On Sun, Aug 06, 2023 at 06:09:39PM +0800, Jisheng Zhang wrote:
> On Fri, Aug 04, 2023 at 08:14:48PM -0700, Drew Fustini wrote:
> > Add basic support for the T-Head TH1520 SoC mmc controller with the new
> > compatible "thead,th1520-dwcmshc".
> >
> > However, quirks are currently set to disable DMA and use PIO. The proper
> > settings for DMA support still need to be determined.
>
> Hi Drew,
>
> Thank you for this patch. I think we need to make DMA work even in the
> first version.
Thanks for your review. I agree that DMA should be made to work.
When I remove the SDHCI_QUIRK_BROKEN_ADMA quirk, I see the following in
the boot log [1]:
[ 3.633611] mmc0: SDHCI controller on ffe7080000.mmc [ffe7080000.mmc] using ADMA 64-bit
[ 3.723080] mmc0: ADMA error: 0x02000000
[ 4.327491] mmc0: error -5 whilst initialising MMC card
I'm going to add some more debug output so I can better understand what
exactly is failing.
>
> Several comments below.
>
> >
> > Another issue is th1520-specific code for MMC_TIMING_MMC_HS400 in
> > dwcmshc_set_uhs_signaling() will run on all platforms which is not
> > correct. One solution could be to add a th1520 flag to dwcmshc_priv but
> > that is hacky. Another solution could be to set the set_uhs_signaling op
> > in sdhci_dwcmshc_th1520_ops to a th1520-specific function. However, that
> > new function would have to duplicate all the code in the current
> > dwcmshc_set_uhs_signaling().
> >
> > Signed-off-by: Drew Fustini <dfustini@xxxxxxxxxxxx>
> > ---
> > drivers/mmc/host/sdhci-of-dwcmshc.c | 336 ++++++++++++++++++++++++++++++++++++
> > 1 file changed, 336 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > index e68cd87998c8..d35e204cdb16 100644
> > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > @@ -71,6 +71,63 @@
> > (((x) & DWCMSHC_EMMC_DLL_TIMEOUT) == 0))
> > #define RK35xx_MAX_CLKS 3
> >
> > +/* T-Head specific registers */
>
> I guess this may not be T-HEAD specific but dwc phy, could you please
> check?
Yes, I will try to find out if if this really is t-head specific or just
standard for the DWC PHY.
> > +#define DWC_MSHC_PTR_PHY_R 0x300
> > +#define PHY_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x00)
> > +#define PHY_RSTN 0x0
> > +#define PAD_SP 0x10
> > +#define PAD_SN 0x14
> > +
> > +#define PHY_CMDPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x04)
> > +#define PHY_DATAPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x06)
> > +#define PHY_CLKPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x08)
> > +#define PHY_STBPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x0a)
> > +#define PHY_RSTNPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x0c)
> > +#define RXSEL 0x0
> > +#define WEAKPULL_EN 0x3
> > +#define TXSLEW_CTRL_P 0x5
> > +#define TXSLEW_CTRL_N 0x9
> > +
> > +#define PHY_PADTEST_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x0e)
> > +#define PHY_PADTEST_OUT_R (DWC_MSHC_PTR_PHY_R + 0x10)
> > +#define PHY_PADTEST_IN_R (DWC_MSHC_PTR_PHY_R + 0x12)
> > +#define PHY_PRBS_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x18)
> > +#define PHY_PHYLBK_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x1a)
> > +#define PHY_COMMDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x1c)
> > +
> > +#define PHY_SDCLKDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x1d)
> > +#define UPDATE_DC 0x4
> > +
> > +#define PHY_SDCLKDL_DC_R (DWC_MSHC_PTR_PHY_R + 0x1e)
> > +#define PHY_SMPLDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x20)
