Re: [PATCH 2/3] mmc: sdhci-of-dwcmshc: Add support for Sophgo SG2042

From: Jisheng Zhang
Date: Tue Apr 16 2024 - 11:51:01 EST


On Tue, Apr 16, 2024 at 05:50:57PM +0800, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@xxxxxxxxxxx>
>
> Add support for the mmc controller of Sophgo SG2042.
>
> SG2042 uses Synopsys PHY the same as TH1520 so we reuse the tuning
> logic from TH1520. Besides this, this patch implement some SG2042
> specific work, such as clocks and reset ops.
>
> Signed-off-by: Chen Wang <unicorn_wang@xxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-of-dwcmshc.c | 173 ++++++++++++++++++++++++++--
> 1 file changed, 166 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index 1a0b7ded7f9f..432ce0398163 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -106,12 +106,13 @@
> #define DWC_MSHC_PTR_PHY_R 0x300
>
> /* PHY general configuration */
> -#define PHY_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x00)
> -#define PHY_CNFG_RSTN_DEASSERT 0x1 /* Deassert PHY reset */
> -#define PHY_CNFG_PAD_SP_MASK GENMASK(19, 16) /* bits [19:16] */
> -#define PHY_CNFG_PAD_SP 0x0c /* PMOS TX drive strength */
> -#define PHY_CNFG_PAD_SN_MASK GENMASK(23, 20) /* bits [23:20] */
> -#define PHY_CNFG_PAD_SN 0x0c /* NMOS TX drive strength */
> +#define PHY_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x00)
> +#define PHY_CNFG_RSTN_DEASSERT 0x1 /* Deassert PHY reset */
> +#define PHY_CNFG_PHY_PWRGOOD_MASK BIT_MASK(1) /* bit [1] */
> +#define PHY_CNFG_PAD_SP_MASK GENMASK(19, 16) /* bits [19:16] */
> +#define PHY_CNFG_PAD_SP 0x0c /* PMOS TX drive strength */
> +#define PHY_CNFG_PAD_SN_MASK GENMASK(23, 20) /* bits [23:20] */
> +#define PHY_CNFG_PAD_SN 0x0c /* NMOS TX drive strength */
>
> /* PHY command/response pad settings */
> #define PHY_CMDPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x04)
> @@ -143,7 +144,8 @@
>
> /* PHY CLK delay line settings */
> #define PHY_SDCLKDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x1d)
> -#define PHY_SDCLKDL_CNFG_UPDATE BIT(4) /* set before writing to SDCLKDL_DC */
> +#define PHY_SDCLKDL_CNFG_EXTDLY_EN BIT(0)
> +#define PHY_SDCLKDL_CNFG_UPDATE BIT(4) /* set before writing to SDCLKDL_DC */
>
> /* PHY CLK delay line delay code */
> #define PHY_SDCLKDL_DC_R (DWC_MSHC_PTR_PHY_R + 0x1e)
> @@ -151,6 +153,9 @@
> #define PHY_SDCLKDL_DC_DEFAULT 0x32 /* default delay code */
> #define PHY_SDCLKDL_DC_HS400 0x18 /* delay code for HS400 mode */
>
> +#define PHY_SMPLDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x20)
> +#define PHY_SMPLDL_CNFG_BYPASS_EN BIT(1)
> +
> /* PHY drift_cclk_rx delay line configuration setting */
> #define PHY_ATDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x21)
> #define PHY_ATDL_CNFG_INPSEL_MASK GENMASK(3, 2) /* bits [3:2] */
> @@ -194,6 +199,11 @@ struct rk35xx_priv {
> u8 txclk_tapnum;
> };
>
> +#define SG2042_MAX_CLKS 2

I don't think "bulk" is suitable here for max 2 clks, no?

