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Subject[PATCH v3 1/2] leds: is31fl32xx: Add shutdown pin and generate a 5ms low pulse when startup
Date
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>
---
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..946ad2f71e00 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 *shutdown_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->shutdown_gpio) {
+ gpiod_direction_output(priv->shutdown_gpio, 0);
+ mdelay(5);
+ gpiod_direction_output(priv->shutdown_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->shutdown_gpio = devm_gpiod_get_optional(dev,
+ "shutdown",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->shutdown_gpio)) {
+ ret = PTR_ERR(priv->shutdown_gpio);
+ dev_err(dev, "Failed to get shutdown 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

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