MIPS: lantiq: handle vmmc memory reservation

The Lantiq SoCs have a 2nd mips core called "voice mips macro core (vmmc)"
which is used to run the voice firmware. This driver allows us to register
a chunk of memory that the voice driver can later use for the 2nd core.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/8042/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/lantiq/xway/Makefile

 obj-y := prom.o sysctrl.o clk.o reset.o dma.o gptu.o dcdc.o
 
+obj-y += vmmc.o
+
 obj-$(CONFIG_XRX200_PHY_FW) += xrx200_phy_fw.o

arch/mips/lantiq/xway/vmmc.c

+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/dma-mapping.h>
+
+#include <lantiq_soc.h>
+
+static unsigned int *cp1_base;
+
+unsigned int *ltq_get_cp1_base(void)
+{
+	if (!cp1_base)
+		panic("no cp1 base was set\n");
+
+	return cp1_base;
+}
+EXPORT_SYMBOL(ltq_get_cp1_base);
+
+static int vmmc_probe(struct platform_device *pdev)
+{
+#define CP1_SIZE       (1 << 20)
+	int gpio_count;
+	dma_addr_t dma;
+
+	cp1_base =
+		(void *) CPHYSADDR(dma_alloc_coherent(NULL, CP1_SIZE,
+						    &dma, GFP_ATOMIC));
+
+	gpio_count = of_gpio_count(pdev->dev.of_node);
+	while (gpio_count > 0) {
+		enum of_gpio_flags flags;
+		int gpio = of_get_gpio_flags(pdev->dev.of_node,
+					     --gpio_count, &flags);
+		if (gpio_request(gpio, "vmmc-relay"))
+			continue;
+		dev_info(&pdev->dev, "requested GPIO %d\n", gpio);
+		gpio_direction_output(gpio,
+				      (flags & OF_GPIO_ACTIVE_LOW) ? (0) : (1));
+	}
+
+	dev_info(&pdev->dev, "reserved %dMB at 0x%p", CP1_SIZE >> 20, cp1_base);
+
+	return 0;
+}
+
+static const struct of_device_id vmmc_match[] = {
+	{ .compatible = "lantiq,vmmc-xway" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, vmmc_match);
+
+static struct platform_driver vmmc_driver = {
+	.probe = vmmc_probe,
+	.driver = {
+		.name = "lantiq,vmmc",
+		.owner = THIS_MODULE,
+		.of_match_table = vmmc_match,
+	},
+};
+
+module_platform_driver(vmmc_driver);