Re: [v2] mt9v032: Use the common clock framework

["Peter A. Bigot" <pab@pabigot.com>]

FWIW: I found it necessary to use this along with 
http://git.linuxtv.org/pinchartl/media.git/shortlog/refs/heads/board/overo/mt9v032 
to get the Caspa to work on Gumstix under Linux 3.10.  (Without 
configuring the clock the device won't respond to I2C operations. It 
still doesn't work "right", but that may not be a driver problem.  It's 
also necessary under 3.8, which has serious problems with CCDC idle 
messages that I haven't tracked down yet.)

Peter

On 08/09/2013 05:24 AM, Laurent Pinchart wrote:
> Configure the device external clock using the common clock framework
> instead of a board code callback function.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> ---
> drivers/media/i2c/mt9v032.c | 17 +++++++++++------
>   include/media/mt9v032.h     |  4 ----
>   2 files changed, 11 insertions(+), 10 deletions(-)
>
> Changes since v1:
>
> - Set the pixel clock rate with clk_set_rate()
>
> diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
> index 60c6f67..2c50eff 100644
> --- a/drivers/media/i2c/mt9v032.c
> +++ b/drivers/media/i2c/mt9v032.c
> @@ -12,6 +12,7 @@
>    * published by the Free Software Foundation.
>    */
>   
> +#include <linux/clk.h>
>   #include <linux/delay.h>
>   #include <linux/i2c.h>
>   #include <linux/log2.h>
> @@ -135,6 +136,8 @@ struct mt9v032 {
>   	struct mutex power_lock;
>   	int power_count;
>   
> +	struct clk *clk;
> +
>   	struct mt9v032_platform_data *pdata;
>   
>   	u32 sysclk;
> @@ -219,10 +222,9 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
>   	struct i2c_client *client = v4l2_get_subdevdata(&mt9v032->subdev);
>   	int ret;
>   
> -	if (mt9v032->pdata->set_clock) {
> -		mt9v032->pdata->set_clock(&mt9v032->subdev, mt9v032->sysclk);
> -		udelay(1);
> -	}
> +	clk_set_rate(mt9v032->clk, mt9v032->sysclk);
> +	clk_prepare_enable(mt9v032->clk);
> +	udelay(1);
>   
>   	/* Reset the chip and stop data read out */
>   	ret = mt9v032_write(client, MT9V032_RESET, 1);
> @@ -238,8 +240,7 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
>   
>   static void mt9v032_power_off(struct mt9v032 *mt9v032)
>   {
> -	if (mt9v032->pdata->set_clock)
> -		mt9v032->pdata->set_clock(&mt9v032->subdev, 0);
> +	clk_disable_unprepare(mt9v032->clk);
>   }
>   
>   static int __mt9v032_set_power(struct mt9v032 *mt9v032, bool on)
> @@ -748,6 +749,10 @@ static int mt9v032_probe(struct i2c_client *client,
>   	if (!mt9v032)
>   		return -ENOMEM;
>   
> +	mt9v032->clk = devm_clk_get(&client->dev, NULL);
> +	if (IS_ERR(mt9v032->clk))
> +		return PTR_ERR(mt9v032->clk);
> +
>   	mutex_init(&mt9v032->power_lock);
>   	mt9v032->pdata = pdata;
>   
> diff --git a/include/media/mt9v032.h b/include/media/mt9v032.h
> index 78fd39e..12175a6 100644
> --- a/include/media/mt9v032.h
> +++ b/include/media/mt9v032.h
> @@ -1,13 +1,9 @@
>   #ifndef _MEDIA_MT9V032_H
>   #define _MEDIA_MT9V032_H
>   
> -struct v4l2_subdev;
> -
>   struct mt9v032_platform_data {
>   	unsigned int clk_pol:1;
>   
> -	void (*set_clock)(struct v4l2_subdev *subdev, unsigned int rate);
> -
>   	const s64 *link_freqs;
>   	s64 link_def_freq;
>   };
>
>