From: Hemanth V <hemanthv@xxxxxx> Date: Fri, 21 May 2010 15:52:03 +0530 Subject: [PATCH] misc: ROHM BH1780GLI Ambient light sensor Driver This patch adds support for ROHM BH1780GLI Ambient light sensor. BH1780 supports I2C interface. Driver supports read/update of power state and read of lux value (through SYSFS). Writing value 3 to power_state enables the sensor and current lux value could be read. Signed-off-by: Hemanth V <hemanthv@xxxxxx> --- drivers/misc/Kconfig | 11 ++ drivers/misc/Makefile | 1 + drivers/misc/bh1780gli.c | 278 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 290 insertions(+), 0 deletions(-) create mode 100644 drivers/misc/bh1780gli.c diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 0d0d625..0687a0c 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -278,6 +278,17 @@ config SENSORS_TSL2550 This driver can also be built as a module. If so, the module will be called tsl2550. +config SENSORS_BH1780 + tristate "ROHM BH1780GLI ambient light sensor" + depends on I2C && SYSFS + help + If you say yes here you get support for the ROHM BH1780GLI + ambient light sensor. + + This driver can also be built as a module. If so, the module + will be called bh1780gli. + + config EP93XX_PWM tristate "EP93xx PWM support" depends on ARCH_EP93XX diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 7b6f7ee..c479d91 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -30,3 +30,4 @@ obj-$(CONFIG_IWMC3200TOP) += iwmc3200top/ obj-y += eeprom/ obj-y += cb710/ obj-$(CONFIG_VMWARE_BALLOON) += vmware_balloon.o +obj-$(CONFIG_SENSORS_BH1780) += bh1780gli.o diff --git a/drivers/misc/bh1780gli.c b/drivers/misc/bh1780gli.c new file mode 100644 index 0000000..9b4137d --- /dev/null +++ b/drivers/misc/bh1780gli.c @@ -0,0 +1,278 @@ +/* + * bh1780gli.c + * ROHM Ambient Light Sensor Driver + * + * Copyright (C) 2010 Texas Instruments + * Author: Hemanth V <hemanthv@xxxxxx> + * + * 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; +}; + +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; +} + +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: + if (ddata != NULL) + 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); + + if (ddata != NULL) { + i2c_set_clientdata(client, NULL); + 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; +} +#endif + +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, +#ifdef CONFIG_PM + .suspend = bh1780_suspend, + .resume = bh1780_resume, +#endif + .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@xxxxxx>"); -- 1.5.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
