;
	137	gc->direction_output = mcu_gpio_dir_out;
594fa265	138	gc->of_node = np;
d6c3db83	139
594fa265	140	return gpiochip_add(gc);
d6c3db83 AV	141	}
	142
	143	static int mcu_gpiochip_remove(struct mcu *mcu)
	144	{
594fa265	145	return gpiochip_remove(&mcu->gc);
d6c3db83 AV	146	}
d6c3db83 AV	147
cad5cef6	148	static int mcu_probe(struct i2c_client client, const struct i2c_device_id id)
d6c3db83 AV	149	{
	150	struct mcu *mcu;
	151	int ret;
	152
	153	mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
	154	if (!mcu)
	155	return -ENOMEM;
	156
	157	mutex_init(&mcu->lock);
	158	mcu->client = client;
	159	i2c_set_clientdata(client, mcu);
	160
	161	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
	162	if (ret < 0)
	163	goto err;
	164	mcu->reg_ctrl = ret;
	165
	166	ret = mcu_gpiochip_add(mcu);
	167	if (ret)
	168	goto err;
	169
	170	/* XXX: this is potentially racy, but there is no lock for ppc_md */
	171	if (!ppc_md.power_off) {
	172	glob_mcu = mcu;
	173	ppc_md.power_off = mcu_power_off;
	174	dev_info(&client->dev, "will provide power-off service\n");
	175	}
	176
6ca6ca5d FB	177	if (device_create_file(&client->dev, &dev_attr_status))
	178	dev_err(&client->dev,
	179	"couldn't create device file for status\n");
	180
	181	shutdown_thread = kthread_run(shutdown_thread_fn, NULL,
	182	"mcu-i2c-shdn");
	183
d6c3db83 AV	184	return 0;
	185	err:
	186	kfree(mcu);
	187	return ret;
	188	}
	189
cad5cef6	190	static int mcu_remove(struct i2c_client *client)
d6c3db83 AV	191	{
	192	struct mcu *mcu = i2c_get_clientdata(client);
	193	int ret;
	194
6ca6ca5d FB	195	kthread_stop(shutdown_thread);
	196
	197	device_remove_file(&client->dev, &dev_attr_status);
	198
d6c3db83 AV	199	if (glob_mcu == mcu) {
	200	ppc_md.power_off = NULL;
	201	glob_mcu = NULL;
	202	}
	203
	204	ret = mcu_gpiochip_remove(mcu);
	205	if (ret)
	206	return ret;
	207	i2c_set_clientdata(client, NULL);
	208	kfree(mcu);
	209	return 0;
	210	}
	211
	212	static const struct i2c_device_id mcu_ids[] = {
	213	{ "mcu-mpc8349emitx", },
	214	{},
	215	};
	216	MODULE_DEVICE_TABLE(i2c, mcu_ids);
	217
cad5cef6	218	static struct of_device_id mcu_of_match_table[] = {
2ffe8c5f GL	219	{ .compatible = "fsl,mcu-mpc8349emitx", },
	220	{ },
	221	};
	222
d6c3db83 AV	223	static struct i2c_driver mcu_driver = {
	224	.driver = {
	225	.name = "mcu-mpc8349emitx",
	226	.owner = THIS_MODULE,
2ffe8c5f	227	.of_match_table = mcu_of_match_table,
d6c3db83 AV	228	},
d6c3db83 AV	229	.probe = mcu_probe,
cad5cef6	230	.remove = mcu_remove,
d6c3db83 AV	231	.id_table = mcu_ids,
	232	};
	233
	234	static int __init mcu_init(void)
	235	{
	236	return i2c_add_driver(&mcu_driver);
	237	}
	238	module_init(mcu_init);
	239
	240	static void __exit mcu_exit(void)
	241	{
	242	i2c_del_driver(&mcu_driver);
	243	}
	244	module_exit(mcu_exit);
	245
	246	MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
	247	"MPC8349E-mITX-compatible MCU");
	248	MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
	249	MODULE_LICENSE("GPL");