// SPDX-License-Identifier: GPL-2.0 // TI LM3532 LED driver // Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/ // https://www.ti.com/lit/ds/symlink/lm3532.pdf #include #include #include #include #include #include #include #include #include #define LM3532_NAME "lm3532-led" #define LM3532_BL_MODE_MANUAL 0x00 #define LM3532_BL_MODE_ALS 0x01 #define LM3532_REG_OUTPUT_CFG 0x10 #define LM3532_REG_STARTSHUT_RAMP 0x11 #define LM3532_REG_RT_RAMP 0x12 #define LM3532_REG_PWM_A_CFG 0x13 #define LM3532_REG_PWM_B_CFG 0x14 #define LM3532_REG_PWM_C_CFG 0x15 #define LM3532_REG_ZONE_CFG_A 0x16 #define LM3532_REG_CTRL_A_FS_CURR 0x17 #define LM3532_REG_ZONE_CFG_B 0x18 #define LM3532_REG_CTRL_B_FS_CURR 0x19 #define LM3532_REG_ZONE_CFG_C 0x1a #define LM3532_REG_CTRL_C_FS_CURR 0x1b #define LM3532_REG_ENABLE 0x1d #define LM3532_ALS_CONFIG 0x23 #define LM3532_REG_ZN_0_HI 0x60 #define LM3532_REG_ZN_0_LO 0x61 #define LM3532_REG_ZN_1_HI 0x62 #define LM3532_REG_ZN_1_LO 0x63 #define LM3532_REG_ZN_2_HI 0x64 #define LM3532_REG_ZN_2_LO 0x65 #define LM3532_REG_ZN_3_HI 0x66 #define LM3532_REG_ZN_3_LO 0x67 #define LM3532_REG_ZONE_TRGT_A 0x70 #define LM3532_REG_ZONE_TRGT_B 0x75 #define LM3532_REG_ZONE_TRGT_C 0x7a #define LM3532_REG_MAX 0x7e /* Control Enable */ #define LM3532_CTRL_A_ENABLE BIT(0) #define LM3532_CTRL_B_ENABLE BIT(1) #define LM3532_CTRL_C_ENABLE BIT(2) /* PWM Zone Control */ #define LM3532_PWM_ZONE_MASK 0x7c #define LM3532_PWM_ZONE_0_EN BIT(2) #define LM3532_PWM_ZONE_1_EN BIT(3) #define LM3532_PWM_ZONE_2_EN BIT(4) #define LM3532_PWM_ZONE_3_EN BIT(5) #define LM3532_PWM_ZONE_4_EN BIT(6) /* Brightness Configuration */ #define LM3532_I2C_CTRL BIT(0) #define LM3532_ALS_CTRL 0 #define LM3532_LINEAR_MAP BIT(1) #define LM3532_ZONE_MASK (BIT(2) | BIT(3) | BIT(4)) #define LM3532_ZONE_0 0 #define LM3532_ZONE_1 BIT(2) #define LM3532_ZONE_2 BIT(3) #define LM3532_ZONE_3 (BIT(2) | BIT(3)) #define LM3532_ZONE_4 BIT(4) #define LM3532_ENABLE_ALS BIT(3) #define LM3532_ALS_SEL_SHIFT 6 /* Zone Boundary Register */ #define LM3532_ALS_WINDOW_mV 2000 #define LM3532_ALS_ZB_MAX 4 #define LM3532_ALS_OFFSET_mV 2 #define LM3532_CONTROL_A 0 #define LM3532_CONTROL_B 1 #define LM3532_CONTROL_C 2 #define LM3532_MAX_CONTROL_BANKS 3 #define LM3532_MAX_LED_STRINGS 3 #define LM3532_OUTPUT_CFG_MASK 0x3 #define LM3532_BRT_VAL_ADJUST 8 #define LM3532_RAMP_DOWN_SHIFT 3 #define LM3532_NUM_RAMP_VALS 8 #define LM3532_NUM_AVG_VALS 8 #define LM3532_NUM_IMP_VALS 32 #define LM3532_FS_CURR_MIN 5000 #define LM3532_FS_CURR_MAX 29800 #define LM3532_FS_CURR_STEP 800 /* * struct lm3532_als_data * @config - value of ALS configuration register * @als1_imp_sel - value of ALS1 resistor select register * @als2_imp_sel - value of ALS2 resistor select register * @als_avrg_time - ALS averaging time * @als_input_mode - ALS input mode for brightness control * @als_vmin - Minimum ALS voltage * @als_vmax - Maximum ALS voltage * @zone_lo - values of ALS lo ZB(Zone Boundary) registers * @zone_hi - values of ALS hi ZB(Zone Boundary) registers */ struct lm3532_als_data { u8 config; u8 als1_imp_sel; u8 als2_imp_sel; u8 als_avrg_time; u8 als_input_mode; u32 als_vmin; u32 als_vmax; u8 zones_lo[LM3532_ALS_ZB_MAX]; u8 zones_hi[LM3532_ALS_ZB_MAX]; }; /** * struct lm3532_led * @led_dev: led class device * @priv - Pointer the device data structure * @control_bank - Control bank the LED is associated to * @mode - Mode of the LED string * @ctrl_brt_pointer - Zone target register that controls the sink * @num_leds - Number of LED strings are supported in this array * @full_scale_current - The full-scale current setting for the current sink. * @led_strings - The LED strings supported in this array * @enabled - Enabled status */ struct lm3532_led { struct led_classdev led_dev; struct lm3532_data *priv; int control_bank; int mode; int ctrl_brt_pointer; int num_leds; int full_scale_current; unsigned int enabled:1; u32 led_strings[LM3532_MAX_CONTROL_BANKS]; }; /** * struct lm3532_data * @enable_gpio - Hardware enable gpio * @regulator: regulator * @client: i2c client * @regmap - Devices register map * @dev - Pointer to the devices device struct * @lock - Lock for reading/writing the device * @als_data - Pointer to the als data struct * @runtime_ramp_up - Runtime ramp up setting * @runtime_ramp_down - Runtime ramp down setting * @leds - Array of LED strings */ struct lm3532_data { struct gpio_desc *enable_gpio; struct regulator *regulator; struct i2c_client *client; struct regmap *regmap; struct device *dev; struct mutex lock; struct lm3532_als_data *als_data; u32 runtime_ramp_up; u32 runtime_ramp_down; struct lm3532_led leds[]; }; static const struct reg_default lm3532_reg_defs[] = { {LM3532_REG_OUTPUT_CFG, 0xe4}, {LM3532_REG_STARTSHUT_RAMP, 0xc0}, {LM3532_REG_RT_RAMP, 0xc0}, {LM3532_REG_PWM_A_CFG, 0x82}, {LM3532_REG_PWM_B_CFG, 0x82}, {LM3532_REG_PWM_C_CFG, 0x82}, {LM3532_REG_ZONE_CFG_A, 0xf1}, {LM3532_REG_CTRL_A_FS_CURR, 0xf3}, {LM3532_REG_ZONE_CFG_B, 0xf1}, {LM3532_REG_CTRL_B_FS_CURR, 0xf3}, {LM3532_REG_ZONE_CFG_C, 0xf1}, {LM3532_REG_CTRL_C_FS_CURR, 0xf3}, {LM3532_REG_ENABLE, 0xf8}, {LM3532_ALS_CONFIG, 0x44}, {LM3532_REG_ZN_0_HI, 0x35}, {LM3532_REG_ZN_0_LO, 0x33}, {LM3532_REG_ZN_1_HI, 0x6a}, {LM3532_REG_ZN_1_LO, 0x66}, {LM3532_REG_ZN_2_HI, 0xa1}, {LM3532_REG_ZN_2_LO, 0x99}, {LM3532_REG_ZN_3_HI, 0xdc}, {LM3532_REG_ZN_3_LO, 0xcc}, }; static const struct regmap_config lm3532_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = LM3532_REG_MAX, .reg_defaults = lm3532_reg_defs, .num_reg_defaults = ARRAY_SIZE(lm3532_reg_defs), .cache_type = REGCACHE_FLAT, }; static const int als_imp_table[LM3532_NUM_IMP_VALS] = {37000, 18500, 12330, 92500, 7400, 6170, 5290, 4630, 4110, 3700, 3360, 3080, 2850, 2640, 2440, 2310, 2180, 2060, 1950, 1850, 1760, 1680, 1610, 1540, 1480, 1420, 1370, 1320, 1280, 1230, 1190}; static int lm3532_get_als_imp_index(int als_imped) { int i; if (als_imped > als_imp_table[1]) return 0; if (als_imped < als_imp_table[LM3532_NUM_IMP_VALS - 1]) return LM3532_NUM_IMP_VALS - 1; for (i = 1; i < LM3532_NUM_IMP_VALS; i++) { if (als_imped == als_imp_table[i]) return i; /* Find an approximate index by looking up the table */ if (als_imped < als_imp_table[i - 1] && als_imped > als_imp_table[i]) { if (als_imped - als_imp_table[i - 1] < als_imp_table[i] - als_imped) return i + 1; else return i; } } return -EINVAL; } static int lm3532_get_index(const int table[], int size, int value) { int i; for (i = 1; i < size; i++) { if (value == table[i]) return i; /* Find an approximate index by looking up the table */ if (value > table[i - 1] && value < table[i]) { if (value - table[i - 1] < table[i] - value) return i - 1; else return i; } } return -EINVAL; } static const int als_avrg_table[LM3532_NUM_AVG_VALS] = {17920, 35840, 71680, 1433360, 286720, 573440, 1146880, 2293760}; static int lm3532_get_als_avg_index(int avg_time) { if (avg_time <= als_avrg_table[0]) return 0; if (avg_time > als_avrg_table[LM3532_NUM_AVG_VALS - 1]) return LM3532_NUM_AVG_VALS - 1; return lm3532_get_index(&als_avrg_table[0], LM3532_NUM_AVG_VALS, avg_time); } static const int ramp_table[LM3532_NUM_RAMP_VALS] = { 