Re: [PATCH v3 2/2] backlight: lm3630a: add an enable gpio for the HWEN pin

From: Dan Murphy
Date: Thu Sep 12 2019 - 07:40:45 EST


Andreas

On 9/11/19 12:21 PM, Andreas Kemnade wrote:
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@xxxxxxxxxxxx>
---
changes in v2:
- simplification
- correct gpio direction initialisation

changes in v3:
- removed legacy include

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 8f84f3684f04..d9e67b9b2571 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;
};
@@ -535,6 +537,13 @@ 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) {

Thanks for the explanation

It looks good to me

Reviewed-by: Dan Murphy <dmurphy@xxxxxx>