omap3: nand: configurable transfer type per board

nand transfer type (sDMA, Polled, prefetch) can be select from board file,
enabling all transfer type in driver, by default.

this helps in multi-omap build and to select different transfer type for
different board.

Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

3 files changed, 41 insertions, 77 deletions

diff --git a/arch/arm/plat-omap/include/plat/nand.h b/arch/arm/plat-omap/include/plat/nand.h
index 6562cd082bb1..78c0bdb98c18 100644
--- a/arch/arm/plat-omap/include/plat/nand.h
+++ b/arch/arm/plat-omap/include/plat/nand.h
@@ -10,6 +10,12 @@
 
 #include <linux/mtd/partitions.h>
 
+enum nand_io {
+        NAND_OMAP_PREFETCH_POLLED = 0,  /* prefetch polled mode, default */
+        NAND_OMAP_POLLED,               /* polled mode, without prefetch */
+        NAND_OMAP_PREFETCH_DMA          /* prefetch enabled sDMA mode */
+};
+
 struct omap_nand_platform_data {
         unsigned int            options;
         int                     cs;
@@ -20,6 +26,7 @@ struct omap_nand_platform_data {
         int                     (*nand_setup)(void);
         int                     (*dev_ready)(struct omap_nand_platform_data *);
         int                     dma_channel;
+        enum nand_io            xfer_type;
         unsigned long           phys_base;
         int                     devsize;
 };
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index c89592239bc7..178e2006063d 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -106,23 +106,6 @@ config MTD_NAND_OMAP2
         help
           Support for NAND flash on Texas Instruments OMAP2 and OMAP3 platforms.
 
-config MTD_NAND_OMAP_PREFETCH
-        bool "GPMC prefetch support for NAND Flash device"
-        depends on MTD_NAND_OMAP2
-        default y
-        help
-         The NAND device can be accessed for Read/Write using GPMC PREFETCH engine
-         to improve the performance.
-
-config MTD_NAND_OMAP_PREFETCH_DMA
-        depends on MTD_NAND_OMAP_PREFETCH
-        bool "DMA mode"
-        default n
-        help
-         The GPMC PREFETCH engine can be configured eigther in MPU interrupt mode
-         or in DMA interrupt mode.
-         Say y for DMA mode or MPU mode will be used
-
 config MTD_NAND_IDS
         tristate
 
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 7c04cd6fb7aa..60bac8e6e9fa 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -96,27 +96,6 @@
 static const char *part_probes[] = { "cmdlinepart", NULL };
 #endif
 
-#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH
-static int use_prefetch = 1;
-
-/* "modprobe ... use_prefetch=0" etc */
-module_param(use_prefetch, bool, 0);
-MODULE_PARM_DESC(use_prefetch, "enable/disable use of PREFETCH");
-
-#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH_DMA
-static int use_dma = 1;
-
-/* "modprobe ... use_dma=0" etc */
-module_param(use_dma, bool, 0);
-MODULE_PARM_DESC(use_dma, "enable/disable use of DMA");
-#else
-static const int use_dma;
-#endif
-#else
-const int use_prefetch;
-static const int use_dma;
-#endif
-
 struct omap_nand_info {
         struct nand_hw_control          controller;
         struct omap_nand_platform_data  *pdata;
@@ -324,7 +303,6 @@ static void omap_write_buf_pref(struct mtd_info *mtd,
         }
 }
 
-#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH_DMA
 /*
  * omap_nand_dma_cb: callback on the completion of dma transfer
  * @lch: logical channel
@@ -426,14 +404,6 @@ out_copy:
                         : omap_write_buf8(mtd, (u_char *) addr, len);
         return 0;
 }
-#else
-static void omap_nand_dma_cb(int lch, u16 ch_status, void *data) {}
-static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
-                                        unsigned int len, int is_write)
-{
-        return 0;
-}
-#endif
 
 /**
  * omap_read_buf_dma_pref - read data from NAND controller into buffer
@@ -842,28 +812,13 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
                 info->nand.chip_delay = 50;
         }
 
