[PATCH 5.4 190/191] mmc: sdhci-of-esdhc: fix up erratum A-008171 workaround

Greg Kroah-Hartman
2020-01-02T22:18:35Z

From: Yangbo Lu <yangbo.lu@nxp.com>

[ Upstream commit 22dc132d5448db1b1c021de0c34aa8033ca7d98f ]

A previous patch implemented an incomplete workaround of erratum
A-008171. The complete workaround is as below. This patch is to
implement the complete workaround which uses SW tuning if HW tuning
fails, and retries both HW/SW tuning once with reduced clock if
workaround fails. This is suggested by hardware team, and the patch
had been verified on LS1046A eSDHC + Phison 32G eMMC which could
trigger the erratum.

Workaround:
/* For T1040, T2080, LS1021A, T1023 Rev 1: */
1. Program TBPTR[TB_WNDW_END_PTR] = 3*DIV_RATIO.
2. Program TBPTR[TB_WNDW_START_PTR] = 5*DIV_RATIO.
3. Program the software tuning mode by setting TBCTL[TB_MODE] = 2'h3.
4. Set SYSCTL2[EXTN] and SYSCTL2[SAMPCLKSEL].
5. Issue SEND_TUNING_BLK Command (CMD19 for SD, CMD21 for MMC).
6. Wait for IRQSTAT[BRR], buffer read ready, to be set.
7. Clear IRQSTAT[BRR].
8. Check SYSCTL2[EXTN] to be cleared.
9. Check SYSCTL2[SAMPCLKSEL], Sampling Clock Select. It's set value
indicate tuning procedure success, and clear indicate failure.
In case of tuning failure, fixed sampling scheme could be used by
clearing TBCTL[TB_EN].
/* For LS1080A Rev 1, LS2088A Rev 1.0, LA1575A Rev 1.0: */
1. Read the TBCTL[31:0] register. Write TBCTL[11:8]=4'h8 and wait for
1ms.
2. Read the TBCTL[31:0] register and rewrite again. Wait for 1ms second.
3. Read the TBSTAT[31:0] register twice.
3.1 Reset data lines by setting ESDHCCTL[RSTD] bit.
3.2 Check ESDHCCTL[RSTD] bit.
3.3 If ESDHCCTL[RSTD] is 0, go to step 3.4 else go to step 3.2.
3.4 Write 32'hFFFF_FFFF to IRQSTAT register.
4. if TBSTAT[15:8]-TBSTAT[7:0] > 4*DIV_RATIO or TBSTAT[7:0]-TBSTAT[15:8]
> 4*DIV_RATIO , then program TBPTR[TB_WNDW_END_PTR] = 4*DIV_RATIO and
program TBPTR[TB_WNDW_START_PTR] = 8*DIV_RATIO.
/* For LS1012A Rev1, LS1043A Rev 1.x, LS1046A 1.0: */
1. Read the TBCTL[0:31] register. Write TBCTL[20:23]=4'h8 and wait for
1ms.
2. Read the TBCTL[0:31] register and rewrite again. Wait for 1ms second.
3. Read the TBSTAT[0:31] register twice.
3.1 Reset data lines by setting ESDHCCTL[RSTD] bit.
3.2 Check ESDHCCTL[RSTD] bit.
3.3 If ESDHCCTL[RSTD] is 0, go to step 3.4 else go to step 3.2.
3.4 Write 32'hFFFF_FFFF to IRQSTAT register.
4. if TBSTAT[16:23]-TBSTAT[24:31] > 4*DIV_RATIO or TBSTAT[24:31]-
TBSTAT[16:23] > 4* DIV_RATIO , then program TBPTR[TB_WNDW_END_PTR] =
4*DIV_RATIO and program TBPTR[TB_WNDW_START_PTR] = 8*DIV_RATIO.
/* For LS1080A Rev 1, LS2088A Rev 1.0, LA1575A Rev 1.0 LS1012A Rev1,
* LS1043A Rev 1.x, LS1046A 1.0:
*/
5. else program TBPTR[TB_WNDW_END_PTR] = 3*DIV_RATIO and program
TBPTR[TB_WNDW_START_PTR] = 5*DIV_RATIO.
6. Program the software tuning mode by setting TBCTL[TB_MODE] = 2'h3.
7. Set SYSCTL2[EXTN], wait 1us and SYSCTL2[SAMPCLKSEL].
8. Issue SEND_TUNING_BLK Command (CMD19 for SD, CMD21 for MMC).
9. Wait for IRQSTAT[BRR], buffer read ready, to be set.
10. Clear IRQSTAT[BRR].
11. Check SYSCTL2[EXTN] to be cleared.
12. Check SYSCTL2[SAMPCLKSEL], Sampling Clock Select. It's set value
indicate tuning procedure success, and clear indicate failure.
In case of tuning failure, fixed sampling scheme could be used by
clearing TBCTL[TB_EN].

