[net-next-2.6.git] / drivers / misc / bh1780gli.c

/*
 * bh1780gli.c
 * ROHM Ambient Light Sensor Driver
 *
 * Copyright (C) 2010 Texas Instruments
 * Author: Hemanth V <hemanthv@ti.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/delay.h>

#define BH1780_REG_CONTROL	0x80
#define BH1780_REG_PARTID	0x8A
#define BH1780_REG_MANFID	0x8B
#define BH1780_REG_DLOW	0x8C
#define BH1780_REG_DHIGH	0x8D

#define BH1780_REVMASK		(0xf)
#define BH1780_POWMASK		(0x3)
#define BH1780_POFF		(0x0)
#define BH1780_PON		(0x3)

/* power on settling time in ms */
#define BH1780_PON_DELAY	2

struct bh1780_data {
	struct i2c_client *client;
	int power_state;
	/* lock for sysfs operations */
	struct mutex lock;
};

static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg)
{
	int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
	if (ret < 0)
		dev_err(&ddata->client->dev,
			"i2c_smbus_write_byte_data failed error %d\
			Register (%s)\n", ret, msg);
	return ret;
}

static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg)
{
	int ret = i2c_smbus_read_byte_data(ddata->client, reg);
	if (ret < 0)
		dev_err(&ddata->client->dev,
			"i2c_smbus_read_byte_data failed error %d\
			 Register (%s)\n", ret, msg);
	return ret;
}

static ssize_t bh1780_show_lux(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct bh1780_data *ddata = platform_get_drvdata(pdev);
	int lsb, msb;

	lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
	if (lsb < 0)
		return lsb;

	msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
	if (msb < 0)
		return msb;

	return sprintf(buf, "%d\n", (msb << 8) | lsb);
}

static ssize_t bh1780_show_power_state(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct bh1780_data *ddata = platform_get_drvdata(pdev);
	int state;

	state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
	if (state < 0)
		return state;

	return sprintf(buf, "%d\n", state & BH1780_POWMASK);
}

static ssize_t bh1780_store_power_state(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct bh1780_data *ddata = platform_get_drvdata(pdev);
	unsigned long val;
	int error;

	error = strict_strtoul(buf, 0, &val);
	if (error)
		return error;

	if (val < BH1780_POFF || val > BH1780_PON)
		return -EINVAL;

	mutex_lock(&ddata->lock);

	error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
	if (error < 0) {
		mutex_unlock(&ddata->lock);
		return error;
	}

	msleep(BH1780_PON_DELAY);
	ddata->power_state = val;
	mutex_unlock(&ddata->lock);

	return count;
}

static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);

static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
		bh1780_show_power_state, bh1780_store_power_state);

static struct attribute *bh1780_attributes[] = {
	&dev_attr_power_state.attr,
	&dev_attr_lux.attr,
	NULL
};

static const struct attribute_group bh1780_attr_group = {
	.attrs = bh1780_attributes,
};

static int __devinit bh1780_probe(struct i2c_client *client,
						const struct i2c_device_id *id)
{
	int ret;
	struct bh1780_data *ddata = NULL;
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
		ret = -EIO;
		goto err_op_failed;
	}

	ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL);
	if (ddata == NULL) {
		ret = -ENOMEM;
		goto err_op_failed;
	}

	ddata->client = client;
	i2c_set_clientdata(client, ddata);

	ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
	if (ret < 0)
		goto err_op_failed;

	dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
			(ret & BH1780_REVMASK));

	mutex_init(&ddata->lock);

	ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
	if (ret)
		goto err_op_failed;

	return 0;

err_op_failed:
	kfree(ddata);
	return ret;
}

static int __devexit bh1780_remove(struct i2c_client *client)
{
	struct bh1780_data *ddata;

	ddata = i2c_get_clientdata(client);
	sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
	kfree(ddata);

	return 0;
}

#ifdef CONFIG_PM
static int bh1780_suspend(struct i2c_client *client, pm_message_t mesg)
{
	struct bh1780_data *ddata;
	int state, ret;

	ddata = i2c_get_clientdata(client);
	state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
	if (state < 0)
		return state;

	ddata->power_state = state & BH1780_POWMASK;

	ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
				"CONTROL");

	if (ret < 0)
		return ret;

	return 0;
}

static int bh1780_resume(struct i2c_client *client)
{
	struct bh1780_data *ddata;
	int state, ret;

	ddata = i2c_get_clientdata(client);
	state = ddata->power_state;

	ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
				"CONTROL");

	if (ret < 0)
		return ret;

	return 0;
}
#else
#define bh1780_suspend NULL
#define bh1780_resume NULL
#endif /* CONFIG_PM */

static const struct i2c_device_id bh1780_id[] = {
	{ "bh1780", 0 },
	{ },
};

static struct i2c_driver bh1780_driver = {
	.probe		= bh1780_probe,
	.remove		= bh1780_remove,
	.id_table	= bh1780_id,
	.suspend	= bh1780_suspend,
	.resume		= bh1780_resume,
	.driver = {
		.name = "bh1780"
	},
};

static int __init bh1780_init(void)
{
	return i2c_add_driver(&bh1780_driver);
}

static void __exit bh1780_exit(void)
{
	i2c_del_driver(&bh1780_driver);
}

module_init(bh1780_init)
module_exit(bh1780_exit)

MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");
Commit	Line	Data
7efe15f2 H	1	/*
	2	* bh1780gli.c
	3	* ROHM Ambient Light Sensor Driver
	4	*
	5	* Copyright (C) 2010 Texas Instruments
	6	* Author: Hemanth V <hemanthv@ti.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License version 2 as published by
	10	* the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but WITHOUT
	13	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	15	* more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along with
	18	* this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20	#include <linux/i2c.h>
	21	#include <linux/slab.h>
	22	#include <linux/mutex.h>
	23	#include <linux/platform_device.h>
	24	#include <linux/delay.h>
	25
	26	#define BH1780_REG_CONTROL 0x80
	27	#define BH1780_REG_PARTID 0x8A
	28	#define BH1780_REG_MANFID 0x8B
	29	#define BH1780_REG_DLOW 0x8C
	30	#define BH1780_REG_DHIGH 0x8D
	31
	32	#define BH1780_REVMASK (0xf)
	33	#define BH1780_POWMASK (0x3)
	34	#define BH1780_POFF (0x0)
	35	#define BH1780_PON (0x3)
	36
	37	/* power on settling time in ms */
	38	#define BH1780_PON_DELAY 2
	39
	40	struct bh1780_data {
	41	struct i2c_client *client;
	42	int power_state;
	43	/* lock for sysfs operations */
	44	struct mutex lock;
	45	};
	46
	47	static int bh1780_write(struct bh1780_data ddata, u8 reg, u8 val, char msg)
	48	{
	49	int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
	50	if (ret < 0)
	51	dev_err(&ddata->client->dev,
	52	"i2c_smbus_write_byte_data failed error %d\
	53	Register (%s)\n", ret, msg);
	54	return ret;
	55	}
	56
	57	static int bh1780_read(struct bh1780_data ddata, u8 reg, char msg)
	58	{
	59	int ret = i2c_smbus_read_byte_data(ddata->client, reg);
	60	if (ret < 0)
	61	dev_err(&ddata->client->dev,
	62	"i2c_smbus_read_byte_data failed error %d\
	63	Register (%s)\n", ret, msg);
	64	return ret;
65	}
66
67	static ssize_t bh1780_show_lux(struct device *dev,
68	struct device_attribute attr, char buf)
69	{
70	struct platform_device *pdev = to_platform_device(dev);
71	struct bh1780_data *ddata = platform_get_drvdata(pdev);
72	int lsb, msb;
73
74	lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
75	if (lsb < 0)
76	return lsb;
77
78	msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
79	if (msb < 0)
80	return msb;
81
82	return sprintf(buf, "%d\n", (msb << 8) \| lsb);
83	}
84
85	static ssize_t bh1780_show_power_state(struct device *dev,
86	struct device_attribute *attr,
87	char *buf)
88	{
89	struct platform_device *pdev = to_platform_device(dev);
90	struct bh1780_data *ddata = platform_get_drvdata(pdev);
91	int state;
92
93	state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
94	if (state < 0)
95	return state;
96
97	return sprintf(buf, "%d\n", state & BH1780_POWMASK);
98	}
99
100	static ssize_t bh1780_store_power_state(struct device *dev,
101	struct device_attribute *attr,
102	const char *buf, size_t count)
103	{
104	struct platform_device *pdev = to_platform_device(dev);
