[PATCH v8 4/7] omap3: nand: prefetch in irq mode support
Sukumar Ghorai
s-ghorai at ti.com
Fri Jul 8 13:49:54 EDT 2011
This patch enable prefetch-irq mode for nand transfer(read, write)
Signed-off-by: Vimal Singh <vimalsingh at ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai at ti.com>
---
arch/arm/mach-omap2/board-flash.c | 2 +
arch/arm/plat-omap/include/plat/nand.h | 4 +-
drivers/mtd/nand/omap2.c | 198 ++++++++++++++++++++++++++++++--
3 files changed, 194 insertions(+), 10 deletions(-)
diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c
index f6b7253..1964509 100644
--- a/arch/arm/mach-omap2/board-flash.c
+++ b/arch/arm/mach-omap2/board-flash.c
@@ -16,6 +16,7 @@
#include <linux/platform_device.h>
#include <linux/mtd/physmap.h>
#include <linux/io.h>
+#include <plat/irqs.h>
#include <plat/gpmc.h>
#include <plat/nand.h>
@@ -147,6 +148,7 @@ __init board_nand_init(struct mtd_partition *nand_parts,
board_nand_data.nr_parts = nr_parts;
board_nand_data.devsize = nand_type;
+ board_nand_data.gpmc_irq = OMAP_GPMC_IRQ_BASE + cs;
gpmc_nand_init(&board_nand_data);
}
#else
diff --git a/arch/arm/plat-omap/include/plat/nand.h b/arch/arm/plat-omap/include/plat/nand.h
index 78c0bdb..ae5e053 100644
--- a/arch/arm/plat-omap/include/plat/nand.h
+++ b/arch/arm/plat-omap/include/plat/nand.h
@@ -13,7 +13,8 @@
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 */
+ NAND_OMAP_PREFETCH_DMA, /* prefetch enabled sDMA mode */
+ NAND_OMAP_PREFETCH_IRQ /* prefetch enabled irq mode */
};
struct omap_nand_platform_data {
@@ -26,6 +27,7 @@ struct omap_nand_platform_data {
int (*nand_setup)(void);
int (*dev_ready)(struct omap_nand_platform_data *);
int dma_channel;
+ int gpmc_irq;
enum nand_io xfer_type;
unsigned long phys_base;
int devsize;
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 60bac8e..fbe8414 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -11,6 +11,7 @@
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
+#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/mtd/mtd.h>
@@ -24,6 +25,7 @@
#include <plat/nand.h>
#define DRIVER_NAME "omap2-nand"
+#define OMAP_NAND_TIMEOUT_MS 5000
#define NAND_Ecc_P1e (1 << 0)
#define NAND_Ecc_P2e (1 << 1)
@@ -108,6 +110,13 @@ struct omap_nand_info {
unsigned long phys_base;
struct completion comp;
int dma_ch;
+ int gpmc_irq;
+ enum {
+ OMAP_NAND_IO_READ = 0, /* read */
+ OMAP_NAND_IO_WRITE, /* write */
+ } iomode;
+ u_char *buf;
+ int buf_len;
};
/**
@@ -267,9 +276,10 @@ static void omap_write_buf_pref(struct mtd_info *mtd,
{
struct omap_nand_info *info = container_of(mtd,
struct omap_nand_info, mtd);
- uint32_t pref_count = 0, w_count = 0;
+ uint32_t w_count = 0;
int i = 0, ret = 0;
u16 *p;
+ unsigned long tim, limit;
/* take care of subpage writes */
if (len % 2 != 0) {
@@ -295,9 +305,12 @@ static void omap_write_buf_pref(struct mtd_info *mtd,
iowrite16(*p++, info->nand.IO_ADDR_W);
}
/* wait for data to flushed-out before reset the prefetch */
- do {
- pref_count = gpmc_read_status(GPMC_PREFETCH_COUNT);
- } while (pref_count);
+ tim = 0;
+ limit = (loops_per_jiffy *
+ msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
+ while (gpmc_read_status(GPMC_PREFETCH_COUNT) && (tim++ < limit))
+ cpu_relax();
+
/* disable and stop the PFPW engine */
gpmc_prefetch_reset(info->gpmc_cs);
}
@@ -326,11 +339,11 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
{
struct omap_nand_info *info = container_of(mtd,
struct omap_nand_info, mtd);
- uint32_t prefetch_status = 0;
enum dma_data_direction dir = is_write ? DMA_TO_DEVICE :
DMA_FROM_DEVICE;
dma_addr_t dma_addr;
int ret;
+ unsigned long tim, limit;
/* The fifo depth is 64 bytes. We have a sync at each frame and frame
* length is 64 bytes.
