[PATCH] mmc: tmio: Disable 1/1024 clock divider on Renesas R-Car platforms

[PATCH] mmc: tmio: Disable 1/1024 clock divider on Renesas R-Car platforms

[Marek Vasut]

The R-Car Gen3 SD_CLK_CTRL register does not use BIT(16) to implement
divider 1/1024, instead BIT(16) is reserved bit and divider 1/1024 is
not supported. The divider 1/1024 is specific to Socionext variant of
the IP, as is indicated by Linux commit:

0196c8db8363 ("mmc: tmio: move tmio_mmc_set_clock() to platform hook")
"
Socionext (and Panasonic) uses bit 10 (CLKSEL) for 1/1.  Also, newer
versions of UniPhier SoC variants use bit 16 for 1/1024.
"

Do not set the TMIO_SD_CAP_DIV1024 on Renesas R-Car platforms even if
the IP VERSION register does exist, and indicates IP version is newer
or equal to version 1.0 . The IP version 1.0 or newer does not imply
presence of the 1/1024 divider.

Since the TMIO driver is used exactly by two supported platforms, that
is Renesas R-Car and Socionext UniPhier, it is OK to check whether the
TMIO_SD_CAP_RCAR capability is not set to identify the UniPhier platform
and add the capability only on that platform.

Fixes: 58c35b17aa8f ("mmc: matsushita-common: Always check controller version")
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
Cc: Peng Fan <peng.fan@nxp.com>
---
 drivers/mmc/tmio-common.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/tmio-common.c b/drivers/mmc/tmio-common.c
index 83eaf361f0c..890c496b535 100644
--- a/drivers/mmc/tmio-common.c
+++ b/drivers/mmc/tmio-common.c
@@ -759,7 +759,8 @@ int tmio_sd_probe(struct udevice *dev, u32 quirks)
 	dev_dbg(dev, "version %x\n", priv->version);
 	if (priv->version >= 0x10) {
 		priv->caps |= TMIO_SD_CAP_DMA_INTERNAL;
-		priv->caps |= TMIO_SD_CAP_DIV1024;
+		if (!(priv->caps & TMIO_SD_CAP_RCAR))
+			priv->caps |= TMIO_SD_CAP_DIV1024;
 	}
 
 	if (fdt_get_property(gd->fdt_blob, dev_of_offset(dev), "non-removable",
-- 
2.42.0

Re: [PATCH] mmc: tmio: Disable 1/1024 clock divider on Renesas R-Car platforms

[Paul Barker]

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On Sun, Oct 22, 2023 at 11:40:43PM +0200, Marek Vasut wrote:
> The R-Car Gen3 SD_CLK_CTRL register does not use BIT(16) to implement
> divider 1/1024, instead BIT(16) is reserved bit and divider 1/1024 is
> not supported. The divider 1/1024 is specific to Socionext variant of
> the IP, as is indicated by Linux commit:
> 
> 0196c8db8363 ("mmc: tmio: move tmio_mmc_set_clock() to platform hook")
> "
> Socionext (and Panasonic) uses bit 10 (CLKSEL) for 1/1.  Also, newer
> versions of UniPhier SoC variants use bit 16 for 1/1024.
> "
> 
> Do not set the TMIO_SD_CAP_DIV1024 on Renesas R-Car platforms even if
> the IP VERSION register does exist, and indicates IP version is newer
> or equal to version 1.0 . The IP version 1.0 or newer does not imply
> presence of the 1/1024 divider.
> 
> Since the TMIO driver is used exactly by two supported platforms, that
> is Renesas R-Car and Socionext UniPhier, it is OK to check whether the
> TMIO_SD_CAP_RCAR capability is not set to identify the UniPhier platform
> and add the capability only on that platform.
> 
> Fixes: 58c35b17aa8f ("mmc: matsushita-common: Always check controller version")
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

I've confirmed that the 1/1024 divider doesn't exist in the RZ/G2L
datasheet.

Acked-by: Paul Barker <paul.barker.ct@bp.renesas.com>

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RE: [PATCH] mmc: tmio: Disable 1/1024 clock divider on Renesas R-Car platforms

[Yoshihiro Shimoda]

Hello Marek-san,

> From: U-Boot  On Behalf Of Marek Vasut, Sent: Monday, October 23, 2023 6:41 AM
> 
> The R-Car Gen3 SD_CLK_CTRL register does not use BIT(16) to implement
> divider 1/1024, instead BIT(16) is reserved bit and divider 1/1024 is
> not supported. The divider 1/1024 is specific to Socionext variant of
> the IP, as is indicated by Linux commit:
> 
> 0196c8db8363 ("mmc: tmio: move tmio_mmc_set_clock() to platform hook")
> "
> Socionext (and Panasonic) uses bit 10 (CLKSEL) for 1/1.  Also, newer
> versions of UniPhier SoC variants use bit 16 for 1/1024.
> "
> 
> Do not set the TMIO_SD_CAP_DIV1024 on Renesas R-Car platforms even if
> the IP VERSION register does exist, and indicates IP version is newer
> or equal to version 1.0 . The IP version 1.0 or newer does not imply
> presence of the 1/1024 divider.
> 
> Since the TMIO driver is used exactly by two supported platforms, that
> is Renesas R-Car and Socionext UniPhier, it is OK to check whether the
> TMIO_SD_CAP_RCAR capability is not set to identify the UniPhier platform
> and add the capability only on that platform.
> 
> Fixes: 58c35b17aa8f ("mmc: matsushita-common: Always check controller version")
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Thank you for the patch. It looks good to me. So,

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Also, our outsourcing member tested it on R-Car H3 Salvator-XS and
it works without any regression. So,

Tested-by: Thuan Nguyen Hong <thuan.nguyen-hong@banvien.com.vn>

Best regards,
Yoshihiro Shimoda

> ---
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
> Cc: Paul Barker <paul.barker.ct@bp.renesas.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/mmc/tmio-common.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/tmio-common.c b/drivers/mmc/tmio-common.c
> index 83eaf361f0c..890c496b535 100644
> --- a/drivers/mmc/tmio-common.c
> +++ b/drivers/mmc/tmio-common.c
> @@ -759,7 +759,8 @@ int tmio_sd_probe(struct udevice *dev, u32 quirks)
>  	dev_dbg(dev, "version %x\n", priv->version);
>  	if (priv->version >= 0x10) {
>  		priv->caps |= TMIO_SD_CAP_DMA_INTERNAL;
> -		priv->caps |= TMIO_SD_CAP_DIV1024;
> +		if (!(priv->caps & TMIO_SD_CAP_RCAR))
> +			priv->caps |= TMIO_SD_CAP_DIV1024;
>  	}
> 
>  	if (fdt_get_property(gd->fdt_blob, dev_of_offset(dev), "non-removable",
> --
> 2.42.0