mmc: mxs-mmc: add device tree support

It adds device tree probe support for mxs-mmc driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Chris Ball <cjb@laptop.org>

2 files changed, 68 insertions, 5 deletions

diff --git a/Documentation/devicetree/bindings/mmc/mxs-mmc.txt b/Documentation/devicetree/bindings/mmc/mxs-mmc.txt
new file mode 100644
index 000000000000..14d870a9e3db
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/mxs-mmc.txt
@@ -0,0 +1,25 @@
+* Freescale MXS MMC controller
+
+The Freescale MXS Synchronous Serial Ports (SSP) can act as a MMC controller
+to support MMC, SD, and SDIO types of memory cards.
+
+Required properties:
+- compatible: Should be "fsl,<chip>-mmc".  The supported chips include
+  imx23 and imx28.
+- reg: Should contain registers location and length
+- interrupts: Should contain ERROR and DMA interrupts
+- fsl,ssp-dma-channel: APBH DMA channel for the SSP
+- bus-width: Number of data lines, can be <1>, <4>, or <8>
+
+Optional properties:
+- wp-gpios: Specify GPIOs for write protection
+
+Examples:
+
+ssp0: ssp@80010000 {
+        compatible = "fsl,imx28-mmc";
+        reg = <0x80010000 2000>;
+        interrupts = <96 82>;
+        fsl,ssp-dma-channel = <0>;
+        bus-width = <8>;
+};
diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index 76232dd277c9..34a90266ab11 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -23,6 +23,9 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
@@ -685,8 +688,18 @@ static struct platform_device_id mxs_mmc_ids[] = {
 };
 MODULE_DEVICE_TABLE(platform, mxs_mmc_ids);
 
+static const struct of_device_id mxs_mmc_dt_ids[] = {
+        { .compatible = "fsl,imx23-mmc", .data = (void *) IMX23_MMC, },
+        { .compatible = "fsl,imx28-mmc", .data = (void *) IMX28_MMC, },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_mmc_dt_ids);
+
 static int mxs_mmc_probe(struct platform_device *pdev)
 {
+        const struct of_device_id *of_id =
+                        of_match_device(mxs_mmc_dt_ids, &pdev->dev);
+        struct device_node *np = pdev->dev.of_node;
         struct mxs_mmc_host *host;
         struct mmc_host *mmc;
         struct resource *iores, *dmares;
@@ -699,7 +712,7 @@ static int mxs_mmc_probe(struct platform_device *pdev)
         dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
         irq_err = platform_get_irq(pdev, 0);
         irq_dma = platform_get_irq(pdev, 1);
-        if (!iores || !dmares || irq_err < 0 || irq_dma < 0)
+        if (!iores || irq_err < 0 || irq_dma < 0)
                 return -EINVAL;
 
         mmc = mmc_alloc_host(sizeof(struct mxs_mmc_host), &pdev->dev);
@@ -713,15 +726,31 @@ static int mxs_mmc_probe(struct platform_device *pdev)
                 goto out_mmc_free;
         }
 
-        host->devid = pdev->id_entry->driver_data;
+        if (np) {
+                host->devid = (enum mxs_mmc_id) of_id->data;
+                /*
+                 * TODO: This is a temporary solution and should be changed
+                 * to use generic DMA binding later when the helpers get in.
+                 */
+                ret = of_property_read_u32(np, "fsl,ssp-dma-channel",
+                                           &host->dma_channel);
+                if (ret) {
+                        dev_err(mmc_dev(host->mmc),
+                                "failed to get dma channel\n");
+                        goto out_mmc_free;
+                }
+        } else {
+                host->devid = pdev->id_entry->driver_data;
+                host->dma_channel = dmares->start;
+        }
+
         host->mmc = mmc;
-        host->dma_channel = dmares->start;
         host->sdio_irq_en = 0;
 
         pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
         if (IS_ERR(pinctrl)) {
                 ret = PTR_ERR(pinctrl);
-                goto out_iounmap;
+                goto out_mmc_free;
         }
 
         host->clk = clk_get(&pdev->dev, NULL);
@@ -749,7 +778,15 @@ static int mxs_mmc_probe(struct platform_device *pdev)
                     MMC_CAP_SDIO_IRQ | MMC_CAP_NEEDS_POLL;
 
         pdata = mmc_dev(host->mmc)->platform_data;
-        if (pdata) {
+        if (!pdata) {
+                u32 bus_width = 0;
+                of_property_read_u32(np, "bus-width", &bus_width);
+                if (bus_width == 4)
+                        mmc->caps |= MMC_CAP_4_BIT_DATA;
+                else if (bus_width == 8)
+                        mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA;
+                host->wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
+        } else {
                 if (pdata->flags & SLOTF_8_BIT_CAPABLE)
                         mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA;
                 if (pdata->flags & SLOTF_4_BIT_CAPABLE)
@@ -857,6 +894,7 @@ static struct platform_driver mxs_mmc_driver = {
                 .owner  = THIS_MODULE,
 #ifdef CONFIG_PM
                 .pm     = &mxs_mmc_pm_ops,
+                .of_match_table = mxs_mmc_dt_ids,
 #endif
         },
 };