> > +#define PHY_ATDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x21)
> > +#define INPSEL_CNFG 2
> > +
> > +#define PHY_DLL_CTRL_R (DWC_MSHC_PTR_PHY_R + 0x24)
> > +#define DLL_EN 0x0
> > +
> > +#define PHY_DLL_CNFG1_R (DWC_MSHC_PTR_PHY_R + 0x25)
> > +#define PHY_DLL_CNFG2_R (DWC_MSHC_PTR_PHY_R + 0x26)
> > +#define PHY_DLLDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x28)
> > +#define SLV_INPSEL 0x5
> > +
> > +#define P_VENDOR_SPECIFIC_AREA 0x500
> > +#define EMMC_CTRL_R (P_VENDOR_SPECIFIC_AREA + 0x2c)
> > +#define AT_CTRL_R (P_VENDOR_SPECIFIC_AREA + 0x40)
> > +#define AT_EN 0x0
> > +#define CI_SEL 0x1
> > +#define SWIN_TH_EN 0x2
> > +#define RPT_TUNE_ERR 0x3
> > +#define SW_TUNE_EN 0x4
> > +#define WIN_EDGE_SEL 0x8
> > +#define TUNE_CLK_STOP_EN 0x10
> > +#define PRE_CHANGE_DLY 0x11
> > +#define POST_CHANGE_DLY 0x13
> > +#define SWIN_TH_VAL 0x18
> > +
> > +#define DELAY_LINE_HS400 24
> > +#define DELAY_LINE_DEFAULT 50
> > +
> > #define BOUNDARY_OK(addr, len) \
> > ((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
> >
> > @@ -91,6 +148,10 @@ struct dwcmshc_priv {
> > struct clk *bus_clk;
> > int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA reg */
> > void *priv; /* pointer to SoC private stuff */
> > + uint32_t delay_line;
> > + bool non_removable;
>
> can be replaced with mmc_host.caps & MMC_CAP_NONREMOVABLE
Thank you, I'll change in the next version.
>
> > + bool pull_up_en;
> > + bool io_fixed_1v8;
>
> replace them with flag?
Do you mean that I should replace the above bool's with a single flags
field in the struct where the bool's would become bit fields in flags?
>
> > };
> >
> > /*
> > @@ -156,11 +217,171 @@ static void dwcmshc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> > sdhci_request(mmc, mrq);
> > }
> >
> > +static void sdhci_phy_1_8v_init_no_pull(struct sdhci_host *host)
> > +{
> > + uint32_t val;
> > + sdhci_writel(host, 1, DWC_MSHC_PTR_PHY_R);
> > + sdhci_writeb(host, 1 << 4, PHY_SDCLKDL_CNFG_R);
> > + sdhci_writeb(host, 0x40, PHY_SDCLKDL_DC_R);
>
> These magic numbers need a proper macro definitions.
I'll try to find out their meaning and document it.
>
> > +
> > + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> > + val &= ~(1 << 4);
>
> ditto
>
> > + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> > +
> > +
> > + val = sdhci_readw(host, PHY_CMDPAD_CNFG_R);
> > + sdhci_writew(host, val | 1, PHY_CMDPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_DATAPAD_CNFG_R);
> > + sdhci_writew(host, val | 1, PHY_DATAPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_RSTNPAD_CNFG_R);
> > + sdhci_writew(host, val | 1, PHY_RSTNPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_STBPAD_CNFG_R);
> > + sdhci_writew(host, val | 1, PHY_STBPAD_CNFG_R);
> > +
> > + val = sdhci_readb(host, PHY_DLL_CTRL_R);
> > + sdhci_writeb(host, val | 1, PHY_DLL_CTRL_R);
> > +}
> > +
> > +static void sdhci_phy_3_3v_init_no_pull(struct sdhci_host *host)
> > +{
> > + uint32_t val;
> > +
> > + sdhci_writel(host, 1, DWC_MSHC_PTR_PHY_R);
> > + sdhci_writeb(host, 1 << 4, PHY_SDCLKDL_CNFG_R);
> > + sdhci_writeb(host, 0x40, PHY_SDCLKDL_DC_R);
> > +
> > + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> > + val &= ~(1 << 4);
> > + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_CMDPAD_CNFG_R);
> > + sdhci_writew(host, val | 2, PHY_CMDPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_DATAPAD_CNFG_R);
> > + sdhci_writew(host, val | 2, PHY_DATAPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_RSTNPAD_CNFG_R);
