On 05/10/16 17:40, Ritesh Harjani wrote:
> From: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
>
> In HS400 mode a new RCLK is introduced on the interface for read data
> transfers. The eMMC5.0 device transmits the read data to the host with
> respect to rising and falling edges of RCLK. In order to ensure correct
> operation of read data transfers in HS400 mode, the incoming RX data
> needs to be sampled by delayed version of RCLK.
>
> The CDCLP533 delay circuit shifts the RCLK by T/4. It needs to be
> initialized, configured and enabled once during HS400 mode switch and
> when operational voltage/clock is changed.
>
> Signed-off-by: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
> Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-msm.c | 178 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 178 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 612fa82..dbf80a9c 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -57,6 +57,7 @@
> #define CORE_DLL_PDN BIT(29)
> #define CORE_DLL_RST BIT(30)
> #define CORE_DLL_CONFIG 0x100
> +#define CORE_CMD_DAT_TRACK_SEL BIT(0)
> #define CORE_DLL_STATUS 0x108
>
> #define CORE_DLL_CONFIG_2 0x1b4
> @@ -72,8 +73,36 @@
> #define CORE_HC_SELECT_IN_HS400 (6 << 19)
> #define CORE_HC_SELECT_IN_MASK (7 << 19)
>
> +#define CORE_CSR_CDC_CTLR_CFG0 0x130
> +#define CORE_SW_TRIG_FULL_CALIB BIT(16)
> +#define CORE_HW_AUTOCAL_ENA BIT(17)
> +
> +#define CORE_CSR_CDC_CTLR_CFG1 0x134
> +#define CORE_CSR_CDC_CAL_TIMER_CFG0 0x138
> +#define CORE_TIMER_ENA BIT(16)
> +
> +#define CORE_CSR_CDC_CAL_TIMER_CFG1 0x13C
> +#define CORE_CSR_CDC_REFCOUNT_CFG 0x140
> +#define CORE_CSR_CDC_COARSE_CAL_CFG 0x144
> +#define CORE_CDC_OFFSET_CFG 0x14C
> +#define CORE_CSR_CDC_DELAY_CFG 0x150
> +#define CORE_CDC_SLAVE_DDA_CFG 0x160
> +#define CORE_CSR_CDC_STATUS0 0x164
> +#define CORE_CALIBRATION_DONE BIT(0)
> +
> +#define CORE_CDC_ERROR_CODE_MASK 0x7000000
> +
> +#define CORE_CSR_CDC_GEN_CFG 0x178
> +#define CORE_CDC_SWITCH_BYPASS_OFF BIT(0)
> +#define CORE_CDC_SWITCH_RC_EN BIT(1)
> +
> +#define CORE_DDR_200_CFG 0x184
> +#define CORE_CDC_T4_DLY_SEL BIT(0)
> +#define CORE_START_CDC_TRAFFIC BIT(6)
> +
> #define CORE_VENDOR_SPEC_CAPABILITIES0 0x11c
>
> +#define INVALID_TUNING_PHASE -1
> #define TCXO_FREQ 19200000
> #define SDHCI_MSM_MIN_CLOCK 400000
> #define CORE_FREQ_100MHZ (100 * 1000 * 1000)
> @@ -97,6 +126,7 @@ struct sdhci_msm_host {
> bool use_14lpp_dll_reset;
> bool tuning_done;
> bool calibration_done;
> + u8 saved_tuning_phase;
> };
>
> /* Platform specific tuning */
> @@ -426,6 +456,136 @@ static int msm_init_cm_dll(struct sdhci_host *host)
> return 0;
> }
>
> +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);
> + u32 wait_cnt, config;
> + int ret;
> +
> + pr_debug("%s: Enter %s\n", mmc_hostname(host->mmc), __func__);
> +
> + /*
> + * Retuning in HS400 (DDR mode) will fail, just reset the
> + * tuning block and restore the saved tuning phase.
