mmc: atmel-mci: add device tree support

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 151 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
new file mode 100644
index 000000000000..0a85c70cd30a
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
@@ -0,0 +1,68 @@
+* Atmel High Speed MultiMedia Card Interface
+
+This controller on atmel products provides an interface for MMC, SD and SDIO
+types of memory cards.
+
+This file documents differences between the core properties described
+by mmc.txt and the properties used by the atmel-mci driver.
+
+1) MCI node
+
+Required properties:
+- compatible: should be "atmel,hsmci"
+- #address-cells: should be one. The cell is the slot id.
+- #size-cells: should be zero.
+- at least one slot node
+
+The node contains child nodes for each slot that the platform uses
+
+Example MCI node:
+
+mmc0: mmc@f0008000 {
+        compatible = "atmel,hsmci";
+        reg = <0xf0008000 0x600>;
+        interrupts = <12 4>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        [ child node definitions...]
+};
+
+2) slot nodes
+
+Required properties:
+- reg: should contain the slot id.
+- bus-width: number of data lines connected to the controller
+
+Optional properties:
+- cd-gpios: specify GPIOs for card detection
+- cd-inverted: invert the value of external card detect gpio line
+- wp-gpios: specify GPIOs for write protection
+
+Example slot node:
+
+slot@0 {
+        reg = <0>;
+        bus-width = <4>;
+        cd-gpios = <&pioD 15 0>
+        cd-inverted;
+};
+
+Example full MCI node:
+mmc0: mmc@f0008000 {
+        compatible = "atmel,hsmci";
+        reg = <0xf0008000 0x600>;
+        interrupts = <12 4>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        slot@0 {
+                reg = <0>;
+                bus-width = <4>;
+                cd-gpios = <&pioD 15 0>
+                cd-inverted;
+        };
+        slot@1 {
+                reg = <1>;
+                bus-width = <4>;
+        };
+};
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index a53c7c478e05..8c72828239b2 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -19,6 +19,9 @@
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/scatterlist.h>
 #include <linux/seq_file.h>
@@ -500,6 +503,70 @@ err:
         dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmci_dt_ids[] = {
+        { .compatible = "atmel,hsmci" },
+        { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmci_dt_ids);
+
+static struct mci_platform_data __devinit*
+atmci_of_init(struct platform_device *pdev)
+{
+        struct device_node *np = pdev->dev.of_node;
+        struct device_node *cnp;
+        struct mci_platform_data *pdata;
+        u32 slot_id;
+
+        if (!np) {
+                dev_err(&pdev->dev, "device node not found\n");
+                return ERR_PTR(-EINVAL);
+        }
+
+        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata) {
+                dev_err(&pdev->dev, "could not allocate memory for pdata\n");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        for_each_child_of_node(np, cnp) {
+                if (of_property_read_u32(cnp, "reg", &slot_id)) {
+                        dev_warn(&pdev->dev, "reg property is missing for %s\n",
+                                 cnp->full_name);
+                        continue;
+                }
+
+                if (slot_id >= ATMCI_MAX_NR_SLOTS) {
+                        dev_warn(&pdev->dev, "can't have more than %d slots\n",
+                                 ATMCI_MAX_NR_SLOTS);
+                        break;
+                }
+
+                if (of_property_read_u32(cnp, "bus-width",
+                                         &pdata->slot[slot_id].bus_width))
+                        pdata->slot[slot_id].bus_width = 1;
+
+                pdata->slot[slot_id].detect_pin =
+                        of_get_named_gpio(cnp, "cd-gpios", 0);
+
+                pdata->slot[slot_id].detect_is_active_high =
+                        of_property_read_bool(cnp, "cd-inverted");
+
+                pdata->slot[slot_id].wp_pin =
+                        of_get_named_gpio(cnp, "wp-gpios", 0);
+        }
+
+        return pdata;
+}
+#else /* CONFIG_OF */
+static inline struct mci_platform_data*
+atmci_of_init(struct platform_device *dev)
+{
+        return ERR_PTR(-EINVAL);
+}
+#endif
+
 static inline unsigned int atmci_get_version(struct atmel_mci *host)
 {
         return atmci_readl(host, ATMCI_VERSION) & 0x00000fff;
@@ -2046,6 +2113,13 @@ static int __init atmci_init_slot(struct atmel_mci *host,
         slot->sdc_reg = sdc_reg;
         slot->sdio_irq = sdio_irq;
 
+        dev_dbg(&mmc->class_dev,
+                "slot[%u]: bus_width=%u, detect_pin=%d, "
+                "detect_is_active_high=%s, wp_pin=%d\n",
+                id, slot_data->bus_width, slot_data->detect_pin,
+                slot_data->detect_is_active_high ? "true" : "false",
+                slot_data->wp_pin);
+
         mmc->ops = &atmci_ops;
         mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
         mmc->f_max = host->bus_hz / 2;
@@ -2268,8 +2342,14 @@ static int __init atmci_probe(struct platform_device *pdev)
         if (!regs)
                 return -ENXIO;
         pdata = pdev->dev.platform_data;
-        if (!pdata)
-                return -ENXIO;
+        if (!pdata) {
+                pdata = atmci_of_init(pdev);
+                if (IS_ERR(pdata)) {
+                        dev_err(&pdev->dev, "platform data not available\n");
+                        return PTR_ERR(pdata);
+                }
+        }
+
         irq = platform_get_irq(pdev, 0);
         if (irq < 0)
                 return irq;
@@ -2487,6 +2567,7 @@ static struct platform_driver atmci_driver = {
         .driver         = {
                 .name           = "atmel_mci",
                 .pm             = ATMCI_PM_OPS,
+                .of_match_table = of_match_ptr(atmci_dt_ids),
         },
 };