mmc: omap_hsmmc: Add support for quirky omap3 hsmmc controller

When device is booted using devicetree, platforms impacted by Erratum
2.1.1.128 is not detected easily in the mmc driver. This erratum
indicates that the module cannot do multi-block transfers. Platforms
such as LDP which use OMAP3 ES revision prior to ES3.0 are impacted by
this.

Provide a new compatible property "ti,omap3-pre-es3-hsmmc" to allow
driver to determine if driver needs to implement quirks associated
with the specific module version (primarily because the IP revision
information is not sufficient for the same).

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <chris@printf.net>

Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt

@@ -10,6 +10,7 @@ Required properties:
 - compatible:
  Should be "ti,omap2-hsmmc", for OMAP2 controllers
  Should be "ti,omap3-hsmmc", for OMAP3 controllers
+ Should be "ti,omap3-pre-es3-hsmmc" for OMAP3 controllers pre ES3.0
  Should be "ti,omap4-hsmmc", for OMAP4 controllers
 - ti,hwmods: Must be "mmc<n>", n is controller instance starting 1
 

drivers/mmc/host/omap_hsmmc.c

@@ -192,6 +192,11 @@ struct omap_hsmmc_host {
 	struct	omap_mmc_platform_data	*pdata;
 };
 
+struct omap_mmc_of_data {
+	u32 reg_offset;
+	u8 controller_flags;
+};
+
 static int omap_hsmmc_card_detect(struct device *dev, int slot)
 {
 	struct omap_hsmmc_host *host = dev_get_drvdata(dev);
@@ -1677,18 +1682,29 @@ static void omap_hsmmc_debugfs(struct mmc_host *mmc)
 #endif
 
 #ifdef CONFIG_OF
-static u16 omap4_reg_offset = 0x100;
+static const struct omap_mmc_of_data omap3_pre_es3_mmc_of_data = {
+	/* See 35xx errata 2.1.1.128 in SPRZ278F */
+	.controller_flags = OMAP_HSMMC_BROKEN_MULTIBLOCK_READ,
+};
+
+static const struct omap_mmc_of_data omap4_mmc_of_data = {
+	.reg_offset = 0x100,
+};
 
 static const struct of_device_id omap_mmc_of_match[] = {
 	{
 		.compatible = "ti,omap2-hsmmc",
 	},
+	{
+		.compatible = "ti,omap3-pre-es3-hsmmc",
+		.data = &omap3_pre_es3_mmc_of_data,
+	},
 	{
 		.compatible = "ti,omap3-hsmmc",
 	},
 	{
 		.compatible = "ti,omap4-hsmmc",
-		.data = &omap4_reg_offset,
+		.data = &omap4_mmc_of_data,
 	},
 	{},
 };
@@ -1758,6 +1774,7 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 	dma_cap_mask_t mask;
 	unsigned tx_req, rx_req;
 	struct pinctrl *pinctrl;
+	const struct omap_mmc_of_data *data;
 
 	match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev);
 	if (match) {
@@ -1767,8 +1784,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 			return PTR_ERR(pdata);
 
 		if (match->data) {
-			const u16 *offsetp = match->data;
-			pdata->reg_offset = *offsetp;
+			data = match->data;
+			pdata->reg_offset = data->reg_offset;
+			pdata->controller_flags |= data->controller_flags;
 		}
 	}