Hi Sascha, On Mon, Sep 24, 2012 at 09:22:24AM +0200, Sascha Hauer wrote: > The i.MX ESDHC controller version register is a mess: > > - i.MX25 has a v1 controller which identifies itself as v2 > - i.MX6Q has a v3 controller which identifies itself as v4 > - i.MX35,51,53 have v2 controllers which identify themselves correctly
When looking at these a second time, I start doubting the statement about i.MX25. Since i.MX25 is actually a newer SoC than i.MX35, it sounds unreasonable that i.MX35 runs a v2 controller while i.MX25 runs a v1. The confirmation from designer tells that i.MX25 runs a v2 controller too. This also matches the statement of "SD Host Controller Standard Specification Version 2.0" listed in IMX25RM 23.1.1 Features chapter. You probably got the impression that i.MX25 has a v1 controller by reading the HOSTVER_SVN bit description. While it says 0x00 - SD Host Specification Version 1.0, the register value is actually 0x01. So the esdhc host version register indeed encodes the correct value for all i.MX SoCs except imx6q. Thus, I prefer to replace the patch with the one below. Also I'm working on a big series to make esdhc driver more feature complete for imx6q, including 8bit support, so I would like to pick up your work from here. Shawn ---8<------ [PATCH] mmc: sdhci-esdhc-imx: fix host version read When commit 95a2482 (mmc: sdhci-esdhc-imx: add basic imx6q usdhc support) works around host version issue on imx6q, it gets the register address fixup "reg ^= 2" lost for imx25/35/51/53 esdhc. Thus, the controller version on these SoCs is wrongly identified as v1 while it's actually v2. Add the address fixup back and take a different approach to correct imx6q host version, so that the host version read gets back to work for all SoCs. Signed-off-by: Shawn Guo <[email protected]> Cc: <[email protected]> --- drivers/mmc/host/sdhci-esdhc-imx.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index e07df81..b503113 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -237,15 +237,18 @@ static void esdhc_writel_le(struct sdhci_host *host, u32 val, int reg) static u16 esdhc_readw_le(struct sdhci_host *host, int reg) { + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct pltfm_imx_data *imx_data = pltfm_host->priv; + if (unlikely(reg == SDHCI_HOST_VERSION)) { - u16 val = readw(host->ioaddr + (reg ^ 2)); - /* - * uSDHC supports SDHCI v3.0, but it's encoded as value - * 0x3 in host controller version register, which violates - * SDHCI_SPEC_300 definition. Work it around here. - */ - if ((val & SDHCI_SPEC_VER_MASK) == 3) - return --val; + reg ^= 2; + if (is_imx6q_usdhc(imx_data)) { + /* + * The usdhc register returns a wrong host version. + * Correct it here. + */ + return SDHCI_SPEC_300; + } } return readw(host->ioaddr + reg); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
