Re: [PATCH] dmaengine: txx9dmac: use devm_platform_ioremap_resource()

On Tue, Jul 14, 2026 at 04:47:42PM -0700, Rosen Penev wrote:
> Replace the open-coded platform_get_resource() plus devm_request_mem_region()
> and devm_ioremap() sequence with a single devm_platform_ioremap_resource()
> call, which folds the resource lookup, region reservation and mapping into
> one step and returns an ERR_PTR on failure, checked with IS_ERR() and
> propagated via PTR_ERR().
>
> This is behaviorally equivalent: the driver already reserved the region
> with devm_request_mem_region(), so the non-overlapping reg requirement of
> devm_platform_ioremap_resource() was already satisfied. The txx9dmac
> platform device (arch/mips/txx9/generic/setup.c) provides a single
> IORESOURCE_MEM window per DMAC instance, and the child txx9dmac-chan
> devices carry only IRQ resources, so no region conflict is introduced.
>
> Assisted-by: opencode:hy3-free
> Signed-off-by: Rosen Penev <[email protected]>
> ---

Reviewed-by: Frank Li <[email protected]>

>  drivers/dma/txx9dmac.c | 16 +++++-----------
>  1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/dma/txx9dmac.c b/drivers/dma/txx9dmac.c
> index 05622b68a936..6595a54a4b97 100644
> --- a/drivers/dma/txx9dmac.c
> +++ b/drivers/dma/txx9dmac.c
> @@ -1167,26 +1167,20 @@ static void txx9dmac_chan_remove(struct platform_device *pdev)
>  static int __init txx9dmac_probe(struct platform_device *pdev)
>  {
>  	struct txx9dmac_platform_data *pdata = dev_get_platdata(&pdev->dev);
> -	struct resource *io;
>  	struct txx9dmac_dev *ddev;
> +	void __iomem *regs;
>  	u32 mcr;
>  	int err;
>
> -	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (!io)
> -		return -EINVAL;
> +	regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(regs))
> +		return PTR_ERR(regs);
>
>  	ddev = devm_kzalloc(&pdev->dev, sizeof(*ddev), GFP_KERNEL);
>  	if (!ddev)
>  		return -ENOMEM;
>
> -	if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io),
> -				     dev_name(&pdev->dev)))
> -		return -EBUSY;
> -
> -	ddev->regs = devm_ioremap(&pdev->dev, io->start, resource_size(io));
> -	if (!ddev->regs)
> -		return -ENOMEM;
> +	ddev->regs = regs;
>  	ddev->have_64bit_regs = pdata->have_64bit_regs;
>  	if (__is_dmac64(ddev))
>  		ddev->descsize = sizeof(struct txx9dmac_hwdesc);
> --
> 2.55.0
>