mmc: s3cmci: port DMA code to dmaengine API

Utilise new s3c24xx-dma dmaengine driver for DMA ops.

Signed-off-by: Vasily Khoruzhick <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/Kconfig

···
 config MMC_S3C
 	tristate "Samsung S3C SD/MMC Card Interface support"
 	depends on ARCH_S3C24XX
+	depends on S3C24XX_DMAC
 	help
 	  This selects a driver for the MCI interface found in
           Samsung's S3C2410, S3C2412, S3C2440, S3C2442 CPUs.
···
 	  Currently, the DMA support in this driver seems to not be
 	  working properly and needs to be debugged before this
 	  option is useful.
-
-config MMC_S3C_PIODMA
-	bool "Support for both PIO and DMA"
-	help
-	  Compile both the PIO and DMA transfer routines into the
-	  driver and let the platform select at run-time which one
-	  is best.
-
-	  See notes for the DMA option.
 
 endchoice
 

drivers/mmc/host/s3cmci.c

···
  */
 
 #include <linux/module.h>
+#include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/clk.h>
 #include <linux/mmc/host.h>
···
 #include <mach/dma.h>
 #include <mach/gpio-samsung.h>
 
+#include <linux/platform_data/dma-s3c24xx.h>
 #include <linux/platform_data/mmc-s3cmci.h>
 
 #include "s3cmci.h"
···
 		dev_dbg(&host->pdev->dev, args);  \
 	} while (0)
 
-static struct s3c2410_dma_client s3cmci_dma_client = {
-	.name		= "s3c-mci",
-};
-
 static void finalize_request(struct s3cmci_host *host);
 static void s3cmci_send_request(struct mmc_host *mmc);
 static void s3cmci_reset(struct s3cmci_host *host);
···
 {
 #ifdef CONFIG_MMC_S3C_PIO
 	return false;
-#elif defined(CONFIG_MMC_S3C_DMA)
+#else /* CONFIG_MMC_S3C_DMA */
 	return true;
-#else
-	return host->dodma;
-#endif
-}
-
-/**
- * s3cmci_host_canpio - return true if host has pio code available
- *
- * Return true if the driver has been compiled with the PIO support code
- * available.
- */
-static inline bool s3cmci_host_canpio(void)
-{
-#ifdef CONFIG_MMC_S3C_PIO
-	return true;
-#else
-	return false;
 #endif
 }
 
···
 	return IRQ_HANDLED;
 }
 
-static void s3cmci_dma_done_callback(struct s3c2410_dma_chan *dma_ch,
-				     void *buf_id, int size,
-				     enum s3c2410_dma_buffresult result)
+static void s3cmci_dma_done_callback(void *arg)
 {
-	struct s3cmci_host *host = buf_id;
+	struct s3cmci_host *host = arg;
 	unsigned long iflags;
-	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt;
-
-	mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
-	mci_dsta = readl(host->base + S3C2410_SDIDSTA);
-	mci_fsta = readl(host->base + S3C2410_SDIFSTA);
-	mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
 
 	BUG_ON(!host->mrq);
 	BUG_ON(!host->mrq->data);
-	BUG_ON(!host->dmatogo);
 
 	spin_lock_irqsave(&host->complete_lock, iflags);
 
-	if (result != S3C2410_RES_OK) {
-		dbg(host, dbg_fail, "DMA FAILED: csta=0x%08x dsta=0x%08x "
-			"fsta=0x%08x dcnt:0x%08x result:0x%08x toGo:%u\n",
-			mci_csta, mci_dsta, mci_fsta,
-			mci_dcnt, result, host->dmatogo);
-
-		goto fail_request;
-	}
-
-	host->dmatogo--;
-	if (host->dmatogo) {
-		dbg(host, dbg_dma, "DMA DONE  Size:%i DSTA:[%08x] "
-			"DCNT:[%08x] toGo:%u\n",
-			size, mci_dsta, mci_dcnt, host->dmatogo);
-
-		goto out;
-	}
-
-	dbg(host, dbg_dma, "DMA FINISHED Size:%i DSTA:%08x DCNT:%08x\n",
-		size, mci_dsta, mci_dcnt);
+	dbg(host, dbg_dma, "DMA FINISHED\n");
 
 	host->dma_complete = 1;
 	host->complete_what = COMPLETION_FINALIZE;
 
-out:
 	tasklet_schedule(&host->pio_tasklet);
 	spin_unlock_irqrestore(&host->complete_lock, iflags);
-	return;
 
