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 00000000000..fb2921f8099
--- /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);