On 01/31/2017 11:20 AM, Sakari Ailus wrote:
> Hi Hans,
>
> Thank you for the patchset!
>
> On Mon, Jan 30, 2017 at 03:06:22PM +0100, Hans Verkuil wrote:
>> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>>
>> Convert v4l2_clk to normal clk, enable the clock and fix the power/reset
>> handling.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> ---
>> drivers/media/i2c/ov2640.c | 80 +++++++++++++++++-----------------------------
>> 1 file changed, 29 insertions(+), 51 deletions(-)
>>
>> diff --git a/drivers/media/i2c/ov2640.c b/drivers/media/i2c/ov2640.c
>> index 83f88ef..565742b 100644
>> --- a/drivers/media/i2c/ov2640.c
>> +++ b/drivers/media/i2c/ov2640.c
>> @@ -16,15 +16,14 @@
>> #include <linux/init.h>
>> #include <linux/module.h>
>> #include <linux/i2c.h>
>> +#include <linux/clk.h>
>> #include <linux/slab.h>
>> #include <linux/delay.h>
>> #include <linux/gpio.h>
>> #include <linux/gpio/consumer.h>
>> -#include <linux/of_gpio.h>
>> #include <linux/v4l2-mediabus.h>
>> #include <linux/videodev2.h>
>>
>> -#include <media/v4l2-clk.h>
>> #include <media/v4l2-device.h>
>> #include <media/v4l2-subdev.h>
>> #include <media/v4l2-ctrls.h>
>> @@ -284,7 +283,7 @@ struct ov2640_priv {
>> struct v4l2_subdev subdev;
>> struct v4l2_ctrl_handler hdl;
>> u32 cfmt_code;
>> - struct v4l2_clk *clk;
>> + struct clk *clk;
>
> Nice!
>
>> const struct ov2640_win_size *win;
>>
>> struct gpio_desc *resetb_gpio;
>> @@ -656,8 +655,9 @@ static int ov2640_mask_set(struct i2c_client *client,
>> return i2c_smbus_write_byte_data(client, reg, val);
>> }
>>
>> -static int ov2640_reset(struct i2c_client *client)
>> +static int ov2640_reset(struct v4l2_subdev *sd, u32 val)
>> {
>> + struct i2c_client *client = v4l2_get_subdevdata(sd);
>> int ret;
>> const struct regval_list reset_seq[] = {
>> {BANK_SEL, BANK_SEL_SENS},
>> @@ -735,21 +735,6 @@ static int ov2640_s_register(struct v4l2_subdev *sd,
>> }
>> #endif
>>
>> -static int ov2640_s_power(struct v4l2_subdev *sd, int on)
>> -{
>> - struct i2c_client *client = v4l2_get_subdevdata(sd);
>> - struct ov2640_priv *priv = to_ov2640(client);
>> -
>> - gpiod_direction_output(priv->pwdn_gpio, !on);
>> - if (on && 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);
>
> Do you still perform the reset sequence somewhere? This could be crucial for
> reliability.
All I can go with is what soc_camera did, and there the reset is performed only
once, when the sensor driver is bound to soc_camera. This is the equivalent of
that. The reset is now performed in ov2640_init_gpio although it doesn't do a
full reset there. See more about this below.
>
>> - }
>> - return 0;
>> -}
>> -
>> /* Select the nearest higher resolution for capture */
>> static const struct ov2640_win_size *ov2640_select_win(u32 *width, u32 *height)
>> {
>> @@ -769,9 +754,10 @@ static const struct ov2640_win_size *ov2640_select_win(u32 *width, u32 *height)
>> return &ov2640_supported_win_sizes[default_size];
>> }
>>
>> -static int ov2640_set_params(struct i2c_client *client, u32 *width, u32 *height,
>> +static int ov2640_set_params(struct v4l2_subdev *sd, u32 *width, u32 *height,
>> u32 code)
>> {
>> + struct i2c_client *client = v4l2_get_subdevdata(sd);
>> struct ov2640_priv *priv = to_ov2640(client);
>> const struct regval_list *selected_cfmt_regs;
>> int ret;
>> @@ -802,7 +788,7 @@ static int ov2640_set_params(struct i2c_client *client, u32 *width, u32 *height,
>> }
>>
>> /* reset hardware */
>> - ov2640_reset(client);
>> + ov2640_reset(sd, 0);
>>
>> /* initialize the sensor with default data */
>> dev_dbg(&client->dev, "%s: Init default", __func__);
>> @@ -840,7 +826,7 @@ static int ov2640_set_params(struct i2c_client *client, u32 *width, u32 *height,
>>
>> err:
>> dev_err(&client->dev, "%s: Error %d", __func__, ret);
>> - ov2640_reset(client);
>> + ov2640_reset(sd, 0);
>> priv->win = NULL;
>>
>> return ret;
>> @@ -877,7 +863,6 @@ static int ov2640_set_fmt(struct v4l2_subdev *sd,
>> struct v4l2_subdev_format *format)
>> {
>> struct v4l2_mbus_framefmt *mf = &format->format;
>> - struct i2c_client *client = v4l2_get_subdevdata(sd);
>>
>> if (format->pad)
>> return -EINVAL;
>> @@ -902,7 +887,7 @@ static int ov2640_set_fmt(struct v4l2_subdev *sd,
>> }
>>
>> if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE)
>> - return ov2640_set_params(client, &mf->width,
>> + return ov2640_set_params(sd, &mf->width,
>> &mf->height, mf->code);
>> cfg->try_fmt = *mf;
>> return 0;
>> @@ -947,10 +932,6 @@ static int ov2640_video_probe(struct i2c_client *client)
>> const char *devname;
>> int ret;
>>
>> - ret = ov2640_s_power(&priv->subdev, 1);
>> - if (ret < 0)
>> - return ret;
>> -
>> /*
>> * check and show product ID and manufacturer ID
>> */
>> @@ -978,7 +959,6 @@ static int ov2640_video_probe(struct i2c_client *client)
>> ret = v4l2_ctrl_handler_setup(&priv->hdl);
>>
>> done:
>> - ov2640_s_power(&priv->subdev, 0);
>> return ret;
>> }
>>
>> @@ -991,7 +971,7 @@ static struct v4l2_subdev_core_ops ov2640_subdev_core_ops = {
>> .g_register = ov2640_g_register,
>> .s_register = ov2640_s_register,
>> #endif
>> - .s_power = ov2640_s_power,
>> + .reset = ov2640_reset,
>
> Why?
