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453 lines
10 KiB
453 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* tsl2550.c - Linux kernel modules for ambient light sensor |
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* |
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* Copyright (C) 2007 Rodolfo Giometti <[email protected]> |
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* Copyright (C) 2007 Eurotech S.p.A. <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/i2c.h> |
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#include <linux/mutex.h> |
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#define TSL2550_DRV_NAME "tsl2550" |
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#define DRIVER_VERSION "1.2" |
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/* |
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* Defines |
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*/ |
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#define TSL2550_POWER_DOWN 0x00 |
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#define TSL2550_POWER_UP 0x03 |
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#define TSL2550_STANDARD_RANGE 0x18 |
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#define TSL2550_EXTENDED_RANGE 0x1d |
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#define TSL2550_READ_ADC0 0x43 |
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#define TSL2550_READ_ADC1 0x83 |
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/* |
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* Structs |
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*/ |
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struct tsl2550_data { |
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struct i2c_client *client; |
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struct mutex update_lock; |
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unsigned int power_state:1; |
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unsigned int operating_mode:1; |
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}; |
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/* |
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* Global data |
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*/ |
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static const u8 TSL2550_MODE_RANGE[2] = { |
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TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE, |
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}; |
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/* |
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* Management functions |
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*/ |
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static int tsl2550_set_operating_mode(struct i2c_client *client, int mode) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]); |
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data->operating_mode = mode; |
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return ret; |
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} |
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static int tsl2550_set_power_state(struct i2c_client *client, int state) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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int ret; |
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if (state == 0) |
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ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN); |
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else { |
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ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP); |
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/* On power up we should reset operating mode also... */ |
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tsl2550_set_operating_mode(client, data->operating_mode); |
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} |
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data->power_state = state; |
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return ret; |
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} |
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static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd) |
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{ |
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int ret; |
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ret = i2c_smbus_read_byte_data(client, cmd); |
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if (ret < 0) |
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return ret; |
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if (!(ret & 0x80)) |
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return -EAGAIN; |
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return ret & 0x7f; /* remove the "valid" bit */ |
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} |
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/* |
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* LUX calculation |
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*/ |
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#define TSL2550_MAX_LUX 1846 |
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static const u8 ratio_lut[] = { |
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100, 100, 100, 100, 100, 100, 100, 100, |
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100, 100, 100, 100, 100, 100, 99, 99, |
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99, 99, 99, 99, 99, 99, 99, 99, |
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99, 99, 99, 98, 98, 98, 98, 98, |
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98, 98, 97, 97, 97, 97, 97, 96, |
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96, 96, 96, 95, 95, 95, 94, 94, |
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93, 93, 93, 92, 92, 91, 91, 90, |
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89, 89, 88, 87, 87, 86, 85, 84, |
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83, 82, 81, 80, 79, 78, 77, 75, |
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74, 73, 71, 69, 68, 66, 64, 62, |
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60, 58, 56, 54, 52, 49, 47, 44, |
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42, 41, 40, 40, 39, 39, 38, 38, |
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37, 37, 37, 36, 36, 36, 35, 35, |
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35, 35, 34, 34, 34, 34, 33, 33, |
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33, 33, 32, 32, 32, 32, 32, 31, |
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31, 31, 31, 31, 30, 30, 30, 30, |
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30, |
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}; |
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static const u16 count_lut[] = { |
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0, 1, 2, 3, 4, 5, 6, 7, |
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8, 9, 10, 11, 12, 13, 14, 15, |
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16, 18, 20, 22, 24, 26, 28, 30, |
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32, 34, 36, 38, 40, 42, 44, 46, |
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49, 53, 57, 61, 65, 69, 73, 77, |
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81, 85, 89, 93, 97, 101, 105, 109, |
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115, 123, 131, 139, 147, 155, 163, 171, |
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179, 187, 195, 203, 211, 219, 227, 235, |
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247, 263, 279, 295, 311, 327, 343, 359, |
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375, 391, 407, 423, 439, 455, 471, 487, |
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511, 543, 575, 607, 639, 671, 703, 735, |
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767, 799, 831, 863, 895, 927, 959, 991, |
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1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487, |
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1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999, |
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2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991, |
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3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015, |
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}; |
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/* |
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* This function is described into Taos TSL2550 Designer's Notebook |
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* pages 2, 3. |
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*/ |