> +struct sg2042_priv {
> + struct clk_bulk_data clks[SG2042_MAX_CLKS];

useless either

> +};
> +
> struct dwcmshc_priv {
> struct clk *bus_clk;
> int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA reg */
> @@ -690,6 +700,76 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> sdhci_writel(host, val, priv->vendor_specific_area1 + CV18XX_SDHCI_PHY_TX_RX_DLY);
> }
>
> +static inline void sg2042_sdhci_phy_init(struct sdhci_host *host)
> +{
> + u32 val;
> +
> + /* Asset phy reset & set tx drive strength */
> + val = sdhci_readl(host, PHY_CNFG_R);
> + val &= ~PHY_CNFG_RSTN_DEASSERT;
> + val |= FIELD_PREP(PHY_CNFG_PHY_PWRGOOD_MASK, 1);
> + val |= FIELD_PREP(PHY_CNFG_PAD_SP_MASK, 9);
> + val |= FIELD_PREP(PHY_CNFG_PAD_SN_MASK, 8);
> + sdhci_writel(host, val, PHY_CNFG_R);
> +
> + /* Configure phy pads */
> + val = PHY_PAD_RXSEL_3V3;
> + val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLUP);
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, 3);
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, 2);
> + sdhci_writew(host, val, PHY_CMDPAD_CNFG_R);
> + sdhci_writew(host, val, PHY_DATAPAD_CNFG_R);
> + sdhci_writew(host, val, PHY_RSTNPAD_CNFG_R);
> +
> + val = PHY_PAD_RXSEL_3V3;
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, 3);
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, 2);
> + sdhci_writew(host, val, PHY_CLKPAD_CNFG_R);
> +
> + val = PHY_PAD_RXSEL_3V3;
> + val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLDOWN);
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, 3);
> + val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, 2);
> + sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
> +
> + /* Configure delay line */
> + /* Enable fixed delay */
> + sdhci_writeb(host, PHY_SDCLKDL_CNFG_EXTDLY_EN, PHY_SDCLKDL_CNFG_R);
> + /*
> + * Set delay line.
> + * Its recommended that bit UPDATE_DC[4] is 1 when SDCLKDL_DC is being written.
> + * Ensure UPDATE_DC[4] is '0' when not updating code.
> + */
> + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> + val |= PHY_SDCLKDL_CNFG_UPDATE;
> + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> + /* Add 10 * 70ps = 0.7ns for output delay */
> + sdhci_writeb(host, 10, PHY_SDCLKDL_DC_R);
> + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> + val &= ~(PHY_SDCLKDL_CNFG_UPDATE);
> + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> +
> + /* Set SMPLDL_CNFG, Bypass */
> + sdhci_writeb(host, PHY_SMPLDL_CNFG_BYPASS_EN, PHY_SMPLDL_CNFG_R);
> +
> + /* Set ATDL_CNFG, tuning clk not use for init */
> + val = FIELD_PREP(PHY_ATDL_CNFG_INPSEL_MASK, 2);

magic "2" needs a meaningful macro definition.

> + sdhci_writeb(host, val, PHY_ATDL_CNFG_R);
> +
> + /* Deasset phy reset */
> + val = sdhci_readl(host, PHY_CNFG_R);
> + val |= PHY_CNFG_RSTN_DEASSERT;
> + sdhci_writel(host, val, PHY_CNFG_R);
> +}
> +
> +static void sg2042_sdhci_reset(struct sdhci_host *host, u8 mask)
> +{
> + sdhci_reset(host, mask);
> +
> + if (mask & SDHCI_RESET_ALL)
> + sg2042_sdhci_phy_init(host);
> +}
> +
> static const struct sdhci_ops sdhci_dwcmshc_ops = {
> .set_clock = sdhci_set_clock,
> .set_bus_width = sdhci_set_bus_width,
> @@ -728,6 +808,16 @@ static const struct sdhci_ops sdhci_dwcmshc_cv18xx_ops = {
> .adma_write_desc = dwcmshc_adma_write_desc,
> };
>
> +static const struct sdhci_ops sdhci_dwcmshc_sg2042_ops = {
> + .set_clock = sdhci_set_clock,
> + .set_bus_width = sdhci_set_bus_width,
> + .set_uhs_signaling = dwcmshc_set_uhs_signaling,
> + .get_max_clock = dwcmshc_get_max_clock,
> + .platform_execute_tuning = th1520_execute_tuning,
> + .reset = sg2042_sdhci_reset,
> + .adma_write_desc = dwcmshc_adma_write_desc,
> +};
> +
> static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
> .ops = &sdhci_dwcmshc_ops,
> .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
> @@ -763,6 +853,13 @@ static const struct sdhci_pltfm_data sdhci_dwcmshc_cv18xx_pdata = {
> .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> };
>
> +static const struct sdhci_pltfm_data sdhci_dwcmshc_sg2042_pdata = {
> + .ops = &sdhci_dwcmshc_sg2042_ops,
> + .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
> + SDHCI_QUIRK_INVERTED_WRITE_PROTECT,