8, 1024, 2048, 4096, 8192, 16384, 32768, 65536}; static int lm3532_get_ramp_index(int ramp_time) { if (ramp_time <= ramp_table[0]) return 0; if (ramp_time > ramp_table[LM3532_NUM_RAMP_VALS - 1]) return LM3532_NUM_RAMP_VALS - 1; return lm3532_get_index(&ramp_table[0], LM3532_NUM_RAMP_VALS, ramp_time); } /* Caller must take care of locking */ static int lm3532_led_enable(struct lm3532_led *led_data) { int ctrl_en_val = BIT(led_data->control_bank); int ret; if (led_data->enabled) return 0; ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE, ctrl_en_val, ctrl_en_val); if (ret) { dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret); return ret; } ret = regulator_enable(led_data->priv->regulator); if (ret < 0) return ret; led_data->enabled = 1; return 0; } /* Caller must take care of locking */ static int lm3532_led_disable(struct lm3532_led *led_data) { int ctrl_en_val = BIT(led_data->control_bank); int ret; if (!led_data->enabled) return 0; ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE, ctrl_en_val, 0); if (ret) { dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret); return ret; } ret = regulator_disable(led_data->priv->regulator); if (ret < 0) return ret; led_data->enabled = 0; return 0; } static int lm3532_brightness_set(struct led_classdev *led_cdev, enum led_brightness brt_val) { struct lm3532_led *led = container_of(led_cdev, struct lm3532_led, led_dev); u8 brightness_reg; int ret; mutex_lock(&led->priv->lock); if (led->mode == LM3532_ALS_CTRL) { if (brt_val > LED_OFF) ret = lm3532_led_enable(led); else ret = lm3532_led_disable(led); goto unlock; } if (brt_val == LED_OFF) { ret = lm3532_led_disable(led); goto unlock; } ret = lm3532_led_enable(led); if (ret) goto unlock; brightness_reg = LM3532_REG_ZONE_TRGT_A + led->control_bank * 5 + (led->ctrl_brt_pointer >> 2); ret = regmap_write(led->priv->regmap, brightness_reg, brt_val); unlock: mutex_unlock(&led->priv->lock); return ret; } static int lm3532_init_registers(struct lm3532_led *led) { struct lm3532_data *drvdata = led->priv; unsigned int runtime_ramp_val; unsigned int output_cfg_val = 0; unsigned int output_cfg_shift = 0; unsigned int output_cfg_mask = 0; unsigned int brightness_config_reg; unsigned int brightness_config_val; int fs_current_reg; int fs_current_val; int ret, i; if (drvdata->enable_gpio) gpiod_direction_output(drvdata->enable_gpio, 1); brightness_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2; /* * This could be hard coded to the default value but the control * brightness register may have changed during boot. */ ret = regmap_read(drvdata->regmap, brightness_config_reg, &led->ctrl_brt_pointer); if (ret) return ret; led->ctrl_brt_pointer &= LM3532_ZONE_MASK; brightness_config_val = led->ctrl_brt_pointer | led->mode; ret = regmap_write(drvdata->regmap, brightness_config_reg, brightness_config_val); if (ret) return ret; if (led->full_scale_current) { fs_current_reg = LM3532_REG_CTRL_A_FS_CURR + led->control_bank * 2; fs_current_val = (led->full_scale_current - LM3532_FS_CURR_MIN) / LM3532_FS_CURR_STEP; ret = regmap_write(drvdata->regmap, fs_current_reg, fs_current_val); if (ret) return ret; } for (i = 0; i < led->num_leds; i++) { output_cfg_shift = led->led_strings[i] * 2; output_cfg_val |= (led->control_bank << output_cfg_shift); output_cfg_mask |= LM3532_OUTPUT_CFG_MASK << output_cfg_shift; } ret = regmap_update_bits(drvdata->regmap, LM3532_REG_OUTPUT_CFG, output_cfg_mask, output_cfg_val); if (ret) return ret; runtime_ramp_val = drvdata->runtime_ramp_up | (drvdata->runtime_ramp_down << LM3532_RAMP_DOWN_SHIFT); return regmap_write(drvdata->regmap, LM3532_REG_RT_RAMP, runtime_ramp_val); } static int lm3532_als_configure(struct lm3532_data *priv, struct lm3532_led *led) { struct lm3532_als_data *als = priv->als_data; u32 als_vmin, als_vmax, als_vstep; int zone_reg = LM3532_REG_ZN_0_HI; int ret; int i; als_vmin = als->als_vmin; als_vmax = als->als_vmax; als_vstep = (als_vmax - als_vmin) / ((LM3532_ALS_ZB_MAX + 1) * 2); for (i = 0; i < LM3532_ALS_ZB_MAX; i++) { als->zones_lo[i] = ((als_vmin + als_vstep + (i * als_vstep)) * LED_FULL) / 1000; als->zones_hi[i] = ((als_vmin + LM3532_ALS_OFFSET_mV + als_vstep + (i * als_vstep)) * LED_FULL) / 1000; zone_reg = LM3532_REG_ZN_0_HI + i * 2; ret = regmap_write(priv->regmap, zone_reg, als->zones_lo[i]); if (ret) return ret; zone_reg += 1; ret = regmap_write(priv->regmap, zone_reg, als->zones_hi[i]); if (ret) return ret; } als->config = (als->als_avrg_time | (LM3532_ENABLE_ALS) | (als->als_input_mode << LM3532_ALS_SEL_SHIFT)); return regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config); } static int lm3532_parse_als(struct lm3532_data *priv) { struct lm3532_als_data *als; int als_avg_time; int als_impedance; int ret; als = devm_kzalloc(priv->dev, sizeof(*als), GFP_KERNEL); if (als == NULL) return -ENOMEM; ret = device_property_read_u32(&priv->client->dev, "ti,als-vmin", &als->als_vmin); if (ret) als->als_vmin = 0; ret = device_property_read_u32(&priv->client->dev, "ti,als-vmax", &als->als_vmax); if (ret) als->als_vmax = LM3532_ALS_WINDOW_mV; if (als->als_vmax > LM3532_ALS_WINDOW_mV) { ret = -EINVAL; return ret; } ret = device_property_read_u32(&priv->client->dev, "ti,als1-imp-sel", &als_impedance); if (ret) als->als1_imp_sel = 0; else als->als1_imp_sel = lm3532_get_als_imp_index(als_impedance); ret = device_property_read_u32(&priv->client->dev, "ti,als2-imp-sel", &als_impedance); if (ret) als->als2_imp_sel = 0; else als->als2_imp_sel = lm3532_get_als_imp_index(als_impedance); ret = device_property_read_u32(&priv->client->dev, "ti,als-avrg-time-us", &als_avg_time); if (ret) als->als_avrg_time = 0; else als->als_avrg_time = lm3532_get_als_avg_index(als_avg_time); ret = device_property_read_u8(&priv->client->dev, "ti,als-input-mode", &als->als_input_mode); if (ret) als->als_input_mode = 0; if (als->als_input_mode > LM3532_BL_MODE_ALS) { ret = -EINVAL; return ret; } priv->als_data = als; return ret; } static int lm3532_parse_node(struct lm3532_data *priv) { struct fwnode_handle *child = NULL; struct lm3532_led *led; int control_bank; u32 ramp_time; size_t i = 0; int ret; priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev, "enable", GPIOD_OUT_LOW); if (IS_ERR(priv->enable_gpio)) priv->enable_gpio = NULL; priv->regulator = devm_regulator_get(&priv->client->dev, "vin"); if (IS_ERR(priv->regulator)) priv->regulator = NULL; ret = device_property_read_u32(&priv->client->dev, "ramp-up-us", &ramp_time); if (ret) dev_info(&priv->client->dev, "ramp-up-ms property missing\n"); else priv->runtime_ramp_up = lm3532_get_ramp_index(ramp_time); ret = device_property_read_u32(&priv->client->dev, "ramp-down-us", &ramp_time); if (ret) dev_info(&priv->client->dev, "ramp-down-ms property missing\n"); else priv->runtime_ramp_down = lm3532_get_ramp_index(ramp_time); device_for_each_child_node(priv->dev, child) { struct led_init_data idata = { .fwnode = child, .default_label = ":", .devicename = priv->client->name, }; led = &priv->leds[i]; ret = fwnode_property_read_u32(child, "reg", &control_bank); if (ret) { dev_err(&priv->client->dev, "reg