/* * isl29003.c - Linux kernel module for * Intersil ISL29003 ambient light sensor * * See file:Documentation/misc-devices/isl29003 * * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de> * * Based on code written by * Rodolfo Giometti <giometti@linux.it> * Eurotech S.p.A. <info@eurotech.it> * * 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. * * 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, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/mutex.h> #include <linux/delay.h> #define ISL29003_DRV_NAME "isl29003" #define DRIVER_VERSION "1.0" #define ISL29003_REG_COMMAND 0x00 #define ISL29003_ADC_ENABLED (1 << 7) #define ISL29003_ADC_PD (1 << 6) #define ISL29003_TIMING_INT (1 << 5) #define ISL29003_MODE_SHIFT (2) #define ISL29003_MODE_MASK (0x3 << ISL29003_MODE_SHIFT) #define ISL29003_RES_SHIFT (0) #define ISL29003_RES_MASK (0x3 << ISL29003_RES_SHIFT) #define ISL29003_REG_CONTROL 0x01 #define ISL29003_INT_FLG (1 << 5) #define ISL29003_RANGE_SHIFT (2) #define ISL29003_RANGE_MASK (0x3 << ISL29003_RANGE_SHIFT) #define ISL29003_INT_PERSISTS_SHIFT (0) #define ISL29003_INT_PERSISTS_MASK (0xf << ISL29003_INT_PERSISTS_SHIFT) #define ISL29003_REG_IRQ_THRESH_HI 0x02 #define ISL29003_REG_IRQ_THRESH_LO 0x03 #define ISL29003_REG_LSB_SENSOR 0x04 #define ISL29003_REG_MSB_SENSOR 0x05 #define ISL29003_REG_LSB_TIMER 0x06 #define ISL29003_REG_MSB_TIMER 0x07 #define ISL29003_NUM_CACHABLE_REGS 4 struct isl29003_data { struct i2c_client *client; struct mutex lock; u8 reg_cache[ISL29003_NUM_CACHABLE_REGS]; u8 power_state_before_suspend; }; static int gain_range[] = { 1000, 4000, 16000, 64000 }; /* * register access helpers */ static int __isl29003_read_reg(struct i2c_client *client, u32 reg, u8 mask, u8 shift) { struct isl29003_data *data = i2c_get_clientdata(client); return (data->reg_cache[reg] & mask) >> shift; } static int __isl29003_write_reg(struct i2c_client *client, u32 reg, u8 mask, u8 shift, u8 val) { struct isl29003_data *data = i2c_get_clientdata(client); int ret = 0; u8 tmp; if (reg >= ISL29003_NUM_CACHABLE_REGS) return -EINVAL; mutex_lock(&data->lock); tmp = data->reg_cache[reg]; tmp &= ~mask; tmp |= val << shift; ret = i2c_smbus_write_byte_data(client, reg, tmp); if (!ret) data->reg_cache[reg] = tmp; mutex_unlock(&data->lock); return ret; } /* * internally used functions */ /* range */ static int isl29003_get_range(struct i2c_client *client) { return __isl29003_read_reg(client, ISL29003_REG_CONTROL, ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT); } static int isl29003_set_range(struct i2c_client *client, int range) { return __isl29003_write_reg(client, ISL29003_REG_CONTROL, ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range); } /* resolution */ static int isl29003_get_resolution(struct i2c_client *client) { return __isl29003_read_reg(client, ISL29003_REG_COMMAND, ISL29003_RES_MASK, ISL29003_RES_SHIFT); } static int isl29003_set_resolution(struct i2c_client *client, int res) { return __isl29003_write_reg(client, ISL29003_REG_COMMAND, ISL29003_RES_MASK, ISL29003_RES_SHIFT, res); } /* mode */ static int isl29003_get_mode(struct i2c_client *client) { return __isl29003_read_reg(client, ISL29003_REG_COMMAND, ISL29003_RES_MASK, ISL29003_RES_SHIFT); } static int isl29003_set_mode(struct i2c_client *client, int mode) { return __isl29003_write_reg(client, ISL29003_REG_COMMAND, ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode); } /* power_state */ static int isl29003_set_power_state(struct i2c_client *client, int state) { return __isl29003_write_reg(client, ISL29003_REG_COMMAND, ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0, state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD); } static int isl29003_get_power_state(struct i2c_client *client) { struct isl29003_data *data = i2c_get_clientdata(client); u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND]; return ~cmdreg & ISL29003_ADC_PD; } static int isl29003_get_adc_value(struct i2c_client *client) { struct isl29003_data *data = i2c_get_clientdata(client); int lsb, msb, range, bitdepth; mutex_lock(&data->lock); lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR); if (lsb < 0) { mutex_unlock(&data->lock); return lsb; } msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR); mutex_unlock(&data->lock); if (msb < 0) return msb; range = isl29003_get_range(client); bitdepth = (4 - isl29003_get_resolution(client)) * 4; return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth; } /* * sysfs layer */ /* range */ static ssize_t isl29003_show_range(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%i\n", isl29003_get_range(client)); } static ssize_t isl29003_store_range(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); unsigned long val; int ret; if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3)) return -EINVAL; ret = isl29003_set_range(client, val); if (ret < 0) return ret; return