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static int tsl2550_calculate_lux(u8 ch0, u8 ch1) |
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{ |
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unsigned int lux; |
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/* Look up count from channel values */ |
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u16 c0 = count_lut[ch0]; |
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u16 c1 = count_lut[ch1]; |
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/* Avoid division by 0 and count 1 cannot be greater than count 0 */ |
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if (c1 <= c0) |
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if (c0) { |
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/* |
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* Calculate ratio. |
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* Note: the "128" is a scaling factor |
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*/ |
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u8 r = c1 * 128 / c0; |
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/* Calculate LUX */ |
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lux = ((c0 - c1) * ratio_lut[r]) / 256; |
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} else |
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lux = 0; |
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else |
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return 0; |
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/* LUX range check */ |
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return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; |
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} |
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/* |
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* SysFS support |
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*/ |
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static ssize_t tsl2550_show_power_state(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); |
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return sprintf(buf, "%u\n", data->power_state); |
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} |
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static ssize_t tsl2550_store_power_state(struct device *dev, |
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struct device_attribute *attr, const char *buf, size_t count) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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unsigned long val = simple_strtoul(buf, NULL, 10); |
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int ret; |
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if (val > 1) |
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return -EINVAL; |
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mutex_lock(&data->update_lock); |
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ret = tsl2550_set_power_state(client, val); |
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mutex_unlock(&data->update_lock); |
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if (ret < 0) |
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return ret; |
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return count; |
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} |
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static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, |
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tsl2550_show_power_state, tsl2550_store_power_state); |
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static ssize_t tsl2550_show_operating_mode(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); |
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return sprintf(buf, "%u\n", data->operating_mode); |
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} |
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static ssize_t tsl2550_store_operating_mode(struct device *dev, |
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struct device_attribute *attr, const char *buf, size_t count) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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unsigned long val = simple_strtoul(buf, NULL, 10); |
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int ret; |
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if (val > 1) |
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return -EINVAL; |
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if (data->power_state == 0) |
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return -EBUSY; |
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mutex_lock(&data->update_lock); |
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ret = tsl2550_set_operating_mode(client, val); |
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mutex_unlock(&data->update_lock); |
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if (ret < 0) |
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return ret; |
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return count; |
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} |
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static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, |
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tsl2550_show_operating_mode, tsl2550_store_operating_mode); |
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static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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u8 ch0, ch1; |
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int ret; |
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ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0); |
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if (ret < 0) |
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return ret; |
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ch0 = ret; |
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ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1); |
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if (ret < 0) |
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return ret; |
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ch1 = ret; |
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/* Do the job */ |
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ret = tsl2550_calculate_lux(ch0, ch1); |
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if (ret < 0) |
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return ret; |
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if (data->operating_mode == 1) |
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ret *= 5; |
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return sprintf(buf, "%d\n", ret); |
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} |
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static ssize_t tsl2550_show_lux1_input(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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int ret; |
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/* No LUX data if not operational */ |
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if (!data->power_state) |
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return -EBUSY; |
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mutex_lock(&data->update_lock); |
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ret = __tsl2550_show_lux(client, buf); |
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mutex_unlock(&data->update_lock); |
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return ret; |
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} |
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static DEVICE_ATTR(lux1_input, S_IRUGO, |
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tsl2550_show_lux1_input, NULL); |
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static struct attribute *tsl2550_attributes[] = { |
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&dev_attr_power_state.attr, |
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&dev_attr_operating_mode.attr, |
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&dev_attr_lux1_input.attr, |
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NULL |
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}; |
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static const struct attribute_group tsl2550_attr_group = { |
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.attrs = tsl2550_attributes, |
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}; |
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/* |
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* Initialization function |
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*/ |
