[PATCH V4 2/2] mmc: sdhci: Fix O2 Host data read/write DLL Lock Phase shift issue

From: Shirley Her (SC)
Date: Fri Aug 02 2019 - 13:40:25 EST


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

Signed-off-by:Shirley Her<shirley.her@xxxxxxxxxxxxxx>
---
change in V4:
1. add a bug fix for V3

change in V3:
1. add more explanation in dll_recovery and execute_tuning function
2. move dll_adjust_count to O2_host struct
3. fix some coding style error
4. renaming O2_PLL_WDT_CONTROL1 TO O2_PLL_DLL_WDT_CONTROL1

change in V2:
1. use usleep_range instead of udelay
2. move dll_adjust_count to sdhci-pci-o2micro.c

chagne in V1:
1. add error recovery function to relock DLL with correct phase
2. retuning HS200 after DLL locked
---
drivers/mmc/host/sdhci-pci-o2micro.c | 305 ++++++++++++++++++++++++-----------
1 file changed, 208 insertions(+), 97 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c
index 186a33d..aee0d15 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -55,9 +55,138 @@
#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};
+
+struct o2_host {
+ u8 dll_adjust_count;
+};
+
+static void sdhci_o2_wait_card_detect_stable(struct sdhci_host *host)
+{
+ ktime_t timeout;
+ u32 scratch32;
+
+ /* Wait max 50 ms */
+ timeout = ktime_add_ms(ktime_get(), 50);
+ while (1) {
+ bool timedout = ktime_after(ktime_get(), timeout);
+
+ scratch32 = sdhci_readl(host, SDHCI_PRESENT_STATE);
+ if ((scratch32 & SDHCI_CARD_PRESENT) >> SDHCI_CARD_PRES_SHIFT
+ == (scratch32 & SDHCI_CD_LVL) >> SDHCI_CD_LVL_SHIFT)
+ break;
+
+ if (timedout) {
+ pr_err("%s: Card Detect debounce never finished.\n",
+ mmc_hostname(host->mmc));
+ sdhci_dumpregs(host);
+ return;
+ }
+ udelay(10);
+ }
+}
+
+static void sdhci_o2_enable_internal_clock(struct sdhci_host *host)
+{
+ ktime_t timeout;
+ u16 scratch;
+ u32 scratch32;
+
+ /* PLL software reset */
+ scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
+ scratch32 |= O2_PLL_SOFT_RESET;
+ sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
+ udelay(1);
+ scratch32 &= ~(O2_PLL_SOFT_RESET);
+ sdhci_writel(host, scratch32, O2_PLL_DLL_WDT_CONTROL1);
+
+ /* PLL force active */
+ scratch32 |= O2_PLL_FORCE_ACTIVE;
+ 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_DLL_WDT_CONTROL1);
+ if (scratch & O2_PLL_LOCK_STATUS)
+ break;
+ if (timedout) {
+ pr_err("%s: Internal clock never stabilised.\n",
+ mmc_hostname(host->mmc));
+ sdhci_dumpregs(host);
+ goto out;
+ }
+ udelay(10);
+ }
+
+ /* Wait for card detect finish */
+ udelay(1);
+ sdhci_o2_wait_card_detect_stable(host);
+
+out:
+ /* Cancel PLL force active */
+ scratch32 = sdhci_readl(host, O2_PLL_DLL_WDT_CONTROL1);
+ scratch32 &= ~O2_PLL_FORCE_ACTIVE;
+ 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);
+
+ 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);
+}
+
+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 1 s */
+ timeout = ktime_add_ms(ktime_get(), 1000);
+ 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;
+ }
+}
+
static void sdhci_o2_set_tuning_mode(struct sdhci_host *host)
{
u16 reg;
@@ -73,7 +202,6 @@ static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode)
int i;

sdhci_send_tuning(host, MMC_SEND_TUNING_BLOCK_HS200);
-
for (i = 0; i < 150; i++) {
u16 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

@@ -95,12 +223,87 @@ static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode)
sdhci_reset_tuning(host);
}

