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>

diff --git a/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
new file mode 100644 (file)
index 0000000..0a85c70
--- /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 a53c7c478e054c8c47df5a5a219a2b1ed1e6836b..8c72828239b21fb6064ac076a6759052bdb6dd1c 100644 (file)
--- 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),
        },
 };