property missing\n"); fwnode_handle_put(child); goto child_out; } if (control_bank > LM3532_CONTROL_C) { dev_err(&priv->client->dev, "Control bank invalid\n"); continue; } led->control_bank = control_bank; ret = fwnode_property_read_u32(child, "ti,led-mode", &led->mode); if (ret) { dev_err(&priv->client->dev, "ti,led-mode property missing\n"); fwnode_handle_put(child); goto child_out; } if (fwnode_property_present(child, "led-max-microamp") && fwnode_property_read_u32(child, "led-max-microamp", &led->full_scale_current)) dev_err(&priv->client->dev, "Failed getting led-max-microamp\n"); else led->full_scale_current = min(led->full_scale_current, LM3532_FS_CURR_MAX); if (led->mode == LM3532_BL_MODE_ALS) { led->mode = LM3532_ALS_CTRL; ret = lm3532_parse_als(priv); if (ret) dev_err(&priv->client->dev, "Failed to parse als\n"); else lm3532_als_configure(priv, led); } else { led->mode = LM3532_I2C_CTRL; } led->num_leds = fwnode_property_count_u32(child, "led-sources"); if (led->num_leds > LM3532_MAX_LED_STRINGS) { dev_err(&priv->client->dev, "Too many LED string defined\n"); continue; } ret = fwnode_property_read_u32_array(child, "led-sources", led->led_strings, led->num_leds); if (ret) { dev_err(&priv->client->dev, "led-sources property missing\n"); fwnode_handle_put(child); goto child_out; } fwnode_property_read_string(child, "linux,default-trigger", &led->led_dev.default_trigger); led->priv = priv; led->led_dev.brightness_set_blocking = lm3532_brightness_set; ret = devm_led_classdev_register_ext(priv->dev, &led->led_dev, &idata); if (ret) { dev_err(&priv->client->dev, "led register err: %d\n", ret); fwnode_handle_put(child); goto child_out; } ret = lm3532_init_registers(led); if (ret) { dev_err(&priv->client->dev, "register init err: %d\n", ret); fwnode_handle_put(child); goto child_out; } i++; } child_out: return ret; } static int lm3532_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct lm3532_data *drvdata; int ret = 0; int count; count = device_get_child_node_count(&client->dev); if (!count) { dev_err(&client->dev, "LEDs are not defined in device tree!"); return -ENODEV; } drvdata = devm_kzalloc(&client->dev, struct_size(drvdata, leds, count), GFP_KERNEL); if (drvdata == NULL) return -ENOMEM; drvdata->client = client; drvdata->dev = &client->dev; drvdata->regmap = devm_regmap_init_i2c(client, &lm3532_regmap_config); if (IS_ERR(drvdata->regmap)) { ret = PTR_ERR(drvdata->regmap); dev_err(&client->dev, "Failed to allocate register map: %d\n", ret); return ret; } mutex_init(&drvdata->lock); i2c_set_clientdata(client, drvdata); ret = lm3532_parse_node(drvdata); if (ret) { dev_err(&client->dev, "Failed to parse node\n"); return ret; } return ret; } static int lm3532_remove(struct i2c_client *client) { struct lm3532_data *drvdata = i2c_get_clientdata(client); mutex_destroy(&drvdata->lock); if (drvdata->enable_gpio) gpiod_direction_output(drvdata->enable_gpio, 0); return 0; } static const struct of_device_id of_lm3532_leds_match[] = { { .compatible = "ti,lm3532", }, {}, }; MODULE_DEVICE_TABLE(of, of_lm3532_leds_match); static const struct i2c_device_id lm3532_id[] = { {LM3532_NAME, 0}, {} }; MODULE_DEVICE_TABLE(i2c, lm3532_id); static struct i2c_driver lm3532_i2c_driver = { .probe = lm3532_probe, .remove = lm3532_remove, .id_table = lm3532_id, .driver = { .name = LM3532_NAME, .of_match_table = of_lm3532_leds_match, }, }; module_i2c_driver(lm3532_i2c_driver); MODULE_DESCRIPTION("Back Light driver for LM3532"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Dan Murphy ");