[PATCH] dmaengine: txx9dmac: use devm_platform_ioremap_resource()

[Rosen Penev]

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 <rosenp@xxxxxxxxx>
---
 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