> + */
> + ret = msm_init_cm_dll(host);
> + if (ret)
> + goto out;
> +
> + /* Set the selected phase in delay line hw block */
> + ret = msm_config_cm_dll_phase(host, msm_host->saved_tuning_phase);
> + if (ret)
> + goto out;
> +
> + /* Write 1 to CMD_DAT_TRACK_SEL field in DLL_CONFIG */
> + config = readl_relaxed(host->ioaddr + CORE_DLL_CONFIG);
> + config |= CORE_CMD_DAT_TRACK_SEL;
> + writel_relaxed(config, host->ioaddr + CORE_DLL_CONFIG);
> +
> + /* Write 0 to CDC_T4_DLY_SEL field in VENDOR_SPEC_DDR200_CFG */
> + config = readl_relaxed(host->ioaddr + CORE_DDR_200_CFG);
> + config &= ~CORE_CDC_T4_DLY_SEL;
> + writel_relaxed(config, host->ioaddr + CORE_DDR_200_CFG);
> +
> + /* Write 0 to CDC_SWITCH_BYPASS_OFF field in CORE_CSR_CDC_GEN_CFG */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_GEN_CFG);
> + config &= ~CORE_CDC_SWITCH_BYPASS_OFF;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_GEN_CFG);
> +
> + /* Write 1 to CDC_SWITCH_RC_EN field in CORE_CSR_CDC_GEN_CFG */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_GEN_CFG);
> + config |= CORE_CDC_SWITCH_RC_EN;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_GEN_CFG);
> +
> + /* Write 0 to START_CDC_TRAFFIC field in CORE_DDR200_CFG */
> + config = readl_relaxed(host->ioaddr + CORE_DDR_200_CFG);
> + config &= ~CORE_START_CDC_TRAFFIC;
> + writel_relaxed(config, host->ioaddr + CORE_DDR_200_CFG);
> +
> + /*
> + * Perform CDC Register Initialization Sequence
> + *
> + * CORE_CSR_CDC_CTLR_CFG0 0x11800EC
> + * CORE_CSR_CDC_CTLR_CFG1 0x3011111
> + * CORE_CSR_CDC_CAL_TIMER_CFG0 0x1201000
> + * CORE_CSR_CDC_CAL_TIMER_CFG1 0x4
> + * CORE_CSR_CDC_REFCOUNT_CFG 0xCB732020
> + * CORE_CSR_CDC_COARSE_CAL_CFG 0xB19
> + * CORE_CSR_CDC_DELAY_CFG 0x3AC
> + * CORE_CDC_OFFSET_CFG 0x0
> + * CORE_CDC_SLAVE_DDA_CFG 0x16334
> + */
> +
> + writel_relaxed(0x11800EC, host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> + writel_relaxed(0x3011111, host->ioaddr + CORE_CSR_CDC_CTLR_CFG1);
> + writel_relaxed(0x1201000, host->ioaddr + CORE_CSR_CDC_CAL_TIMER_CFG0);
> + writel_relaxed(0x4, host->ioaddr + CORE_CSR_CDC_CAL_TIMER_CFG1);
> + writel_relaxed(0xCB732020, host->ioaddr + CORE_CSR_CDC_REFCOUNT_CFG);
> + writel_relaxed(0xB19, host->ioaddr + CORE_CSR_CDC_COARSE_CAL_CFG);
> + writel_relaxed(0x3AC, host->ioaddr + CORE_CSR_CDC_DELAY_CFG);
> + writel_relaxed(0x0, host->ioaddr + CORE_CDC_OFFSET_CFG);
> + writel_relaxed(0x16334, host->ioaddr + CORE_CDC_SLAVE_DDA_CFG);
> +
> + /* CDC HW Calibration */
> +
> + /* Write 1 to SW_TRIG_FULL_CALIB field in CORE_CSR_CDC_CTLR_CFG0 */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> + config |= CORE_SW_TRIG_FULL_CALIB;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> +
> + /* Write 0 to SW_TRIG_FULL_CALIB field in CORE_CSR_CDC_CTLR_CFG0 */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> + config &= ~CORE_SW_TRIG_FULL_CALIB;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> +
> + /* Write 1 to HW_AUTOCAL_ENA field in CORE_CSR_CDC_CTLR_CFG0 */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> + config |= CORE_HW_AUTOCAL_ENA;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_CTLR_CFG0);
> +
> + /* Write 1 to TIMER_ENA field in CORE_CSR_CDC_CAL_TIMER_CFG0 */
