--- /dev/null
+/*
+ * 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];
+};
+
+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 __devinit 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 __devexit 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)
+{
+ 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 0;
+}
+
+#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 = __devexit_p(isl29003_remove),
+ .id_table = isl29003_id,
+};
+
+static int __init isl29003_init(void)
+{
+ return i2c_add_driver(&isl29003_driver);
+}
+
+static void __exit isl29003_exit(void)
+{
+ i2c_del_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);
+
+module_init(isl29003_init);
+module_exit(isl29003_exit);
+
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