Patchwork [v7,4/7] omap3: nand: prefetch in irq mode support

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Submitter Sukumar Ghorai
Date Dec. 29, 2010, 1:32 p.m.
Message ID <1293629546-18831-5-git-send-email-s-ghorai@ti.com>
Download mbox | patch
Permalink /patch/76923/
State New
Headers show

Comments

Sukumar Ghorai - Dec. 29, 2010, 1:32 p.m.
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>
---
 arch/arm/mach-omap2/board-flash.c      |    2 +
 arch/arm/plat-omap/include/plat/nand.h |    4 +-
 drivers/mtd/nand/omap2.c               |  169 ++++++++++++++++++++++++++++++++
 3 files changed, 174 insertions(+), 1 deletions(-)
Sekhar Nori - Jan. 3, 2011, 11:49 a.m.
Hi Sukumar,

On Wed, Dec 29, 2010 at 19:02:23, Ghorai, Sukumar wrote:
> 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>
> ---
>  arch/arm/mach-omap2/board-flash.c      |    2 +
>  arch/arm/plat-omap/include/plat/nand.h |    4 +-
>  drivers/mtd/nand/omap2.c               |  169 ++++++++++++++++++++++++++++++++
>  3 files changed, 174 insertions(+), 1 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 66b7428..007862e 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>
> @@ -108,6 +109,13 @@ 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;
>  };
>  
>  /**
> @@ -436,6 +444,153 @@ 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))

Meant to use logical AND here?

> +			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);

irq_stat update remains unused.

> +
> +	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 = OMAP_NAND_IO_READ;
> +	info->buf = buf;
> +	init_completion(&info->comp);

You can use INIT_COMPLETION to reset the completion variable.
Same change can be done in write below.

> +
> +	/*  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 */

s/methode/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;
> +	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 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);

Please have a timeout for this while loop in case hardware does
not become ready. Also, consider using cpu_relax() inside the
tight loop.

> +	/* 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
> @@ -769,6 +924,7 @@ 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);
> @@ -846,6 +1002,19 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
>  		}
>  		break;
>  
> +	case NAND_OMAP_PREFETCH_IRQ:
> +		err = request_irq(info->gpmc_irq,
> +				omap_nand_irq, IRQF_SHARED, "gpmc-nand", info);

I was expecting to see a free_irq() in the remove.

Thanks,
Sekhar

> +		if (err) {
> +			dev_err(&pdev->dev, "requesting irq(%d) error:%d",
> +							info->gpmc_irq, err);
> +			goto out_release_mem_region;
> +		} else {
> +			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);
> -- 
> 1.7.0.4
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
Sukumar Ghorai - Jan. 4, 2011, 8:50 a.m.
[..snip...]
> > +		if (info->buf_len & (info->buf_len < bytes))
> 
> Meant to use logical AND here?
[Ghorai] thanks, you are right.

[..snip..]
> > +	init_completion(&info->comp);
> 
> You can use INIT_COMPLETION to reset the completion variable.
> Same change can be done in write below.
[..snip..]
> s/methode/method
> 
[Ghorai] yes. I will do this 

[..snip..]
> > +	/* 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);
> 
> Please have a timeout for this while loop in case hardware does
> not become ready. Also, consider using cpu_relax() inside the
> tight loop.
> 
[Ghorai] Thanks. I will send again.

Patch

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 66b7428..007862e 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>
@@ -108,6 +109,13 @@  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;
 };
 
 /**
@@ -436,6 +444,153 @@  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);
+	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 = 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 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 = 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 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
@@ -769,6 +924,7 @@  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);
@@ -846,6 +1002,19 @@  static int __devinit omap_nand_probe(struct platform_device *pdev)
 		}
 		break;
 
+	case NAND_OMAP_PREFETCH_IRQ:
+		err = request_irq(info->gpmc_irq,
+				omap_nand_irq, IRQF_SHARED, "gpmc-nand", info);
+		if (err) {
+			dev_err(&pdev->dev, "requesting irq(%d) error:%d",
+							info->gpmc_irq, err);
+			goto out_release_mem_region;
+		} else {
+			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);