[PATCH v3 1/2] leds: is31fl319x: Add shutdown pin and generate a 5ms low pulse when startup

From: Grant Feng
Date: Tue Aug 25 2020 - 04:23:20 EST


generate a 5ms low pulse on shutdown pin when startup, then the chip
becomes more stable in the complex EM environment.

Signed-off-by: Grant Feng <von81@xxxxxxx>
---
drivers/leds/leds-is31fl319x.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/leds/leds-is31fl319x.c b/drivers/leds/leds-is31fl319x.c
index ca6634b8683c..54ac50740d43 100644
--- a/drivers/leds/leds-is31fl319x.c
+++ b/drivers/leds/leds-is31fl319x.c
@@ -16,6 +16,8 @@
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>

/* register numbers */
#define IS31FL319X_SHUTDOWN 0x00
@@ -61,6 +63,7 @@
struct is31fl319x_chip {
const struct is31fl319x_chipdef *cdef;
struct i2c_client *client;
+ struct gpio_desc *shutdown_gpio;
struct regmap *regmap;
struct mutex lock;
u32 audio_gain_db;
@@ -207,6 +210,15 @@ static int is31fl319x_parse_dt(struct device *dev,
if (!np)
return -ENODEV;

+ is31->shutdown_gpio = devm_gpiod_get_optional(dev,
+ "shutdown",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(is31->shutdown_gpio)) {
+ ret = PTR_ERR(is31->shutdown_gpio);
+ dev_err(dev, "Failed to get shutdown gpio: %d\n", ret);
+ return ret;
+ }
+
of_dev_id = of_match_device(of_is31fl319x_match, dev);
if (!of_dev_id) {
dev_err(dev, "Failed to match device with supported chips\n");
@@ -350,6 +362,12 @@ static int is31fl319x_probe(struct i2c_client *client,
if (err)
goto free_mutex;

+ if (is31->shutdown_gpio) {
+ gpiod_direction_output(is31->shutdown_gpio, 0);
+ mdelay(5);
+ gpiod_direction_output(is31->shutdown_gpio, 1);
+ }
+
is31->client = client;
is31->regmap = devm_regmap_init_i2c(client, &regmap_config);
if (IS_ERR(is31->regmap)) {
--
2.17.1