From: b32955@freescale.com (Huang Shijie)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 9/9] mtd: gpmi: initialize the timing registers only one time
Date: Thu, 13 Sep 2012 14:58:00 +0800 [thread overview]
Message-ID: <1347519480-31106-10-git-send-email-b32955@freescale.com> (raw)
In-Reply-To: <1347519480-31106-1-git-send-email-b32955@freescale.com>
The current code initializes the timing registers at very time
we call the gpmi_begin(). This really wastes the cpu cycles.
Add a new flag to let the gpmi driver initializes the timing registers
only one time.
Signed-off-by: Huang Shijie <b32955@freescale.com>
---
drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 8 ++++++++
drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 +
2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
index c036e51..3502acc 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
@@ -914,6 +914,9 @@ static int enable_edo_mode(struct gpmi_nand_data *this, int mode)
rate = (mode == 5) ? 100000000 : 80000000;
clk_set_rate(r->clock[0], rate);
+ /* Let the gpmi_begin() re-compute the timing again. */
+ this->flags &= ~GPMI_TIMING_INIT_OK;
+
this->flags |= GPMI_ASYNC_EDO_ENABLED;
this->timing_mode = mode;
dev_info(this->dev, "enable the asynchronous EDO mode %d\n", mode);
@@ -964,6 +967,11 @@ void gpmi_begin(struct gpmi_nand_data *this)
goto err_out;
}
+ /* Only initialize the timing once */
+ if (this->flags & GPMI_TIMING_INIT_OK)
+ return;
+ this->flags |= GPMI_TIMING_INIT_OK;
+
if (this->flags & GPMI_ASYNC_EDO_ENABLED)
gpmi_compute_edo_timing(this, &hw);
else
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
index 5b6d546..7ac25c1 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
@@ -124,6 +124,7 @@ struct nand_timing {
struct gpmi_nand_data {
/* flags */
#define GPMI_ASYNC_EDO_ENABLED (1 << 0)
+#define GPMI_TIMING_INIT_OK (1 << 1)
int flags;
/* System Interface */
--
1.7.0.4
next prev parent reply other threads:[~2012-09-13 6:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 6:57 [PATCH v2 0/9] add EDO feature for gpmi-nand driver Huang Shijie
2012-09-13 6:57 ` [PATCH v2 1/9] mtd: add helpers to set/get features for ONFI nand Huang Shijie
2012-09-13 6:57 ` [PATCH v2 2/9] mtd: add helpers to get the supportted ONFI timing mode Huang Shijie
2012-09-13 6:57 ` [PATCH v2 3/9] mtd: gpmi: add a new field for HW_GPMI_TIMING1 Huang Shijie
2012-09-13 6:57 ` [PATCH v2 4/9] mtd: gpmi: do not get the clock frequency in gpmi_begin() Huang Shijie
2012-09-13 6:57 ` [PATCH v2 5/9] mtd: gpmi: add a new field for HW_GPMI_CTRL1 Huang Shijie
2012-09-13 6:57 ` [PATCH v2 6/9] mtd: gpmi: simplify the setting DLL code Huang Shijie
2012-09-13 6:57 ` [PATCH v2 7/9] mtd: gpmi: do not set the default values for the extra clocks Huang Shijie
2012-09-13 6:57 ` [PATCH v2 8/9] mtd: gpmi: add EDO feature for imx6q Huang Shijie
2012-09-13 6:58 ` Huang Shijie [this message]
2012-09-26 8:17 ` [PATCH v2 0/9] add EDO feature for gpmi-nand driver Artem Bityutskiy
2012-10-04 20:24 ` Marek Vasut
2012-10-04 20:56 ` Marek Vasut
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