Re: [PATCH v12 16/17] media: ti: j721e-csi2rx: Support runtime suspend

[Rishikesh Donadkar <r-donadkar@ti.com>]

On 19/05/26 18:01, Sakari Ailus wrote:
> Hi Rishikesh,

Hi Sakari,

Thank you for the review !

>
> On Fri, Mar 13, 2026 at 02:37:00PM +0530, Rishikesh Donadkar wrote:
>> From: Jai Luthra <jai.luthra@ideasonboard.com>
>>
>> Add support for runtime power-management to enable powering off the
>> shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
>> the device(s) are not in use.
>>
>> When powering off the IP, the PSI-L endpoint loses the paired DMA
>> channels. Thus we have to release the DMA channels at runtime suspend
>> and request them again at resume.
>>
>> Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
>> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   drivers/media/platform/ti/Kconfig             |  1 +
>>   .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
>>   2 files changed, 54 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
>> index da33facf44678..d0cb05481bd85 100644
>> --- a/drivers/media/platform/ti/Kconfig
>> +++ b/drivers/media/platform/ti/Kconfig
>> @@ -83,6 +83,7 @@ config VIDEO_TI_J721E_CSI2RX
>>   	depends on VIDEO_CADENCE_CSI2RX
>>   	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
>>   	depends on ARCH_K3 || COMPILE_TEST
>> +	depends on PM
>>   	select VIDEOBUF2_DMA_CONTIG
>>   	select V4L2_FWNODE
>>   	help
>> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> index dda8a66babeca..52c93a11ce8b7 100644
>> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> @@ -13,6 +13,7 @@
>>   #include <linux/module.h>
>>   #include <linux/of_platform.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>>   #include <linux/property.h>
>>   
>>   #include <media/cadence/cdns-csi2rx.h>
>> @@ -966,12 +967,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   	unsigned long flags;
>>   	int ret = 0;
> Redundant initialisation.
>
>>   
>> +	ret = pm_runtime_resume_and_get(csi->dev);
>> +	if (ret)
>> +		return ret;
>> +
>>   	spin_lock_irqsave(&dma->lock, flags);
>>   	if (list_empty(&dma->queue))
>>   		ret = -EIO;
>>   	spin_unlock_irqrestore(&dma->lock, flags);
>>   	if (ret)
>> -		return ret;
>> +		goto err;
>>   
>>   	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
>>   	if (ret)
>> @@ -993,6 +998,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
>>   err:
>>   	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
>> +	pm_runtime_put(csi->dev);
>> +
>>   	return ret;
>>   }
>>   
>> @@ -1012,6 +1019,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
>>   
>>   	ti_csi2rx_stop_dma(ctx);
>>   	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
>> +	pm_runtime_put(csi->dev);
>>   }
>>   
>>   static const struct vb2_ops csi_vb2_qops = {
>> @@ -1257,7 +1265,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
>>   
>>   static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
>>   {
>> -	dma_release_channel(ctx->dma.chan);
>> +	if (!pm_runtime_status_suspended(ctx->csi->dev))
>> +		dma_release_channel(ctx->dma.chan);
>> +
>>   	vb2_queue_release(&ctx->vidq);
>>   
>>   	video_unregister_device(&ctx->vdev);
>> @@ -1507,6 +1517,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
>>   	return ret;
>>   }
>>   
>> +static int ti_csi2rx_runtime_suspend(struct device *dev)
>> +{
>> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
>> +	int i;
>> +
>> +	if (csi->enable_count != 0)
>> +		return -EBUSY;
>> +
>> +	for (i = 0; i < csi->num_ctx; i++)
> You could declare i here, and I'd use unsigned int.
>
>> +		dma_release_channel(csi->ctx[i].dma.chan);
>> +
>> +	return 0;
>> +}
>> +
>> +static int ti_csi2rx_runtime_resume(struct device *dev)
>> +{
>> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
>> +	unsigned int ret, i;
> Ret should be signed and could be declared below (up to you).
>
>> +
>> +	for (i = 0; i < csi->num_ctx; i++) {
> i could be declared here.


Thanks for pointing out, Will do all the changes in v13


Rishikesh

>
>> +		ret = ti_csi2rx_init_dma(&csi->ctx[i]);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct dev_pm_ops ti_csi2rx_pm_ops = {
>> +	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
>> +		       NULL)
>> +};
>> +
>>   static int ti_csi2rx_probe(struct platform_device *pdev)
>>   {
>>   	struct device_node *np = pdev->dev.of_node;
>> @@ -1562,6 +1605,9 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
>>   			goto err_ctx;
>>   	}
>>   
>> +	pm_runtime_set_active(csi->dev);
>> +	pm_runtime_enable(csi->dev);
>> +
>>   	ret = ti_csi2rx_notifier_register(csi);
>>   	if (ret)
>>   		goto err_ctx;
>> @@ -1592,6 +1638,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
>>   	struct ti_csi2rx_dev *csi = platform_get_drvdata(pdev);
>>   	unsigned int i;
>>   
>> +	if (!pm_runtime_status_suspended(&pdev->dev))
>> +		pm_runtime_set_suspended(&pdev->dev);
>> +
>>   	for (i = 0; i < csi->num_ctx; i++)
>>   		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
>>   
>> @@ -1599,6 +1648,7 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
>>   	ti_csi2rx_cleanup_v4l2(csi);
>>   	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
>>   			  csi->drain.paddr);
>> +	pm_runtime_disable(&pdev->dev);
>>   }
>>   
>>   static const struct of_device_id ti_csi2rx_of_match[] = {
>> @@ -1613,6 +1663,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
>>   	.driver = {
>>   		.name = TI_CSI2RX_MODULE_NAME,
>>   		.of_match_table = ti_csi2rx_of_match,
>> +		.pm		= &ti_csi2rx_pm_ops,
>>   	},
>>   };
>>