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static int tsl2550_init_client(struct i2c_client *client) |
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{ |
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struct tsl2550_data *data = i2c_get_clientdata(client); |
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int err; |
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/* |
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* Probe the chip. To do so we try to power up the device and then to |
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* read back the 0x03 code |
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*/ |
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err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP); |
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if (err < 0) |
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return err; |
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if (err != TSL2550_POWER_UP) |
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return -ENODEV; |
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data->power_state = 1; |
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/* Set the default operating mode */ |
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err = i2c_smbus_write_byte(client, |
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TSL2550_MODE_RANGE[data->operating_mode]); |
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if (err < 0) |
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return err; |
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return 0; |
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} |
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/* |
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* I2C init/probing/exit functions |
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*/ |
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static struct i2c_driver tsl2550_driver; |
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static int tsl2550_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct i2c_adapter *adapter = client->adapter; |
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struct tsl2550_data *data; |
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int *opmode, err = 0; |
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE |
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| I2C_FUNC_SMBUS_READ_BYTE_DATA)) { |
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err = -EIO; |
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goto exit; |
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} |
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data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); |
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if (!data) { |
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err = -ENOMEM; |
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goto exit; |
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} |
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data->client = client; |
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i2c_set_clientdata(client, data); |
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/* Check platform data */ |
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opmode = client->dev.platform_data; |
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if (opmode) { |
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if (*opmode < 0 || *opmode > 1) { |
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dev_err(&client->dev, "invalid operating_mode (%d)\n", |
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*opmode); |
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err = -EINVAL; |
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goto exit_kfree; |
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} |
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data->operating_mode = *opmode; |
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} else |
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data->operating_mode = 0; /* default mode is standard */ |
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dev_info(&client->dev, "%s operating mode\n", |
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data->operating_mode ? "extended" : "standard"); |
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mutex_init(&data->update_lock); |
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/* Initialize the TSL2550 chip */ |
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err = tsl2550_init_client(client); |
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if (err) |
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goto exit_kfree; |
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/* Register sysfs hooks */ |
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err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); |
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if (err) |
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goto exit_kfree; |
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dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); |
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return 0; |
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exit_kfree: |
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kfree(data); |
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exit: |
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return err; |
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} |
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static int tsl2550_remove(struct i2c_client *client) |
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{ |
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sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); |
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/* Power down the device */ |
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tsl2550_set_power_state(client, 0); |
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kfree(i2c_get_clientdata(client)); |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int tsl2550_suspend(struct device *dev) |
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{ |
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return tsl2550_set_power_state(to_i2c_client(dev), 0); |
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} |
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static int tsl2550_resume(struct device *dev) |
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{ |
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return tsl2550_set_power_state(to_i2c_client(dev), 1); |
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} |
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static SIMPLE_DEV_PM_OPS(tsl2550_pm_ops, tsl2550_suspend, tsl2550_resume); |
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#define TSL2550_PM_OPS (&tsl2550_pm_ops) |
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#else |
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#define TSL2550_PM_OPS NULL |
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#endif /* CONFIG_PM_SLEEP */ |
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static const struct i2c_device_id tsl2550_id[] = { |
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{ "tsl2550", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, tsl2550_id); |
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static const struct of_device_id tsl2550_of_match[] = { |
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{ .compatible = "taos,tsl2550" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, tsl2550_of_match); |
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static struct i2c_driver tsl2550_driver = { |
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.driver = { |
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.name = TSL2550_DRV_NAME, |
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.of_match_table = tsl2550_of_match, |
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.pm = TSL2550_PM_OPS, |
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}, |
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.probe = tsl2550_probe, |
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.remove = tsl2550_remove, |
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.id_table = tsl2550_id, |
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}; |
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module_i2c_driver(tsl2550_driver); |
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MODULE_AUTHOR("Rodolfo Giometti <[email protected]>"); |
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MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_VERSION(DRIVER_VERSION);
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