leds: is31fl319x: Add shutdown pin and generate a 5ms low pulse when startup

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@163.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

diff --git a/drivers/leds/leds-is31fl319x.c b/drivers/leds/leds-is31fl319x.c
index ca6634b8683cb65c2bec3922f104e5d3bb0f0bfe..54ac50740d43d6b303cbfed04c96db147bb07a45 100644 (file)
--- 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)) {