count; } static DEVICE_ATTR(range, S_IWUSR | S_IRUGO, isl29003_show_range, isl29003_store_range); /* resolution */ static ssize_t isl29003_show_resolution(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%d\n", isl29003_get_resolution(client)); } static ssize_t isl29003_store_resolution(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); unsigned long val; int ret; if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3)) return -EINVAL; ret = isl29003_set_resolution(client, val); if (ret < 0) return ret; return count; } static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO, isl29003_show_resolution, isl29003_store_resolution); /* mode */ static ssize_t isl29003_show_mode(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%d\n", isl29003_get_mode(client)); } static ssize_t isl29003_store_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); unsigned long val; int ret; if ((strict_strtoul(buf, 10, &val) < 0) || (val > 2)) return -EINVAL; ret = isl29003_set_mode(client, val); if (ret < 0) return ret; return count; } static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, isl29003_show_mode, isl29003_store_mode); /* power state */ static ssize_t isl29003_show_power_state(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%d\n", isl29003_get_power_state(client)); } static ssize_t isl29003_store_power_state(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); unsigned long val; int ret; if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1)) return -EINVAL; ret = isl29003_set_power_state(client, val); return ret ? ret : count; } static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, isl29003_show_power_state, isl29003_store_power_state); /* lux */ static ssize_t isl29003_show_lux(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); /* No LUX data if not operational */ if (!isl29003_get_power_state(client)) return -EBUSY; return sprintf(buf, "%d\n", isl29003_get_adc_value(client)); } static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL); static struct attribute *isl29003_attributes[] = { &dev_attr_range.attr, &dev_attr_resolution.attr, &dev_attr_mode.attr, &dev_attr_power_state.attr, &dev_attr_lux.attr, NULL }; static const struct attribute_group isl29003_attr_group = { .attrs = isl29003_attributes, }; static int isl29003_init_client(struct i2c_client *client) { struct isl29003_data *data = i2c_get_clientdata(client); int i; /* read all the registers once to fill the cache. * if one of the reads fails, we consider the init failed */ for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) { int v = i2c_smbus_read_byte_data(client, i); if (v < 0) return -ENODEV; data->reg_cache[i] = v; } /* set defaults */ isl29003_set_range(client, 0); isl29003_set_resolution(client, 0); isl29003_set_mode(client, 0); isl29003_set_power_state(client, 0); return 0; } /* * I2C layer */ static int isl29003_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); struct isl29003_data *data; int err = 0; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) return -EIO; data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; i2c_set_clientdata(client, data); mutex_init(&data->lock); /* initialize the ISL29003 chip */ err = isl29003_init_client(client); if (err) goto exit_kfree; /* register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group); if (err) goto exit_kfree; dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION); return 0; exit_kfree: kfree(data); return err; } static int isl29003_remove(struct i2c_client *client) { sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group); isl29003_set_power_state(client, 0); kfree(i2c_get_clientdata(client)); return 0; } #ifdef CONFIG_PM static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg) { struct isl29003_data *data = i2c_get_clientdata(client); data->power_state_before_suspend = isl29003_get_power_state(client); return isl29003_set_power_state(client, 0); } static int isl29003_resume(struct i2c_client *client) { int i; struct isl29003_data *data = i2c_get_clientdata(client); /* restore registers from cache */ for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i])) return -EIO; return isl29003_set_power_state(client, data->power_state_before_suspend); } #else #define isl29003_suspend NULL #define isl29003_resume NULL #endif /* CONFIG_PM */ static const struct i2c_device_id isl29003_id[] = { { "isl29003", 0 }, {} }; MODULE_DEVICE_TABLE(i2c, isl29003_id); static struct i2c_driver isl29003_driver = { .driver = { .name = ISL29003_DRV_NAME, .owner = THIS_MODULE, }, .suspend = isl29003_suspend, .resume = isl29003_resume, .probe = isl29003_probe, .remove = isl29003_remove, .id_table = isl29003_id, }; module_i2c_driver(isl29003_driver); MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); MODULE_DESCRIPTION("ISL29003 ambient light sensor driver"); MODULE_LICENSE("GPL v2"); MODULE_VERSION(DRIVER_VERSION);