[PATCH 3/3] mmc: sdhci-of-esdhc: add workaround for T4240 incorrect HOSTVER value

[Yangbo Lu]

For T4240-R1.0-R2.0, the HOSTVER register has incorrcet vender
version value and sdhc spec version value. This will break down
the ADMA data transfer. So add workaround to get right value
VVN=0x13, SVN = 0x1.

Signed-off-by: Yangbo Lu <yangbo.lu at freescale.com>
---
 drivers/mmc/host/sdhci-esdhc.h    |  5 +++++
 drivers/mmc/host/sdhci-of-esdhc.c | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 3497cfa..5174233 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -47,4 +47,9 @@
 
 #define ESDHC_HOST_CONTROL_RES	0x05
 
+unsigned int esdhc_errata;
+
+/* Incorrect host version in T4240 HOSTVER register */
+#define ESDHC_ERRATA_T4240_ERROR_HOSTVER		(1<<0)
+
 #endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 1295a96..c0ad765 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -59,6 +59,11 @@ static u16 esdhc_readw(struct sdhci_host *host, int reg)
 		ret = in_be32(host->ioaddr + base) & 0xffff;
 	else
 		ret = (in_be32(host->ioaddr + base) >> shift) & 0xffff;
+
+	if ((reg == SDHCI_HOST_VERSION) &&
+			(esdhc_errata & ESDHC_ERRATA_T4240_ERROR_HOSTVER))
+		ret = (VENDOR_V_23 << SDHCI_VENDOR_VER_SHIFT) | SDHCI_SPEC_200;
+
 	return ret;
 }
 
@@ -352,6 +357,9 @@ static void esdhc_get_property(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct device_node *cpus;
+	const u32 *prop;
+	u8 rev = 0xff;
 
 	sdhci_get_of_property(pdev);
 
@@ -359,6 +367,11 @@ static void esdhc_get_property(struct platform_device *pdev)
 	mmc_of_parse(host->mmc);
 	mmc_of_parse_voltage(np, &host->ocr_mask);
 
+	cpus = of_find_node_by_path("/cpus");
+	prop = of_get_property(cpus, "cpu-rev", NULL);
+	if (prop)
+		rev = *(u8 *)prop;
+
 	if (of_device_is_compatible(np, "fsl,p5040-esdhc") ||
 	    of_device_is_compatible(np, "fsl,p5020-esdhc") ||
 	    of_device_is_compatible(np, "fsl,p4080-esdhc") ||
@@ -373,6 +386,11 @@ static void esdhc_get_property(struct platform_device *pdev)
 		 */
 		host->quirks2 |= SDHCI_QUIRK2_BROKEN_HOST_CONTROL;
 	}
+
+	esdhc_errata = 0;
+
+	if (of_device_is_compatible(np, "fsl,t4240-esdhc") && rev <= 0x20)
+		esdhc_errata |= ESDHC_ERRATA_T4240_ERROR_HOSTVER;
 }
 
 static int sdhci_esdhc_probe(struct platform_device *pdev)
-- 
2.1.0.27.g96db324