mmc: sirf: update sdhci_sirf_execute_tuning procedure

For the original tuning code, delay value is set to SD Bus Clock Delay
Register (SD_CLK_DELAY_SETTING) as (val | (Val << 7) | (val << 16)),
which means CLK_DELAY_IN1, CLK_DELAY_IN2 and CLK_DELAY_OUT are the
same and with 128 steps. This is doubtful. In CSR design specification
documents CS-304575-DR-3H, this issue is clarified, the delay[13:0] in
SD_CLK_DELAY_SETTING is simplied to the concatenation of {CLK_DELAY_IN2,
CLK_DELAY_IN1}.
Besides, for CMD19 tuning, no need to set CLK_DELAY_OUT([22,16]
of SD_CLK_DELAY_SETTING).

Signed-off-by: weijun yang <york.yang@csr.com>
Signed-off-by: Barry Song <baohua.song@csr.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-sirf.c b/drivers/mmc/host/sdhci-sirf.c
index f6f82ec..4331409 100644 (file)
--- a/drivers/mmc/host/sdhci-sirf.c
+++ b/drivers/mmc/host/sdhci-sirf.c
@@ -56,7 +56,7 @@ static int sdhci_sirf_execute_tuning(struct sdhci_host *host, u32 opcode)
        int tuning_seq_cnt = 3;
        u8 phase, tuned_phases[SIRF_TUNING_COUNT];
        u8 tuned_phase_cnt = 0;
-       int rc, longest_range = 0;
+       int rc = 0, longest_range = 0;
        int start = -1, end = 0, tuning_value = -1, range = 0;
        u16 clock_setting;
        struct mmc_host *mmc = host->mmc;
@@ -68,7 +68,7 @@ retry:
        phase = 0;
        do {
                sdhci_writel(host,
-                       clock_setting | phase | (phase << 7) | (phase << 16),
+                       clock_setting | phase,
                        SDHCI_CLK_DELAY_SETTING);
 
                if (!mmc_send_tuning(mmc)) {
@@ -102,7 +102,7 @@ retry:
                 */
                phase = tuning_value;
                sdhci_writel(host,
-                       clock_setting | phase | (phase << 7) | (phase << 16),
+                       clock_setting | phase,
                        SDHCI_CLK_DELAY_SETTING);
 
                dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",