> + config = readl_relaxed(host->ioaddr + CORE_CSR_CDC_CAL_TIMER_CFG0);
> + config |= CORE_TIMER_ENA;
> + writel_relaxed(config, host->ioaddr + CORE_CSR_CDC_CAL_TIMER_CFG0);
> +
> + wmb(); /* drain writebuffer */
> +
> + /* Poll on CALIBRATION_DONE field in CORE_CSR_CDC_STATUS0 to be 1 */
> + wait_cnt = 50;
> + while (!(readl_relaxed(host->ioaddr + CORE_CSR_CDC_STATUS0)
> + & CORE_CALIBRATION_DONE)) {
> + /* max. wait for 50us sec for CALIBRATION_DONE bit to be set */
> + if (--wait_cnt == 0) {
> + pr_err("%s: %s: CDC Calibration was not completed\n",
> + mmc_hostname(host->mmc), __func__);
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> + /* wait for 1us before polling again */
> + udelay(1);
> + }
> +
> + /* Verify CDC_ERROR_CODE field in CORE_CSR_CDC_STATUS0 is 0 */
> + ret = readl_relaxed(host->ioaddr + CORE_CSR_CDC_STATUS0)
> + & CORE_CDC_ERROR_CODE_MASK;
> + if (ret) {
> + pr_err("%s: %s: CDC Error Code %d\n",
> + mmc_hostname(host->mmc), __func__, ret);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + /* Write 1 to START_CDC_TRAFFIC field in CORE_DDR200_CFG */
> + config = readl_relaxed(host->ioaddr + CORE_DDR_200_CFG);
> + config |= CORE_START_CDC_TRAFFIC;
> + writel_relaxed(config, host->ioaddr + CORE_DDR_200_CFG);
> +out:
> + pr_debug("%s: Exit %s, ret:%d\n", mmc_hostname(host->mmc),
> + __func__, ret);
> + return ret;
> +}
> +
> static int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
> {
> int tuning_seq_cnt = 3;
> @@ -433,6 +593,8 @@ static int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
> int rc;
> struct mmc_host *mmc = host->mmc;
> struct mmc_ios ios = host->mmc->ios;
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>
> /*
> * Tuning is required for SDR104, HS200 and HS400 cards and
> @@ -457,6 +619,7 @@ retry:
> if (rc)
> return rc;
>
> + msm_host->saved_tuning_phase = phase;
> rc = mmc_send_tuning(mmc, opcode, NULL);
> if (!rc) {
> /* Tuning is successful at this tuning point */
> @@ -492,6 +655,8 @@ retry:
> rc = -EIO;
> }
>
> + if (!rc)
> + msm_host->tuning_done = true;
> return rc;
> }
>
> @@ -565,6 +730,17 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
> dev_dbg(mmc_dev(mmc), "%s: clock=%u uhs=%u ctrl_2=0x%x\n",
> mmc_hostname(host->mmc), host->clock, uhs, ctrl_2);
> sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> +
> + spin_unlock_irq(&host->lock);
> +
> + /* CDCLP533 HW calibration is only required for HS400 mode*/
> + if (host->clock > CORE_FREQ_100MHZ &&
> + msm_host->tuning_done && !msm_host->calibration_done &&
> + (mmc->ios.timing == MMC_TIMING_MMC_HS400))
> + if (!sdhci_msm_cdclp533_calibration(host))
> + msm_host->calibration_done = true;
> +
> + spin_lock_irq(&host->lock);
> }
>
> static void sdhci_msm_voltage_switch(struct sdhci_host *host)
> @@ -907,6 +1083,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>
> sdhci_msm_populate_dt(&pdev->dev, msm_host);
>
> + msm_host->saved_tuning_phase = INVALID_TUNING_PHASE;
There is never a check for INVALID_TUNING_PHASE which begs the question: why
have it?
> +
> /* Setup SDCC bus voter clock. */
> msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
> if (!IS_ERR(msm_host->bus_clk)) {
>
--
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