105	struct bh1780_data *ddata = platform_get_drvdata(pdev);
106	unsigned long val;
107	int error;
108
109	error = strict_strtoul(buf, 0, &val);
110	if (error)
111	return error;
112
113	if (val < BH1780_POFF \|\| val > BH1780_PON)
114	return -EINVAL;
115
116	mutex_lock(&ddata->lock);
117
118	error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
119	if (error < 0) {
120	mutex_unlock(&ddata->lock);
121	return error;
122	}
123
124	msleep(BH1780_PON_DELAY);
125	ddata->power_state = val;
126	mutex_unlock(&ddata->lock);
127
128	return count;
129	}
130
131	static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
132
133	static DEVICE_ATTR(power_state, S_IWUSR \| S_IRUGO,
134	bh1780_show_power_state, bh1780_store_power_state);
135
136	static struct attribute *bh1780_attributes[] = {
137	&dev_attr_power_state.attr,
138	&dev_attr_lux.attr,
139	NULL
140	};
141
142	static const struct attribute_group bh1780_attr_group = {
143	.attrs = bh1780_attributes,
144	};
145
146	static int __devinit bh1780_probe(struct i2c_client *client,
147	const struct i2c_device_id *id)
148	{
149	int ret;
150	struct bh1780_data *ddata = NULL;
151	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
152
153	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
154	ret = -EIO;
155	goto err_op_failed;
156	}
157
158	ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL);
159	if (ddata == NULL) {
160	ret = -ENOMEM;
161	goto err_op_failed;
162	}
163
164	ddata->client = client;
165	i2c_set_clientdata(client, ddata);
166
167	ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
168	if (ret < 0)
169	goto err_op_failed;
170
171	dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
172	(ret & BH1780_REVMASK));
173
174	mutex_init(&ddata->lock);
175
176	ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
177	if (ret)
178	goto err_op_failed;
179
180	return 0;
181
182	err_op_failed:
183	kfree(ddata);
184	return ret;
185	}
186
187	static int __devexit bh1780_remove(struct i2c_client *client)
188	{
189	struct bh1780_data *ddata;
190
191	ddata = i2c_get_clientdata(client);
192	sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
7efe15f2 H	193	kfree(ddata);
	194
	195	return 0;
	196	}
	197
	198	#ifdef CONFIG_PM
	199	static int bh1780_suspend(struct i2c_client *client, pm_message_t mesg)
	200	{
	201	struct bh1780_data *ddata;
	202	int state, ret;
	203
	204	ddata = i2c_get_clientdata(client);
	205	state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
	206	if (state < 0)
	207	return state;
	208
	209	ddata->power_state = state & BH1780_POWMASK;
	210
	211	ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
	212	"CONTROL");
	213
	214	if (ret < 0)
	215	return ret;
	216
	217	return 0;
	218	}
	219
	220	static int bh1780_resume(struct i2c_client *client)
	221	{
	222	struct bh1780_data *ddata;
	223	int state, ret;
	224
	225	ddata = i2c_get_clientdata(client);
	226	state = ddata->power_state;
	227
	228	ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
	229	"CONTROL");
	230
	231	if (ret < 0)
	232	return ret;
	233
	234	return 0;
	235	}
	236	#else
	237	#define bh1780_suspend NULL
	238	#define bh1780_resume NULL
	239	#endif /* CONFIG_PM */
	240
	241	static const struct i2c_device_id bh1780_id[] = {
	242	{ "bh1780", 0 },
	243	{ },
	244	};
	245
	246	static struct i2c_driver bh1780_driver = {
	247	.probe = bh1780_probe,
	248	.remove = bh1780_remove,
	249	.id_table = bh1780_id,
	250	.suspend = bh1780_suspend,
	251	.resume = bh1780_resume,
	252	.driver = {
	253	.name = "bh1780"
	254	},
	255	};
	256
257	static int __init bh1780_init(void)
258	{
259	return i2c_add_driver(&bh1780_driver);
260	}
261
262	static void __exit bh1780_exit(void)
263	{
264	i2c_del_driver(&bh1780_driver);
265	}
266
267	module_init(bh1780_init)
268	module_exit(bh1780_exit)
269
270	MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
271	MODULE_LICENSE("GPL");
272	MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");