@@ -376,7 +389,7 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
/* configure and start prefetch transfer */
ret = gpmc_prefetch_enable(info->gpmc_cs, 0x1, len, is_write);
if (ret)
- /* PFPW engine is busy, use cpu copy methode */
+ /* PFPW engine is busy, use cpu copy method */
goto out_copy;
init_completion(&info->comp);
@@ -385,10 +398,11 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
/* setup and start DMA using dma_addr */
wait_for_completion(&info->comp);
+ tim = 0;
+ limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
+ while (gpmc_read_status(GPMC_PREFETCH_COUNT) && (tim++ < limit))
+ cpu_relax();
- do {
- prefetch_status = gpmc_read_status(GPMC_PREFETCH_COUNT);
- } while (prefetch_status);
/* disable and stop the PFPW engine */
gpmc_prefetch_reset(info->gpmc_cs);
@@ -436,6 +450,155 @@ static void omap_write_buf_dma_pref(struct mtd_info *mtd,
omap_nand_dma_transfer(mtd, (u_char *) buf, len, 0x1);
}
+/*
+ * omap_nand_irq - GMPC irq handler
+ * @this_irq: gpmc irq number
+ * @dev: omap_nand_info structure pointer is passed here
+ */
+static irqreturn_t omap_nand_irq(int this_irq, void *dev)
+{
+ struct omap_nand_info *info = (struct omap_nand_info *) dev;
+ u32 bytes;
+ u32 irq_stat;
+
+ irq_stat = gpmc_read_status(GPMC_GET_IRQ_STATUS);
+ bytes = gpmc_read_status(GPMC_PREFETCH_FIFO_CNT);
+ bytes = bytes & 0xFFFC; /* io in multiple of 4 bytes */
+ if (info->iomode == OMAP_NAND_IO_WRITE) { /* checks for write io */
+ if (irq_stat & 0x2)
+ goto done;
+
+ if (info->buf_len && (info->buf_len < bytes))
+ bytes = info->buf_len;
+ else if (!info->buf_len)
+ bytes = 0;
+ iowrite32_rep(info->nand.IO_ADDR_W,
+ (u32 *)info->buf, bytes >> 2);
+ info->buf = info->buf + bytes;
+ info->buf_len -= bytes;
+
+ } else {
+ ioread32_rep(info->nand.IO_ADDR_R,
+ (u32 *)info->buf, bytes >> 2);
+ info->buf = info->buf + bytes;
+
+ if (irq_stat & 0x2)
+ goto done;
+ }
+ gpmc_cs_configure(info->gpmc_cs, GPMC_SET_IRQ_STATUS, irq_stat);
+
+ return IRQ_HANDLED;
+
+done:
+ complete(&info->comp);
+ /* disable irq */
+ gpmc_cs_configure(info->gpmc_cs, GPMC_ENABLE_IRQ, 0);
+
+ /* clear status */
+ gpmc_cs_configure(info->gpmc_cs, GPMC_SET_IRQ_STATUS, irq_stat);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * omap_read_buf_irq_pref - read data from NAND controller into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ */
+static void omap_read_buf_irq_pref(struct mtd_info *mtd, u_char *buf, int len)
+{
+ struct omap_nand_info *info = container_of(mtd,
+ struct omap_nand_info, mtd);
+ int ret = 0;
+
+ if (len <= mtd->oobsize) {
+ omap_read_buf_pref(mtd, buf, len);
+ return;
+ }
+
+ info->iomode = OMAP_NAND_IO_READ;
+ info->buf = buf;
+ init_completion(&info->comp);
+
+ /* configure and start prefetch transfer */
+ ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x0);
+ if (ret)
+ /* PFPW engine is busy, use cpu copy method */
