--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * TI LM3532 LED driver
+ *
+ * Copyright (c) 2019 Texas Instruments Incorporated
+ * Copyright (c) 2025 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
+
+#include <backlight.h>
+#include <dm.h>
+#include <dm/ofnode.h>
+#include <i2c.h>
+#include <log.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <asm/gpio.h>
+#include <power/regulator.h>
+
+#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),
+};
git.openpandora.org / pandora-u-boot.git / commitdiff