>
> We have s_power() callback. Shouldn't you run the reset sequence when the
> device is powered on?
>
> Few if any bridge / ISP drivers will use the reset op. It should rather be
> removed.
Good point. I'm not sure why I did this.
I will restore the s_power callback. I seem to remember that I had problems
with s_power, but I will have to retest this.
>
>> };
>>
>> static const struct v4l2_subdev_pad_ops ov2640_subdev_pad_ops = {
>> @@ -1006,9 +986,17 @@ static struct v4l2_subdev_ops ov2640_subdev_ops = {
>> .pad = &ov2640_subdev_pad_ops,
>> };
>>
>> -static int ov2640_probe_dt(struct i2c_client *client,
>> - struct ov2640_priv *priv)
>> +static int ov2640_init_gpio(struct i2c_client *client,
>> + struct ov2640_priv *priv)
>> {
>> + /* Request the power down GPIO deasserted */
>> + priv->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "pwdn",
>> + GPIOD_OUT_LOW);
>> + if (!priv->pwdn_gpio)
>> + dev_dbg(&client->dev, "pwdn gpio is not assigned!\n");
>
> I'm pretty sure not finding a GPIO using devm_gpiod_get_optional() already
> produces at least one line of output elsewhere.
No, it doesn't. It's optional, after all.
>
>> + else if (IS_ERR(priv->pwdn_gpio))
>> + return PTR_ERR(priv->pwdn_gpio);
>> +
>> /* Request the reset GPIO deasserted */
>> priv->resetb_gpio = devm_gpiod_get_optional(&client->dev, "resetb",
>> GPIOD_OUT_LOW);
>> @@ -1017,14 +1005,6 @@ static int ov2640_probe_dt(struct i2c_client *client,
>> 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");
>
> Same here.
>
>> - else if (IS_ERR(priv->pwdn_gpio))
>> - return PTR_ERR(priv->pwdn_gpio);
>> -
>> return 0;
>> }
>>
>> @@ -1051,9 +1031,10 @@ static int ov2640_probe(struct i2c_client *client,
>> return -ENOMEM;
>> }
>>
>> - priv->clk = v4l2_clk_get(&client->dev, "xvclk");
>> + priv->clk = clk_get(&client->dev, "xvclk");
>> if (IS_ERR(priv->clk))
>> return -EPROBE_DEFER;
>> + clk_prepare_enable(priv->clk);
>
> I wonder V4L2 clock framework did this. This should be done in the s_power()
> callback, not here.
Yeah, I'll need to revisit this.
>
>>
>> if (!client->dev.of_node) {
>> dev_err(&client->dev, "Missing platform_data for driver\n");
>> @@ -1061,9 +1042,9 @@ static int ov2640_probe(struct i2c_client *client,
>> goto err_clk;
>> }
>>
>> - ret = ov2640_probe_dt(client, priv);
>> + ret = ov2640_init_gpio(client, priv);
>> if (ret)
>> - goto err_clk;
>> + return ret;
>>
>> v4l2_i2c_subdev_init(&priv->subdev, client, &ov2640_subdev_ops);
>> v4l2_ctrl_handler_init(&priv->hdl, 2);
>> @@ -1074,25 +1055,23 @@ static int ov2640_probe(struct i2c_client *client,
>> priv->subdev.ctrl_handler = &priv->hdl;
>> if (priv->hdl.error) {
>> ret = priv->hdl.error;
>> - goto err_clk;
>> + goto err_hdl;
>> }
>>
>> ret = ov2640_video_probe(client);
>> if (ret < 0)
>> - goto err_videoprobe;
>> + goto err_hdl;
>>
>> ret = v4l2_async_register_subdev(&priv->subdev);
>> if (ret < 0)
>> - goto err_videoprobe;
>> + goto err_hdl;
>>
>> dev_info(&adapter->dev, "OV2640 Probed\n");
>>
>> return 0;
>>
>> -err_videoprobe:
>> +err_hdl:
>> v4l2_ctrl_handler_free(&priv->hdl);
>> -err_clk:
>> - v4l2_clk_put(priv->clk);
>> return ret;
>> }
>>
>> @@ -1101,9 +1080,8 @@ static int ov2640_remove(struct i2c_client *client)
>> struct ov2640_priv *priv = to_ov2640(client);
>>
>> v4l2_async_unregister_subdev(&priv->subdev);
>> - v4l2_clk_put(priv->clk);
>> - v4l2_device_unregister_subdev(&priv->subdev);
>> v4l2_ctrl_handler_free(&priv->hdl);
>
> Shouldn't you free the control handler afterwards? I'm not sure if this
> makes a lot of difference though.
The order makes no difference here.
Regards,
Hans
>
>> + v4l2_device_unregister_subdev(&priv->subdev);
>> return 0;
>> }
>>
>
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