MIPS: Add initial support for the Atheros AR71XX/AR724X/AR931X SoCs

This patch adds initial support for various Atheros SoCs based on the
MIPS 24Kc core. The following models are supported at the moment:

  - AR7130
  - AR7141
  - AR7161
  - AR9130
  - AR9132
  - AR7240
  - AR7241
  - AR7242

The current patch contains minimal support only, but the resulting
kernel can boot into user-space with using of an initramfs image on
various boards which are using these SoCs. Support for more built-in
devices and individual boards will be implemented in further patches.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Cliff Holden <Cliff.Holden@Atheros.com>
Cc: Kathy Giori <Kathy.Giori@Atheros.com>
Patchwork: https://patchwork.linux-mips.org/patch/1947/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath79/setup.c b/arch/mips/ath79/setup.c
new file mode 100644
index 0000000..175def8
--- /dev/null
+++ b/arch/mips/ath79/setup.c
@@ -0,0 +1,190 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X specific setup
+ *
+ *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  Parts of this file are based on Atheros' 2.6.15 BSP
+ *
+ *  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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <asm/bootinfo.h>
+#include <asm/time.h>		/* for mips_hpt_frequency */
+#include <asm/reboot.h>		/* for _machine_{restart,halt} */
+
+#include <asm/mach-ath79/ath79.h>
+#include <asm/mach-ath79/ar71xx_regs.h>
+#include "common.h"
+#include "dev-common.h"
+
+#define ATH79_SYS_TYPE_LEN	64
+
+#define AR71XX_BASE_FREQ	40000000
+#define AR724X_BASE_FREQ	5000000
+#define AR913X_BASE_FREQ	5000000
+
+static char ath79_sys_type[ATH79_SYS_TYPE_LEN];
+
+static void ath79_restart(char *command)
+{
+	ath79_device_reset_set(AR71XX_RESET_FULL_CHIP);
+	for (;;)
+		if (cpu_wait)
+			cpu_wait();
+}
+
+static void ath79_halt(void)
+{
+	while (1)
+		cpu_wait();
+}
+
+static void __init ath79_detect_mem_size(void)
+{
+	unsigned long size;
+
+	for (size = ATH79_MEM_SIZE_MIN; size < ATH79_MEM_SIZE_MAX;
+	     size <<= 1) {
+		if (!memcmp(ath79_detect_mem_size,
+			    ath79_detect_mem_size + size, 1024))
+			break;
+	}
+
+	add_memory_region(0, size, BOOT_MEM_RAM);
+}
+
+static void __init ath79_detect_sys_type(void)
+{
+	char *chip = "????";
+	u32 id;
+	u32 major;
+	u32 minor;
+	u32 rev = 0;
+
+	id = ath79_reset_rr(AR71XX_RESET_REG_REV_ID);
+	major = id & REV_ID_MAJOR_MASK;
+
+	switch (major) {
+	case REV_ID_MAJOR_AR71XX:
+		minor = id & AR71XX_REV_ID_MINOR_MASK;
+		rev = id >> AR71XX_REV_ID_REVISION_SHIFT;
+		rev &= AR71XX_REV_ID_REVISION_MASK;
+		switch (minor) {
+		case AR71XX_REV_ID_MINOR_AR7130:
+			ath79_soc = ATH79_SOC_AR7130;
+			chip = "7130";
+			break;
+
+		case AR71XX_REV_ID_MINOR_AR7141:
+			ath79_soc = ATH79_SOC_AR7141;
+			chip = "7141";
+			break;
+
+		case AR71XX_REV_ID_MINOR_AR7161:
+			ath79_soc = ATH79_SOC_AR7161;
+			chip = "7161";
+			break;
+		}
+		break;
+
+	case REV_ID_MAJOR_AR7240:
+		ath79_soc = ATH79_SOC_AR7240;
+		chip = "7240";
+		rev = (id & AR724X_REV_ID_REVISION_MASK);
+		break;
+
+	case REV_ID_MAJOR_AR7241:
+		ath79_soc = ATH79_SOC_AR7241;
+		chip = "7241";
+		rev = (id & AR724X_REV_ID_REVISION_MASK);
+		break;
+
+	case REV_ID_MAJOR_AR7242:
+		ath79_soc = ATH79_SOC_AR7242;
+		chip = "7242";
+		rev = (id & AR724X_REV_ID_REVISION_MASK);
+		break;
+
+	case REV_ID_MAJOR_AR913X:
+		minor = id & AR913X_REV_ID_MINOR_MASK;
+		rev = id >> AR913X_REV_ID_REVISION_SHIFT;
+		rev &= AR913X_REV_ID_REVISION_MASK;
+		switch (minor) {
+		case AR913X_REV_ID_MINOR_AR9130:
+			ath79_soc = ATH79_SOC_AR9130;
+			chip = "9130";
+			break;
+
+		case AR913X_REV_ID_MINOR_AR9132:
+			ath79_soc = ATH79_SOC_AR9132;
+			chip = "9132";
+			break;
+		}
+		break;
+
+	default:
+		panic("ath79: unknown SoC, id:0x%08x\n", id);
+	}
+
+	sprintf(ath79_sys_type, "Atheros AR%s rev %u", chip, rev);
+	pr_info("SoC: %s\n", ath79_sys_type);
+}
+
+const char *get_system_type(void)
+{
+	return ath79_sys_type;
+}
+
+unsigned int __cpuinit get_c0_compare_int(void)
+{
+	return CP0_LEGACY_COMPARE_IRQ;
+}
+
+void __init plat_mem_setup(void)
+{
+	set_io_port_base(KSEG1);
+
+	ath79_reset_base = ioremap_nocache(AR71XX_RESET_BASE,
+					   AR71XX_RESET_SIZE);
+	ath79_pll_base = ioremap_nocache(AR71XX_PLL_BASE,
+					 AR71XX_PLL_SIZE);
+
+	ath79_ddr_base = ioremap_nocache(AR71XX_DDR_CTRL_BASE,
+					 AR71XX_DDR_CTRL_SIZE);
+
+	ath79_detect_sys_type();
+	ath79_detect_mem_size();
+	ath79_clocks_init();
+
+	_machine_restart = ath79_restart;
+	_machine_halt = ath79_halt;
+	pm_power_off = ath79_halt;
+}
+
+void __init plat_time_init(void)
+{
+	struct clk *clk;
+
+	clk = clk_get(NULL, "cpu");
+	if (IS_ERR(clk))
+		panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));
+
+	mips_hpt_frequency = clk_get_rate(clk) / 2;
+}
+
+static int __init ath79_setup(void)
+{
+	ath79_register_uart();
+	return 0;
+}
+
+arch_initcall(ath79_setup);