Fix data read/write error in HS200 mode due to chip DLL lock phase shift

Signed-off-by:Shirley Her<[email protected]>
---
change in V2:
  1. Use usleep_range instead of udelay
  2. move dll_adjust_count to sdhci-pci-o2micro.c

change in V1:
  1. Add error recovery function to relock the DLL with correct phase
  2. Retuning HS200 after DLL locked
---
---
 drivers/mmc/host/sdhci-pci-o2micro.c | 157 +++++++++++++++++++++++++++++------
 1 file changed, 133 insertions(+), 24 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c 
b/drivers/mmc/host/sdhci-pci-o2micro.c
index 9dc4548..c43b2ce 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -51,13 +51,60 @@
 #define O2_SD_VENDOR_SETTING2  0x1C8
 #define O2_SD_HW_TUNING_DISABLE        BIT(4)
 
-#define O2_PLL_WDT_CONTROL1    0x1CC
+#define O2_PLL_DLL_WDT_CONTROL1        0x1CC
 #define  O2_PLL_FORCE_ACTIVE   BIT(18)
 #define  O2_PLL_LOCK_STATUS    BIT(14)
 #define  O2_PLL_SOFT_RESET     BIT(12)
+#define  O2_DLL_LOCK_STATUS    BIT(11)
 
 #define O2_SD_DETECT_SETTING 0x324
 
+static const u32 dmdn_table[5] = {0x25100000, 0x2B1C0000,
+       0x2C1A0000, 0x371B0000, 0x35100000};
+static u8 dll_adjust_count;
+static int sdhci_o2_get_cd(struct mmc_host *mmc);
+
+static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
+{
+       u32 scratch_32;
+
+       pci_read_config_dword(chip->pdev,
+                             O2_SD_PLL_SETTING, &scratch_32);
+
+       scratch_32 &= 0x0000FFFF;
+       scratch_32 |= value;
+
+       pci_write_config_dword(chip->pdev,
+                              O2_SD_PLL_SETTING, scratch_32);
+}
+
+static int sdhci_o2_wait_dll_detect_lock(struct sdhci_host *host)
+{
+       ktime_t timeout;
+       u32 scratch32;
+
+       usleep_range(5000, 6000);
+       scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
+       if (!(scratch32 & O2_DLL_LOCK_STATUS)) {
+               pr_warn("%s: DLL is still unlocked after wait 5ms\n",
+                       mmc_hostname(host->mmc));
+       }
+
+       /* Detect 500 ms */
+       timeout = ktime_add_ms(ktime_get(), 500);
+       while (1) {
+               bool timedout = ktime_after(ktime_get(), timeout);
+
+               scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
+               if (!(scratch32 & O2_DLL_LOCK_STATUS))
+                       return 0;
+
+               if (timedout)
+                       return 1;
+               usleep_range(10, 1000);
+       }
+}
+
 static void sdhci_o2_set_tuning_mode(struct sdhci_host *host)
 {
        u16 reg;
@@ -95,11 +142,85 @@ static void __sdhci_o2_execute_tuning(struct sdhci_host 
*host, u32 opcode)
        sdhci_reset_tuning(host);
 }
 
+static int sdhci_o2_error_recovery(struct sdhci_pci_chip *chip,
+                                struct sdhci_host *host)
+{
+       int ret = 0;
+       u8 scratch_8 = 0;
+       u32 scratch_32 = 0;
+       /* Disable clock */
+       sdhci_writeb(host, 0, SDHCI_CLOCK_CONTROL);
+
+DLL_ADJUST:
+       if (dll_adjust_count >= 5) {
+               dll_adjust_count = 4;
+               pr_warn("%s: error recovery failed with the dll_adjust_count 
over max value.\n",
+                       mmc_hostname(host->mmc));
+       }
+
+       /* UnLock WP */
+       ret = pci_read_config_byte(chip->pdev,
+                       O2_SD_LOCK_WP, &scratch_8);
+       if (ret)
+               return ret;
+
+       scratch_8 &= 0x7f;
+       pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
+
+       /* PLL software reset */
+       scratch_32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
+       scratch_32 |= O2_PLL_SOFT_RESET;
+       sdhci_writel(host, scratch_32, O2_PLL_DLL_WDT_CONTROL1);
+
+       ret = pci_read_config_dword(chip->pdev,
+                                   O2_SD_FUNC_REG4,
+                                   &scratch_32);
+       /* Enable Base Clk setting change */
+       scratch_32 |= O2_SD_FREG4_ENABLE_CLK_SET;
+       pci_write_config_dword(chip->pdev, O2_SD_FUNC_REG4, scratch_32);
+       o2_pci_set_baseclk(chip, dmdn_table[dll_adjust_count]);
+
+
+       /* Enable internal clock */
+       scratch_8 = SDHCI_CLOCK_INT_EN;
+       sdhci_writeb(host, scratch_8, SDHCI_CLOCK_CONTROL);
+
+       if (sdhci_o2_get_cd(host->mmc)) {
+               if (sdhci_o2_wait_dll_detect_lock(host)) {
+                       scratch_8 |= SDHCI_CLOCK_CARD_EN;
+                       sdhci_writeb(host, scratch_8, SDHCI_CLOCK_CONTROL);
+                       ret = 1;
+               } else {
+
+                       pr_warn("%s: DLL unlocked when dll_adjust_count is 
%d.\n",
+                       mmc_hostname(host->mmc), dll_adjust_count);
+                       dll_adjust_count++;
+                       goto DLL_ADJUST;
+               }
+       } else
+               goto DLL_ADJUST;
+
+               /* Lock WP */
+       ret = pci_read_config_byte(chip->pdev,
+                                  O2_SD_LOCK_WP, &scratch_8);
+       if (ret)
+               return ret;
+       scratch_8 |= 0x80;
+       pci_write_config_byte(chip->pdev, O2_SD_LOCK_WP, scratch_8);
+       return ret;
+}
+
 static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
        struct sdhci_host *host = mmc_priv(mmc);
+       struct sdhci_pci_slot *slot = sdhci_priv(host);
        int current_bus_width = 0;
 
