i.MX2 family: Add basic mach support (sources)

This patch adds basic mach support for the mx2 processor family, based
on the original freescale code and adapted to mainline kernel coding
style.

Signed-off-by: Juergen Beisert <[e-mail]>

arch/arm/mach-mx2/Kconfig

···
+comment "MX2 family CPU support"
+	depends on ARCH_MX2
+
+comment "MX2 Platforms"
+	depends on ARCH_MX2

arch/arm/mach-mx2/Makefile

···
+#
+# Makefile for the linux kernel.
+#
+
+# Object file lists.
+
+obj-y	:=  system.o generic.o

arch/arm/mach-mx2/Makefile.boot

···
+   zreladdr-y	:= 0xA0008000
+params_phys-y	:= 0xA0000100
+initrd_phys-y	:= 0xA0800000

arch/arm/mach-mx2/generic.c

···
+/*
+ * generic.c
+ *
+ * Copyright (C) 2008 Juergen Beisert ([e-mail])
+ *
+ * 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.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <asm/hardware.h>
+#include <asm/pgtable.h>
+#include <asm/mach/map.h>
+
+/* MX27 memory map definition */
+static struct map_desc mxc_io_desc[] __initdata = {
+	/*
+	 * this fixed mapping covers:
+	 * - AIPI1
+	 * - AIPI2
+	 * - AITC
+	 * - ROM Patch
+	 * - and some reserved space
+	 */
+	{
+		.virtual = AIPI_BASE_ADDR_VIRT,
+		.pfn = __phys_to_pfn(AIPI_BASE_ADDR),
+		.length = AIPI_SIZE,
+		.type = MT_DEVICE
+	},
+	/*
+	 * this fixed mapping covers:
+	 * - CSI
+	 * - ATA
+	 */
+	{
+		.virtual = SAHB1_BASE_ADDR_VIRT,
+		.pfn = __phys_to_pfn(SAHB1_BASE_ADDR),
+		.length = SAHB1_SIZE,
+		.type = MT_DEVICE
+	},
+	/*
+	 * this fixed mapping covers:
+	 * - EMI
+	 */
+	{
+		.virtual = X_MEMC_BASE_ADDR_VIRT,
+		.pfn = __phys_to_pfn(X_MEMC_BASE_ADDR),
+		.length = X_MEMC_SIZE,
+		.type = MT_DEVICE
+	}
+};
+
+/*
+ * Initialize the memory map. It is called during the
+ * system startup to create static physical to virtual
+ * memory map for the IO modules.
+ */
+void __init mxc_map_io(void)
+{
+	iotable_init(mxc_io_desc, ARRAY_SIZE(mxc_io_desc));
+}

arch/arm/mach-mx2/system.c

···
+/*
+ * Copyright (C) 1999 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd
+ * Copyright 2006-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Juergen Beisert, [e-mail]
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/proc-fns.h>
+#include <asm/system.h>
+
+/*
+ * Put the CPU into idle mode. It is called by default_idle()
+ * in process.c file.
+ */
+void arch_idle(void)
+{
+	/*
+	 * This should do all the clock switching
+	 * and wait for interrupt tricks.
+	 */
+	cpu_do_idle();
+}
+
+#define WDOG_WCR_REG                    IO_ADDRESS(WDOG_BASE_ADDR)
+#define WDOG_WCR_SRS                    (1 << 4)
+
+/*
+ * Reset the system. It is called by machine_restart().
+ */
+void arch_reset(char mode)
+{
+	struct clk *clk;
+
+	clk = clk_get(NULL, "wdog_clk");
+	if (!clk) {
+		printk(KERN_ERR"Cannot activate the watchdog. Giving up\n");
+		return;
+	}
+
+	clk_enable(clk);
+
+	/* Assert SRS signal */
+	__raw_writew(__raw_readw(WDOG_WCR_REG) & ~WDOG_WCR_SRS, WDOG_WCR_REG);
+}