[PATCH v3 1/4] omap3: nand: prefetch in irq mode support
Sukumar Ghorai
s-ghorai at ti.com
Tue Jul 13 00:45:34 EDT 2010
This patch enable prefetch-irq mode for NAND.
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 | 1 +
arch/arm/mach-omap2/gpmc.c | 4 +
arch/arm/mach-omap2/include/mach/board-flash.h | 3 +
arch/arm/plat-omap/include/plat/gpmc.h | 4 +
arch/arm/plat-omap/include/plat/nand.h | 1 +
drivers/mtd/nand/Kconfig | 14 ++-
drivers/mtd/nand/omap2.c | 196 +++++++++++++++++++++++-
7 files changed, 217 insertions(+), 6 deletions(-)
diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c
index ac834aa..c6a07dd 100644
--- a/arch/arm/mach-omap2/board-flash.c
+++ b/arch/arm/mach-omap2/board-flash.c
@@ -133,6 +133,7 @@ static struct omap_nand_platform_data board_nand_data = {
.nand_setup = NULL,
.gpmc_t = &nand_timings,
.dma_channel = -1, /* disable DMA in OMAP NAND driver */
+ .gpmc_irq = GPMC_IRQ_NUMBER,
.dev_ready = NULL,
.devsize = 0, /* '0' for 8-bit, '1' for 16-bit device */
};
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index e301e7e..2c100e4 100755
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -487,6 +487,10 @@ int gpmc_cs_configure(int cs, int cmd, int wval)
u32 regval = 0;
switch (cmd) {
+ case GPMC_ENABLE_IRQ:
+ gpmc_write_reg(GPMC_IRQENABLE, wval);
+ break;
+
case GPMC_SET_IRQ_STATUS:
gpmc_write_reg(GPMC_IRQSTATUS, wval);
break;
diff --git a/arch/arm/mach-omap2/include/mach/board-flash.h b/arch/arm/mach-omap2/include/mach/board-flash.h
index b2242ae..37567a7 100644
--- a/arch/arm/mach-omap2/include/mach/board-flash.h
+++ b/arch/arm/mach-omap2/include/mach/board-flash.h
@@ -19,6 +19,9 @@
#define PDC_ONENAND 3
#define DBG_MPDB 4
+/* Interrupt number to the MPU Subsystem for GPMC */
+#define GPMC_IRQ_NUMBER 20
+
struct flash_partitions {
struct mtd_partition *parts;
int nr_parts;
diff --git a/arch/arm/plat-omap/include/plat/gpmc.h b/arch/arm/plat-omap/include/plat/gpmc.h
index 9fd99b9..054e704 100644
--- a/arch/arm/plat-omap/include/plat/gpmc.h
+++ b/arch/arm/plat-omap/include/plat/gpmc.h
@@ -41,6 +41,8 @@
#define GPMC_NAND_ADDRESS 0x0000000b
#define GPMC_NAND_DATA 0x0000000c
+#define GPMC_ENABLE_IRQ 0x0000000d
+
/* ECC commands */
#define GPMC_ECC_READ 0 /* Reset Hardware ECC for read */
#define GPMC_ECC_WRITE 1 /* Reset Hardware ECC for write */
@@ -78,6 +80,8 @@
#define WR_RD_PIN_MONITORING 0x00600000
#define GPMC_PREFETCH_STATUS_FIFO_CNT(val) ((val >> 24) & 0x7F)
#define GPMC_PREFETCH_STATUS_COUNT(val) (val & 0x00003fff)
+#define GPMC_IRQ_FIFOEVENTENABLE 0x01
+#define GPMC_IRQ_COUNT_EVENT 0x02
/*
* Note that all values in this struct are in nanoseconds, while
diff --git a/arch/arm/plat-omap/include/plat/nand.h b/arch/arm/plat-omap/include/plat/nand.h
index 6562cd0..5e69463 100644
--- a/arch/arm/plat-omap/include/plat/nand.h
+++ b/arch/arm/plat-omap/include/plat/nand.h
@@ -20,6 +20,7 @@ struct omap_nand_platform_data {
int (*nand_setup)(void);
int (*dev_ready)(struct omap_nand_platform_data *);
int dma_channel;
+ int gpmc_irq;
unsigned long phys_base;
int devsize;
};
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index ffc3720..46361ef 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -112,6 +112,9 @@ config MTD_NAND_OMAP_PREFETCH
help
The NAND device can be accessed for Read/Write using GPMC PREFETCH engine
to improve the performance.
