From: Svyatoslav Ryhel Date: Wed, 19 Mar 2025 11:51:58 +0000 (+0200) Subject: video: backlight: add TI LM3532 led controller X-Git-Tag: v2025.07-rc1~69^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=041cb0b23acfaff8978ee6e4204147e9ae9b7dd9;p=pandora-u-boot.git video: backlight: add TI LM3532 led controller The LM3532 is a 500-kHz fixed frequency asynchronous boost converter which provides the power for 3 high-voltage, low-side current sinks. The device is programmable over an I2C-compatible interface and has independent current control for all three channels. Signed-off-by: Svyatoslav Ryhel --- diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 6c323be3e32..73353944971 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -738,6 +738,15 @@ config ATMEL_HLCD help HLCDC supports video output to an attached LCD panel. +config BACKLIGHT_LM3532 + bool "Backlight Driver for LM3532" + depends on BACKLIGHT + select DM_I2C + help + Say Y to enable the backlight driver for National Semiconductor / TI + LM3532 Lighting Power chip. Only backlight functions is supported as + for now. Supported backlight level range is from 1 to 255. + config BACKLIGHT_LM3533 bool "Backlight Driver for LM3533" depends on BACKLIGHT diff --git a/drivers/video/Makefile b/drivers/video/Makefile index 2145afa2686..fbdb058647a 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_$(PHASE_)BMP) += bmp.o endif +obj-$(CONFIG_BACKLIGHT_LM3532) += lm3532_backlight.o obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_backlight.o obj-$(CONFIG_BACKLIGHT_LP855x) += lp855x_backlight.o obj-${CONFIG_EXYNOS_FB} += exynos/ diff --git a/drivers/video/lm3532_backlight.c b/drivers/video/lm3532_backlight.c new file mode 100644 index 00000000000..81b3b910196 --- /dev/null +++ b/drivers/video/lm3532_backlight.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * TI LM3532 LED driver + * + * Copyright (c) 2019 Texas Instruments Incorporated + * Copyright (c) 2025 Svyatoslav Ryhel + */ + +#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_bank_data { + int control_bank; + int mode; + int ctrl_brt_pointer; + int num_leds; + int full_scale_current; + u32 present:1; + u32 led_strings[LM3532_MAX_CONTROL_BANKS]; +}; + +struct lm3532_backlight_priv { + struct gpio_desc enable_gpio; + struct udevice *regulator; + + u32 runtime_ramp_up; + u32 runtime_ramp_down; + + struct lm3532_bank_data bank[LM3532_MAX_CONTROL_BANKS]; +}; + +/* This device does not like i2c md so use this instead */ +static void __maybe_unused dump_i2c(struct udevice *dev) +{ + int i, c; + + for (i = 0; i < 0x10; i++) { + printf("00%02x: %02x", i * 0x10, dm_i2c_reg_read(dev, i * 0x10)); + for (c = 1; c < 0xf; c++) + printf(" %02x", dm_i2c_reg_read(dev, i * 0x10 + c)); + printf(" %02x\n", dm_i2c_reg_read(dev, i * 0x10 + 0xf)); + } +} + +static int lm3532_backlight_enable(struct udevice *dev) +{ + struct lm3532_backlight_priv *priv = dev_get_priv(dev); + int ret, i; + + for (i = 0; i < LM3532_MAX_CONTROL_BANKS; i++) { + if (priv->bank[i].present) { + u32 ctrl_en_val = BIT(priv->bank[i].control_bank); + + ret = dm_i2c_reg_clrset(dev, LM3532_REG_ENABLE, + ctrl_en_val, ctrl_en_val); + if (ret) { + log_debug("%s: failed to set ctrl: %d\n", + __func__, ret); + return ret; + } + } + } + + regulator_set_enable_if_allowed(priv->regulator, 1); + + return 0; +} + +static int lm3532_backlight_set_brightness(struct udevice *dev, int percent) +{ + struct lm3532_backlight_priv *priv = dev_get_priv(dev); + struct lm3532_bank_data *bank; + int ret, i; + + for (i = 0; i < LM3532_MAX_CONTROL_BANKS; i++) { + if (priv->bank[i].present) { + bank = &priv->bank[i]; + u32 brightness_reg = LM3532_REG_ZONE_TRGT_A + + bank->control_bank * 5 + + (bank->ctrl_brt_pointer >> 2); + + ret = dm_i2c_reg_write(dev, brightness_reg, percent); + if (ret) { + log_debug("%s: failed to set brightness: %d\n", + __func__, ret); + return ret; + } + } + } + + return 0; +} + +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) +{ + int i; + + if (ramp_time <= ramp_table[0]) + return 0; + + if (ramp_time > ramp_table[LM3532_NUM_RAMP_VALS - 1]) + return LM3532_NUM_RAMP_VALS - 1; + + for (i = 1; i < LM3532_NUM_RAMP_VALS; i++) { + if (ramp_time == ramp_table[i]) + return i; + + /* Find an approximate index by looking up the table */ + if (ramp_time > ramp_table[i - 1] && + ramp_time < ramp_table[i]) { + if (ramp_time - ramp_table[i - 1] < ramp_table[i] - ramp_time) + return i - 1; + else + return i; + } + } + + return 0; +} + +static int lm3532_backlight_of_to_plat(struct udevice *dev) +{ + struct lm3532_backlight_priv *priv = dev_get_priv(dev); + u32 ramp_time, reg; + ofnode child; + int ret; + + ret = gpio_request_by_name(dev, "enable-gpios", 0, + &priv->enable_gpio, GPIOD_IS_OUT); + if (ret) { + log_debug("%s: could not decode enable-gpios (%d)\n", __func__, ret); + return ret; + } + + ret = device_get_supply_regulator(dev, "vin-supply", &priv->regulator); + if (ret) { + log_debug("%s: vin regulator not defined: %d\n", __func__, ret); + if (ret != -ENOENT) + return log_ret(ret); + } + + ramp_time = dev_read_u32_default(dev, "ramp-up-us", 0); + priv->runtime_ramp_up = lm3532_get_ramp_index(ramp_time); + + ramp_time = dev_read_u32_default(dev, "ramp-down-us", 0); + priv->runtime_ramp_down = lm3532_get_ramp_index(ramp_time); + + /* Backlight is one of children but has no dedicated driver */ + ofnode_for_each_subnode(child, dev_ofnode(dev)) { + ret = ofnode_read_u32(child, "reg", ®); + if (ret || reg > LM3532_CONTROL_C) { + log_debug("%s: control bank invalid %d\n", __func__, reg); + continue; + } + + struct lm3532_bank_data *bank = &priv->bank[reg]; + + bank->control_bank = reg; + bank->present = 1; + bank->mode = ofnode_read_u32_default(child, "ti,led-mode", + LM3532_BL_MODE_MANUAL); + bank->mode = LM3532_BL_MODE_ALS ? LM3532_ALS_CTRL : LM3532_I2C_CTRL; + + if (ofnode_read_bool(child, "ti,linear-mapping-mode")) + bank->mode |= LM3532_LINEAR_MAP; + + bank->num_leds = ofnode_read_size(child, "led-sources"); + bank->num_leds /= sizeof(u32); + if (bank->num_leds > LM3532_MAX_LED_STRINGS) { + log_debug("%s: too many LED string defined %d\n", + __func__, bank->num_leds); + continue; + } + + ret = ofnode_read_u32_array(child, "led-sources", + bank->led_strings, + bank->num_leds); + if (ret) { + log_debug("%s: led-sources property missing %d\n", + __func__, ret); + continue; + } + + ret = ofnode_read_u32(child, "led-max-microamp", + &bank->full_scale_current); + if (ret) + log_debug("%s: failed getting led-max-microamp %d\n", + __func__, ret); + else + bank->full_scale_current = min(bank->full_scale_current, + LM3532_FS_CURR_MAX); + } + + return 0; +} + +static int lm3532_backlight_init_registers(struct udevice *dev, + struct lm3532_bank_data *bank) +{ + struct lm3532_backlight_priv *priv = dev_get_priv(dev); + u32 brightness_config_val, runtime_ramp_val; + u32 output_cfg_val = 0, output_cfg_shift = 0, output_cfg_mask = 0; + int fs_current_reg, fs_current_val; + int ret, i; + + if (!bank->present) + return 0; + + u32 brightness_config_reg = LM3532_REG_ZONE_CFG_A + bank->control_bank * 2; + /* + * This could be hard coded to the default value but the control + * brightness register may have changed during boot. + */ + ret = dm_i2c_reg_read(dev, brightness_config_reg); + if (ret < 0) + return ret; + + bank->ctrl_brt_pointer = ret & ~LM3532_ZONE_MASK; + brightness_config_val = bank->ctrl_brt_pointer | bank->mode; + + ret = dm_i2c_reg_write(dev, brightness_config_reg, brightness_config_val); + if (ret) + return ret; + + if (bank->full_scale_current) { + fs_current_reg = LM3532_REG_CTRL_A_FS_CURR + bank->control_bank * 2; + fs_current_val = (bank->full_scale_current - LM3532_FS_CURR_MIN) / + LM3532_FS_CURR_STEP; + + ret = dm_i2c_reg_write(dev, fs_current_reg, fs_current_val); + if (ret) + return ret; + } + + for (i = 0; i < bank->num_leds; i++) { + output_cfg_shift = bank->led_strings[i] * 2; + output_cfg_val |= (bank->control_bank << output_cfg_shift); + output_cfg_mask |= LM3532_OUTPUT_CFG_MASK << output_cfg_shift; + } + + ret = dm_i2c_reg_clrset(dev, LM3532_REG_OUTPUT_CFG, output_cfg_mask, + output_cfg_val); + if (ret) + return ret; + + runtime_ramp_val = priv->runtime_ramp_up | + (priv->runtime_ramp_down << LM3532_RAMP_DOWN_SHIFT); + + return dm_i2c_reg_write(dev, LM3532_REG_RT_RAMP, runtime_ramp_val); +} + +static int lm3532_backlight_probe(struct udevice *dev) +{ + struct lm3532_backlight_priv *priv = dev_get_priv(dev); + int ret, i; + + if (device_get_uclass_id(dev->parent) != UCLASS_I2C) + return -EPROTONOSUPPORT; + + dm_gpio_set_value(&priv->enable_gpio, 1); + + for (i = 0; i < LM3532_MAX_CONTROL_BANKS; i++) { + ret = lm3532_backlight_init_registers(dev, &priv->bank[i]); + if (ret) + return ret; + } + + return 0; +} + +static const struct backlight_ops lm3532_backlight_ops = { + .enable = lm3532_backlight_enable, + .set_brightness = lm3532_backlight_set_brightness, +}; + +static const struct udevice_id lm3532_backlight_ids[] = { + { .compatible = "ti,lm3532" }, + { } +}; + +U_BOOT_DRIVER(lm3532_backlight) = { + .name = "lm3532_backlight", + .id = UCLASS_PANEL_BACKLIGHT, + .of_match = lm3532_backlight_ids, + .of_to_plat = lm3532_backlight_of_to_plat, + .probe = lm3532_backlight_probe, + .ops = &lm3532_backlight_ops, + .priv_auto = sizeof(struct lm3532_backlight_priv), +};