From 28d5bdbe5c0adcc11b7b63e65cf002a1ebaf3ca4 Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Mon, 14 Dec 2015 12:41:51 -0200 Subject: [PATCH] [media] mt9v032: Add reset and standby gpios Add optional reset and standby gpios. The reset gpio is used to reset the chip in power_on(). The standby gpio is not used currently. It is just unset, so the chip is not in standby. Signed-off-by: Markus Pargmann Reviewed-by: Philipp Zabel Acked-by: Rob Herring Acked-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- .../devicetree/bindings/media/i2c/mt9v032.txt | 2 ++ drivers/media/i2c/mt9v032.c | 28 +++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/Documentation/devicetree/bindings/media/i2c/mt9v032.txt b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt index 202565313e82..100f0ae43269 100644 --- a/Documentation/devicetree/bindings/media/i2c/mt9v032.txt +++ b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt @@ -20,6 +20,8 @@ Optional Properties: - link-frequencies: List of allowed link frequencies in Hz. Each frequency is expressed as a 64-bit big-endian integer. +- reset-gpios: GPIO handle which is connected to the reset pin of the chip. +- standby-gpios: GPIO handle which is connected to the standby pin of the chip. For further reading on port node refer to Documentation/devicetree/bindings/media/video-interfaces.txt. diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c index 2e1d116a64e7..501b37039449 100644 --- a/drivers/media/i2c/mt9v032.c +++ b/drivers/media/i2c/mt9v032.c @@ -14,6 +14,7 @@ #include #include +#include #include #include #include @@ -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; -- 2.39.5