Hi, Laurent
On 12/9/2014 2:39 AM, Laurent Pinchart wrote:
Hi Josh,
Thank you for the patch.
On Monday 08 December 2014 19:29:05 Josh Wu wrote:
Add device tree support for ov2640.
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
---
v1 -> v2:
1. use gpiod APIs.
2. change the gpio pin's name according to datasheet.
3. reduce the delay for .reset() function.
drivers/media/i2c/soc_camera/ov2640.c | 86 +++++++++++++++++++++++++++++---
1 file changed, 80 insertions(+), 6 deletions(-)
diff --git a/drivers/media/i2c/soc_camera/ov2640.c
b/drivers/media/i2c/soc_camera/ov2640.c index 9ee910d..2a57979 100644
--- a/drivers/media/i2c/soc_camera/ov2640.c
+++ b/drivers/media/i2c/soc_camera/ov2640.c
@@ -18,6 +18,8 @@
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/v4l2-mediabus.h>
#include <linux/videodev2.h>
@@ -283,6 +285,10 @@ struct ov2640_priv {
u32 cfmt_code;
struct v4l2_clk *clk;
const struct ov2640_win_size *win;
+
+ struct soc_camera_subdev_desc ssdd_dt;
+ struct gpio_desc *resetb_gpio;
+ struct gpio_desc *pwdn_gpio;
};
/*
@@ -1047,6 +1053,61 @@ static struct v4l2_subdev_ops ov2640_subdev_ops = {
.video = &ov2640_subdev_video_ops,
};
+/* OF probe functions */
+static int ov2640_hw_power(struct device *dev, int on)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ov2640_priv *priv = to_ov2640(client);
+
+ dev_dbg(&client->dev, "%s: %s the camera\n",
+ __func__, on ? "ENABLE" : "DISABLE");
+
+ if (priv->pwdn_gpio && !IS_ERR(priv->pwdn_gpio))
No need to test for IS_ERR, as the probe function would have failed in that
case.
right. I'll change it.
+ gpiod_direction_output(priv->pwdn_gpio, !on);
+
+ return 0;
+}
+
+static int ov2640_hw_reset(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ov2640_priv *priv = to_ov2640(client);
+
+ /* If enabled, give a reset impulse */
+ if (priv->resetb_gpio && !IS_ERR(priv->resetb_gpio)) {
Same here.
ditto.
+ gpiod_direction_output(priv->resetb_gpio, 0);
Given that your DT should specify the active low GPIO flag, and that the gpiod
API inverts the value in that case, you should set the value to 1 here.
Thanks for the information. I'll fix it.
+ usleep_range(3000, 5000);
+ gpiod_direction_output(priv->resetb_gpio, 1);
And to 0 here.
yes.
+ }
+
+ return 0;
+}
+
+static int ov2640_probe_dt(struct i2c_client *client,
+ struct ov2640_priv *priv)
+{
+ priv->resetb_gpio = devm_gpiod_get_optional(&client->dev, "resetb",
+ GPIOD_OUT_HIGH);
+ if (!priv->resetb_gpio)
+ dev_warn(&client->dev, "resetb gpio not found!\n");
No need to warn here, it's perfectly fine if the reset signal isn't connected
to a GPIO.
I want to print some information if no GPIO is assigned. So I'd like use
dev_dbg() here.
What do you feel?
+ else if (IS_ERR(priv->resetb_gpio))
+ return -EINVAL;
+
+ priv->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "pwdn",
+ GPIOD_OUT_HIGH);
+ if (!priv->pwdn_gpio)
+ dev_warn(&client->dev, "pwdn gpio not found!\n");
Same here.
ditto.
+ else if (IS_ERR(priv->pwdn_gpio))
+ return -EINVAL;
+
+ /* Initialize the soc_camera_subdev_desc */
+ priv->ssdd_dt.power = ov2640_hw_power;
+ priv->ssdd_dt.reset = ov2640_hw_reset;
+ client->dev.platform_data = &priv->ssdd_dt;
+
+ return 0;
+}
+
/*
* i2c_driver functions
*/
@@ -1058,12 +1119,6 @@ static int ov2640_probe(struct i2c_client *client,
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
int ret;
- if (!ssdd) {
- dev_err(&adapter->dev,
- "OV2640: Missing platform_data for driver\n");
- return -EINVAL;
- }
-
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
dev_err(&adapter->dev,
"OV2640: I2C-Adapter doesn't support SMBUS\n");
@@ -1077,6 +1132,18 @@ static int ov2640_probe(struct i2c_client *client,
return -ENOMEM;
}
+ if (!ssdd) {
+ if (client->dev.of_node) {
+ ret = ov2640_probe_dt(client, priv);
+ if (ret)
+ return ret;
+ } else {
+ dev_err(&client->dev,
+ "Missing platform_data for driver\n");
+ return -EINVAL;
+ }
I would test for !client->dev.of_node and return the error, you could then get
rid of the else and lower the indentation level for the call to
ov2640_probe_dt().
Okay. I'll change it in next version.
Best Regards,
Josh Wu
+ }
+
v4l2_i2c_subdev_init(&priv->subdev, client, &ov2640_subdev_ops);
v4l2_ctrl_handler_init(&priv->hdl, 2);
v4l2_ctrl_new_std(&priv->hdl, &ov2640_ctrl_ops,
@@ -1123,9 +1190,16 @@ static const struct i2c_device_id ov2640_id[] = {
};
MODULE_DEVICE_TABLE(i2c, ov2640_id);
+static const struct of_device_id ov2640_of_match[] = {
+ {.compatible = "ovti,ov2640", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ov2640_of_match);
+
static struct i2c_driver ov2640_i2c_driver = {
.driver = {
.name = "ov2640",
+ .of_match_table = of_match_ptr(ov2640_of_match),
},
.probe = ov2640_probe,
.remove = ov2640_remove,
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