emmc: using rx delay to avoid invalid tuning

PD#165303: emmc: using rx delay to avoid invalid tuning

When emmc work at hs200@200Mhz, tuning result using fixed
adj mode may got a full window. The tuning result contains
invalid point. we have to adjust rx-delay to avoid it.

Change-Id: I33c5e234fe0f480180b0c9312641ba7a0a4e9cfb
Signed-off-by: Yonghui Yu <yonghui.yu@amlogic.com>

diff --git a/drivers/amlogic/mmc/aml_sd_emmc_v3.c b/drivers/amlogic/mmc/aml_sd_emmc_v3.c
index 7f6e591..5691e70 100644 (file)
--- a/drivers/amlogic/mmc/aml_sd_emmc_v3.c
+++ b/drivers/amlogic/mmc/aml_sd_emmc_v3.c
@@ -985,13 +985,22 @@ static int _aml_sd_emmc_execute_tuning(struct mmc_host *mmc, u32 opcode,
        u8 tuning_num = 0;
        u32 clk_div;
        u32 adj_delay_find;
-       int wrap_win_start = -1, wrap_win_size = 0;
-       int best_win_start = -1, best_win_size = 0;
-       int curr_win_start = -1, curr_win_size = 0;
+       int wrap_win_start, wrap_win_size;
+       int best_win_start, best_win_size;
+       int curr_win_start, curr_win_size;
+       u32 rxdly[3] = {0xA28A28A, 0x15500514, 0x1FF8079E};
 
        writel(0, host->base + SD_EMMC_ADJUST_V3);
 
 tunning:
+       /* renew */
+       wrap_win_start = -1;
+       wrap_win_size = 0;
+       best_win_start = -1;
+       best_win_size = 0;
+       curr_win_start = -1;
+       curr_win_size = 0;
+
        spin_lock_irqsave(&host->mrq_lock, flags);
        pdata->need_retuning = false;
        spin_unlock_irqrestore(&host->mrq_lock, flags);
@@ -1075,6 +1084,18 @@ tunning:
                pr_info("%s: tuning failed, reduce freq and retuning\n",
                        mmc_hostname(host->mmc));
                goto tunning;
+       } else if (best_win_size == clk_div) {
+               if (++tuning_num > MAX_TUNING_RETRY) {
+                       pr_err("%s: tuning failed\n",
+                               mmc_hostname(host->mmc));
+                       return -1;
+               }
+               pr_warn("wave is not sharp, again\n");
+               /* add basic data rx delay */
+               writel(rxdly[tuning_num-1], host->base + SD_EMMC_DELAY1_V3);
+               writel(rxdly[tuning_num-1], host->base + SD_EMMC_DELAY2_V3);
+               pr_warn("rxdly @ %x\n", rxdly[tuning_num-1]);
+               goto tunning;
        } else
                pr_info("%s: best_win_start =%d, best_win_size =%d\n",
                                mmc_hostname(host->mmc),