[v5,3/4] media: ov2640: add primary dt support

Commit Message

Josh Wu Feb. 10, 2015, 9:31 a.m. UTC

Add device tree support for ov2640.
In device tree, user needs to provide the master clock (xvclk).
User can add the reset/pwdn pins if they have.

Cc: [e-mail]
Signed-off-by: Josh Wu <[e-mail]>
Acked-by: Laurent Pinchart <[e-mail]>
---

Changes in v5:
- change the 'mclk' to 'xvclk'. As v4l2-clk will handle the CCF xvclk
  and v4l2 master clock internally.

Changes in v4:
- modify the code comment.
- Add Laurent's acked by.

Changes in v3:
- fix gpiod usage.
- refine the ov2640_probe() function.

Changes in v2:
- use gpiod APIs.
- change the gpio pin's name according to datasheet.
- reduce the delay for .reset() function.

 drivers/media/i2c/soc_camera/ov2640.c | 90 ++++++++++++++++++++++++++++++++---
 1 file changed, 83 insertions(+), 7 deletions(-)

Comments

Lad, Prabhakar Feb. 16, 2015, 4:48 p.m. UTC | #1

Hi Josh,

Thanks for the patch.

On Tue, Feb 10, 2015 at 9:31 AM, Josh Wu <[e-mail]> wrote:
[Snip]
>
> -       priv->clk = v4l2_clk_get(&client->dev, "mclk");
> +       priv->clk = v4l2_clk_get(&client->dev, "xvclk");

with this change don’t you need to update the board file using this driver/
the bridge driver ?

Regards,
--Prabhakar Lad

Josh Wu Feb. 25, 2015, 3:54 a.m. UTC | #2

Hi, Prabhakar Lad

On 2/17/2015 12:48 AM, Lad, Prabhakar wrote:
> Hi Josh,
>
> Thanks for the patch.
>
> On Tue, Feb 10, 2015 at 9:31 AM, Josh Wu <[e-mail]> wrote:
> [Snip]
>> -       priv->clk = v4l2_clk_get(&client->dev, "mclk");
>> +       priv->clk = v4l2_clk_get(&client->dev, "xvclk");
> with this change don’t you need to update the board file using this driver/
> the bridge driver ?
I think no.

First, my patch should be on top of the following two patches, which 
changed the *v4l2_clk_get()* behavior:
[v3,1/2] V4L: remove clock name from v4l2_clk API
https://patchwork.linuxtv.org/patch/28108/
[v4,2/2] V4L: add CCF support to the v4l2_clk API
https://patchwork.linuxtv.org/patch/28111/

After applied above two patches, v4l2_clk_get() function is changed. The 
name "mclk" is refer to a CCF clock of the ov2640 device.
If not found such a "mclk" CCF clock, v4l2_clk_get() will try to get the 
internal register clock in soc_camera.c.
As the CCF dt clock is not support by ov2640 until I add DT support, 
that means current ov2640 driver will always not found the "mclk" CCF 
clock, and they will use internal clock.
So after I changed the name "mclk" to "xvclk", the default behavior will 
not change (still using internal clock registered by soc-camera.c).

Best Regards,
Josh Wu

>
> Regards,
> --Prabhakar Lad

Lad, Prabhakar Feb. 26, 2015, 12:36 a.m. UTC | #3

Hi Josh,

On Wed, Feb 25, 2015 at 3:54 AM, Josh Wu <[e-mail]> wrote:
> Hi, Prabhakar Lad
>
>
> On 2/17/2015 12:48 AM, Lad, Prabhakar wrote:
>>
>> Hi Josh,
>>
>> Thanks for the patch.
>>
>> On Tue, Feb 10, 2015 at 9:31 AM, Josh Wu <[e-mail]> wrote:
>> [Snip]
>>>
>>> -       priv->clk = v4l2_clk_get(&client->dev, "mclk");
>>> +       priv->clk = v4l2_clk_get(&client->dev, "xvclk");
>>
>> with this change don’t you need to update the board file using this
>> driver/
>> the bridge driver ?
>
> I think no.
>
> First, my patch should be on top of the following two patches, which changed
> the *v4l2_clk_get()* behavior:
> [v3,1/2] V4L: remove clock name from v4l2_clk API
> https://patchwork.linuxtv.org/patch/28108/
> [v4,2/2] V4L: add CCF support to the v4l2_clk API
> https://patchwork.linuxtv.org/patch/28111/
>
Thanks I missed the dependent patches.

Cheers,
--Prabhakar Lad

Patch

diff --git a/drivers/media/i2c/soc_camera/ov2640.c b/drivers/media/i2c/soc_camera/ov2640.c
index 057dd49..c70e9e7 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;
 };
 
 /*
@@ -1038,6 +1044,63 @@  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)
+		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 (priv->resetb_gpio) {
+		/* Active the resetb pin to perform a reset pulse */
+		gpiod_direction_output(priv->resetb_gpio, 1);
+		usleep_range(3000, 5000);
+		gpiod_direction_output(priv->resetb_gpio, 0);
+	}
+
+	return 0;
+}
+
+static int ov2640_probe_dt(struct i2c_client *client,
+		struct ov2640_priv *priv)
+{
+	/* Request the reset GPIO deasserted */
+	priv->resetb_gpio = devm_gpiod_get_optional(&client->dev, "resetb",
+			GPIOD_OUT_LOW);
+	if (!priv->resetb_gpio)
+		dev_dbg(&client->dev, "resetb gpio is not assigned!\n");
+	else if (IS_ERR(priv->resetb_gpio))
+		return PTR_ERR(priv->resetb_gpio);
+
+	/* Request the power down GPIO asserted */
+	priv->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "pwdn",
+			GPIOD_OUT_HIGH);
+	if (!priv->pwdn_gpio)
+		dev_dbg(&client->dev, "pwdn gpio is not assigned!\n");
+	else if (IS_ERR(priv->pwdn_gpio))
+		return PTR_ERR(priv->pwdn_gpio);
+
+	/* 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
  */
@@ -1049,12 +1112,6 @@  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");
@@ -1068,10 +1125,22 @@  static int ov2640_probe(struct i2c_client *client,
 		return -ENOMEM;
 	}
 
-	priv->clk = v4l2_clk_get(&client->dev, "mclk");
+	priv->clk = v4l2_clk_get(&client->dev, "xvclk");
 	if (IS_ERR(priv->clk))
 		return -EPROBE_DEFER;
 
+	if (!ssdd && !client->dev.of_node) {
+		dev_err(&client->dev, "Missing platform_data for driver\n");
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	if (!ssdd) {
+		ret = ov2640_probe_dt(client, priv);
+		if (ret)
+			goto err_clk;
+	}
+
 	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,
@@ -1121,9 +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,