> > + sdhci_writew(host, val | 2, PHY_RSTNPAD_CNFG_R);
> > +
> > + val = sdhci_readw(host, PHY_STBPAD_CNFG_R);
> > + sdhci_writew(host, val | 2, PHY_STBPAD_CNFG_R);
> > +
> > + val = sdhci_readb(host, PHY_DLL_CTRL_R);
> > + sdhci_writeb(host, val | 1, PHY_DLL_CTRL_R);
> > +}
> > +
> > +static void th1520_phy_1_8v_init(struct sdhci_host *host)
> > +{
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > + u32 val;
> > +
> > + if (!priv)
> > + return;
> > +
> > + if (priv->pull_up_en == 0) {
> > + sdhci_phy_1_8v_init_no_pull(host);
> > + return;
> > + }
> > +
> > + /* set driving force */
> > + sdhci_writel(host, (1 << PHY_RSTN) | (0xc << PAD_SP) | (0xc << PAD_SN), PHY_CNFG_R);
> > +
> > + /* disable delay lane */
> > + sdhci_writeb(host, 1 << UPDATE_DC, PHY_SDCLKDL_CNFG_R);
> > +
> > + /* set delay lane */
> > + sdhci_writeb(host, priv->delay_line, PHY_SDCLKDL_DC_R);
> > + sdhci_writeb(host, 0xa, PHY_DLL_CNFG2_R);
> > +
> > + /* enable delay lane */
> > + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> > + val &= ~(1 << UPDATE_DC);
> > + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> > +
> > + val = (1 << RXSEL) | (1 << WEAKPULL_EN) | (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + 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 = (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + sdhci_writew(host, val, PHY_CLKPAD_CNFG_R);
> > +
> > + val = (1 << RXSEL) | (2 << WEAKPULL_EN) | (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
> > +
> > + /* enable data strobe mode */
> > + sdhci_writeb(host, 3 << SLV_INPSEL, PHY_DLLDL_CNFG_R);
> > + sdhci_writeb(host, (1 << DLL_EN), PHY_DLL_CTRL_R);
> > +}
> > +
> > +static void th1520_phy_3_3v_init(struct sdhci_host *host)
> > +{
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > + u32 val;
> > +
> > + if (priv->pull_up_en == 0) {
> > + sdhci_phy_3_3v_init_no_pull(host);
> > + return;
> > + }
> > +
> > + /* set driving force */
> > + sdhci_writel(host, (1 << PHY_RSTN) | (0xc << PAD_SP) | (0xc << PAD_SN), PHY_CNFG_R);
> > +
> > + /* disable delay lane */
> > + sdhci_writeb(host, 1 << UPDATE_DC, PHY_SDCLKDL_CNFG_R);
> > +
> > + /* set delay lane */
> > + sdhci_writeb(host, priv->delay_line, PHY_SDCLKDL_DC_R);
> > + sdhci_writeb(host, 0xa, PHY_DLL_CNFG2_R);
> > +
> > + /* enable delay lane */
> > + val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
> > + val &= ~(1 << UPDATE_DC);
> > + sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
> > +
> > + val = (2 << RXSEL) | (1 << WEAKPULL_EN) | (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + 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 = (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + sdhci_writew(host, val, PHY_CLKPAD_CNFG_R);
> > +
> > + val = (2 << RXSEL) | (2 << WEAKPULL_EN) | (3 << TXSLEW_CTRL_P) | (3 << TXSLEW_CTRL_N);
> > + sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
> > +}
> > +
> > +
> > +static void th1520_sdhci_set_phy(struct sdhci_host *host)
> > +{
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > + u8 emmc_ctl;
> > +
> > + /* Before power on, set PHY configs */
> > + emmc_ctl = sdhci_readw(host, EMMC_CTRL_R);
> > + if (priv->non_removable) {
> > + th1520_phy_1_8v_init(host);
> > + emmc_ctl |= (1 << DWCMSHC_CARD_IS_EMMC);
> > + } else {
> > + th1520_phy_3_3v_init(host);
> > + emmc_ctl &=~(1 << DWCMSHC_CARD_IS_EMMC);
> > + }
> > + sdhci_writeb(host, emmc_ctl, EMMC_CTRL_R);
> > + sdhci_writeb(host, 0x25, PHY_DLL_CNFG1_R);
>
> magic 0x25 needs a meaningful MACRO definition.
