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From: b32955@freescale.com (Huang Shijie)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 6/9] mtd: gpmi: simplify the setting DLL code
Date: Thu, 13 Sep 2012 14:57:57 +0800	[thread overview]
Message-ID: <1347519480-31106-7-git-send-email-b32955@freescale.com> (raw)
In-Reply-To: <1347519480-31106-1-git-send-email-b32955@freescale.com>

The setting DLL code is a little mess.
Just simplify the code and the comments.

Signed-off-by: Huang Shijie <b32955@freescale.com>
---
 drivers/mtd/nand/gpmi-nand/gpmi-lib.c |   22 +++++++++-------------
 1 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
index 2d1f77c..010665c 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
@@ -779,30 +779,26 @@ void gpmi_begin(struct gpmi_nand_data *this)
 	writel(BM_GPMI_CTRL1_DLL_ENABLE, gpmi_regs + HW_GPMI_CTRL1_CLR);
 
 	/* Clear out the DLL control fields. */
-	writel(BM_GPMI_CTRL1_RDN_DELAY,   gpmi_regs + HW_GPMI_CTRL1_CLR);
-	writel(BM_GPMI_CTRL1_HALF_PERIOD, gpmi_regs + HW_GPMI_CTRL1_CLR);
+	reg = BM_GPMI_CTRL1_RDN_DELAY | BM_GPMI_CTRL1_HALF_PERIOD;
+	writel(reg, gpmi_regs + HW_GPMI_CTRL1_CLR);
 
 	/* If no sample delay is called for, return immediately. */
 	if (!hw.sample_delay_factor)
 		return;
 
-	/* Configure the HALF_PERIOD flag. */
-	if (hw.use_half_periods)
-		writel(BM_GPMI_CTRL1_HALF_PERIOD,
-						gpmi_regs + HW_GPMI_CTRL1_SET);
+	/* Set RDN_DELAY or HALF_PERIOD. */
+	reg = ((hw.use_half_periods) ? BM_GPMI_CTRL1_HALF_PERIOD : 0)
+		| BF_GPMI_CTRL1_RDN_DELAY(hw.sample_delay_factor);
 
-	/* Set the delay factor. */
-	writel(BF_GPMI_CTRL1_RDN_DELAY(hw.sample_delay_factor),
-						gpmi_regs + HW_GPMI_CTRL1_SET);
+	writel(reg, gpmi_regs + HW_GPMI_CTRL1_SET);
 
-	/* Enable the DLL. */
+	/* At last, we enable the DLL. */
 	writel(BM_GPMI_CTRL1_DLL_ENABLE, gpmi_regs + HW_GPMI_CTRL1_SET);
 
 	/*
 	 * After we enable the GPMI DLL, we have to wait 64 clock cycles before
-	 * we can use the GPMI.
-	 *
-	 * Calculate the amount of time we need to wait, in microseconds.
+	 * we can use the GPMI. Calculate the amount of time we need to wait,
+	 * in microseconds.
 	 */
 	clock_period_in_ns = NSEC_PER_SEC / clk_get_rate(r->clock[0]);
 	dll_wait_time_in_us = (clock_period_in_ns * 64) / 1000;
-- 
1.7.0.4

  parent reply	other threads:[~2012-09-13  6:57 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 ` Huang Shijie [this message]
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 ` [PATCH v2 9/9] mtd: gpmi: initialize the timing registers only one time Huang Shijie
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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