Subject: [PATCH v3 2/3] media: atmel-isi: add runtime pm support

From: [email-masked] (Josh Wu)
Date: Tue, 12 May 2015 11:04:30 +0800

On 5/6/2015 6:25 PM, Josh Wu wrote:
> The runtime pm resume/suspend will enable/disable pclk (ISI peripheral
> clock).
> And we need to call runtime_pm_get_sync()/runtime_pm_put() when we need
> access ISI registers.
>
> In the meantime, as clock_start()/clock_stop() is used to control the
> mclk not ISI peripheral clock. So move this to start[stop]_streaming()
> function.
>
> Signed-off-by: Josh Wu <[email-masked]>
> ---
>
> Changes in v3: None
> Changes in v2:
> - merged v1 two patch into one.
> - use runtime_pm_put() instead of runtime_pm_put_sync()
> - enable peripheral clock before access ISI registers.
>
>   drivers/media/platform/soc_camera/atmel-isi.c | 51 +++++++++++++++++++++++----
>   1 file changed, 45 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
> index 31254b4..2b05f89 100644
> --- a/drivers/media/platform/soc_camera/atmel-isi.c
> +++ b/drivers/media/platform/soc_camera/atmel-isi.c
> @@ -20,6 +20,7 @@
>   #include <linux/kernel.h>
>   #include <linux/module.h>
>   #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>   #include <linux/slab.h>
>   
>   #include <media/atmel-isi.h>
> @@ -384,6 +385,8 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
>   	struct atmel_isi *isi = ici->priv;
>   	int ret;
>   
> +	pm_runtime_get_sync(ici->v4l2_dev.dev);
> +
>   	/* Reset ISI */
>   	ret = atmel_isi_wait_status(isi, WAIT_ISI_RESET);
>   	if (ret < 0) {
> @@ -441,6 +444,8 @@ static void stop_streaming(struct vb2_queue *vq)
>   	ret = atmel_isi_wait_status(isi, WAIT_ISI_DISABLE);
>   	if (ret < 0)
>   		dev_err(icd->parent, "Disable ISI timed out\n");
> +
> +	pm_runtime_put(ici->v4l2_dev.dev);
>   }
>   
>   static struct vb2_ops isi_video_qops = {
> @@ -509,7 +514,13 @@ static int isi_camera_set_fmt(struct soc_camera_device *icd,
>   	if (mf.code != xlate->code)
>   		return -EINVAL;
>   
> +	/* Enable PM and peripheral clock before operate isi registers */
> +	pm_runtime_get_sync(ici->v4l2_dev.dev);
> +
>   	ret = configure_geometry(isi, pix->width, pix->height, xlate->code);
> +
> +	pm_runtime_put(ici->v4l2_dev.dev);
> +
>   	if (ret < 0)
>   		return ret;
>   
> @@ -722,14 +733,9 @@ static int isi_camera_clock_start(struct soc_camera_host *ici)
>   	struct atmel_isi *isi = ici->priv;
>   	int ret;
>   
> -	ret = clk_prepare_enable(isi->pclk);
> -	if (ret)
> -		return ret;
> -
>   	if (!IS_ERR(isi->mck)) {
>   		ret = clk_prepare_enable(isi->mck);
>   		if (ret) {
> -			clk_disable_unprepare(isi->pclk);
>   			return ret;
>   		}
>   	}
> @@ -744,7 +750,6 @@ static void isi_camera_clock_stop(struct soc_camera_host *ici)
>   
>   	if (!IS_ERR(isi->mck))
>   		clk_disable_unprepare(isi->mck);
> -	clk_disable_unprepare(isi->pclk);
>   }
>   
>   static unsigned int isi_camera_poll(struct file *file, poll_table *pt)
> @@ -841,8 +846,13 @@ static int isi_camera_set_bus_param(struct soc_camera_device *icd)
>   
>   	cfg1 |= ISI_CFG1_THMASK_BEATS_16;
>   
> +	/* Enable PM and peripheral clock before operate isi registers */
> +	pm_runtime_get_sync(ici->v4l2_dev.dev);
> +
>   	isi_writel(isi, ISI_CFG1, cfg1);
>   
> +	pm_runtime_put(ici->v4l2_dev.dev);
> +
>   	return 0;
>   }
>   
> @@ -1039,6 +1049,9 @@ static int atmel_isi_probe(struct platform_device *pdev)
>   	soc_host->v4l2_dev.dev	= &pdev->dev;
>   	soc_host->nr		= pdev->id;
>   
> +	pm_suspend_ignore_children(&pdev->dev, true);
> +	pm_runtime_enable(&pdev->dev);
> +
>   	if (isi->pdata.asd_sizes) {
>   		soc_host->asd = isi->pdata.asd;
>   		soc_host->asd_sizes = isi->pdata.asd_sizes;
> @@ -1052,6 +1065,7 @@ static int atmel_isi_probe(struct platform_device *pdev)
>   	return 0;
>   
>   err_register_soc_camera_host:
> +	pm_runtime_disable(&pdev->dev);

This function is missed in atmel_isi_remove(). I'll fix it.

Best Regards,
Josh Wu
>   err_req_irq:
>   err_ioremap:
>   	vb2_dma_contig_cleanup_ctx(isi->alloc_ctx);
> @@ -1064,6 +1078,30 @@ err_alloc_ctx:
>   	return ret;
>   }
>   
> +static int atmel_isi_runtime_suspend(struct device *dev)
> +{
> +	struct soc_camera_host *soc_host = to_soc_camera_host(dev);
> +	struct atmel_isi *isi = container_of(soc_host,
> +					struct atmel_isi, soc_host);
> +
> +	clk_disable_unprepare(isi->pclk);
> +
> +	return 0;
> +}
> +static int atmel_isi_runtime_resume(struct device *dev)
> +{
> +	struct soc_camera_host *soc_host = to_soc_camera_host(dev);
> +	struct atmel_isi *isi = container_of(soc_host,
> +					struct atmel_isi, soc_host);
> +
> +	return clk_prepare_enable(isi->pclk);
> +}
> +
> +static const struct dev_pm_ops atmel_isi_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(atmel_isi_runtime_suspend,
> +				atmel_isi_runtime_resume, NULL)
> +};
> +
>   static const struct of_device_id atmel_isi_of_match[] = {
>   	{ .compatible = "atmel,at91sam9g45-isi" },
>   	{ }
> @@ -1075,6 +1113,7 @@ static struct platform_driver atmel_isi_driver = {
>   	.driver		= {
>   		.name = "atmel_isi",
>   		.of_match_table = of_match_ptr(atmel_isi_of_match),
> +		.pm	= &atmel_isi_dev_pm_ops,
>   	},
>   };
>