Okay, I'll investigate the meaning of that value and define it.
>
> > +}
> > +
> > static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
> > unsigned int timing)
> > {
> > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > +
>
> we don't need this extra blank line
Okay
>
> > u16 ctrl, ctrl_2;
> >
> > ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > @@ -188,7 +409,22 @@ static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
> > ctrl_2 |= DWCMSHC_CTRL_HS400;
> > }
> >
> > + if (priv->io_fixed_1v8)
> > + ctrl_2 |= SDHCI_CTRL_VDD_180;
> > +
> > sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> > +
> > + /* TODO: add check so that this only runs on th1520 */
>
> this TODO needs to be solved since it affects other platforms such as NV
> and RK
Yes, I need to fix this. For the next version, I am considering adding
a flag to dwcmshc_priv that would gate the following code block.
> > + if (timing == MMC_TIMING_MMC_HS400) {
> > + /* disable auto tuning */
> > + u32 reg = sdhci_readl(host, AT_CTRL_R);
> > + reg &= ~1;
> > + sdhci_writel(host, reg, AT_CTRL_R);
> > + priv->delay_line = DELAY_LINE_HS400;
> > + th1520_sdhci_set_phy(host);
> > + } else {
> > + sdhci_writeb(host, 0, PHY_DLLDL_CNFG_R);
> > + }
> > }
> >
> > static void dwcmshc_hs400_enhanced_strobe(struct mmc_host *mmc,
> > @@ -337,6 +573,49 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> > sdhci_reset(host, mask);
> > }
> >
> > +static int th1520_execute_tuning(struct sdhci_host *host, u32 opcode)
> > +{
> > + u32 val = 0;
> > +
> > + sdhci_writeb(host, 3 << INPSEL_CNFG, PHY_ATDL_CNFG_R);
> > +
> > + val = sdhci_readl(host, AT_CTRL_R);
> > + val &= ~((1 << CI_SEL) | (1 << RPT_TUNE_ERR) \
> > + | (1 << SW_TUNE_EN) |(0xf << WIN_EDGE_SEL));
> > + val |= (1 << AT_EN) | (1 << SWIN_TH_EN) | (1 << TUNE_CLK_STOP_EN)\
> > + | (1 << PRE_CHANGE_DLY) | (3 << POST_CHANGE_DLY) | (9 << SWIN_TH_VAL);
> > +
> > + sdhci_writel(host, val, AT_CTRL_R);
> > +
> > + val = sdhci_readl(host, AT_CTRL_R);
> > + if(!(val & (1 << AT_EN))) {
> > + pr_warn("%s(): auto tuning is not enabled", __func__);
>
> AFAIK, the controller supports both auto tuning and sw tuning.
Okay, I'll have to investigate further why it is like this in the vendor
kernel [2].
>
> > + return -1;
>
> can we replace -1 with meaningful error number?
>
Yes, will do for next version.