Fixes: b1f378ab5334 ("mmc: sdhci-of-esdhc: add erratum A008171 support")
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/sdhci-esdhc.h | 14 ++
drivers/mmc/host/sdhci-of-esdhc.c | 222 +++++++++++++++++++++++++-----
2 files changed, 203 insertions(+), 33 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 57b582bf73d9..9289bb4d633e 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -51,6 +51,11 @@
#define ESDHC_CLOCK_HCKEN 0x00000002
#define ESDHC_CLOCK_IPGEN 0x00000001

+/* System Control 2 Register */
+#define ESDHC_SYSTEM_CONTROL_2 0x3c
+#define ESDHC_SMPCLKSEL 0x00800000
+#define ESDHC_EXTN 0x00400000
+
/* Host Controller Capabilities Register 2 */
#define ESDHC_CAPABILITIES_1 0x114

@@ -59,7 +64,16 @@
#define ESDHC_HS400_WNDW_ADJUST 0x00000040
#define ESDHC_HS400_MODE 0x00000010
#define ESDHC_TB_EN 0x00000004
+#define ESDHC_TB_MODE_MASK 0x00000003
+#define ESDHC_TB_MODE_SW 0x00000003
+#define ESDHC_TB_MODE_3 0x00000002
+
+#define ESDHC_TBSTAT 0x124
+
#define ESDHC_TBPTR 0x128
+#define ESDHC_WNDW_STRT_PTR_SHIFT 8
+#define ESDHC_WNDW_STRT_PTR_MASK (0x7f << 8)
+#define ESDHC_WNDW_END_PTR_MASK 0x7f

/* SD Clock Control Register */
#define ESDHC_SDCLKCTL 0x144
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 889ed98ec0e7..14f0cb7fa374 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -77,8 +77,10 @@ struct sdhci_esdhc {
bool quirk_incorrect_hostver;
bool quirk_limited_clk_division;
bool quirk_unreliable_pulse_detection;
- bool quirk_fixup_tuning;
+ bool quirk_tuning_erratum_type1;
+ bool quirk_tuning_erratum_type2;
bool quirk_ignore_data_inhibit;
+ bool in_sw_tuning;
unsigned int peripheral_clock;
const struct esdhc_clk_fixup *clk_fixup;
u32 div_ratio;
@@ -408,6 +410,8 @@ static void esdhc_le_writel(struct sdhci_host *host, u32 val, int reg)

