ata: pata_ep93xx: add device tree support

- add OF ID match table
- drop platform DMA and filters
- change DMA setup to OF, so we can defer probe

Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Acked-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: maquefel

drivers/ata/pata_ep93xx.c

@@ -44,8 +44,8 @@
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
 #include <linux/ktime.h>
+#include <linux/mod_devicetable.h>
 
-#include <linux/platform_data/dma-ep93xx.h>
 #include <linux/soc/cirrus/ep93xx.h>
 
 #define DRV_NAME	"ep93xx-ide"
@@ -126,7 +126,7 @@ enum {
 };
 
 struct ep93xx_pata_data {
-	const struct platform_device *pdev;
+	struct platform_device *pdev;
 	void __iomem *ide_base;
 	struct ata_timing t;
 	bool iordy;
@@ -135,9 +135,7 @@ struct ep93xx_pata_data {
 	unsigned long udma_out_phys;
 
 	struct dma_chan *dma_rx_channel;
-	struct ep93xx_dma_data dma_rx_data;
 	struct dma_chan *dma_tx_channel;
-	struct ep93xx_dma_data dma_tx_data;
 };
 
 static void ep93xx_pata_clear_regs(void __iomem *base)
@@ -637,20 +635,13 @@ static void ep93xx_pata_release_dma(struct ep93xx_pata_data *drv_data)
 	}
 }
 
-static bool ep93xx_pata_dma_filter(struct dma_chan *chan, void *filter_param)
+static int ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
 {
-	if (ep93xx_dma_chan_is_m2p(chan))
-		return false;
-
-	chan->private = filter_param;
-	return true;
-}
-
-static void ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
-{
-	const struct platform_device *pdev = drv_data->pdev;
+	struct platform_device *pdev = drv_data->pdev;
+	struct device *dev = &pdev->dev;
 	dma_cap_mask_t mask;
 	struct dma_slave_config conf;
+	int ret;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
@@ -660,44 +651,48 @@ static void ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
 	 * to request only one channel, and reprogram it's direction at
 	 * start of new transfer.
 	 */
-	drv_data->dma_rx_data.port = EP93XX_DMA_IDE;
-	drv_data->dma_rx_data.direction = DMA_DEV_TO_MEM;
-	drv_data->dma_rx_data.name = "ep93xx-pata-rx";
-	drv_data->dma_rx_channel = dma_request_channel(mask,
-		ep93xx_pata_dma_filter, &drv_data->dma_rx_data);
-	if (!drv_data->dma_rx_channel)
-		return;
-
-	drv_data->dma_tx_data.port = EP93XX_DMA_IDE;
-	drv_data->dma_tx_data.direction = DMA_MEM_TO_DEV;
-	drv_data->dma_tx_data.name = "ep93xx-pata-tx";
-	drv_data->dma_tx_channel = dma_request_channel(mask,
-		ep93xx_pata_dma_filter, &drv_data->dma_tx_data);
-	if (!drv_data->dma_tx_channel) {
-		dma_release_channel(drv_data->dma_rx_channel);
-		return;
+	drv_data->dma_rx_channel = dma_request_chan(dev, "rx");
+	if (IS_ERR(drv_data->dma_rx_channel))
+		return dev_err_probe(dev, PTR_ERR(drv_data->dma_rx_channel),
+				     "rx DMA setup failed\n");
+
+	drv_data->dma_tx_channel = dma_request_chan(&pdev->dev, "tx");
+	if (IS_ERR(drv_data->dma_tx_channel)) {
+		ret = dev_err_probe(dev, PTR_ERR(drv_data->dma_tx_channel),
+				    "tx DMA setup failed\n");
+		goto fail_release_rx;
 	}
 
 	/* Configure receive channel direction and source address */
 	memset(&conf, 0, sizeof(conf));
 	conf.direction = DMA_DEV_TO_MEM;
 	conf.src_addr = drv_data->udma_in_phys;
 	conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
-	if (dmaengine_slave_config(drv_data->dma_rx_channel, &conf)) {
-		dev_err(&pdev->dev, "failed to configure rx dma channel\n");
-		ep93xx_pata_release_dma(drv_data);
-		return;
+	ret = dmaengine_slave_config(drv_data->dma_rx_channel, &conf);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to configure rx dma channel");
+		goto fail_release_dma;
 	}
 
 	/* Configure transmit channel direction and destination address */
 	memset(&conf, 0, sizeof(conf));
 	conf.direction = DMA_MEM_TO_DEV;
 	conf.dst_addr = drv_data->udma_out_phys;
 	conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
-	if (dmaengine_slave_config(drv_data->dma_tx_channel, &conf)) {
-		dev_err(&pdev->dev, "failed to configure tx dma channel\n");
-		ep93xx_pata_release_dma(drv_data);
+	ret = dmaengine_slave_config(drv_data->dma_tx_channel, &conf);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to configure tx dma channel");
+		goto fail_release_dma;
 	}
+
+	return 0;
+
+fail_release_rx:
+	dma_release_channel(drv_data->dma_rx_channel);
+fail_release_dma:
+	ep93xx_pata_release_dma(drv_data);
+
+	return ret;
 }
 
 static void ep93xx_pata_dma_start(struct ata_queued_cmd *qc)
@@ -954,7 +949,9 @@ static int ep93xx_pata_probe(struct platform_device *pdev)
 	drv_data->ide_base = ide_base;
 	drv_data->udma_in_phys = mem_res->start + IDEUDMADATAIN;
 	drv_data->udma_out_phys = mem_res->start + IDEUDMADATAOUT;
-	ep93xx_pata_dma_init(drv_data);
+	err = ep93xx_pata_dma_init(drv_data);
+	if (err)
+		return err;
 
 	/* allocate host */
 	host = ata_host_alloc(&pdev->dev, 1);
@@ -1021,9 +1018,16 @@ static void ep93xx_pata_remove(struct platform_device *pdev)
 	ep93xx_ide_release_gpio(pdev);
 }
 
+static const struct of_device_id ep93xx_pata_of_ids[] = {
+	{ .compatible = "cirrus,ep9312-pata" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ep93xx_pata_of_ids);
+
 static struct platform_driver ep93xx_pata_platform_driver = {
 	.driver = {
 		.name = DRV_NAME,
+		.of_match_table = ep93xx_pata_of_ids,
 	},
 	.probe = ep93xx_pata_probe,
 	.remove_new = ep93xx_pata_remove,