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