[PATCH 15/23] spi: s3c64xx: move to generic dmaengine API

[arnd@arndb.de (Arnd Bergmann)]

The spi-s3c64xx uses a Samsung proprietary interface for
talking to the DMA engine, which does not work with
multiplatform kernels. Since the driver can also operate
in PIO mode without any DMA, older platforms that do
not support the DMA engine API will still work, although
slower.

The conversion was rather mechanical, since the samsung
interface is just a shallow wrapper around the dmaengine
interface.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/plat-samsung/devs.c              |  10 +++
 drivers/spi/spi-s3c64xx.c                 | 107 ++++++++++++++----------------
 include/linux/platform_data/spi-s3c64xx.h |   3 +
 3 files changed, 62 insertions(+), 58 deletions(-)

diff --git a/arch/arm/plat-samsung/devs.c b/arch/arm/plat-samsung/devs.c
index 76209c9..58fb02a 100644
--- a/arch/arm/plat-samsung/devs.c
+++ b/arch/arm/plat-samsung/devs.c
@@ -10,6 +10,7 @@
  * published by the Free Software Foundation.
 */
 
+#include <linux/amba/pl330.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
@@ -1551,6 +1552,9 @@ void __init s3c64xx_spi0_set_platdata(int (*cfg_gpio)(void), int src_clk_nr,
 	pd.num_cs = num_cs;
 	pd.src_clk_nr = src_clk_nr;
 	pd.cfg_gpio = (cfg_gpio) ? cfg_gpio : s3c64xx_spi0_cfg_gpio;
+#ifdef CONFIG_PL330_DMA
+	pd.filter = pl330_filter;
+#endif
 
 	s3c_set_platdata(&pd, sizeof(pd), &s3c64xx_device_spi0);
 }
@@ -1589,6 +1593,9 @@ void __init s3c64xx_spi1_set_platdata(int (*cfg_gpio)(void), int src_clk_nr,
 	pd.num_cs = num_cs;
 	pd.src_clk_nr = src_clk_nr;
 	pd.cfg_gpio = (cfg_gpio) ? cfg_gpio : s3c64xx_spi1_cfg_gpio;
+#ifdef CONFIG_PL330_DMA
+	pd.filter = pl330_filter;
+#endif
 
 	s3c_set_platdata(&pd, sizeof(pd), &s3c64xx_device_spi1);
 }
@@ -1627,6 +1634,9 @@ void __init s3c64xx_spi2_set_platdata(int (*cfg_gpio)(void), int src_clk_nr,
 	pd.num_cs = num_cs;
 	pd.src_clk_nr = src_clk_nr;
 	pd.cfg_gpio = (cfg_gpio) ? cfg_gpio : s3c64xx_spi2_cfg_gpio;
+#ifdef CONFIG_PL330_DMA
+	pd.filter = pl330_filter;
+#endif
 
 	s3c_set_platdata(&pd, sizeof(pd), &s3c64xx_device_spi2);
 }
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index e862ab8..9be07a6 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -22,8 +22,10 @@
 #include <linux/workqueue.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/amba/pl330.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
@@ -31,7 +33,6 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 
-#include <mach/dma.h>
 #include <linux/platform_data/spi-s3c64xx.h>
 
 #define MAX_SPI_PORTS		3
@@ -131,9 +132,9 @@
 #define TXBUSY    (1<<3)
 
 struct s3c64xx_spi_dma_data {
-	unsigned		ch;
+	struct dma_chan *ch;
 	enum dma_transfer_direction direction;
-	enum dma_ch	dmach;
+	unsigned int request;
 };
 
 /**
@@ -195,16 +196,11 @@ struct s3c64xx_spi_driver_data {
 	unsigned                        cur_speed;
 	struct s3c64xx_spi_dma_data	rx_dma;
 	struct s3c64xx_spi_dma_data	tx_dma;
-	struct samsung_dma_ops		*ops;
 	struct s3c64xx_spi_port_config	*port_conf;
 	unsigned int			port_id;
 	unsigned long			gpios[4];
 };
 
