mmc_spi: Add support for OpenFirmware bindings

The support is implemented via platform data accessors, new module
(of_mmc_spi) will be created automatically when the driver compiles
on OpenFirmware platforms. Link-time dependency will load the module
automatically.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 149 insertions, 0 deletions

diff --git a/drivers/mmc/host/of_mmc_spi.c b/drivers/mmc/host/of_mmc_spi.c
new file mode 100644
index 000000000000..fb2921f8099d
--- /dev/null
+++ b/drivers/mmc/host/of_mmc_spi.c
@@ -0,0 +1,149 @@
+/*
+ * OpenFirmware bindings for the MMC-over-SPI driver
+ *
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/mmc_spi.h>
+#include <linux/mmc/core.h>
+#include <linux/mmc/host.h>
+
+enum {
+        CD_GPIO = 0,
+        WP_GPIO,
+        NUM_GPIOS,
+};
+
+struct of_mmc_spi {
+        int gpios[NUM_GPIOS];
+        bool alow_gpios[NUM_GPIOS];
+        struct mmc_spi_platform_data pdata;
+};
+
+static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
+{
+        return container_of(dev->platform_data, struct of_mmc_spi, pdata);
+}
+
+static int of_mmc_spi_read_gpio(struct device *dev, int gpio_num)
+{
+        struct of_mmc_spi *oms = to_of_mmc_spi(dev);
+        bool active_low = oms->alow_gpios[gpio_num];
+        bool value = gpio_get_value(oms->gpios[gpio_num]);
+
+        return active_low ^ value;
+}
+
+static int of_mmc_spi_get_cd(struct device *dev)
+{
+        return of_mmc_spi_read_gpio(dev, CD_GPIO);
+}
+
+static int of_mmc_spi_get_ro(struct device *dev)
+{
+        return of_mmc_spi_read_gpio(dev, WP_GPIO);
+}
+
+struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
+{
+        struct device *dev = &spi->dev;
+        struct device_node *np = dev_archdata_get_node(&dev->archdata);
+        struct of_mmc_spi *oms;
+        const u32 *voltage_ranges;
+        int num_ranges;
+        int i;
+        int ret = -EINVAL;
+
+        if (dev->platform_data || !np)
+                return dev->platform_data;
+
+        oms = kzalloc(sizeof(*oms), GFP_KERNEL);
+        if (!oms)
+                return NULL;
+
+        voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
+        num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
+        if (!voltage_ranges || !num_ranges) {
+                dev_err(dev, "OF: voltage-ranges unspecified\n");
+                goto err_ocr;
+        }
+
+        for (i = 0; i < num_ranges; i++) {
+                const int j = i * 2;
+                u32 mask;
+
+                mask = mmc_vddrange_to_ocrmask(voltage_ranges[j],
+                                               voltage_ranges[j + 1]);
+                if (!mask) {
+                        ret = -EINVAL;
+                        dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
+                        goto err_ocr;
+                }
+                oms->pdata.ocr_mask |= mask;
+        }
+
+        for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
+                enum of_gpio_flags gpio_flags;
+
+                oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
+                if (!gpio_is_valid(oms->gpios[i]))
+                        continue;
+
+                ret = gpio_request(oms->gpios[i], dev->bus_id);
+                if (ret < 0) {
+                        oms->gpios[i] = -EINVAL;
+                        continue;
+                }
+
+                if (gpio_flags & OF_GPIO_ACTIVE_LOW)
+                        oms->alow_gpios[i] = true;
+        }
+
+        if (gpio_is_valid(oms->gpios[CD_GPIO]))
+                oms->pdata.get_cd = of_mmc_spi_get_cd;
+        if (gpio_is_valid(oms->gpios[WP_GPIO]))
+                oms->pdata.get_ro = of_mmc_spi_get_ro;
+
+        /* We don't support interrupts yet, let's poll. */
+        oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
+
+        dev->platform_data = &oms->pdata;
+        return dev->platform_data;
+err_ocr:
+        kfree(oms);
+        return NULL;
+}
+EXPORT_SYMBOL(mmc_spi_get_pdata);
+
+void mmc_spi_put_pdata(struct spi_device *spi)
+{
+        struct device *dev = &spi->dev;
+        struct device_node *np = dev_archdata_get_node(&dev->archdata);
+        struct of_mmc_spi *oms = to_of_mmc_spi(dev);
+        int i;
+
+        if (!dev->platform_data || !np)
+                return;
+
+        for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
+                if (gpio_is_valid(oms->gpios[i]))
+                        gpio_free(oms->gpios[i]);
+        }
+        kfree(oms);
+        dev->platform_data = NULL;
+}
+EXPORT_SYMBOL(mmc_spi_put_pdata);