leds: qpnp-flash-v2: Add operational current property

Add the qcom,current-ma property to specify the operational
current for the flash led. Also limit the minimum flash current
to 25mA since currents below this value cause unstable flash
operation.

CRs-Fixed: 1033071
Change-Id: Ia133b6c0cf0c21484f61631f04cba0d1112c9d48
Signed-off-by: Devesh Jhunjhunwala <deveshj@codeaurora.org>

3 files changed, 58 insertions, 18 deletions

diff --git a/Documentation/devicetree/bindings/leds/leds-qpnp-flash-v2.txt b/Documentation/devicetree/bindings/leds/leds-qpnp-flash-v2.txt
index ce2cec5582f3..f1a8c77c8387 100644
--- a/Documentation/devicetree/bindings/leds/leds-qpnp-flash-v2.txt
+++ b/Documentation/devicetree/bindings/leds/leds-qpnp-flash-v2.txt
@@ -36,6 +36,8 @@ serve as an overall switch.
 			  10ms resolution. This is not required for switch node.
 
 Optional properties inside child node:
+- qcom,current-ma	: operational current intensity for LED in mA. Accepted values are a
+			  positive integer in the range of 0 to qcom,max-current inclusive.
 - qcom,ires-ua		: Integer type to specify current resolution. Accepted values should be
 			  12500, 10000, 7500, and 5000. Unit is uA.
 - qcom,hdrm-voltage-mv	: Integer type specifying headroom voltage. Values are from 125mV to 500mV
@@ -69,6 +71,7 @@ Example:
 			qcom,default-led-trigger =
 						"flash0_trigger";
 			qcom,id = <0>;
+			qcom,current-ma = <1000>;
 			qcom,duration-ms = <1280>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
@@ -82,6 +85,7 @@ Example:
 			qcom,default-led-trigger =
 						"flash1_trigger";
 			qcom,id = <1>;
+			qcom,current-ma = <1000>;
 			qcom,duration-ms = <1280>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
@@ -95,6 +99,7 @@ Example:
 			qcom,default-led-trigger =
 						"flash2_trigger";
 			qcom,id = <2>;
+			qcom,current-ma = <500>;
 			qcom,duration-ms = <1280>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
@@ -111,6 +116,7 @@ Example:
 			qcom,default-led-trigger =
 						"torch0_trigger";
 			qcom,id = <0>;
+			qcom,current-ma = <300>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
 			qcom,hdrm-vol-hi-lo-win-mv = <100>;
@@ -123,6 +129,7 @@ Example:
 			qcom,default-led-trigger =
 						"torch1_trigger";
 			qcom,id = <1>;
+			qcom,current-ma = <300>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
 			qcom,hdrm-vol-hi-lo-win-mv = <100>;
@@ -135,6 +142,7 @@ Example:
 			qcom,default-led-trigger =
 						"torch2_trigger";
 			qcom,id = <2>;
+			qcom,current-ma = <300>;
 			qcom,ires-ua = <12500>;
 			qcom,hdrm-voltage-mv = <325>;
 			qcom,hdrm-vol-hi-lo-win-mv = <100>;
diff --git a/drivers/leds/leds-qpnp-flash-v2.c b/drivers/leds/leds-qpnp-flash-v2.c
index 89636557dec1..6f7ba0461800 100644
--- a/drivers/leds/leds-qpnp-flash-v2.c
+++ b/drivers/leds/leds-qpnp-flash-v2.c
@@ -38,8 +38,6 @@
 #define	FLASH_LED_MOD_CTRL_MASK			0x80
 #define	FLASH_LED_ISC_DELAY_MASK		0x03
 
-#define	FLASH_LED_TYPE_FLASH			0
-#define	FLASH_LED_TYPE_TORCH			1
 #define	FLASH_LED_HEADROOM_AUTO_MODE_ENABLED	true
 #define	FLASH_LED_ISC_DELAY_SHIFT		6
 #define	FLASH_LED_ISC_DELAY_DEFAULT_US		3
@@ -60,6 +58,12 @@
 #define	FLASH_LED_MOD_ENABLE			0x80
 #define	FLASH_LED_DISABLE			0x00
 #define	FLASH_LED_SAFETY_TMR_DISABLED		0x13
+#define	FLASH_LED_MIN_CURRENT_MA		25
+
+enum flash_led_type {
+	FLASH_LED_TYPE_FLASH,
+	FLASH_LED_TYPE_TORCH,
+};
 
 /*
  * Flash LED configuration read from device tree
@@ -141,13 +145,17 @@ static int qpnp_flash_led_init_settings(struct qpnp_flash_led *led)
 
 static void qpnp_flash_led_node_set(struct flash_node_data *fnode, int value)
 {
-	int prgm_current_ma;
+	int prgm_current_ma = value;
 