-static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
-	.name = "samsung-spi-dma",
-};
-
 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
 {
 	void __iomem *regs = sdd->regs;
@@ -285,50 +281,42 @@ static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
 					unsigned len, dma_addr_t buf)
 {
 	struct s3c64xx_spi_driver_data *sdd;
-	struct samsung_dma_prep info;
-	struct samsung_dma_config config;
+	struct dma_slave_config config;
+	struct scatterlist sg;
+	struct dma_async_tx_descriptor *desc;
 
 	if (dma->direction == DMA_DEV_TO_MEM) {
 		sdd = container_of((void *)dma,
 			struct s3c64xx_spi_driver_data, rx_dma);
-		config.direction = sdd->rx_dma.direction;
-		config.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
-		config.width = sdd->cur_bpw / 8;
-		sdd->ops->config(sdd->rx_dma.ch, &config);
+		config.direction = dma->direction;
+		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
+		config.src_addr_width = sdd->cur_bpw / 8;
+		config.src_maxburst = 1;
+		dmaengine_slave_config(dma->ch, &config);
 	} else {
 		sdd = container_of((void *)dma,
 			struct s3c64xx_spi_driver_data, tx_dma);
-		config.direction =  sdd->tx_dma.direction;
-		config.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
-		config.width = sdd->cur_bpw / 8;
-		sdd->ops->config(sdd->tx_dma.ch, &config);
+		config.direction = dma->direction;
+		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
+		config.dst_addr_width = sdd->cur_bpw / 8;
+		config.dst_maxburst = 1;
+		dmaengine_slave_config(dma->ch, &config);
 	}
 
-	info.cap = DMA_SLAVE;
-	info.len = len;
-	info.fp = s3c64xx_spi_dmacb;
-	info.fp_param = dma;
-	info.direction = dma->direction;
-	info.buf = buf;
+	sg_init_table(&sg, 1);
+	sg_dma_len(&sg) = len;
+	sg_set_page(&sg, pfn_to_page(PFN_DOWN(buf)),
+		    len, offset_in_page(buf));
+	sg_dma_address(&sg) = buf;
 
-	sdd->ops->prepare(dma->ch, &info);
-	sdd->ops->trigger(dma->ch);
-}
+	desc = dmaengine_prep_slave_sg(dma->ch,
+		&sg, 1, dma->direction, DMA_PREP_INTERRUPT);
 
-static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
-{
-	struct samsung_dma_req req;
-	struct device *dev = &sdd->pdev->dev;
+	desc->callback = s3c64xx_spi_dmacb;
+	desc->callback_param = dma;
 
-	sdd->ops = samsung_dma_get_ops();
-
-	req.cap = DMA_SLAVE;
-	req.client = &s3c64xx_spi_dma_client;
-
-	sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &req, dev, "rx");
-	sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &req, dev, "tx");
-
-	return 1;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(dma->ch);
 }
 
 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
@@ -713,9 +701,9 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
 		}
 
 		/* Polling method for xfers not bigger than FIFO capacity */
-		if (xfer->len <= ((FIFO_LVL_MASK(sdd) >> 1) + 1))
-			use_dma = 0;
-		else
+		use_dma = 0;
+		if (sdd->rx_dma.ch && sdd->tx_dma.ch &&
+		    (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1)))
 			use_dma = 1;
 
 		spin_lock_irqsave(&sdd->lock, flags);
@@ -750,10 +738,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
 			if (use_dma) {
 				if (xfer->tx_buf != NULL
 						&& (sdd->state & TXBUSY))
-					sdd->ops->stop(sdd->tx_dma.ch);
+					dmaengine_terminate_all(sdd->tx_dma.ch);
 				if (xfer->rx_buf != NULL
 						&& (sdd->state & RXBUSY))
-					sdd->ops->stop(sdd->rx_dma.ch);
+					dmaengine_terminate_all(sdd->rx_dma.ch);
 			}
 
 			goto out;
@@ -793,11 +781,18 @@ out:
 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
 {
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
+	dma_filter_fn filter = sdd->cntrlr_info->filter;
+	struct device *dev = &sdd->pdev->dev;
+	dma_cap_mask_t mask;
 
