mtd: gpmi: simplify the DLL setting code

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

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
index 2d1f77c..010665c 100644 (file)
--- 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;