mmc: esdhc: Add support for 8-bit bus width and non-removable card

This patch adds support of connecting an MMC media using an 8-bit
bus width connection to Freescale's P2020 H/W SDHC controller. During
the probe function, the generic function mmc_of_parse is called to
detect whether the controller is configured with 8-bit bus width.

Also, the generic function detects if the non-removable property is
set in the device tree.  The function esdhc_pltfm_bus_width was added
because the bus width configuration is platform specific.

Signed-off-by: Oded Gabbay <ogabbay@advaoptical.com>
Reviewed-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 50 insertions, 1 deletions

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 6f16406c37cd..a2a06420e463 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -36,6 +36,13 @@
 /* pltfm-specific */
 #define ESDHC_HOST_CONTROL_LE   0x20
 
+/*
+ * P2020 interpretation of the SDHCI_HOST_CONTROL register
+ */
+#define ESDHC_CTRL_4BITBUS          (0x1 << 1)
+#define ESDHC_CTRL_8BITBUS          (0x2 << 1)
+#define ESDHC_CTRL_BUSWIDTH_MASK    (0x3 << 1)
+
 /* OF-specific */
 #define ESDHC_DMA_SYSCTL        0x40c
 #define ESDHC_DMA_SNOOP         0x00000040
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 2b7369729f91..b2a635e73aee 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -13,6 +13,7 @@
  * your option) any later version.
  */
 
+#include <linux/err.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/delay.h>
@@ -230,6 +231,30 @@ static void esdhc_of_platform_init(struct sdhci_host *host)
                 host->quirks &= ~SDHCI_QUIRK_NO_BUSY_IRQ;
 }
 
+static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width)
+{
+        u32 ctrl;
+
+        switch (width) {
+        case MMC_BUS_WIDTH_8:
+                ctrl = ESDHC_CTRL_8BITBUS;
+                break;
+
+        case MMC_BUS_WIDTH_4:
+                ctrl = ESDHC_CTRL_4BITBUS;
+                break;
+
+        default:
+                ctrl = 0;
+                break;
+        }
+
+        clrsetbits_be32(host->ioaddr + SDHCI_HOST_CONTROL,
+                        ESDHC_CTRL_BUSWIDTH_MASK, ctrl);
+
+        return 0;
+}
+
 static const struct sdhci_ops sdhci_esdhc_ops = {
         .read_l = esdhc_readl,
         .read_w = esdhc_readw,
@@ -247,6 +272,7 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
         .platform_resume = esdhc_of_resume,
 #endif
         .adma_workaround = esdhci_of_adma_workaround,
+        .platform_bus_width = esdhc_pltfm_bus_width,
 };
 
 static const struct sdhci_pltfm_data sdhci_esdhc_pdata = {
@@ -262,7 +288,23 @@ static const struct sdhci_pltfm_data sdhci_esdhc_pdata = {
 
 static int sdhci_esdhc_probe(struct platform_device *pdev)
 {
-        return sdhci_pltfm_register(pdev, &sdhci_esdhc_pdata, 0);
+        struct sdhci_host *host;
+        int ret;
+
+        host = sdhci_pltfm_init(pdev, &sdhci_esdhc_pdata, 0);
+        if (IS_ERR(host))
+                return PTR_ERR(host);
+
+        sdhci_get_of_property(pdev);
+
+        /* call to generic mmc_of_parse to support additional capabilities */
+        mmc_of_parse(host->mmc);
+
+        ret = sdhci_add_host(host);
+        if (ret)
+                sdhci_pltfm_free(pdev);
+
+        return ret;
 }
 
 static int sdhci_esdhc_remove(struct platform_device *pdev)