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Commit 28d5bdbe authored by Markus Pargmann's avatar Markus Pargmann Committed by Mauro Carvalho Chehab
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[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: default avatarMarkus Pargmann <mpa@pengutronix.de>
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent c1ae8f3a

Documentation/devicetree/bindings/media/i2c/mt9v032.txt

+2 −0
Original line number Diff line number Diff line
@@ -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.

drivers/media/i2c/mt9v032.c

+28 −0
Original line number Diff line number Diff line
@@ -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;