+ GPMC PREFETCH can be configured eigther in MPU interrupt mode or in DMA
+ interrupt mode. If not selected any of them prefetch will be used in
+ polling mode.
config MTD_NAND_OMAP_PREFETCH_DMA
depends on MTD_NAND_OMAP_PREFETCH
@@ -120,7 +123,16 @@ config MTD_NAND_OMAP_PREFETCH_DMA
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
+ Say y for DMA mode
+
+config MTD_NAND_OMAP_PREFETCH_IRQ
+ depends on MTD_NAND_OMAP_PREFETCH && !MTD_NAND_OMAP_PREFETCH_DMA
+ bool "IRQ mode"
+ default n
+ help
+ The GPMC PREFETCH engine can be configured eigther in MPU interrupt mode
+ or in DMA interrupt mode.
+ Say y for IRQ mode
config MTD_NAND_IDS
tristate
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 133d515..6a57743 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -12,6 +12,7 @@
#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>
@@ -105,17 +106,27 @@ module_param(use_prefetch, bool, 0);
MODULE_PARM_DESC(use_prefetch, "enable/disable use of PREFETCH");
#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH_DMA
+const int use_interrupt;
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");
+MODULE_PARM_DESC(use_dma, "enable/disable use of DMA mode");
+#elif defined(CONFIG_MTD_NAND_OMAP_PREFETCH_IRQ)
+const int use_dma;
+static int use_interrupt = 1;
+
+/* "modprobe ... use_dma=0" etc */
+module_param(use_interrupt, bool, 0);
+MODULE_PARM_DESC(use_interrupt, "enable/disable use of IRQ mode");
#else
const int use_dma;
+const int use_interrupt;
#endif
#else
const int use_prefetch;
const int use_dma;
+const int use_interrupt;
#endif
struct omap_nand_info {
@@ -130,6 +141,13 @@ struct omap_nand_info {
unsigned long phys_base;
struct completion comp;
int dma_ch;
+ int gpmc_irq;
+ enum {
+ NAND_IO_READ = 0, /* read */
+ NAND_IO_WRITE, /* write */
+ } iomode;
+ u_char *buf;
+ int buf_len;
};
/**
@@ -467,6 +485,152 @@ 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 == NAND_IO_WRITE) { /* checks for write operaiton */
+ 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);
+ irq_stat = gpmc_read_status(GPMC_GET_IRQ_STATUS);
+
+ 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);
+ irq_stat = gpmc_read_status(GPMC_GET_IRQ_STATUS);
+
+ 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 = 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 methode */
+ 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;
+ if (len <= mtd->oobsize) {
+ omap_write_buf_pref(mtd, buf, len);
+ return;
+ }
+
+ info->iomode = 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 methode */
+ 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 */
+ do {
+ ret = gpmc_read_status(GPMC_PREFETCH_COUNT);
+ } while (ret);
+ /* 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
@@ -800,6 +964,7 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
info->gpmc_cs = pdata->cs;
info->phys_base = pdata->phys_base;
+ info->gpmc_irq = pdata->gpmc_irq;
info->mtd.priv = &info->nand;
info->mtd.name = dev_name(&pdev->dev);
@@ -863,7 +1028,20 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
info->nand.read_buf = omap_read_buf_dma_pref;
info->nand.write_buf = omap_write_buf_dma_pref;
}
+ } else if (use_interrupt) {
+ err = request_irq(info->gpmc_irq, omap_nand_irq,
+ IRQF_SHARED, info->mtd.name, info);
+ if (err) {
+ printk(KERN_INFO"failure requesting irq %i."
+ " Prefetch will work in mpu"
+ " poling mode.\n",
+ info->gpmc_irq);
+ } else {
+ info->nand.read_buf = omap_read_buf_irq_pref;
+ info->nand.write_buf = omap_write_buf_irq_pref;
+ }
}
+
} else {
if (info->nand.options & NAND_BUSWIDTH_16) {
info->nand.read_buf = omap_read_buf16;
@@ -953,11 +1131,19 @@ static int __init omap_nand_init(void)
/* 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");
+
+ if ((0 == use_prefetch) && (1 == (use_dma | use_interrupt))) {
+ printk(KERN_INFO "Wrong parameters: Neither 'dma' nor 'irq' "
+ "can used without 'use_prefetch' selected.\n");
+ printk(KERN_INFO "Prefetch will not be used in any mode: "
+ "poll, mpu or dma\n");
+ } else if ((1 == use_prefetch) && (1 == (use_interrupt & use_dma))) {
+ printk(KERN_INFO "Wrong parameters: Both DMA and IRQ"
+ " modes can not be used together.\n");
+ printk(KERN_INFO "It has to be selected at compile "
+ "time and same will be used.\n");
}
+
return platform_driver_register(&omap_nand_driver);
}
More information about the linux-arm-kernel
mailing list