static void esdhc_be_writew(struct sdhci_host *host, u16 val, int reg)
{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
int base = reg & ~0x3;
u32 value;
u32 ret;
@@ -416,10 +420,24 @@ static void esdhc_be_writew(struct sdhci_host *host, u16 val, int reg)
ret = esdhc_writew_fixup(host, reg, val, value);
if (reg != SDHCI_TRANSFER_MODE)
iowrite32be(ret, host->ioaddr + base);
+
+ /* Starting SW tuning requires ESDHC_SMPCLKSEL to be set
+ * 1us later after ESDHC_EXTN is set.
+ */
+ if (base == ESDHC_SYSTEM_CONTROL_2) {
+ if (!(value & ESDHC_EXTN) && (ret & ESDHC_EXTN) &&
+ esdhc->in_sw_tuning) {
+ udelay(1);
+ ret |= ESDHC_SMPCLKSEL;
+ iowrite32be(ret, host->ioaddr + base);
+ }
+ }
}

static void esdhc_le_writew(struct sdhci_host *host, u16 val, int reg)
{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
int base = reg & ~0x3;
u32 value;
u32 ret;
@@ -428,6 +446,18 @@ static void esdhc_le_writew(struct sdhci_host *host, u16 val, int reg)
ret = esdhc_writew_fixup(host, reg, val, value);
if (reg != SDHCI_TRANSFER_MODE)
iowrite32(ret, host->ioaddr + base);
+
+ /* Starting SW tuning requires ESDHC_SMPCLKSEL to be set
+ * 1us later after ESDHC_EXTN is set.
+ */
+ if (base == ESDHC_SYSTEM_CONTROL_2) {
+ if (!(value & ESDHC_EXTN) && (ret & ESDHC_EXTN) &&
+ esdhc->in_sw_tuning) {
+ udelay(1);
+ ret |= ESDHC_SMPCLKSEL;
+ iowrite32(ret, host->ioaddr + base);
+ }
+ }
}

static void esdhc_be_writeb(struct sdhci_host *host, u8 val, int reg)
@@ -793,16 +823,21 @@ static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
}
}

-static struct soc_device_attribute soc_fixup_tuning[] = {
+static struct soc_device_attribute soc_tuning_erratum_type1[] = {
+ { .family = "QorIQ T1023", .revision = "1.0", },
{ .family = "QorIQ T1040", .revision = "1.0", },
{ .family = "QorIQ T2080", .revision = "1.0", },
- { .family = "QorIQ T1023", .revision = "1.0", },
{ .family = "QorIQ LS1021A", .revision = "1.0", },
- { .family = "QorIQ LS1080A", .revision = "1.0", },
- { .family = "QorIQ LS2080A", .revision = "1.0", },
+ { },
+};
+
+static struct soc_device_attribute soc_tuning_erratum_type2[] = {
{ .family = "QorIQ LS1012A", .revision = "1.0", },
{ .family = "QorIQ LS1043A", .revision = "1.*", },
{ .family = "QorIQ LS1046A", .revision = "1.0", },
+ { .family = "QorIQ LS1080A", .revision = "1.0", },
+ { .family = "QorIQ LS2080A", .revision = "1.0", },
+ { .family = "QorIQ LA1575A", .revision = "1.0", },
{ },
};

@@ -826,15 +861,97 @@ static void esdhc_tuning_block_enable(struct sdhci_host *host, bool enable)
esdhc_clock_enable(host, true);
}

