mmc: sdhci: add standard hw auto retuning support

If HW supports SDHCI_TUNING_MODE_3 which is auto retuning, we won't
retune during runtime suspend and resume, instead we use Re-tuning
Request signaled via SDHCI_INT_RETUNE interrupt to do retuning and
hw auto retuning during data transfer to guarantee the signal sample
window correction.

This can avoid a mass of repeatedly retuning during small file system
data access and improve the performance.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 7894652b992908e2501f549574a0d9795cb1ced2..31c14b0ff8e2ca63950c807e169e83587a70b0c0 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -229,6 +229,10 @@ static void sdhci_init(struct sdhci_host *host, int soft)
                    SDHCI_INT_TIMEOUT | SDHCI_INT_DATA_END |
                    SDHCI_INT_RESPONSE;
 
+       if (host->tuning_mode == SDHCI_TUNING_MODE_2 ||
+           host->tuning_mode == SDHCI_TUNING_MODE_3)
+               host->ier |= SDHCI_INT_RETUNE;
+
        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 
@@ -2673,6 +2677,9 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
                        pr_err("%s: Card is consuming too much power!\n",
                                mmc_hostname(host->mmc));
 
+               if (intmask & SDHCI_INT_RETUNE)
+                       mmc_retune_needed(host->mmc);
+
                if (intmask & SDHCI_INT_CARD_INT) {
                        sdhci_enable_sdio_irq_nolock(host, false);
                        host->thread_isr |= SDHCI_INT_CARD_INT;
@@ -2682,7 +2689,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
                intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
                             SDHCI_INT_CMD_MASK | SDHCI_INT_DATA_MASK |
                             SDHCI_INT_ERROR | SDHCI_INT_BUS_POWER |
-                            SDHCI_INT_CARD_INT);
+                            SDHCI_INT_RETUNE | SDHCI_INT_CARD_INT);
 
                if (intmask) {
                        unexpected |= intmask;
@@ -2787,7 +2794,8 @@ int sdhci_suspend_host(struct sdhci_host *host)
        sdhci_disable_card_detection(host);
 
        mmc_retune_timer_stop(host->mmc);
-       mmc_retune_needed(host->mmc);
+       if (host->tuning_mode != SDHCI_TUNING_MODE_3)
+               mmc_retune_needed(host->mmc);
 
        if (!device_may_wakeup(mmc_dev(host->mmc))) {
                host->ier = 0;
@@ -2848,7 +2856,8 @@ int sdhci_runtime_suspend_host(struct sdhci_host *host)
        unsigned long flags;
 
        mmc_retune_timer_stop(host->mmc);
-       mmc_retune_needed(host->mmc);
+       if (host->tuning_mode != SDHCI_TUNING_MODE_3)
+               mmc_retune_needed(host->mmc);
 
        spin_lock_irqsave(&host->lock, flags);
        host->ier &= SDHCI_INT_CARD_INT;

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index e241e11a90d07c5e07b78dfe3a809d239cbc3376..0411c9f364619a5949e999fc4b1b9288504bfcfc 100644 (file)
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -128,6 +128,7 @@
 #define  SDHCI_INT_CARD_INSERT 0x00000040
 #define  SDHCI_INT_CARD_REMOVE 0x00000080
 #define  SDHCI_INT_CARD_INT    0x00000100
+#define  SDHCI_INT_RETUNE      0x00001000
 #define  SDHCI_INT_ERROR       0x00008000
 #define  SDHCI_INT_TIMEOUT     0x00010000
 #define  SDHCI_INT_CRC         0x00020000
@@ -518,6 +519,8 @@ struct sdhci_host {
        unsigned int            tuning_count;   /* Timer count for re-tuning */
        unsigned int            tuning_mode;    /* Re-tuning mode supported by host */
 #define SDHCI_TUNING_MODE_1    0
+#define SDHCI_TUNING_MODE_2    1
+#define SDHCI_TUNING_MODE_3    2
 
        unsigned long private[0] ____cacheline_aligned;
 };