Merge tag 'drm/panel/for-4.6-rc1' of http://anongit.freedesktop.org/git/tegra/linux...

[cascardo/linux.git] / drivers / media / i2c / mt9v032.c

diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
index 2e1d116..501b370 100644 (file)
--- a/drivers/media/i2c/mt9v032.c
+++ b/drivers/media/i2c/mt9v032.c
@@ -14,6 +14,7 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/log2.h>
 #include <linux/mutex.h>
@@ -251,6 +252,8 @@ struct mt9v032 {
 
        struct regmap *regmap;
        struct clk *clk;
+       struct gpio_desc *reset_gpio;
+       struct gpio_desc *standby_gpio;
 
        struct mt9v032_platform_data *pdata;
        const struct mt9v032_model_info *model;
@@ -312,16 +315,31 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
        struct regmap *map = mt9v032->regmap;
        int ret;
 
+       if (mt9v032->reset_gpio)
+               gpiod_set_value_cansleep(mt9v032->reset_gpio, 1);
+
        ret = clk_set_rate(mt9v032->clk, mt9v032->sysclk);
        if (ret < 0)
                return ret;
 
+       /* System clock has to be enabled before releasing the reset */
        ret = clk_prepare_enable(mt9v032->clk);
        if (ret)
                return ret;
 
        udelay(1);
 
+       if (mt9v032->reset_gpio) {
+               gpiod_set_value_cansleep(mt9v032->reset_gpio, 0);
+
+               /* After releasing reset we need to wait 10 clock cycles
+                * before accessing the sensor over I2C. As the minimum SYSCLK
+                * frequency is 13MHz, waiting 1µs will be enough in the worst
+                * case.
+                */
+               udelay(1);
+       }
+
        /* Reset the chip and stop data read out */
        ret = regmap_write(map, MT9V032_RESET, 1);
        if (ret < 0)
@@ -954,6 +972,16 @@ static int mt9v032_probe(struct i2c_client *client,
        if (IS_ERR(mt9v032->clk))
                return PTR_ERR(mt9v032->clk);
 
+       mt9v032->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+                                                     GPIOD_OUT_HIGH);
+       if (IS_ERR(mt9v032->reset_gpio))
+               return PTR_ERR(mt9v032->reset_gpio);
+
+       mt9v032->standby_gpio = devm_gpiod_get_optional(&client->dev, "standby",
+                                                       GPIOD_OUT_LOW);
+       if (IS_ERR(mt9v032->standby_gpio))
+               return PTR_ERR(mt9v032->standby_gpio);
+
        mutex_init(&mt9v032->power_lock);
        mt9v032->pdata = pdata;
        mt9v032->model = (const void *)did->driver_data;