[mirror_ubuntu-zesty-kernel.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 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");
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;
	38	struct device_node *np;
	39	struct i2c_client *client;
	40	struct of_gpio_chip of_gc;
	41	u8 reg_ctrl;
	42	};
	43
	44	static struct mcu *glob_mcu;
	45
	46	static void mcu_power_off(void)
	47	{
	48	struct mcu *mcu = glob_mcu;
	49
	50	pr_info("Sending power-off request to the MCU...\n");
	51	mutex_lock(&mcu->lock);
	52	i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
	53	mcu->reg_ctrl \| MCU_CTRL_POFF);
	54	mutex_unlock(&mcu->lock);
	55	}
	56
	57	static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	58	{
	59	struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
	60	struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
	61	u8 bit = 1 << (4 + gpio);
	62
	63	mutex_lock(&mcu->lock);
	64	if (val)
	65	mcu->reg_ctrl &= ~bit;
	66	else
	67	mcu->reg_ctrl \|= bit;
	68
	69	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
	70	mutex_unlock(&mcu->lock);
	71	}
	72
	73	static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	74	{
	75	mcu_gpio_set(gc, gpio, val);
	76	return 0;
	77	}
	78
	79	static int mcu_gpiochip_add(struct mcu *mcu)
	80	{
	81	struct device_node *np;
	82	struct of_gpio_chip *of_gc = &mcu->of_gc;
	83	struct gpio_chip *gc = &of_gc->gc;
	84	int ret;
	85
	86	np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
	87	if (!np)
88	return -ENODEV;
89
90	gc->owner = THIS_MODULE;
91	gc->label = np->full_name;
92	gc->can_sleep = 1;
93	gc->ngpio = MCU_NUM_GPIO;
94	gc->base = -1;
95	gc->set = mcu_gpio_set;
96	gc->direction_output = mcu_gpio_dir_out;
97	of_gc->gpio_cells = 2;
98	of_gc->xlate = of_gpio_simple_xlate;
99
100	np->data = of_gc;
101	mcu->np = np;
102
103	/*
104	* We don't want to lose the node, its ->data and ->full_name...
105	* So, if succeeded, we don't put the node here.
106	*/
107	ret = gpiochip_add(gc);
108	if (ret)
109	of_node_put(np);
110	return ret;
111	}
112
113	static int mcu_gpiochip_remove(struct mcu *mcu)
114	{
115	int ret;
116
117	ret = gpiochip_remove(&mcu->of_gc.gc);
118	if (ret)
119	return ret;
120	of_node_put(mcu->np);
121
122	return 0;
123	}
124
125	static int __devinit mcu_probe(struct i2c_client *client,
126	const struct i2c_device_id *id)
127	{
128	struct mcu *mcu;
129	int ret;
130
131	mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
132	if (!mcu)
133	return -ENOMEM;
134
135	mutex_init(&mcu->lock);
136	mcu->client = client;
137	i2c_set_clientdata(client, mcu);
138
139	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
140	if (ret < 0)
141	goto err;
142	mcu->reg_ctrl = ret;
143
144	ret = mcu_gpiochip_add(mcu);
145	if (ret)
146	goto err;
147
148	/* XXX: this is potentially racy, but there is no lock for ppc_md */
149	if (!ppc_md.power_off) {
150	glob_mcu = mcu;
151	ppc_md.power_off = mcu_power_off;
152	dev_info(&client->dev, "will provide power-off service\n");
153	}
154
155	return 0;
156	err:
157	kfree(mcu);
158	return ret;
159	}
160
161	static int __devexit mcu_remove(struct i2c_client *client)
162	{
163	struct mcu *mcu = i2c_get_clientdata(client);
164	int ret;
165
166	if (glob_mcu == mcu) {
167	ppc_md.power_off = NULL;
168	glob_mcu = NULL;
169	}
170
171	ret = mcu_gpiochip_remove(mcu);
172	if (ret)
173	return ret;
174	i2c_set_clientdata(client, NULL);
175	kfree(mcu);
176	return 0;
177	}
178
179	static const struct i2c_device_id mcu_ids[] = {
180	{ "mcu-mpc8349emitx", },
181	{},
182	};
183	MODULE_DEVICE_TABLE(i2c, mcu_ids);
184
185	static struct i2c_driver mcu_driver = {
186	.driver = {
187	.name = "mcu-mpc8349emitx",
188	.owner = THIS_MODULE,
189	},
190	.probe = mcu_probe,
191	.remove = __devexit_p(mcu_remove),
192	.id_table = mcu_ids,
193	};
194
195	static int __init mcu_init(void)
196	{
197	return i2c_add_driver(&mcu_driver);
198	}
199	module_init(mcu_init);
200
201	static void __exit mcu_exit(void)
202	{
203	i2c_del_driver(&mcu_driver);
204	}
205	module_exit(mcu_exit);
206
207	MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
208	"MPC8349E-mITX-compatible MCU");
209	MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
210	MODULE_LICENSE("GPL");