-	/* Acquire DMA channels */
-	while (!acquire_dma(sdd))
-		usleep_range(10000, 11000);
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
 
+	/* Acquire DMA channels */
+	sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter,
+				(void*)sdd->rx_dma.request, dev, "rx");
+	sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter,
+				(void*)sdd->tx_dma.request, dev, "tx");
 	pm_runtime_get_sync(&sdd->pdev->dev);
 
 	return 0;
@@ -808,11 +803,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
 
 	/* Free DMA channels */
-	sdd->ops->release(sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
-	sdd->ops->release(sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
+	dma_release_channel(sdd->rx_dma.ch);
+	dma_release_channel(sdd->tx_dma.ch);
 
 	pm_runtime_put(&sdd->pdev->dev);
-
 	return 0;
 }
 
@@ -1149,7 +1143,6 @@ static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
 static int s3c64xx_spi_probe(struct platform_device *pdev)
 {
 	struct resource	*mem_res;
-	struct resource	*res;
 	struct s3c64xx_spi_driver_data *sdd;
 	struct s3c64xx_spi_info *sci = pdev->dev.platform_data;
 	struct spi_master *master;
@@ -1207,15 +1200,15 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 	}
 
 	sdd->cur_bpw = 8;
-
 	if (!sdd->pdev->dev.of_node) {
+		struct resource	*res;
 		res = platform_get_resource(pdev, IORESOURCE_DMA,  0);
 		if (!res) {
 			dev_err(&pdev->dev, "Unable to get SPI tx dma "
 					"resource\n");
 			return -ENXIO;
 		}
-		sdd->tx_dma.dmach = res->start;
+		sdd->tx_dma.request = res->start;
 
 		res = platform_get_resource(pdev, IORESOURCE_DMA,  1);
 		if (!res) {
@@ -1223,12 +1216,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 					"resource\n");
 			return -ENXIO;
 		}
-		sdd->rx_dma.dmach = res->start;
+		sdd->rx_dma.request = res->start;
 	}
 
 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
-
 	master->dev.of_node = pdev->dev.of_node;
 	master->bus_num = sdd->port_id;
 	master->setup = s3c64xx_spi_setup;
@@ -1314,8 +1306,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 					sdd->port_id, master->num_chipselect);
 	dev_dbg(&pdev->dev, "\tIOmem=[0x%x-0x%x]\tDMA=[Rx-%d, Tx-%d]\n",
 					mem_res->end, mem_res->start,
-					sdd->rx_dma.dmach, sdd->tx_dma.dmach);
-
+					sdd->rx_dma.request, sdd->tx_dma.request);
 	pm_runtime_enable(&pdev->dev);
 
 	return 0;
diff --git a/include/linux/platform_data/spi-s3c64xx.h b/include/linux/platform_data/spi-s3c64xx.h
index ceba18d..8447f63 100644
--- a/include/linux/platform_data/spi-s3c64xx.h
+++ b/include/linux/platform_data/spi-s3c64xx.h
@@ -11,6 +11,8 @@
 #ifndef __S3C64XX_PLAT_SPI_H
 #define __S3C64XX_PLAT_SPI_H
 
+#include <linux/dmaengine.h>
+
 struct platform_device;
 
 /**
@@ -38,6 +40,7 @@ struct s3c64xx_spi_info {
 	int src_clk_nr;
 	int num_cs;
 	int (*cfg_gpio)(void);
+	dma_filter_fn filter;
 };
 
 /**
-- 
1.8.1.2