[deliverable/linux.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 <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 i2c_client *client;
	struct gpio_chip 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 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 __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 of_device_id mcu_of_match_table[] __devinitdata = {
	{ .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	= __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");
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>
d6c3db83 AV	24	#include <asm/prom.h>
	25	#include <asm/machdep.h>
	26
	27	/*
	28	* I don't have specifications for the MCU firmware, I found this register
	29	* and bits positions by the trial&error method.
	30	*/
	31	#define MCU_REG_CTRL 0x20
	32	#define MCU_CTRL_POFF 0x40
	33
	34	#define MCU_NUM_GPIO 2
	35
	36	struct mcu {
	37	struct mutex lock;
d6c3db83	38	struct i2c_client *client;
a19e3da5	39	struct gpio_chip gc;
d6c3db83 AV	40	u8 reg_ctrl;
	41	};
	42
	43	static struct mcu *glob_mcu;
	44
	45	static void mcu_power_off(void)
	46	{
	47	struct mcu *mcu = glob_mcu;
	48
	49	pr_info("Sending power-off request to the MCU...\n");
	50	mutex_lock(&mcu->lock);
	51	i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
	52	mcu->reg_ctrl \| MCU_CTRL_POFF);
	53	mutex_unlock(&mcu->lock);
	54	}
	55
	56	static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	57	{
a19e3da5	58	struct mcu *mcu = container_of(gc, struct mcu, gc);
d6c3db83 AV	59	u8 bit = 1 << (4 + gpio);
	60
	61	mutex_lock(&mcu->lock);
	62	if (val)
	63	mcu->reg_ctrl &= ~bit;
	64	else
	65	mcu->reg_ctrl \|= bit;
	66
	67	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
	68	mutex_unlock(&mcu->lock);
	69	}
	70
	71	static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	72	{
	73	mcu_gpio_set(gc, gpio, val);
	74	return 0;
	75	}
	76
	77	static int mcu_gpiochip_add(struct mcu *mcu)
	78	{
	79	struct device_node *np;
a19e3da5	80	struct gpio_chip *gc = &mcu->gc;
d6c3db83 AV	81
	82	np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
	83	if (!np)
	84	return -ENODEV;
	85
	86	gc->owner = THIS_MODULE;
	87	gc->label = np->full_name;
	88	gc->can_sleep = 1;
	89	gc->ngpio = MCU_NUM_GPIO;
	90	gc->base = -1;
	91	gc->set = mcu_gpio_set;
	92	gc->direction_output = mcu_gpio_dir_out;
594fa265	93	gc->of_node = np;
d6c3db83	94
594fa265	95	return gpiochip_add(gc);
d6c3db83 AV	96	}
	97
	98	static int mcu_gpiochip_remove(struct mcu *mcu)
	99	{
594fa265	100	return gpiochip_remove(&mcu->gc);
d6c3db83 AV	101	}
	102
	103	static int __devinit mcu_probe(struct i2c_client *client,
	104	const struct i2c_device_id *id)
	105	{
	106	struct mcu *mcu;
	107	int ret;
	108
	109	mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
	110	if (!mcu)
	111	return -ENOMEM;
	112
	113	mutex_init(&mcu->lock);
	114	mcu->client = client;
	115	i2c_set_clientdata(client, mcu);
	116
	117	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
	118	if (ret < 0)
	119	goto err;
	120	mcu->reg_ctrl = ret;
	121
	122	ret = mcu_gpiochip_add(mcu);
	123	if (ret)
	124	goto err;
	125
	126	/* XXX: this is potentially racy, but there is no lock for ppc_md */
	127	if (!ppc_md.power_off) {
	128	glob_mcu = mcu;
	129	ppc_md.power_off = mcu_power_off;
	130	dev_info(&client->dev, "will provide power-off service\n");
	131	}
	132
	133	return 0;
	134	err:
	135	kfree(mcu);
	136	return ret;
	137	}
	138
	139	static int __devexit mcu_remove(struct i2c_client *client)
	140	{
	141	struct mcu *mcu = i2c_get_clientdata(client);
	142	int ret;
	143
	144	if (glob_mcu == mcu) {
	145	ppc_md.power_off = NULL;
	146	glob_mcu = NULL;
	147	}
	148
	149	ret = mcu_gpiochip_remove(mcu);
	150	if (ret)
	151	return ret;
	152	i2c_set_clientdata(client, NULL);
	153	kfree(mcu);
	154	return 0;
	155	}
	156
	157	static const struct i2c_device_id mcu_ids[] = {
	158	{ "mcu-mpc8349emitx", },
	159	{},
	160	};
	161	MODULE_DEVICE_TABLE(i2c, mcu_ids);
	162
2ffe8c5f GL	163	static struct of_device_id mcu_of_match_table[] __devinitdata = {
	164	{ .compatible = "fsl,mcu-mpc8349emitx", },
	165	{ },
	166	};
	167
d6c3db83 AV	168	static struct i2c_driver mcu_driver = {
	169	.driver = {
	170	.name = "mcu-mpc8349emitx",
	171	.owner = THIS_MODULE,
2ffe8c5f	172	.of_match_table = mcu_of_match_table,
d6c3db83 AV	173	},
	174	.probe = mcu_probe,
	175	.remove = __devexit_p(mcu_remove),
	176	.id_table = mcu_ids,
	177	};
	178
	179	static int __init mcu_init(void)
	180	{
	181	return i2c_add_driver(&mcu_driver);
	182	}
	183	module_init(mcu_init);
	184
	185	static void __exit mcu_exit(void)
	186	{
	187	i2c_del_driver(&mcu_driver);
	188	}
	189	module_exit(mcu_exit);
	190
	191	MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
	192	"MPC8349E-mITX-compatible MCU");
	193	MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
	194	MODULE_LICENSE("GPL");