linux/drivers/misc/bh1780gli.c
Linus Walleij bc34268976 misc: bh1780: probe from compatible string
Currently the BH1780GLI I2C driver relies on the device tree node
having the right name, but this is fragile. Use the compatible
string to probe the driver instead.

Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03 16:02:35 -07:00

273 lines
6.2 KiB
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>
#include <linux/module.h>
#include <linux/of.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 = kstrtoul(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 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 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_SLEEP
static int bh1780_suspend(struct device *dev)
{
struct bh1780_data *ddata;
int state, ret;
struct i2c_client *client = to_i2c_client(dev);
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 device *dev)
{
struct bh1780_data *ddata;
int state, ret;
struct i2c_client *client = to_i2c_client(dev);
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;
}
#endif /* CONFIG_PM_SLEEP */
static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
static const struct i2c_device_id bh1780_id[] = {
{ "bh1780", 0 },
{ },
};
#ifdef CONFIG_OF
static const struct of_device_id of_bh1780_match[] = {
{ .compatible = "rohm,bh1780gli", },
{},
};
MODULE_DEVICE_TABLE(of, of_bh1780_match);
#endif
static struct i2c_driver bh1780_driver = {
.probe = bh1780_probe,
.remove = bh1780_remove,
.id_table = bh1780_id,
.driver = {
.name = "bh1780",
.pm = &bh1780_pm,
.of_match_table = of_match_ptr(of_bh1780_match),
},
};
module_i2c_driver(bh1780_driver);
MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");