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omap3: nand: prefetch in irq mode support 

This patch enable prefetch-irq mode for nand transfer(read, write)

Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Sukumar Ghorai 2011-01-28 15:42:06 +05:30 committed by Tony Lindgren
parent db97eb7dfe
commit 4e07037616
3 changed files with 194 additions and 10 deletions
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2
arch/arm/mach-omap2/board-flash.c
View File

@ -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

4
arch/arm/plat-omap/include/plat/nand.h
View File

@ -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;

198
drivers/mtd/nand/omap2.c
View File

@ -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);