[PATCH] ASoC: fsl: dma: use platform helpers and devm cleanup

[Rosen Penev <rosenp@gmail.com>]

Convert fsl_soc_dma_probe() to managed APIs. Replace the open-coded
of_address_to_resource()/of_iomap() of the DMA channel registers with
devm_platform_ioremap_resource(), and irq_of_parse_and_map() with
platform_get_irq() (which returns a negative errno instead of 0).
Switch the allocation to devm_kzalloc() and register the component via
the devm variant, dropping the now-unneeded error-path cleanup and the
manual fsl_soc_dma_remove().

The SSI node's register resource is still read via of_address_to_resource()
to compute the SSI FIFO physical addresses (dma->ssi_stx_phys /
ssi_srx_phys); only the DMA controller window is mapped.

The DMA controller register window is owned solely by this driver, so the
new region request from devm_platform_ioremap_resource() cannot conflict
with another claimant, and it is mapped exactly once (no double mapping).

The local channel pointer is declared as void __iomem * so the
devm_platform_ioremap_resource() result can be stored before assignment
to dma->channel.

No functional change; built for powerpc (allmodconfig + CONFIG_SND_SOC_FSL_DMA)
with LLVM=1 and sound/soc/fsl/fsl_dma.o compiles cleanly.

Assisted-by: opencode:hy3-free
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 sound/soc/fsl/fsl_dma.c | 68 ++++++++++++++++-------------------------
 1 file changed, 27 insertions(+), 41 deletions(-)

diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
index b12474880185..b1b341132dd6 100644
--- a/sound/soc/fsl/fsl_dma.c
+++ b/sound/soc/fsl/fsl_dma.c
@@ -18,8 +18,6 @@
 #include <linux/delay.h>
 #include <linux/gfp.h>
 #include <linux/of_address.h>
-#include <linux/of_irq.h>
-#include <linux/of_platform.h>
 #include <linux/list.h>
 #include <linux/slab.h>
 
@@ -824,9 +822,34 @@ static int fsl_soc_dma_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct device_node *ssi_np;
 	struct resource res;
+	void __iomem *channel;
 	const uint32_t *iprop;
+	int irq;
 	int ret;
 
+	channel = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(channel))
+		return PTR_ERR(channel);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	dma = devm_kzalloc(&pdev->dev, sizeof(*dma), GFP_KERNEL);
+	if (!dma)
+		return -ENOMEM;
+
+	dma->dai.name = DRV_NAME;
+	dma->dai.open = fsl_dma_open;
+	dma->dai.close = fsl_dma_close;
+	dma->dai.hw_params = fsl_dma_hw_params;
+	dma->dai.hw_free = fsl_dma_hw_free;
+	dma->dai.pointer = fsl_dma_pointer;
+	dma->dai.pcm_new = fsl_dma_new;
+
+	dma->channel = channel;
+	dma->irq = irq;
+
 	/* Find the SSI node that points to us. */
 	ssi_np = find_ssi_node(np);
 	if (!ssi_np) {
@@ -842,55 +865,19 @@ static int fsl_soc_dma_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	dma = kzalloc_obj(*dma);
-	if (!dma) {
-		of_node_put(ssi_np);
-		return -ENOMEM;
-	}
-
-	dma->dai.name = DRV_NAME;
-	dma->dai.open = fsl_dma_open;
-	dma->dai.close = fsl_dma_close;
-	dma->dai.hw_params = fsl_dma_hw_params;
-	dma->dai.hw_free = fsl_dma_hw_free;
-	dma->dai.pointer = fsl_dma_pointer;
-	dma->dai.pcm_new = fsl_dma_new;
-
 	/* Store the SSI-specific information that we need */
 	dma->ssi_stx_phys = res.start + REG_SSI_STX0;
 	dma->ssi_srx_phys = res.start + REG_SSI_SRX0;
 
 	iprop = of_get_property(ssi_np, "fsl,fifo-depth", NULL);
+	of_node_put(ssi_np);
 	if (iprop)
 		dma->ssi_fifo_depth = be32_to_cpup(iprop);
 	else
                 /* Older 8610 DTs didn't have the fifo-depth property */
 		dma->ssi_fifo_depth = 8;
 
-	of_node_put(ssi_np);
-
-	ret = devm_snd_soc_register_component(&pdev->dev, &dma->dai, NULL, 0);
-	if (ret) {
-		dev_err(&pdev->dev, "could not register platform\n");
-		kfree(dma);
-		return ret;
-	}
-
-	dma->channel = of_iomap(np, 0);
-	dma->irq = irq_of_parse_and_map(np, 0);
-
-	dev_set_drvdata(&pdev->dev, dma);
-
-	return 0;
-}
-
-static void fsl_soc_dma_remove(struct platform_device *pdev)
-{
-	struct dma_object *dma = dev_get_drvdata(&pdev->dev);
-
-	iounmap(dma->channel);
-	irq_dispose_mapping(dma->irq);
-	kfree(dma);
+	return devm_snd_soc_register_component(&pdev->dev, &dma->dai, NULL, 0);
 }
 
 static const struct of_device_id fsl_soc_dma_ids[] = {
@@ -905,7 +892,6 @@ static struct platform_driver fsl_soc_dma_driver = {
 		.of_match_table = fsl_soc_dma_ids,
 	},
 	.probe = fsl_soc_dma_probe,
-	.remove = fsl_soc_dma_remove,
 };
 
 module_platform_driver(fsl_soc_dma_driver);
-- 
2.55.0