+static void esdhc_prepare_sw_tuning(struct sdhci_host *host, u8 *window_start,
+ u8 *window_end)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
+ u8 tbstat_15_8, tbstat_7_0;
+ u32 val;
+
+ if (esdhc->quirk_tuning_erratum_type1) {
+ *window_start = 5 * esdhc->div_ratio;
+ *window_end = 3 * esdhc->div_ratio;
+ return;
+ }
+
+ /* Write TBCTL[11:8]=4'h8 */
+ val = sdhci_readl(host, ESDHC_TBCTL);
+ val &= ~(0xf << 8);
+ val |= 8 << 8;
+ sdhci_writel(host, val, ESDHC_TBCTL);
+
+ mdelay(1);
+
+ /* Read TBCTL[31:0] register and rewrite again */
+ val = sdhci_readl(host, ESDHC_TBCTL);
+ sdhci_writel(host, val, ESDHC_TBCTL);
+
+ mdelay(1);
+
+ /* Read the TBSTAT[31:0] register twice */
+ val = sdhci_readl(host, ESDHC_TBSTAT);
+ val = sdhci_readl(host, ESDHC_TBSTAT);
+
+ /* Reset data lines by setting ESDHCCTL[RSTD] */
+ sdhci_reset(host, SDHCI_RESET_DATA);
+ /* Write 32'hFFFF_FFFF to IRQSTAT register */
+ sdhci_writel(host, 0xFFFFFFFF, SDHCI_INT_STATUS);
+
+ /* If TBSTAT[15:8]-TBSTAT[7:0] > 4 * div_ratio
+ * or TBSTAT[7:0]-TBSTAT[15:8] > 4 * div_ratio,
+ * then program TBPTR[TB_WNDW_END_PTR] = 4 * div_ratio
+ * and program TBPTR[TB_WNDW_START_PTR] = 8 * div_ratio.
+ */
+ tbstat_7_0 = val & 0xff;
+ tbstat_15_8 = (val >> 8) & 0xff;
+
+ if (abs(tbstat_15_8 - tbstat_7_0) > (4 * esdhc->div_ratio)) {
+ *window_start = 8 * esdhc->div_ratio;
+ *window_end = 4 * esdhc->div_ratio;
+ } else {
+ *window_start = 5 * esdhc->div_ratio;
+ *window_end = 3 * esdhc->div_ratio;
+ }
+}
+
+static int esdhc_execute_sw_tuning(struct mmc_host *mmc, u32 opcode,
+ u8 window_start, u8 window_end)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
+ u32 val;
+ int ret;
+
+ /* Program TBPTR[TB_WNDW_END_PTR] and TBPTR[TB_WNDW_START_PTR] */
+ val = ((u32)window_start << ESDHC_WNDW_STRT_PTR_SHIFT) &
+ ESDHC_WNDW_STRT_PTR_MASK;
+ val |= window_end & ESDHC_WNDW_END_PTR_MASK;
+ sdhci_writel(host, val, ESDHC_TBPTR);
+
+ /* Program the software tuning mode by setting TBCTL[TB_MODE]=2'h3 */
+ val = sdhci_readl(host, ESDHC_TBCTL);
+ val &= ~ESDHC_TB_MODE_MASK;
+ val |= ESDHC_TB_MODE_SW;
+ sdhci_writel(host, val, ESDHC_TBCTL);
+
+ esdhc->in_sw_tuning = true;
+ ret = sdhci_execute_tuning(mmc, opcode);
+ esdhc->in_sw_tuning = false;
+ return ret;
+}
+
static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
+ u8 window_start, window_end;
+ int ret, retries = 1;
bool hs400_tuning;
unsigned int clk;
u32 val;
- int ret;

/* For tuning mode, the sd clock divisor value
* must be larger than 3 according to reference manual.
@@ -843,39 +960,73 @@ static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
if (host->clock > clk)
esdhc_of_set_clock(host, clk);

- if (esdhc->quirk_limited_clk_division &&
- host->flags & SDHCI_HS400_TUNING)
- esdhc_of_set_clock(host, host->clock);
-
esdhc_tuning_block_enable(host, true);

hs400_tuning = host->flags & SDHCI_HS400_TUNING;
- ret = sdhci_execute_tuning(mmc, opcode);

- if (hs400_tuning) {
- val = sdhci_readl(host, ESDHC_SDTIMNGCTL);
- val |= ESDHC_FLW_CTL_BG;
- sdhci_writel(host, val, ESDHC_SDTIMNGCTL);
- }
+ do {
+ if (esdhc->quirk_limited_clk_division &&
+ hs400_tuning)
+ esdhc_of_set_clock(host, host->clock);

