[Patch v2 5/7] media: i2c: ov2659: Add powerdown/reset gpio handling

From: Benoit Parrot
Date: Thu Sep 19 2019 - 16:38:28 EST


On some board it is possible that the sensor 'powerdown' and or 'reset'
pin might be controlled by gpio instead of being tied.

To implement we add pm_runtime support which will handle the power
up/down sequence.

Now originally the driver assumed tat the sensor would always stay
powered and there keep its register setting. We cannot assume that this
anymore, so every time we "power up" we need to re-program the initial
registers configuration first. This was previously done only at probe
time.

Signed-off-by: Benoit Parrot <bparrot@xxxxxx>
---
drivers/media/i2c/Kconfig | 2 +-
drivers/media/i2c/ov2659.c | 88 +++++++++++++++++++++++++++++++++++++-
2 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 7eee1812bba3..315c1d8bdb7b 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -634,7 +634,7 @@ config VIDEO_OV2640
config VIDEO_OV2659
tristate "OmniVision OV2659 sensor support"
depends on VIDEO_V4L2 && I2C
- depends on MEDIA_CAMERA_SUPPORT
+ depends on MEDIA_CAMERA_SUPPORT && GPIOLIB
select V4L2_FWNODE
help
This is a Video4Linux2 sensor driver for the OmniVision
diff --git a/drivers/media/i2c/ov2659.c b/drivers/media/i2c/ov2659.c
index f77320e8a60d..170f80a1a51f 100644
--- a/drivers/media/i2c/ov2659.c
+++ b/drivers/media/i2c/ov2659.c
@@ -22,9 +22,11 @@

#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of_graph.h>
+#include <linux/pm_runtime.h>

#include <media/i2c/ov2659.h>
#include <media/v4l2-ctrls.h>
@@ -218,6 +220,11 @@ struct ov2659 {
struct sensor_register *format_ctrl_regs;
struct ov2659_pll_ctrl pll;
int streaming;
+ /* used to control the sensor PWDN pin */
+ struct gpio_desc *pwdn_gpio;
+ /* used to control the sensor RESETB pin */
+ struct gpio_desc *resetb_gpio;
+ int on;
};

static const struct sensor_register ov2659_init_regs[] = {
@@ -1184,9 +1191,17 @@ static int ov2659_s_stream(struct v4l2_subdev *sd, int on)
/* Stop Streaming Sequence */
ov2659_set_streaming(ov2659, 0);
ov2659->streaming = on;
+ pm_runtime_put(&client->dev);
goto unlock;
}

+ ret = pm_runtime_get_sync(&client->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(&client->dev);
+ goto unlock;
+ }
+
+ ov2659_init(sd, 0);
ov2659_set_pixel_clock(ov2659);
ov2659_set_frame_size(ov2659);
ov2659_set_format(ov2659);
@@ -1243,6 +1258,32 @@ static const char * const ov2659_test_pattern_menu[] = {
"Vertical Color Bars",
};

+static int ov2659_set_power(struct ov2659 *ov2659, int on)
+{
+ struct i2c_client *client = ov2659->client;
+
+ dev_dbg(&client->dev, "%s: on: %d\n", __func__, on);
+
+ if (on) {
+ if (ov2659->pwdn_gpio)
+ gpiod_direction_output(ov2659->pwdn_gpio, 0);
+
+ if (ov2659->resetb_gpio) {
+ gpiod_set_value(ov2659->resetb_gpio, 1);
+ usleep_range(500, 1000);
+ gpiod_set_value(ov2659->resetb_gpio, 0);
+ usleep_range(3000, 5000);
+ }
+ } else {
+ if (ov2659->pwdn_gpio)
+ gpiod_direction_output(ov2659->pwdn_gpio, 1);
+ }
+
+ ov2659->on = on;
+
+ return 0;
+}
+
/* -----------------------------------------------------------------------------
* V4L2 subdev internal operations
*/
@@ -1323,7 +1364,6 @@ static int ov2659_detect(struct v4l2_subdev *sd)
ret = -ENODEV;
} else {
dev_info(&client->dev, "Found OV%04X sensor\n", id);
- ret = ov2659_init(sd, 0);
}
}

@@ -1400,6 +1440,18 @@ static int ov2659_probe(struct i2c_client *client)
ov2659->xvclk_frequency > 27000000)
return -EINVAL;

+ /* Optional gpio don't fail if not present */
+ ov2659->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(ov2659->pwdn_gpio))
+ return PTR_ERR(ov2659->pwdn_gpio);
+
+ /* Optional gpio don't fail if not present */
+ ov2659->resetb_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(ov2659->resetb_gpio))
+ return PTR_ERR(ov2659->resetb_gpio);
+
v4l2_ctrl_handler_init(&ov2659->ctrls, 2);
ov2659->link_frequency =
v4l2_ctrl_new_std(&ov2659->ctrls, &ov2659_ctrl_ops,
@@ -1445,6 +1497,9 @@ static int ov2659_probe(struct i2c_client *client)
ov2659->frame_size = &ov2659_framesizes[2];
ov2659->format_ctrl_regs = ov2659_formats[0].format_ctrl_regs;

+ pm_runtime_enable(&client->dev);
+ pm_runtime_get_sync(&client->dev);
+
ret = ov2659_detect(sd);
if (ret < 0)
goto error;
@@ -1458,10 +1513,14 @@ static int ov2659_probe(struct i2c_client *client)

dev_info(&client->dev, "%s sensor driver registered !!\n", sd->name);

+ pm_runtime_put(&client->dev);
+
return 0;

error:
v4l2_ctrl_handler_free(&ov2659->ctrls);
+ pm_runtime_put(&client->dev);
+ pm_runtime_disable(&client->dev);
media_entity_cleanup(&sd->entity);
mutex_destroy(&ov2659->lock);
return ret;
@@ -1477,9 +1536,35 @@ static int ov2659_remove(struct i2c_client *client)
media_entity_cleanup(&sd->entity);
mutex_destroy(&ov2659->lock);

+ pm_runtime_disable(&client->dev);
+
return 0;
}

+static int ov2659_runtime_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct v4l2_subdev *sd = i2c_get_clientdata(client);
+ struct ov2659 *ov2659 = to_ov2659(sd);
+
+ ov2659_set_power(ov2659, 0);
+
+ return 0;
+}
+
+static int ov2659_runtime_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct v4l2_subdev *sd = i2c_get_clientdata(client);
+ struct ov2659 *ov2659 = to_ov2659(sd);
+
+ return ov2659_set_power(ov2659, 1);
+}
+
+static const struct dev_pm_ops ov2659_pm_ops = {
+ SET_RUNTIME_PM_OPS(ov2659_runtime_suspend, ov2659_runtime_resume, NULL)
+};
+
static const struct i2c_device_id ov2659_id[] = {
{ "ov2659", 0 },
{ /* sentinel */ },
@@ -1497,6 +1582,7 @@ MODULE_DEVICE_TABLE(of, ov2659_of_match);
static struct i2c_driver ov2659_i2c_driver = {
.driver = {
.name = DRIVER_NAME,
+ .pm = &ov2659_pm_ops,
.of_match_table = of_match_ptr(ov2659_of_match),
},
.probe_new = ov2659_probe,
--
2.17.1