+
+       if (dll_adjust_count)
+               sdhci_o2_error_recovery(slot->chip, host);
+
+       dll_adjust_count++;
        /*
         * This handler only implements the eMMC tuning that is specific to
         * this controller.  Fall back to the standard method for other TIMING.
@@ -131,23 +252,11 @@ static int sdhci_o2_execute_tuning(struct mmc_host *mmc, 
u32 opcode)
                mmc->ios.bus_width = MMC_BUS_WIDTH_8;
                sdhci_set_bus_width(host, current_bus_width);
        }
-
        host->flags &= ~SDHCI_HS400_TUNING;
        return 0;
 }
 
-static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
-{
-       u32 scratch_32;
-       pci_read_config_dword(chip->pdev,
-                             O2_SD_PLL_SETTING, &scratch_32);
 
-       scratch_32 &= 0x0000FFFF;
-       scratch_32 |= value;
-
-       pci_write_config_dword(chip->pdev,
-                              O2_SD_PLL_SETTING, scratch_32);
-}
 
 static void o2_pci_led_enable(struct sdhci_pci_chip *chip)
 {
@@ -316,23 +425,23 @@ static void sdhci_o2_enable_internal_clock(struct 
sdhci_host *host)
        u32 scratch32;
 
        /* PLL software reset */
-       scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
+       scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
        scratch32 |= O2_PLL_SOFT_RESET;
-       sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
+       sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
        udelay(1);
        scratch32 &= ~(O2_PLL_SOFT_RESET);
-       sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
+       sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
 
        /* PLL force active */
        scratch32 |= O2_PLL_FORCE_ACTIVE;
-       sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
+       sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
 
        /* Wait max 20 ms */
        timeout = ktime_add_ms(ktime_get(), 20);
        while (1) {
                bool timedout = ktime_after(ktime_get(), timeout);
 
-               scratch = sdhci_readw(host, O2_PLL_WDT_CONTROL1);
+               scratch = sdhci_readw(host, O2_PLL_DLL_WDT_CONTROL1);
                if (scratch & O2_PLL_LOCK_STATUS)
                        break;
                if (timedout) {
@@ -350,16 +459,16 @@ static void sdhci_o2_enable_internal_clock(struct 
sdhci_host *host)
 
 out:
        /* Cancel PLL force active */
-       scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
+       scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
        scratch32 &= ~O2_PLL_FORCE_ACTIVE;
-       sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
+       sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
 }
 
 static int sdhci_o2_get_cd(struct mmc_host *mmc)
 {
        struct sdhci_host *host = mmc_priv(mmc);
-
-       sdhci_o2_enable_internal_clock(host);
+       if (!(sdhci_readw(host, O2_PLL_DLL_WDT_CONTROL1) & O2_PLL_LOCK_STATUS))
+               sdhci_o2_enable_internal_clock(host);
 
        return !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
 }
@@ -369,7 +478,7 @@ static void sdhci_o2_enable_clk(struct sdhci_host *host, 
u16 clk)
        /* Enable internal clock */
        clk |= SDHCI_CLOCK_INT_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
-
+       sdhci_o2_enable_internal_clock(host);
        if (sdhci_o2_get_cd(host->mmc)) {
                clk |= SDHCI_CLOCK_CARD_EN;
                sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
@@ -400,7 +509,7 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
 
        chip = slot->chip;
        host = slot->host;
-
+       dll_adjust_count = 0;
        caps = sdhci_readl(host, SDHCI_CAPABILITIES);
 
        /*
-- 
2.7.4

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