leds: lm3532: Introduce the lm3532 LED driver

Introduce the Texas Instruments LM3532 White LED driver.
The driver supports ALS configurability or manual brightness
control.

The driver also supports associating LED strings with specific
control banks in a group or as individually controlled strings.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

3 files changed, 694 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a72f97fca57b..da00b9ed5a5c 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -138,6 +138,16 @@ config LEDS_LM3530
 	  controlled manually or using PWM input or using ambient
 	  light automatically.
 
+config LEDS_LM3532
+	tristate "LCD Backlight driver for LM3532"
+	depends on LEDS_CLASS
+	depends on I2C
+	help
+	  This option enables support for the LCD backlight using
+	  LM3532 ambient light sensor chip. This ALS chip can be
+	  controlled manually or using PWM input or using ambient
+	  light automatically.
+
 config LEDS_LM3533
 	tristate "LED support for LM3533"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 4c1b0054f379..7a8b1f55d459 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o
 obj-$(CONFIG_LEDS_CPCAP)		+= leds-cpcap.o
 obj-$(CONFIG_LEDS_LOCOMO)		+= leds-locomo.o
 obj-$(CONFIG_LEDS_LM3530)		+= leds-lm3530.o
+obj-$(CONFIG_LEDS_LM3532)		+= leds-lm3532.o
 obj-$(CONFIG_LEDS_LM3533)		+= leds-lm3533.o
 obj-$(CONFIG_LEDS_LM3642)		+= leds-lm3642.o
 obj-$(CONFIG_LEDS_MIKROTIK_RB532)	+= leds-rb532.o
diff --git a/drivers/leds/leds-lm3532.c b/drivers/leds/leds-lm3532.c
new file mode 100644
index 000000000000..180895b83b88
--- /dev/null
+++ b/drivers/leds/leds-lm3532.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0
+// TI LM3532 LED driver
+// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <uapi/linux/uleds.h>
+#include <linux/gpio/consumer.h>
+
+#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_BRT	0x17
+#define LM3532_REG_ZONE_CFG_B	0x18
+#define LM3532_REG_CTRL_B_BRT	0x19
+#define LM3532_REG_ZONE_CFG_C	0x1a
+#define LM3532_REG_CTRL_C_BRT	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_MAX		0x7e
+
+/* Contorl 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
+
+/*
+ * 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
+ * @num_leds - Number of LED strings are supported in this array
+ * @led_strings - The LED strings supported in this array
+ * @label - LED label
+ */
+struct lm3532_led {
+	struct led_classdev led_dev;
+	struct lm3532_data *priv;
+
+	int control_bank;
+	int mode;
+	int num_leds;
+	u32 led_strings[LM3532_MAX_CONTROL_BANKS];
+	char label[LED_MAX_NAME_SIZE];
+};
+
+/**
+ * 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_BRT, 0xf3},
+	{LM3532_REG_ZONE_CFG_B, 0xf1},
+	{LM3532_REG_CTRL_B_BRT, 0xf3},
+	{LM3532_REG_ZONE_CFG_C, 0xf1},
+	{LM3532_REG_CTRL_C_BRT, 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,
+};
+
+const static 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;
+}
+
+const static 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);
+}
+
+const static 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);
+}
+
+static int lm3532_led_enable(struct lm3532_led *led_data)
+{
+	int ctrl_en_val = BIT(led_data->control_bank);
+	int ret;
+
+	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;
+	}
+
+	return regulator_enable(led_data->priv->regulator);
+}
+
+static int lm3532_led_disable(struct lm3532_led *led_data)
+{
+	int ctrl_en_val = BIT(led_data->control_bank);
+	int ret;
+
+	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;
+	}
+
+	return regulator_disable(led_data->priv->regulator);
+}
+
+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_BL_MODE_ALS) {
+		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_CTRL_A_BRT + led->control_bank * 2;
+	brt_val = brt_val / LM3532_BRT_VAL_ADJUST;
+
+	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;
+	int ret, i;
+
+	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 brightnes_config_reg;
+	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));
+
+	ret = regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
+	if (ret)
+		return ret;
+
+	brightnes_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
+
+	return regmap_update_bits(priv->regmap, brightnes_config_reg,
+				  LM3532_I2C_CTRL, LM3532_ALS_CTRL);
+}
+
+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;
+	const char *name;
+	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) {
+		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 (led->mode == LM3532_BL_MODE_ALS) {
+			ret = lm3532_parse_als(priv);
+			if (ret)
+				dev_err(&priv->client->dev, "Failed to parse als\n");
+			else
+				lm3532_als_configure(priv, led);
+		}
+
+		led->num_leds = fwnode_property_read_u32_array(child,
+							       "led-sources",
+							       NULL, 0);
+
+		if (led->num_leds > LM3532_MAX_LED_STRINGS) {
+			dev_err(&priv->client->dev, "To 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);
+
+		ret = fwnode_property_read_string(child, "label", &name);
+		if (ret)
+			snprintf(led->label, sizeof(led->label),
+				"%s::", priv->client->name);
+		else
+			snprintf(led->label, sizeof(led->label),
+				 "%s:%s", priv->client->name, name);
+
+		led->priv = priv;
+		led->led_dev.name = led->label;
+		led->led_dev.brightness_set_blocking = lm3532_brightness_set;
+
+		ret = devm_led_classdev_register(priv->dev, &led->led_dev);
+		if (ret) {
+			dev_err(&priv->client->dev, "led register err: %d\n",
+				ret);
+			fwnode_handle_put(child);
+			goto child_out;
+		}
+
+		lm3532_init_registers(led);
+
+		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;
+	}
+
+	if (drvdata->enable_gpio)
+		gpiod_direction_output(drvdata->enable_gpio, 1);
+
+	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 <dmurphy@ti.com>");