-        if (use_prefetch) {
-
+        switch (pdata->xfer_type) {
+        case NAND_OMAP_PREFETCH_POLLED:
                 info->nand.read_buf   = omap_read_buf_pref;
                 info->nand.write_buf  = omap_write_buf_pref;
-                if (use_dma) {
-                        err = omap_request_dma(OMAP24XX_DMA_GPMC, "NAND",
-                                omap_nand_dma_cb, &info->comp, &info->dma_ch);
-                        if (err < 0) {
-                                info->dma_ch = -1;
-                                printk(KERN_WARNING "DMA request failed."
-                                        " Non-dma data transfer mode\n");
-                        } else {
-                                omap_set_dma_dest_burst_mode(info->dma_ch,
-                                                OMAP_DMA_DATA_BURST_16);
-                                omap_set_dma_src_burst_mode(info->dma_ch,
-                                                OMAP_DMA_DATA_BURST_16);
-
-                                info->nand.read_buf   = omap_read_buf_dma_pref;
-                                info->nand.write_buf  = omap_write_buf_dma_pref;
-                        }
-                }
-        } else {
+                break;
+
+        case NAND_OMAP_POLLED:
                 if (info->nand.options & NAND_BUSWIDTH_16) {
                         info->nand.read_buf   = omap_read_buf16;
                         info->nand.write_buf  = omap_write_buf16;
@@ -871,7 +826,33 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
                         info->nand.read_buf   = omap_read_buf8;
                         info->nand.write_buf  = omap_write_buf8;
                 }
+                break;
+
+        case NAND_OMAP_PREFETCH_DMA:
+                err = omap_request_dma(OMAP24XX_DMA_GPMC, "NAND",
+                                omap_nand_dma_cb, &info->comp, &info->dma_ch);
+                if (err < 0) {
+                        info->dma_ch = -1;
+                        dev_err(&pdev->dev, "DMA request failed!\n");
+                        goto out_release_mem_region;
+                } else {
+                        omap_set_dma_dest_burst_mode(info->dma_ch,
+                                        OMAP_DMA_DATA_BURST_16);
+                        omap_set_dma_src_burst_mode(info->dma_ch,
+                                        OMAP_DMA_DATA_BURST_16);
+
+                        info->nand.read_buf   = omap_read_buf_dma_pref;
+                        info->nand.write_buf  = omap_write_buf_dma_pref;
+                }
+                break;
+
+        default:
+                dev_err(&pdev->dev,
+                        "xfer_type(%d) not supported!\n", pdata->xfer_type);
+                err = -EINVAL;
+                goto out_release_mem_region;
         }
+
         info->nand.verify_buf = omap_verify_buf;
 
 #ifdef CONFIG_MTD_NAND_OMAP_HWECC
@@ -897,6 +878,7 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
                 }
         }
 
+
 #ifdef CONFIG_MTD_PARTITIONS
         err = parse_mtd_partitions(&info->mtd, part_probes, &info->parts, 0);
         if (err > 0)
@@ -926,7 +908,7 @@ static int omap_nand_remove(struct platform_device *pdev)
                                                         mtd);
 
         platform_set_drvdata(pdev, NULL);
-        if (use_dma)
+        if (info->dma_ch != -1)
                 omap_free_dma(info->dma_ch);
 
         /* Release NAND device, its internal structures and partitions */
@@ -947,16 +929,8 @@ static struct platform_driver omap_nand_driver = {
 
 static int __init omap_nand_init(void)
 {
-        printk(KERN_INFO "%s driver initializing\n", DRIVER_NAME);
+        pr_info("%s driver initializing\n", DRIVER_NAME);
 
-        /* This check is required if driver is being
-         * loaded run time as a module
-         */
-        if ((1 == use_dma) && (0 == use_prefetch)) {
-                printk(KERN_INFO"Wrong parameters: 'use_dma' can not be 1 "
-                                "without use_prefetch'. Prefetch will not be"
-                                " used in either mode (mpu or dma)\n");
-        }
         return platform_driver_register(&omap_nand_driver);
 }