leds: lm3532: Add full scale current configuration

Allow the full scale current to be configured at init.
Valid rangles are 5mA->29.8mA.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

drivers/leds/leds-lm3532.c

@@ -89,6 +89,10 @@
 #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
@@ -121,6 +125,7 @@ struct lm3532_als_data {
  * @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
  * @label - LED label
  */
@@ -132,6 +137,7 @@ struct lm3532_led {
 	int mode;
 	int ctrl_brt_pointer;
 	int num_leds;
+	int full_scale_current;
 	u32 led_strings[LM3532_MAX_CONTROL_BANKS];
 	char label[LED_MAX_NAME_SIZE];
 };
@@ -363,6 +369,8 @@ static int lm3532_init_registers(struct lm3532_led *led)
 	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)
@@ -385,6 +393,17 @@ static int lm3532_init_registers(struct lm3532_led *led)
 	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);
@@ -560,6 +579,12 @@ static int lm3532_parse_node(struct lm3532_data *priv)
 			goto child_out;
 		}
 
+		ret = fwnode_property_read_u32(child, "led-max-microamp",
+					       &led->full_scale_current);
+
+		if (led->full_scale_current > LM3532_FS_CURR_MAX)
+			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);