[PATCH] mmc: sdhci-esdhc-imx: fix host version read

[PATCH] mmc: sdhci-esdhc-imx: fix host version read

[Shawn Guo]

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 <shawn.guo@linaro.org>
Cc: <stable@vger.kernel.org>
---
 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

Re: [PATCH] mmc: sdhci-esdhc-imx: fix host version read

[Chris Ball]

Hi Shawn,

On Tue, Jan 15 2013, Shawn Guo wrote:
> 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 <shawn.guo@linaro.org>
> Cc: <stable@vger.kernel.org>

Thanks, pushed to mmc-next for 3.9.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child