Replace open-coded resource handling with devm helpers:
  - spi_alloc_host -> devm_spi_alloc_host
  - of_address_to_resource + ioremap + request_mem_region
    -> devm_platform_ioremap_resource
  - request_irq -> devm_request_irq
  - remove now-unused mapbase/mapsize fields from struct ppc4xx_spi
  - move of_node_put(opbnp) earlier to simplify error paths
  - delete the entire error-unwinding goto chain

Move devm_platform_ioremap_resource() and platform_get_irq() up in order
to avoid doing work if -EPROBE_DEFER is returned.

Sanity check for devm_platform_ioremap_resource removed as it's
unnecessary.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: mention Sanity check removal.
 drivers/spi/spi-ppc4xx.c | 107 ++++++++++-----------------------------
 1 file changed, 27 insertions(+), 80 deletions(-)

diff --git a/drivers/spi/spi-ppc4xx.c b/drivers/spi/spi-ppc4xx.c
index 46ac58dfb3fc..7823b3814a17 100644
--- a/drivers/spi/spi-ppc4xx.c
+++ b/drivers/spi/spi-ppc4xx.c
@@ -112,8 +112,6 @@ struct ppc4xx_spi {
 	struct spi_bitbang bitbang;
 	struct completion done;
 
-	u64 mapbase;
-	u64 mapsize;
 	int irqnum;
 	/* need this to set the SPI clock */
 	unsigned int opb_freq;
@@ -337,14 +335,24 @@ static int spi_ppc4xx_of_probe(struct platform_device *op)
 	struct ppc4xx_spi *hw;
 	struct spi_controller *host;
 	struct spi_bitbang *bbp;
-	struct resource resource;
 	struct device_node *np = op->dev.of_node;
 	struct device *dev = &op->dev;
 	struct device_node *opbnp;
 	int ret;
-	const unsigned int *clk;
+	unsigned int opb_freq;
+	void __iomem *regs;
+	int irqnum;
+
+	regs = devm_platform_ioremap_resource(op, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
 
-	host = spi_alloc_host(dev, sizeof(*hw));
+	/* Request IRQ */
+	irqnum = platform_get_irq(op, 0);
+	if (irqnum < 0)
+		return irqnum;
+
+	host = devm_spi_alloc_host(dev, sizeof(*hw));
 	if (host == NULL)
 		return -ENOMEM;
 	host->dev.of_node = np;
@@ -379,88 +387,31 @@ static int spi_ppc4xx_of_probe(struct platform_device *op)
 	opbnp = of_find_compatible_node(NULL, NULL, "ibm,opb");
 	if (opbnp == NULL) {
 		dev_err(dev, "OPB: cannot find node\n");
-		ret = -ENODEV;
-		goto free_host;
+		return -ENODEV;
 	}
 	/* Get the clock (Hz) for the OPB */
-	clk = of_get_property(opbnp, "clock-frequency", NULL);
-	if (clk == NULL) {
-		dev_err(dev, "OPB: no clock-frequency property set\n");
-		of_node_put(opbnp);
-		ret = -ENODEV;
-		goto free_host;
-	}
-	hw->opb_freq = *clk;
-	hw->opb_freq >>= 2;
+	ret = of_property_read_u32(opbnp, "clock-frequency", &opb_freq);
 	of_node_put(opbnp);
-
-	ret = of_address_to_resource(np, 0, &resource);
-	if (ret) {
-		dev_err(dev, "error while parsing device node resource\n");
-		goto free_host;
-	}
-	hw->mapbase = resource.start;
-	hw->mapsize = resource_size(&resource);
-
-	/* Sanity check */
-	if (hw->mapsize < sizeof(struct spi_ppc4xx_regs)) {
-		dev_err(dev, "too small to map registers\n");
-		ret = -EINVAL;
-		goto free_host;
-	}
-
-	/* Request IRQ */
-	ret = platform_get_irq(op, 0);
-	if (ret < 0)
-		goto free_host;
-	hw->irqnum = ret;
-
-	ret = request_irq(hw->irqnum, spi_ppc4xx_int,
-			  0, "spi_ppc4xx_of", (void *)hw);
-	if (ret) {
-		dev_err(dev, "unable to allocate interrupt\n");
-		goto free_host;
-	}
-
-	if (!request_mem_region(hw->mapbase, hw->mapsize, DRIVER_NAME)) {
-		dev_err(dev, "resource unavailable\n");
-		ret = -EBUSY;
-		goto request_mem_error;
+	if (ret)
+		dev_err(dev, "OPB: no clock-frequency property set\n");
+		return -ENODEV;
 	}
 
-	hw->regs = ioremap(hw->mapbase, sizeof(struct spi_ppc4xx_regs));
+	hw->opb_freq = opb_freq;
+	hw->opb_freq >>= 2;
+	hw->regs = regs;
+	hw->irqnum = irqnum;
 
-	if (!hw->regs) {
-		dev_err(dev, "unable to memory map registers\n");
-		ret = -ENXIO;
-		goto map_io_error;
-	}
+	ret = devm_request_irq(&op->dev, hw->irqnum, spi_ppc4xx_int,
+			  0, "spi_ppc4xx_of", hw);
+	if (ret)
+		return ret;
 
 	spi_ppc4xx_enable(hw);
 
 	/* Finally register our spi controller */
 	dev->dma_mask = 0;
-	ret = spi_bitbang_start(bbp);
-	if (ret) {
-		dev_err(dev, "failed to register SPI host\n");
-		goto unmap_regs;
-	}
-
-	dev_info(dev, "driver initialized\n");
-
-	return 0;
-
-unmap_regs:
-	iounmap(hw->regs);
-map_io_error:
-	release_mem_region(hw->mapbase, hw->mapsize);
-request_mem_error:
-	free_irq(hw->irqnum, hw);
-free_host:
-	spi_controller_put(host);
-
-	dev_err(dev, "initialization failed\n");
-	return ret;
+	return spi_bitbang_start(bbp);
 }
 
 static void spi_ppc4xx_of_remove(struct platform_device *op)
@@ -469,10 +420,6 @@ static void spi_ppc4xx_of_remove(struct platform_device *op)
 	struct ppc4xx_spi *hw = spi_controller_get_devdata(host);
 
 	spi_bitbang_stop(&hw->bitbang);
-	release_mem_region(hw->mapbase, hw->mapsize);
-	free_irq(hw->irqnum, hw);
-	iounmap(hw->regs);
-	spi_controller_put(host);
 }
 
 static const struct of_device_id spi_ppc4xx_of_match[] = {
-- 
2.55.0