> > + }
> > +
> > + val &= ~(1 << AT_EN);
> > + sdhci_writel(host, val, AT_CTRL_R);
> > +
> > + return 0;
> > +}
> > +
> > +static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
> > +{
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > + u16 ctrl_2;
> > +
> > + sdhci_reset(host, mask);
> > +
> > + if(priv->io_fixed_1v8){
> > + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > + if(! (ctrl_2 & SDHCI_CTRL_VDD_180)){
> > + ctrl_2 |= SDHCI_CTRL_VDD_180;
> > + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> > + }
> > + }
> > +}
> > +
> > static const struct sdhci_ops sdhci_dwcmshc_ops = {
> > .set_clock = sdhci_set_clock,
> > .set_bus_width = sdhci_set_bus_width,
> > @@ -355,6 +634,17 @@ static const struct sdhci_ops sdhci_dwcmshc_rk35xx_ops = {
> > .adma_write_desc = dwcmshc_adma_write_desc,
> > };
> >
> > +static const struct sdhci_ops sdhci_dwcmshc_th1520_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,
> > + .reset = th1520_sdhci_reset,
> > + .adma_write_desc = dwcmshc_adma_write_desc,
> > + .voltage_switch = th1520_phy_1_8v_init,
> > + .platform_execute_tuning = &th1520_execute_tuning,
> > +};
> > +
> > static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
> > .ops = &sdhci_dwcmshc_ops,
> > .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
> > @@ -378,6 +668,15 @@ static const struct sdhci_pltfm_data sdhci_dwcmshc_rk35xx_pdata = {
> > SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
> > };
> >
> > +static const struct sdhci_pltfm_data sdhci_dwcmshc_th1520_pdata = {
> > + .ops = &sdhci_dwcmshc_th1520_ops,
> > +
> > + .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
> > + SDHCI_QUIRK_BROKEN_DMA |
> > + SDHCI_QUIRK_BROKEN_ADMA,
> > + .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> > +};
> > +
> > static int dwcmshc_rk35xx_init(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
> > {
> > int err;
> > @@ -434,6 +733,10 @@ static void dwcmshc_rk35xx_postinit(struct sdhci_host *host, struct dwcmshc_priv
> > }
> >
> > static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
> > + {
> > + .compatible = "thead,th1520-dwcmshc",
> > + .data = &sdhci_dwcmshc_th1520_pdata,
> > + },
> > {
> > .compatible = "rockchip,rk3588-dwcmshc",
> > .data = &sdhci_dwcmshc_rk35xx_pdata,
> > @@ -541,6 +844,39 @@ static int dwcmshc_probe(struct platform_device *pdev)
> > goto err_clk;
> > }
> >
> > + if (pltfm_data == &sdhci_dwcmshc_th1520_pdata) {
> > +
> > + priv->delay_line = DELAY_LINE_DEFAULT;
> > +
> > + if (device_property_present(&pdev->dev, "non-removable"))
> > + priv->non_removable = 1;
> > + else
> > + priv->non_removable = 0;
> > +
> > + if (device_property_present(&pdev->dev, "thead,pull-up"))
> > + priv->pull_up_en = 1;
> > + else
> > + priv->pull_up_en = 0;
> > +
> > + if (device_property_present(&pdev->dev, "thead,io-fixed-1v8"))
> > + priv->io_fixed_1v8 = true;
> > + else
> > + priv->io_fixed_1v8 = false;
> > +
> > + /*
> > + * start_signal_voltage_switch() will try 3.3V first
> > + * then 1.8V. Use SDHCI_SIGNALING_180 ranther than
> > + * SDHCI_SIGNALING_330 to avoid setting voltage to 3.3V
> > + * in sdhci_start_signal_voltage_switch().
> > + */
> > + if(priv->io_fixed_1v8){
> > + host->flags &=~SDHCI_SIGNALING_330;
> > + host->flags |= SDHCI_SIGNALING_180;
> > + }
> > +
> > + sdhci_enable_v4_mode(host);
> > + }
> > +
> > #ifdef CONFIG_ACPI
> > if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
> > sdhci_enable_v4_mode(host);
> >
> > --
> > 2.34.1
> >
Thank you,
Drew
[1] https://gist.github.com/pdp7/a8301b895c2dc293f2e0210e77e45e01
[2] https://git.beagleboard.org/beaglev-ahead/beaglev-ahead-linux/-/blob/beaglev-v5.10.113-1.1.2/drivers/mmc/host/sdhci-of-dwcmshc.c#L238
