[PATCH v2 1/2] leds: is31fl32xx: Add sdb pin and generate a 5ms low pulse when startup

[Grant Feng]

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

Signed-off-by: Grant Feng <vo...@163.com>
---
 drivers/leds/leds-is31fl32xx.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c
index cd768f991da1..07b543120e06 100644
--- a/drivers/leds/leds-is31fl32xx.c
+++ b/drivers/leds/leds-is31fl32xx.c
@@ -16,6 +16,8 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 
 /* Used to indicate a device has no such register */
 #define IS31FL32XX_REG_NONE 0xFF
@@ -43,6 +45,7 @@ struct is31fl32xx_led_data {
 struct is31fl32xx_priv {
        const struct is31fl32xx_chipdef *cdef;
        struct i2c_client *client;
+       struct gpio_desc *sdb_gpio;
        unsigned int num_leds;
        struct is31fl32xx_led_data leds[];
 };
@@ -282,11 +285,17 @@ static int is31fl32xx_software_shutdown(struct 
is31fl32xx_priv *priv,
        return 0;
 }
 
-static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
+static int is31fl32xx_init(struct is31fl32xx_priv *priv)
 {
        const struct is31fl32xx_chipdef *cdef = priv->cdef;
        int ret;
 
+       if (priv->sdb_gpio) {
+               gpiod_direction_output(priv->sdb_gpio, 0);
+               mdelay(5);
+               gpiod_direction_output(priv->sdb_gpio, 1);
+       }
+
        ret = is31fl32xx_reset_regs(priv);
        if (ret)
                return ret;
@@ -372,6 +381,15 @@ static int is31fl32xx_parse_dt(struct device *dev,
        struct device_node *child;
        int ret = 0;
 
+       priv->sdb_gpio = devm_gpiod_get_optional(dev,
+                                               "sdb",
+                                               GPIOD_OUT_HIGH);
+       if (IS_ERR(priv->sdb_gpio)) {
+               ret = PTR_ERR(priv->sdb_gpio);
+               dev_err(dev, "Failed to get sdb gpio: %d\n", ret);
+               return ret;
+       }
+
        for_each_child_of_node(dev->of_node, child) {
                struct is31fl32xx_led_data *led_data =
                        &priv->leds[priv->num_leds];
@@ -453,11 +471,11 @@ static int is31fl32xx_probe(struct i2c_client *client,
        priv->cdef = cdef;
        i2c_set_clientdata(client, priv);
 
-       ret = is31fl32xx_init_regs(priv);
+       ret = is31fl32xx_parse_dt(dev, priv);
        if (ret)
                return ret;
 
-       ret = is31fl32xx_parse_dt(dev, priv);
+       ret = is31fl32xx_init(priv);
        if (ret)
                return ret;
 
-- 
2.17.1