is "wp-inverted" property better?

> + .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> +};
> +
> static void dwcmshc_rk35xx_postinit(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
> {
> /*
> @@ -882,6 +979,58 @@ static int dwcmshc_th1520_init(struct device *dev,
> return 0;
> }
>
> +static int dwcmshc_sg2042_clks_enable(struct dwcmshc_priv *dwc_priv)
> +{
> + int ret = 0;
> + struct sg2042_priv *soc = dwc_priv->priv;
> +
> + if (soc)
> + ret = clk_bulk_prepare_enable(SG2042_MAX_CLKS, soc->clks);
> + return ret;
> +}
> +
> +static void dwcmshc_sg2042_clks_disable(struct dwcmshc_priv *dwc_priv)
> +{
> + struct sg2042_priv *soc = dwc_priv->priv;
> +
> + if (soc)
> + clk_bulk_disable_unprepare(SG2042_MAX_CLKS,
> + soc->clks);
> +}
> +
> +static int dwcmshc_sg2042_init(struct device *dev,
> + struct sdhci_host *host,
> + struct dwcmshc_priv *dwc_priv)
> +{
> + int err;
> + struct sg2042_priv *soc = NULL;
> +
> + soc = devm_kzalloc(dev, sizeof(struct sg2042_priv), GFP_KERNEL);
> + if (!soc)
> + return -ENOMEM;
> +
> + soc->clks[0].id = "card";
> + soc->clks[1].id = "timer";

Interesting, only "card" and "timer", so which clk is for clk input of the ip?

> + err = devm_clk_bulk_get_optional(mmc_dev(host->mmc), SG2042_MAX_CLKS,
> + soc->clks);
> + if (err) {
> + dev_err(mmc_dev(host->mmc), "failed to get clocks %d\n", err);
> + return err;
> + }
> +
> + err = clk_bulk_prepare_enable(SG2042_MAX_CLKS, soc->clks);
> + if (err) {
> + dev_err(mmc_dev(host->mmc), "failed to enable clocks %d\n", err);
> + return err;
> + }
> +
> + dwc_priv->priv = soc;
> + dwc_priv->soc_clks_enable = dwcmshc_sg2042_clks_enable;
> + dwc_priv->soc_clks_disable = dwcmshc_sg2042_clks_disable;
> +
> + return 0;
> +}
> +
> static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
> {
> .compatible = "rockchip,rk3588-dwcmshc",
> @@ -907,6 +1056,10 @@ static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
> .compatible = "thead,th1520-dwcmshc",
> .data = &sdhci_dwcmshc_th1520_pdata,
> },
> + {
> + .compatible = "sophgo,sg2042-dwcmshc",
> + .data = &sdhci_dwcmshc_sg2042_pdata,
> + },
> {},
> };
> MODULE_DEVICE_TABLE(of, sdhci_dwcmshc_dt_ids);
> @@ -994,6 +1147,12 @@ static int dwcmshc_probe(struct platform_device *pdev)
> goto err_clk;
> }
>
> + if (pltfm_data == &sdhci_dwcmshc_sg2042_pdata) {
> + err = dwcmshc_sg2042_init(dev, host, priv);
> + if (err)
> + goto err_clk;
> + }
> +
> #ifdef CONFIG_ACPI
> if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
> sdhci_enable_v4_mode(host);
> --
> 2.25.1
>