[PATCH v5 4/4] mmc: sdhci-msm: Rectify DLL programming sequence for SDCC
From: Ram Prakash Gupta <hidden>
Date: 2025-10-13 14:53:41
Also in:
linux-arm-msm, linux-mmc, lkml
Subsystem:
arm/qualcomm mailing list, multimedia card (mmc), secure digital (sd) and sdio subsystem, secure digital host controller interface (sdhci) driver, the rest · Maintainers:
Ulf Hansson, Adrian Hunter, Linus Torvalds
From: Sachin Gupta <redacted> With the current DLL sequence stability issues for data transfer seen in HS400 and HS200 modes. "mmc0: cqhci: error IRQ status: 0x00000000 cmd error -84 data error 0" Rectify the DLL programming sequence as per latest hardware programming guide Signed-off-by: Sachin Gupta <redacted> Signed-off-by: Ram Prakash Gupta <redacted> --- drivers/mmc/host/sdhci-msm.c | 272 ++++++++++++++++++++++++++++++++--- 1 file changed, 253 insertions(+), 19 deletions(-)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 8038b8def355..a875e92f8663 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c@@ -28,6 +28,7 @@ #define CORE_VERSION_MAJOR_SHIFT 28 #define CORE_VERSION_MAJOR_MASK (0xf << CORE_VERSION_MAJOR_SHIFT) #define CORE_VERSION_MINOR_MASK 0xff +#define SDHCI_MSM_MIN_V_7FF 0x6e #define CORE_MCI_GENERICS 0x70 #define SWITCHABLE_SIGNALING_VOLTAGE BIT(29)
@@ -119,7 +120,8 @@ #define CORE_PWRSAVE_DLL BIT(3) #define DDR_CONFIG_POR_VAL 0x80040873 - +#define DLL_CONFIG_3_POR_VAL 0x10 +#define TCXO_FREQ 19200000 #define INVALID_TUNING_PHASE -1 #define SDHCI_MSM_MIN_CLOCK 400000
@@ -319,6 +321,16 @@ struct sdhci_msm_host { bool artanis_dll; }; +enum dll_init_context { + DLL_INIT_NORMAL, + DLL_INIT_FROM_CX_COLLAPSE_EXIT, +}; + +enum mode { + HS400, // equivalent to SDR104 mode for DLL. + HS200, // equivalent to SDR50 mode for DLL. +}; + static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -803,6 +815,209 @@ static int msm_init_cm_dll(struct sdhci_host *host) return 0; } +static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host) +{ + return SDHCI_MSM_MIN_CLOCK; +} + +static unsigned int sdhci_msm_get_clk_rate(struct sdhci_host *host, u32 req_clk) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + struct clk *core_clk = msm_host->bulk_clks[0].clk; + struct mmc_ios ios = host->mmc->ios; + unsigned int sup_clk; + + if (req_clk < sdhci_msm_get_min_clock(host)) + return sdhci_msm_get_min_clock(host); + + sup_clk = clk_get_rate(core_clk); + + if (ios.timing == MMC_TIMING_MMC_HS400 || + host->flags & SDHCI_HS400_TUNING) + sup_clk = sup_clk / 2; + + return sup_clk; +} + +/* Initialize the DLL (Programmable Delay Line) */ +static int sdhci_msm_configure_dll(struct sdhci_host *host, enum dll_init_context + init_context, enum mode index) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + const struct sdhci_msm_offset *msm_offset = msm_host->offset; + struct mmc_host *mmc = host->mmc; + u32 ddr_cfg_offset, core_vendor_spec, config; + void __iomem *ioaddr = host->ioaddr; + unsigned long flags, dll_clock; + int rc = 0, wait_cnt = 50; + + dll_clock = sdhci_msm_get_clk_rate(host, host->clock); + spin_lock_irqsave(&host->lock, flags); + + core_vendor_spec = readl_relaxed(ioaddr + msm_offset->core_vendor_spec); + + /* + * Always disable PWRSAVE during the DLL power + * up regardless of its current setting. + */ + core_vendor_spec &= ~CORE_CLK_PWRSAVE; + writel_relaxed(core_vendor_spec, ioaddr + msm_offset->core_vendor_spec); + + if (msm_host->use_14lpp_dll_reset) { + /* Disable CK_OUT */ + config = readl_relaxed(ioaddr + msm_offset->core_dll_config); + config &= ~CORE_CK_OUT_EN; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* Disable the DLL clock */ + config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2); + config |= CORE_DLL_CLOCK_DISABLE; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2); + } + + /* + * Write 1 to DLL_RST bit of DLL_CONFIG register + * and Write 1 to DLL_PDN bit of DLL_CONFIG register. + */ + config = readl_relaxed(ioaddr + msm_offset->core_dll_config); + config |= (CORE_DLL_RST | CORE_DLL_PDN); + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* + * Configure DLL_CONFIG_3 and USER_CTRL + * (Only