- if (host->tuning_err == -EAGAIN && esdhc->quirk_fixup_tuning) {
+ /* Do HW tuning */
+ val = sdhci_readl(host, ESDHC_TBCTL);
+ val &= ~ESDHC_TB_MODE_MASK;
+ val |= ESDHC_TB_MODE_3;
+ sdhci_writel(host, val, ESDHC_TBCTL);

- /* program TBPTR[TB_WNDW_END_PTR] = 3*DIV_RATIO and
- * program TBPTR[TB_WNDW_START_PTR] = 5*DIV_RATIO
- */
- val = sdhci_readl(host, ESDHC_TBPTR);
- val = (val & ~((0x7f << 8) | 0x7f)) |
- (3 * esdhc->div_ratio) | ((5 * esdhc->div_ratio) << 8);
- sdhci_writel(host, val, ESDHC_TBPTR);
+ ret = sdhci_execute_tuning(mmc, opcode);
+ if (ret)
+ break;

- /* program the software tuning mode by setting
- * TBCTL[TB_MODE]=2'h3
+ /* If HW tuning fails and triggers erratum,
+ * try workaround.
*/
- val = sdhci_readl(host, ESDHC_TBCTL);
- val |= 0x3;
- sdhci_writel(host, val, ESDHC_TBCTL);
- sdhci_execute_tuning(mmc, opcode);
+ ret = host->tuning_err;
+ if (ret == -EAGAIN &&
+ (esdhc->quirk_tuning_erratum_type1 ||
+ esdhc->quirk_tuning_erratum_type2)) {
+ /* Recover HS400 tuning flag */
+ if (hs400_tuning)
+ host->flags |= SDHCI_HS400_TUNING;
+ pr_info("%s: Hold on to use fixed sampling clock. Try SW tuning!\n",
+ mmc_hostname(mmc));
+ /* Do SW tuning */
+ esdhc_prepare_sw_tuning(host, &window_start,
+ &window_end);
+ ret = esdhc_execute_sw_tuning(mmc, opcode,
+ window_start,
+ window_end);
+ if (ret)
+ break;
+
+ /* Retry both HW/SW tuning with reduced clock. */
+ ret = host->tuning_err;
+ if (ret == -EAGAIN && retries) {
+ /* Recover HS400 tuning flag */
+ if (hs400_tuning)
+ host->flags |= SDHCI_HS400_TUNING;
+
+ clk = host->max_clk / (esdhc->div_ratio + 1);
+ esdhc_of_set_clock(host, clk);
+ pr_info("%s: Hold on to use fixed sampling clock. Try tuning with reduced clock!\n",
+ mmc_hostname(mmc));
+ } else {
+ break;
+ }
+ } else {
+ break;
+ }
+ } while (retries--);
+
+ if (ret) {
+ esdhc_tuning_block_enable(host, false);
+ } else if (hs400_tuning) {
+ val = sdhci_readl(host, ESDHC_SDTIMNGCTL);
+ val |= ESDHC_FLW_CTL_BG;
+ sdhci_writel(host, val, ESDHC_SDTIMNGCTL);
}
+
return ret;
}

@@ -1111,10 +1262,15 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)

pltfm_host = sdhci_priv(host);
esdhc = sdhci_pltfm_priv(pltfm_host);
- if (soc_device_match(soc_fixup_tuning))
- esdhc->quirk_fixup_tuning = true;
+ if (soc_device_match(soc_tuning_erratum_type1))
+ esdhc->quirk_tuning_erratum_type1 = true;
+ else
+ esdhc->quirk_tuning_erratum_type1 = false;
+
+ if (soc_device_match(soc_tuning_erratum_type2))
+ esdhc->quirk_tuning_erratum_type2 = true;
else
- esdhc->quirk_fixup_tuning = false;
+ esdhc->quirk_tuning_erratum_type2 = false;

if (esdhc->vendor_ver == VENDOR_V_22)
host->quirks2 |= SDHCI_QUIRK2_HOST_NO_CMD23;
--
2.20.1