From 0e0e78e32e723a1ee48207a2ad091afb30f6f1c5 Mon Sep 17 00:00:00 2001
From: Andreas Kemnade <andreas@kemnade.info>
Date: Thu, 12 Sep 2019 23:32:57 +0200
Subject: backlight: lm3630a: Add an enable gpio for the HWEN pin
Git-commit: 0e0e78e32e723a1ee48207a2ad091afb30f6f1c5
Patch-mainline: v5.5-rc1
References: bsc#1152489

For now just enable it in the probe function to allow I2C
access. Disabling also means resetting the register values
to default and according to the datasheet does not give
power savings.

Tested on Kobo Clara HD.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/backlight/lm3630a_bl.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index 3614a4edbcd1..ee320883b710 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -12,6 +12,7 @@
 #include <linux/uaccess.h>
 #include <linux/interrupt.h>
 #include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
 #include <linux/pwm.h>
 #include <linux/platform_data/lm3630a_bl.h>
 
@@ -48,6 +49,7 @@ struct lm3630a_chip {
 	struct lm3630a_platform_data *pdata;
 	struct backlight_device *bleda;
 	struct backlight_device *bledb;
+	struct gpio_desc *enable_gpio;
 	struct regmap *regmap;
 	struct pwm_device *pwmd;
 };
@@ -534,6 +536,13 @@ static int lm3630a_probe(struct i2c_client *client,
 	}
 	pchip->pdata = pdata;
 
+	pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
+						GPIOD_OUT_HIGH);
+	if (IS_ERR(pchip->enable_gpio)) {
+		rval = PTR_ERR(pchip->enable_gpio);
+		return rval;
+	}
+
 	/* chip initialize */
 	rval = lm3630a_chip_init(pchip);
 	if (rval < 0) {
-- 
2.28.0