/* * 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> #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 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; } static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume); #define BH1780_PMOPS (&bh1780_pm) #else #define BH1780_PMOPS NULL #endif /* CONFIG_PM */ static const struct i2c_device_id bh1780_id[] = { { "bh1780", 0 }, { }, }; static struct i2c_driver bh1780_driver = { .probe = bh1780_probe, .remove = __devexit_p(bh1780_remove), .id_table = bh1780_id, .driver = { .name = "bh1780", .pm = BH1780_PMOPS, }, }; module_i2c_driver(bh1780_driver); MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");