-fail_request:
-	host->mrq->data->error = -EINVAL;
-	host->complete_what = COMPLETION_FINALIZE;
-	clear_imask(host);
-
-	goto out;
 }
 
 static void finalize_request(struct s3cmci_host *host)
···
 	 * DMA channel and the fifo to clear out any garbage. */
 	if (mrq->data->error != 0) {
 		if (s3cmci_host_usedma(host))
-			s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
+			dmaengine_terminate_all(host->dma);
 
 		if (host->is2440) {
 			/* Clear failure register and reset fifo. */
···
 
 	s3cmci_check_sdio_irq(host);
 	mmc_request_done(host->mmc, mrq);
-}
-
-static void s3cmci_dma_setup(struct s3cmci_host *host,
-			     enum dma_data_direction source)
-{
-	static enum dma_data_direction last_source = -1;
-	static int setup_ok;
-
-	if (last_source == source)
-		return;
-
-	last_source = source;
-
-	s3c2410_dma_devconfig(host->dma, source,
-			      host->mem->start + host->sdidata);
-
-	if (!setup_ok) {
-		s3c2410_dma_config(host->dma, 4);
-		s3c2410_dma_set_buffdone_fn(host->dma,
-					    s3cmci_dma_done_callback);
-		s3c2410_dma_setflags(host->dma, S3C2410_DMAF_AUTOSTART);
-		setup_ok = 1;
-	}
 }
 
 static void s3cmci_send_command(struct s3cmci_host *host,
···
 
 static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
 {
-	int dma_len, i;
 	int rw = data->flags & MMC_DATA_WRITE;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config conf = {
+		.src_addr = host->mem->start + host->sdidata,
+		.dst_addr = host->mem->start + host->sdidata,
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+	};
 
 	BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
 
-	s3cmci_dma_setup(host, rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-	s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
+	/* Restore prescaler value */
+	writel(host->prescaler, host->base + S3C2410_SDIPRE);
 
-	dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+	if (!rw)
+		conf.direction = DMA_DEV_TO_MEM;
+	else
+		conf.direction = DMA_MEM_TO_DEV;
+
+	dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
 			     rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 
-	if (dma_len == 0)
-		return -ENOMEM;
-
-	host->dma_complete = 0;
-	host->dmatogo = dma_len;
-
-	for (i = 0; i < dma_len; i++) {
-		int res;
-
-		dbg(host, dbg_dma, "enqueue %i: %08x@%u\n", i,
-		    sg_dma_address(&data->sg[i]),
-		    sg_dma_len(&data->sg[i]));
-
-		res = s3c2410_dma_enqueue(host->dma, host,
-					  sg_dma_address(&data->sg[i]),
-					  sg_dma_len(&data->sg[i]));
-
-		if (res) {
-			s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
-			return -EBUSY;
-		}
-	}
-
-	s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_START);
+	dmaengine_slave_config(host->dma, &conf);
+	desc = dmaengine_prep_slave_sg(host->dma, data->sg, data->sg_len,
+		conf.direction,
+		DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	if (!desc)
+		goto unmap_exit;
+	desc->callback = s3cmci_dma_done_callback;
+	desc->callback_param = host;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(host->dma);
 
 	return 0;
+
+unmap_exit:
+	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+			     rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	return -ENOMEM;
 }
 
 static void s3cmci_send_request(struct mmc_host *mmc)
···
 	host->complete_what 	= COMPLETION_NONE;
 	host->pio_active 	= XFER_NONE;
 
-#ifdef CONFIG_MMC_S3C_PIODMA
-	host->dodma		= host->pdata->use_dma;
-#endif
-
 	host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!host->mem) {
 		dev_err(&pdev->dev,
···
 	/* depending on the dma state, get a dma channel to use. */
 
 	if (s3cmci_host_usedma(host)) {
-		host->dma = s3c2410_dma_request(DMACH_SDI, &s3cmci_dma_client,
-						host);
-		if (host->dma < 0) {
+		dma_cap_mask_t mask;
+
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+
+		host->dma = dma_request_slave_channel_compat(mask,
+			s3c24xx_dma_filter, (void *)DMACH_SDI, &pdev->dev, "rx-tx");
+		if (!host->dma) {
 			dev_err(&pdev->dev, "cannot get DMA channel.\n");
-			if (!s3cmci_host_canpio()) {
-				ret = -EBUSY;
-				goto probe_free_gpio_wp;
-			} else {
-				dev_warn(&pdev->dev, "falling back to PIO.\n");
-				host->dodma = 0;
-			}
+			ret = -EBUSY;
+			goto probe_free_gpio_wp;
 		}
 	}
 
···
 	mmc->max_segs		= 128;
 
 	dbg(host, dbg_debug,
-	    "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%u.\n",
+	    "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%p.\n",
 	    (host->is2440?"2440":""),
 	    host->base, host->irq, host->irq_cd, host->dma);
 
···
 
  probe_free_dma:
 	if (s3cmci_host_usedma(host))
-		s3c2410_dma_free(host->dma, &s3cmci_dma_client);
+		dma_release_channel(host->dma);
 
  probe_free_gpio_wp:
 	if (!host->pdata->no_wprotect)
···
 	tasklet_disable(&host->pio_tasklet);
 
 	if (s3cmci_host_usedma(host))
-		s3c2410_dma_free(host->dma, &s3cmci_dma_client);
+		dma_release_channel(host->dma);
 
 	free_irq(host->irq, host);
 

drivers/mmc/host/s3cmci.h

···
 	void __iomem		*base;
 	int			irq;
 	int			irq_cd;
-	int			dma;
+	struct dma_chan		*dma;
 
 	unsigned long		clk_rate;
 	unsigned long		clk_div;
···
 	int			is2440;
 	unsigned		sdiimsk;
 	unsigned		sdidata;
-	int			dodma;
-	int			dmatogo;
 
 	bool			irq_disabled;
 	bool			irq_enabled;