Subject: [PATCH v5 2/3] media: atmel-isi: add runtime pm support

From: [email-masked] (Laurent Pinchart)
Date: Tue, 26 May 2015 14:23:54 +0300

Hi Josh,

Thank you for the patch.

On Tuesday 26 May 2015 17:54:46 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 atmel_isi_probe(), remove the isi disable code
> as in the moment ISI peripheral clock is not enable yet.
> 
> 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]>

Acked-by: Laurent Pinchart <[email-masked]>

> ---
> 
> Changes in v5:
> - fix the error path in start_streaming() thanks to Laurent.
> 
> Changes in v4:
> - need to call pm_runtime_disable() in atmel_isi_remove().
> - merged the patch which remove isi disable code in atmel_isi_probe() as
>   isi peripherial clock is not enabled in this moment.
> - refine the commit log
> 
> 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 | 55 ++++++++++++++++++++----
>  1 file changed, 47 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/media/platform/soc_camera/atmel-isi.c
> b/drivers/media/platform/soc_camera/atmel-isi.c index 2227022..0ea360a
> 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>
> @@ -386,10 +387,13 @@ 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) {
>  		dev_err(icd->parent, "Reset ISI timed out\n");
> +		pm_runtime_put(ici->v4l2_dev.dev);
>  		return ret;
>  	}
>  	/* Disable all interrupts */
> @@ -443,6 +447,8 @@ 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 = {
> @@ -514,7 +520,13 @@ 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;
> 
> @@ -734,14 +746,9 @@ 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;
>  		}
>  	}
> @@ -756,7 +763,6 @@ 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)
> @@ -853,9 +859,14 @@ 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_CTRL, ISI_CTRL_DIS);
>  	isi_writel(isi, ISI_CFG1, cfg1);
> 
> +	pm_runtime_put(ici->v4l2_dev.dev);
> +
>  	return 0;
>  }
> 
> @@ -887,6 +898,7 @@ static int atmel_isi_remove(struct platform_device
> *pdev) sizeof(struct fbd) * MAX_BUFFER_NUM,
>  			isi->p_fb_descriptors,
>  			isi->fb_descriptors_phys);
> +	pm_runtime_disable(&pdev->dev);
> 
>  	return 0;
>  }
> @@ -1025,8 +1037,6 @@ static int atmel_isi_probe(struct platform_device
> *pdev) if (isi->pdata.data_width_flags & ISI_DATAWIDTH_10)
>  		isi->width_flags |= 1 << 9;
> 
> -	isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
> -
>  	irq = platform_get_irq(pdev, 0);
>  	if (IS_ERR_VALUE(irq)) {
>  		ret = irq;
> @@ -1047,6 +1057,9 @@ 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;
> @@ -1060,6 +1073,7 @@ static int atmel_isi_probe(struct platform_device
> *pdev) return 0;
> 
>  err_register_soc_camera_host:
> +	pm_runtime_disable(&pdev->dev);
>  err_req_irq:
>  err_ioremap:
>  	vb2_dma_contig_cleanup_ctx(isi->alloc_ctx);
> @@ -1072,6 +1086,30 @@ 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" },
>  	{ }
> @@ -1083,6 +1121,7 @@ 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,
>  	},
>  };

-- 
Regards,

Laurent Pinchart