+/* this function is used to fix o2 dll shift issue */
+static int sdhci_o2_dll_recovery(struct sdhci_host *host)
+{
+ int ret = 0;
+ u8 scratch_8 = 0;
+ u32 scratch_32 = 0;
+ struct sdhci_pci_slot *slot = sdhci_priv(host);
+ struct sdhci_pci_chip *chip = slot->chip;
+ struct o2_host *o2_host = sdhci_pci_priv(slot);
+
+ /* Disable clock */
+ sdhci_writeb(host, 0, SDHCI_CLOCK_CONTROL);
+ while (o2_host->dll_adjust_count < 5) {
+ o2_host->dll_adjust_count++;
+ /* 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[o2_host->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;
+ goto out;
+ } else {
+ pr_warn("%s: DLL unlocked when dll_adjust_count is %d.\n",
+ mmc_hostname(host->mmc),
+ o2_host->dll_adjust_count);
+ }
+ }
+ }
+out:
+ if (o2_host->dll_adjust_count == 5)
+ pr_err("%s: DLL adjust over max times\n",
+ mmc_hostname(host->mmc));
+ /* 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);
int current_bus_width = 0;

/*
+ * Judge the tuning reason, whether caused by dll shift
+ * If cause by dll shift, should call sdhci_o2_dll_recovery
+ */
+ if (!sdhci_o2_wait_dll_detect_lock(host))
+ sdhci_o2_dll_recovery(host);
+
+ /*
* This handler only implements the eMMC tuning that is specific to
* this controller. Fall back to the standard method for other TIMING.
*/
@@ -131,24 +334,10 @@ 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)
{
int ret;
@@ -284,92 +473,12 @@ static void sdhci_pci_o2_enable_msi(struct sdhci_pci_chip *chip,
host->irq = pci_irq_vector(chip->pdev, 0);
}

-static void sdhci_o2_wait_card_detect_stable(struct sdhci_host *host)
-{
- ktime_t timeout;
- u32 scratch32;
-
- /* Wait max 50 ms */
- timeout = ktime_add_ms(ktime_get(), 50);
- while (1) {
- bool timedout = ktime_after(ktime_get(), timeout);
-
- scratch32 = sdhci_readl(host, SDHCI_PRESENT_STATE);
- if ((scratch32 & SDHCI_CARD_PRESENT) >> SDHCI_CARD_PRES_SHIFT
- == (scratch32 & SDHCI_CD_LVL) >> SDHCI_CD_LVL_SHIFT)
- break;
-
- if (timedout) {
- pr_err("%s: Card Detect debounce never finished.\n",
- mmc_hostname(host->mmc));
- sdhci_dumpregs(host);
- return;
- }
- udelay(10);
- }
-}
-
-static void sdhci_o2_enable_internal_clock(struct sdhci_host *host)
-{
- ktime_t timeout;
- u16 scratch;
- u32 scratch32;
-
- /* PLL software reset */
- scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
- scratch32 |= O2_PLL_SOFT_RESET;
- sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
- udelay(1);
- scratch32 &= ~(O2_PLL_SOFT_RESET);
- sdhci_writel(host, scratch32, O2_PLL_WDT_CONTROL1);
-
- /* PLL force active */
- scratch32 |= O2_PLL_FORCE_ACTIVE;
- sdhci_writel(host, scratch32, O2_PLL_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);
- if (scratch & O2_PLL_LOCK_STATUS)
- break;
- if (timedout) {
- pr_err("%s: Internal clock never stabilised.\n",
- mmc_hostname(host->mmc));
- sdhci_dumpregs(host);
- goto out;
- }
- udelay(10);
- }
-
- /* Wait for card detect finish */
- udelay(1);
- sdhci_o2_wait_card_detect_stable(host);
-
-out:
- /* Cancel PLL force active */
- scratch32 = sdhci_readl(host, O2_PLL_WDT_CONTROL1);
- scratch32 &= ~O2_PLL_FORCE_ACTIVE;
- sdhci_writel(host, scratch32, O2_PLL_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);
-
- return !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
-}
-
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);
@@ -395,12 +504,13 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
{
struct sdhci_pci_chip *chip;
struct sdhci_host *host;
+ struct o2_host *o2_host = sdhci_pci_priv(slot);
u32 reg, caps;
int ret;

chip = slot->chip;
host = slot->host;
-
+ o2_host->dll_adjust_count = 0;
caps = sdhci_readl(host, SDHCI_CAPABILITIES);

/*
@@ -687,4 +797,5 @@ const struct sdhci_pci_fixes sdhci_o2 = {
.resume = sdhci_pci_o2_resume,
#endif
.ops = &sdhci_pci_o2_ops,
+ .priv_size = sizeof(struct o2_host),
};
--
2.7.4