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 <m...@pengutronix.de>
Reviewed-by: Philipp Zabel <p.za...@pengutronix.de>
Acked-by: Rob Herring <r...@kernel.org>
---
.../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 a68ce94ee097..c1bc564a0979 100644
--- 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;
--
2.6.2
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