+ goto out_copy;
+
+ info->buf_len = len;
+ /* enable irq */
+ gpmc_cs_configure(info->gpmc_cs, GPMC_ENABLE_IRQ,
+ (GPMC_IRQ_FIFOEVENTENABLE | GPMC_IRQ_COUNT_EVENT));
+
+ /* waiting for read to complete */
+ wait_for_completion(&info->comp);
+
+ /* disable and stop the PFPW engine */
+ gpmc_prefetch_reset(info->gpmc_cs);
+ return;
+
+out_copy:
+ if (info->nand.options & NAND_BUSWIDTH_16)
+ omap_read_buf16(mtd, buf, len);
+ else
+ omap_read_buf8(mtd, buf, len);
+}
+
+/*
+ * omap_write_buf_irq_pref - write buffer to NAND controller
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ */
+static void omap_write_buf_irq_pref(struct mtd_info *mtd,
+ const u_char *buf, int len)
+{
+ struct omap_nand_info *info = container_of(mtd,
+ struct omap_nand_info, mtd);
+ int ret = 0;
+ unsigned long tim, limit;
+
+ if (len <= mtd->oobsize) {
+ omap_write_buf_pref(mtd, buf, len);
+ return;
+ }
+
+ info->iomode = OMAP_NAND_IO_WRITE;
+ info->buf = (u_char *) buf;
+ init_completion(&info->comp);
+
+ /* configure and start prefetch transfer */
+ ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x1);
+ if (ret)
+ /* PFPW engine is busy, use cpu copy method */
+ goto out_copy;
+
+ info->buf_len = len;
+ /* enable irq */
+ gpmc_cs_configure(info->gpmc_cs, GPMC_ENABLE_IRQ,
+ (GPMC_IRQ_FIFOEVENTENABLE | GPMC_IRQ_COUNT_EVENT));
+
+ /* waiting for write to complete */
+ wait_for_completion(&info->comp);
+ /* wait for data to flushed-out before reset the prefetch */
+ tim = 0;
+ limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
+ while (gpmc_read_status(GPMC_PREFETCH_COUNT) && (tim++ < limit))
+ cpu_relax();
+
+ /* disable and stop the PFPW engine */
+ gpmc_prefetch_reset(info->gpmc_cs);
+ return;
+
+out_copy:
+ if (info->nand.options & NAND_BUSWIDTH_16)
+ omap_write_buf16(mtd, buf, len);
+ else
+ omap_write_buf8(mtd, buf, len);
+}
+
/**
* omap_verify_buf - Verify chip data against buffer
* @mtd: MTD device structure
@@ -846,6 +1009,20 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
}
break;
+ case NAND_OMAP_PREFETCH_IRQ:
+ err = request_irq(pdata->gpmc_irq,
+ omap_nand_irq, IRQF_SHARED, "gpmc-nand", info);
+ if (err) {
+ dev_err(&pdev->dev, "requesting irq(%d) error:%d",
+ pdata->gpmc_irq, err);
+ goto out_release_mem_region;
+ } else {
+ info->gpmc_irq = pdata->gpmc_irq;
+ info->nand.read_buf = omap_read_buf_irq_pref;
+ info->nand.write_buf = omap_write_buf_irq_pref;
+ }
+ break;
+
default:
dev_err(&pdev->dev,
"xfer_type(%d) not supported!\n", pdata->xfer_type);
@@ -911,6 +1088,9 @@ static int omap_nand_remove(struct platform_device *pdev)
if (info->dma_ch != -1)
omap_free_dma(info->dma_ch);
+ if (info->gpmc_irq)
+ free_irq(info->gpmc_irq, info);
+
/* Release NAND device, its internal structures and partitions */
nand_release(&info->mtd);
iounmap(info->nand.IO_ADDR_R);
--
1.7.0.4
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