applicable for 7FF projects). + */ + if (msm_host->core_minor >= SDHCI_MSM_MIN_V_7FF) { + writel_relaxed(msm_host->dll[index].dll_config_3, + ioaddr + msm_offset->core_dll_config_3); + writel_relaxed(msm_host->dll[index].dll_usr_ctl, + ioaddr + msm_offset->core_dll_usr_ctl); + } + + /* + * Set DDR_CONFIG since step 7 is setting TEST_CTRL that can be skipped. + */ + ddr_cfg_offset = msm_host->updated_ddr_cfg ? msm_offset->core_ddr_config + : msm_offset->core_ddr_config_old; + + config = msm_host->dll[index].ddr_config; + writel_relaxed(config, ioaddr + ddr_cfg_offset); + + /* Set DLL_CONFIG_2 */ + if (msm_host->use_14lpp_dll_reset) { + u32 mclk_freq; + int cycle_cnt; + + /* + * Only configure the mclk_freq in normal DLL init + * context. If the DLL init is coming from + * CX Collapse Exit context, the host->clock may be zero. + * The DLL_CONFIG_2 register has already been restored to + * proper value prior to getting here. + */ + if (init_context == DLL_INIT_NORMAL) { + cycle_cnt = readl_relaxed(ioaddr + + msm_offset->core_dll_config_2) + & CORE_FLL_CYCLE_CNT ? 8 : 4; + + mclk_freq = DIV_ROUND_CLOSEST_ULL(dll_clock * cycle_cnt, TCXO_FREQ); + + if (dll_clock < 100000000) { + pr_err("%s: %s: Non standard clk freq =%u\n", + mmc_hostname(mmc), __func__, dll_clock); + rc = -EINVAL; + goto out; + } + + config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2); + config = (config & ~GENMASK(17, 10)) | + FIELD_PREP(GENMASK(17, 10), mclk_freq); + writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2); + } + /* wait for 5us before enabling DLL clock */ + udelay(5); + } + + config = msm_host->dll[index].dll_config; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* Wait for 52us */ + spin_unlock_irqrestore(&host->lock, flags); + usleep_range(60, 70); + spin_lock_irqsave(&host->lock, flags); + + /* + * Write 0 to DLL_RST bit of DLL_CONFIG register + * and Write 0 to DLL_PDN bit of DLL_CONFIG register. + */ + config &= ~CORE_DLL_RST; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + config &= ~CORE_DLL_PDN; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + /* Write 1 to DLL_RST bit of DLL_CONFIG register */ + config |= CORE_DLL_RST; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* Write 0 to DLL_RST bit of DLL_CONFIG register */ + config &= ~CORE_DLL_RST; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* Set CORE_DLL_CLOCK_DISABLE to 0 */ + if (msm_host->use_14lpp_dll_reset) { + config = readl_relaxed(ioaddr + msm_offset->core_dll_config_2); + config &= ~CORE_DLL_CLOCK_DISABLE; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config_2); + } + + /* Set DLL_EN bit to 1. */ + config = readl_relaxed(ioaddr + msm_offset->core_dll_config); + config |= CORE_DLL_EN; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* + * Wait for 8000 input clock. Here we calculate the + * delay from fixed clock freq 192MHz, which turns out 42us. + */ + spin_unlock_irqrestore(&host->lock, flags); + usleep_range(50, 60); + spin_lock_irqsave(&host->lock, flags); + + /* Set CK_OUT_EN bit to 1. */ + config |= CORE_CK_OUT_EN; + writel_relaxed(config, ioaddr + msm_offset->core_dll_config); + + /* + * Wait until DLL_LOCK bit of DLL_STATUS register + * becomes '1'. + */ + while (!(readl_relaxed(ioaddr + msm_offset->core_dll_status) & + CORE_DLL_LOCK)) { + /* max. wait for 50us sec for LOCK bit to be set */ + if (--wait_cnt == 0) { + dev_err(mmc_dev(mmc), "%s: DLL failed to LOCK\n", + mmc_hostname(mmc)); + rc = -ETIMEDOUT; + goto out; + } + /* wait for 1us before polling again */ + udelay(1); + } + +out: + if (core_vendor_spec & CORE_CLK_PWRSAVE) { + /* Reenable PWRSAVE as needed */ + config = readl_relaxed(ioaddr + msm_offset->core_vendor_spec); + config |= CORE_CLK_PWRSAVE; + writel_relaxed(config, ioaddr + msm_offset->core_vendor_spec); + } + + spin_unlock_irqrestore(&host->lock, flags); + return rc; +} + static void msm_hc_select_default(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -925,14 +1140,31 @@ static void sdhci_msm_hc_select_mode(struct sdhci_host *host) msm_hc_select_default(host); } +static int sdhci_msm_init_dll(struct sdhci_host *host, enum dll_init_context init_context) +{ + if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 || + host->mmc->ios.timing == MMC_TIMING_MMC_HS400) + return sdhci_msm_configure_dll(host, init_context, HS400); + + return sdhci_msm_configure_dll(host, init_context, HS200); +} + +static int sdhci_msm_dll_config(struct sdhci_host *host, enum dll_init_context init_context) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + + return msm_host->artanis_dll ? sdhci_msm_init_dll(host, init_context) : + msm_init_cm_dll(host); +} + static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + const struct sdhci_msm_offset *msm_offset = msm_host->offset; u32 config, calib_done; int ret; - const struct sdhci_msm_offset *msm_offset = - msm_host->offset; pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
@@ -940,7 +1172,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host) * Retuning in HS400 (DDR mode) will fail, just reset the * tuning block and restore the saved tuning phase. */ - ret = msm_init_cm_dll(host); + ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL); if (ret) goto out;
@@ -1028,7 +1260,7 @@ static int sdhci_msm_cdclp533_calibration(struct sdhci_host *host) return ret; } -static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host) +static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host, enum mode index) { struct mmc_host *mmc = host->mmc; u32 dll_status, config, ddr_cfg_offset;
@@ -1051,7 +1283,11 @@ static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host) ddr_cfg_offset = msm_offset->core_ddr_config; else ddr_cfg_offset = msm_offset->core_ddr_config_old; - writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset); + + if (msm_host->artanis_dll) + writel_relaxed(msm_host->dll[index].ddr_config, host->ioaddr + ddr_cfg_offset); + else + writel_relaxed(msm_host->ddr_config, host->ioaddr + ddr_cfg_offset); if (mmc->ios.enhanced_strobe) { config = readl_relaxed(host->ioaddr +
@@ -1108,11 +1344,10 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + const struct sdhci_msm_offset *msm_offset = msm_host->offset; struct mmc_host *mmc = host->mmc; - int ret; u32 config; - const struct sdhci_msm_offset *msm_offset = - msm_host->offset; + int ret; pr_debug("%s: %s: Enter\n", mmc_hostname(host->mmc), __func__);
@@ -1120,7 +1355,8 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host) * Retuning in HS400 (DDR mode) will fail, just reset the * tuning block and restore the saved tuning phase. */ - ret = msm_init_cm_dll(host); + ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL); + if (ret) goto out;
@@ -1140,7 +1376,7 @@ static int sdhci_msm_hs400_dll_calibration(struct sdhci_host *host) if (msm_host->use_cdclp533) ret = sdhci_msm_cdclp533_calibration(host); else - ret = sdhci_msm_cm_dll_sdc4_calibration(host); + ret = sdhci_msm_cm_dll_sdc4_calibration(host, HS400); out: pr_debug("%s: %s: Exit, ret %d\n", mmc_hostname(host->mmc), __func__, ret);
@@ -1183,7 +1419,8 @@ static int sdhci_msm_restore_sdr_dll_config(struct sdhci_host *host) return 0; /* Reset the tuning block */ - ret = msm_init_cm_dll(host); + ret = sdhci_msm_dll_config(host, DLL_INIT_NORMAL); + if (ret) return ret;
@@ -1257,12 +1494,11 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode) if (host->flags & SDHCI_HS400_TUNING) { sdhci_msm_hc_select_mode(host); msm_set_clock_rate_for_bus_mode(host, ios.clock); - host->flags &= ~SDHCI_HS400_TUNING; } retry: /* First of all reset the tuning block */ - rc = msm_init_cm_dll(host); + rc = sdhci_msm_dll_config(host, DLL_INIT_NORMAL); if (rc) return rc;
@@ -1325,6 +1561,9 @@ static int sdhci_msm_execute_tuning(struct mmc_host *mmc, u32 opcode) rc = -EIO; } + if (host->flags & SDHCI_HS400_TUNING) + host->flags &= ~SDHCI_HS400_TUNING; + if (!rc) msm_host->tuning_done = true; return rc;
@@ -1845,11 +2084,6 @@ static unsigned int sdhci_msm_get_max_clock(struct sdhci_host *host) return clk_round_rate(core_clk, ULONG_MAX); } -static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host) -{ - return SDHCI_MSM_MIN_CLOCK; -} - /* * __sdhci_msm_set_clock - sdhci_msm clock control. *
--
2.34.1