-	prgm_current_ma = value < 0 ? 0 : value;
-	prgm_current_ma = value > fnode->cdev.max_brightness ?
-					fnode->cdev.max_brightness : value;
+	if (value <= 0)
+		prgm_current_ma = 0;
+	else if (value < FLASH_LED_MIN_CURRENT_MA)
+		prgm_current_ma = FLASH_LED_MIN_CURRENT_MA;
+
+	prgm_current_ma = min(prgm_current_ma, fnode->max_current);
+	fnode->current_ma = prgm_current_ma;
 	fnode->cdev.brightness = prgm_current_ma;
-	fnode->brightness = prgm_current_ma * 1000 / fnode->ires_ua + 1;
+	fnode->current_reg_val = prgm_current_ma * 1000 / fnode->ires_ua + 1;
 	fnode->led_on = prgm_current_ma != 0;
 }
 
@@ -182,7 +190,7 @@ static int qpnp_flash_led_switch_set(struct flash_switch_data *snode, bool on)
 
 		rc = qpnp_flash_led_masked_write(led,
 			FLASH_LED_REG_TGR_CURRENT(led->base + addr_offset),
-			FLASH_LED_CURRENT_MASK, led->fnode[i].brightness);
+			FLASH_LED_CURRENT_MASK, led->fnode[i].current_reg_val);
 		if (rc)
 			return rc;
 
@@ -240,6 +248,7 @@ leds_turn_off:
 			FLASH_LED_CURRENT_MASK, 0);
 		if (rc)
 			return rc;
+
 		led->fnode[i].led_on = false;
 
 		if (led->fnode[i].pinctrl) {
@@ -305,14 +314,6 @@ static int qpnp_flash_led_parse_each_led_dt(struct qpnp_flash_led *led,
 		return rc;
 	}
 
-	rc = of_property_read_u32(node, "qcom,max-current", &val);
-	if (!rc) {
-		fnode->cdev.max_brightness = val;
-	} else {
-		dev_err(&led->pdev->dev, "Unable to read max current\n");
-		return rc;
-	}
-
 	rc = of_property_read_string(node, "label", &temp_string);
 	if (!rc) {
 		if (!strcmp(temp_string, "flash"))
@@ -355,6 +356,36 @@ static int qpnp_flash_led_parse_each_led_dt(struct qpnp_flash_led *led,
 		return rc;
 	}
 
+	rc = of_property_read_u32(node, "qcom,max-current", &val);
+	if (!rc) {
+		if (val < FLASH_LED_MIN_CURRENT_MA)
+			val = FLASH_LED_MIN_CURRENT_MA;
+		fnode->max_current = val;
+		fnode->cdev.max_brightness = val;
+	} else {
+		dev_err(&led->pdev->dev,
+				"Unable to read max current, rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = of_property_read_u32(node, "qcom,current-ma", &val);
+	if (!rc) {
+		if (val < FLASH_LED_MIN_CURRENT_MA ||
+				val > fnode->max_current)
+			dev_warn(&led->pdev->dev,
+				 "Invalid operational current specified, capping it\n");
+		if (val < FLASH_LED_MIN_CURRENT_MA)
+			val = FLASH_LED_MIN_CURRENT_MA;
+		if (val > fnode->max_current)
+			val = fnode->max_current;
+		fnode->current_ma = val;
+		fnode->cdev.brightness = val;
+	} else if (rc != -EINVAL) {
+		dev_err(&led->pdev->dev,
+			"Unable to read operational current, rc=%d\n", rc);
+		return rc;
+	}
+
 	fnode->duration = FLASH_LED_SAFETY_TMR_DISABLED;
 	rc = of_property_read_u32(node, "qcom,duration-ms", &val);
 	if (!rc) {
diff --git a/include/linux/leds-qpnp-flash-v2.h b/include/linux/leds-qpnp-flash-v2.h
index 353466f6c108..ae36a163ed21 100644
--- a/include/linux/leds-qpnp-flash-v2.h
+++ b/include/linux/leds-qpnp-flash-v2.h
@@ -26,13 +26,14 @@ struct flash_node_data {
 	struct pinctrl_state		*gpio_state_active;
 	struct pinctrl_state		*gpio_state_suspend;
 	int				ires_ua;
-	u16				prgm_current;
+	int				max_current;
+	int				current_ma;
 	u8				duration;
 	u8				id;
 	u8				type;
 	u8				ires;
 	u8				hdrm_val;
-	u8				brightness;
+	u8				current_reg_val;
 	bool				led_on;
 };