On 14/12/17 15:09, Kishon Vijay Abraham I wrote: > MMC tuning procedure is required to support SD card > UHS1-SDR104 mode and EMMC HS200 mode. > > SDR104/HS200 DLL Tuning Procedure for AM572x platform is mentioned > in Figure 25-51. SDR104/HS200 DLL Tuning Procedure of > AM572x Sitara Processors Silicon Revision 2.0, 1.1 TRM > (SPRUHZ6I - October 2014–Revised April 2017 [1]). > > The tuning function sdhci_omap_execute_tuning() will only be > called by the MMC/SD core if the corresponding speed modes > are supported by the OMAP silicon which is set in the mmc > host "caps" field. > > [1] -> http://www.ti.com/lit/ug/spruhz6i/spruhz6i.pdf > > Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> Apart from 1 minor comment below: Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> > --- > drivers/mmc/host/sdhci-omap.c | 130 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 130 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c > index 8f7239e2edc2..df8a0a472996 100644 > --- a/drivers/mmc/host/sdhci-omap.c > +++ b/drivers/mmc/host/sdhci-omap.c > @@ -37,6 +37,13 @@ > #define CON_INIT BIT(1) > #define CON_OD BIT(0) > > +#define SDHCI_OMAP_DLL 0x0134 > +#define DLL_SWT BIT(20) > +#define DLL_FORCE_SR_C_SHIFT 13 > +#define DLL_FORCE_SR_C_MASK (0x7f << DLL_FORCE_SR_C_SHIFT) > +#define DLL_FORCE_VALUE BIT(12) > +#define DLL_CALIB BIT(1) > + > #define SDHCI_OMAP_CMD 0x20c > > #define SDHCI_OMAP_PSTATE 0x0224 > @@ -66,12 +73,16 @@ > > #define SDHCI_OMAP_AC12 0x23c > #define AC12_V1V8_SIGEN BIT(19) > +#define AC12_SCLK_SEL BIT(23) > > #define SDHCI_OMAP_CAPA 0x240 > #define CAPA_VS33 BIT(24) > #define CAPA_VS30 BIT(25) > #define CAPA_VS18 BIT(26) > > +#define SDHCI_OMAP_CAPA2 0x0244 > +#define CAPA2_TSDR50 BIT(13) > + > #define SDHCI_OMAP_TIMEOUT 1 /* 1 msec */ > > #define SYSCTL_CLKD_MAX 0x3FF > @@ -80,6 +91,8 @@ > #define IOV_3V0 3000000 /* 300000 uV */ > #define IOV_3V3 3300000 /* 330000 uV */ > > +#define MAX_PHASE_DELAY 0x7C > + > struct sdhci_omap_data { > u32 offset; > }; > @@ -204,6 +217,120 @@ static void sdhci_omap_conf_bus_power(struct sdhci_omap_host *omap_host, > } > } > > +static inline void sdhci_omap_set_dll(struct sdhci_omap_host *omap_host, > + int count) > +{ > + int i; > + u32 reg; > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL); > + reg |= DLL_FORCE_VALUE; > + reg &= ~DLL_FORCE_SR_C_MASK; > + reg |= (count << DLL_FORCE_SR_C_SHIFT); > + sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); > + > + reg |= DLL_CALIB; > + sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); > + for (i = 0; i < 1000; i++) { > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL); > + if (reg & DLL_CALIB) > + break; > + } > + reg &= ~DLL_CALIB; > + sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); > +} > + > +static void sdhci_omap_disable_tuning(struct sdhci_omap_host *omap_host) > +{ > + u32 reg; > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12); > + reg &= ~AC12_SCLK_SEL; > + sdhci_omap_writel(omap_host, SDHCI_OMAP_AC12, reg); > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL); > + reg &= ~(DLL_FORCE_VALUE | DLL_SWT); > + sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); > +} > + > +static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) > +{ > + u32 reg; > + int ret = 0; > + u8 cur_match, prev_match = 0; > + u32 phase_delay = 0; > + u32 start_window = 0, max_window = 0; > + u32 length = 0, max_len = 0; > + struct mmc_ios *ios = &mmc->ios; > + struct sdhci_host *host = mmc_priv(mmc); > + struct sdhci_pltfm_host *pltfm_host; > + struct sdhci_omap_host *omap_host; > + struct device *dev; > + > + pltfm_host = sdhci_priv(host); > + omap_host = sdhci_pltfm_priv(pltfm_host); > + dev = omap_host->dev; These initializations can be combined with the declarations. Also try to arrange local variable declaration lines in descending order of length e.g. struct sdhci_host *host = mmc_priv(mmc); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); struct device *dev = omap_host->dev; struct mmc_ios *ios = &mmc->ios; u32 start_window = 0, max_window = 0; u8 cur_match, prev_match = 0; u32 length = 0, max_len = 0; u32 phase_delay = 0; int ret = 0; u32 reg; > + > + /* clock tuning is not needed for upto 52MHz */ > + if (ios->clock <= 52000000) > + return 0; > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA2); > + if (ios->timing == MMC_TIMING_UHS_SDR50 && !(reg & CAPA2_TSDR50)) > + return 0; > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL); > + reg |= DLL_SWT; > + sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); > + > + while (phase_delay <= MAX_PHASE_DELAY) { > + sdhci_omap_set_dll(omap_host, phase_delay); > + > + cur_match = !mmc_send_tuning(mmc, opcode, NULL); > + if (cur_match) { > + if (prev_match) { > + length++; > + } else { > + start_window = phase_delay; > + length = 1; > + } > + } > + > + if (length > max_len) { > + max_window = start_window; > + max_len = length; > + } > + > + prev_match = cur_match; > + phase_delay += 4; > + } > + > + if (!max_len) { > + dev_err(dev, "Unable to find match\n"); > + ret = -EIO; > + goto tuning_error; > + } > + > + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12); > + if (!(reg & AC12_SCLK_SEL)) { > + ret = -EIO; > + goto tuning_error; > + } > + > + phase_delay = max_window + 4 * (max_len >> 1); > + sdhci_omap_set_dll(omap_host, phase_delay); > + > + goto ret; > + > +tuning_error: > + dev_err(dev, "Tuning failed\n"); > + sdhci_omap_disable_tuning(omap_host); > + > +ret: > + sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA); > + return ret; > +} > + > static int sdhci_omap_card_busy(struct mmc_host *mmc) > { > int i; > @@ -312,6 +439,8 @@ static int sdhci_omap_start_signal_voltage_switch(struct mmc_host *mmc, > static void sdhci_omap_set_power_mode(struct sdhci_omap_host *omap_host, > u8 power_mode) > { > + if (omap_host->bus_mode == MMC_POWER_OFF) > + sdhci_omap_disable_tuning(omap_host); > omap_host->power_mode = power_mode; > } > > @@ -648,6 +777,7 @@ static int sdhci_omap_probe(struct platform_device *pdev) > sdhci_omap_start_signal_voltage_switch; > host->mmc_host_ops.set_ios = sdhci_omap_set_ios; > host->mmc_host_ops.card_busy = sdhci_omap_card_busy; > + host->mmc_host_ops.execute_tuning = sdhci_omap_execute_tuning; > > sdhci_read_caps(host); > host->caps |= SDHCI_CAN_DO_ADMA2; > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
