MIPS: Add support for Texas Instruments AR7 System-on-a-Chip

This patch adds support for the Texas Instruments AR7 System-on-a-Chip.
It supports the TNETD7100, 7200 and 7300 versions of the SoC.

Signed-off-by: Matteo Croce <matteo@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Eugene Konev <ejka@openwrt.org>
Signed-off-by: Nicolas Thill <nico@openwrt.org>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ar7/prom.c b/arch/mips/ar7/prom.c
new file mode 100644
index 0000000..a320bce
--- /dev/null
+++ b/arch/mips/ar7/prom.c
@@ -0,0 +1,297 @@
+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ * Putting things on the screen/serial line using YAMONs facilities.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/serial_reg.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/io.h>
+#include <asm/bootinfo.h>
+
+#include <asm/mach-ar7/ar7.h>
+#include <asm/mach-ar7/prom.h>
+
+#define MAX_ENTRY 80
+
+struct env_var {
+	char *name;
+	char *value;
+};
+
+static struct env_var adam2_env[MAX_ENTRY];
+
+char *prom_getenv(const char *name)
+{
+	int i;
+	for (i = 0; (i < MAX_ENTRY) && adam2_env[i].name; i++)
+		if (!strcmp(name, adam2_env[i].name))
+			return adam2_env[i].value;
+
+	return NULL;
+}
+EXPORT_SYMBOL(prom_getenv);
+
+char * __init prom_getcmdline(void)
+{
+	return &(arcs_cmdline[0]);
+}
+
+static void  __init ar7_init_cmdline(int argc, char *argv[])
+{
+	char *cp;
+	int actr;
+
+	actr = 1; /* Always ignore argv[0] */
+
+	cp = &(arcs_cmdline[0]);
+	while (actr < argc) {
+		strcpy(cp, argv[actr]);
+		cp += strlen(argv[actr]);
+		*cp++ = ' ';
+		actr++;
+	}
+	if (cp != &(arcs_cmdline[0])) {
+		/* get rid of trailing space */
+		--cp;
+		*cp = '\0';
+	}
+}
+
+struct psbl_rec {
+	u32 psbl_size;
+	u32 env_base;
+	u32 env_size;
+	u32 ffs_base;
+	u32 ffs_size;
+};
+
+static __initdata char psp_env_version[] = "TIENV0.8";
+
+struct psp_env_chunk {
+	u8 num;
+	u8 ctrl;
+	u16 csum;
+	u8 len;
+	char data[11];
+} __attribute__ ((packed));
+
+struct psp_var_map_entry {
+	u8 num;
+	char *value;
+};
+
+static struct psp_var_map_entry psp_var_map[] = {
+	{ 1, "cpufrequency" },
+	{ 2, "memsize" },
+	{ 3, "flashsize" },
+	{ 4, "modetty0" },
+	{ 5, "modetty1" },
+	{ 8, "maca" },
+	{ 9, "macb" },
+	{ 28, "sysfrequency" },
+	{ 38, "mipsfrequency" },
+};
+
+/*
+
+Well-known variable (num is looked up in table above for matching variable name)
+Example: cpufrequency=211968000
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+| 01 |CTRL|CHECKSUM | 01 | _2 | _1 | _1 | _9 | _6 | _8 | _0 | _0 | _0 | \0 | FF
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+
+Name=Value pair in a single chunk
+Example: NAME=VALUE
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+| 00 |CTRL|CHECKSUM | 01 | _N | _A | _M | _E | _0 | _V | _A | _L | _U | _E | \0
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+
+Name=Value pair in 2 chunks (len is the number of chunks)
+Example: bootloaderVersion=1.3.7.15
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+| 00 |CTRL|CHECKSUM | 02 | _b | _o | _o | _t | _l | _o | _a | _d | _e | _r | _V
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+| _e | _r | _s | _i | _o | _n | \0 | _1 | _. | _3 | _. | _7 | _. | _1 | _5 | \0
++----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
+
+Data is padded with 0xFF
+
+*/
+
+#define PSP_ENV_SIZE  4096
+
+static char psp_env_data[PSP_ENV_SIZE] = { 0, };
+
+static char * __init lookup_psp_var_map(u8 num)
+{
+	int i;
+
+	for (i = 0; i < sizeof(psp_var_map); i++)
+		if (psp_var_map[i].num == num)
+			return psp_var_map[i].value;
+
+	return NULL;
+}
+
+static void __init add_adam2_var(char *name, char *value)
+{
+	int i;
+	for (i = 0; i < MAX_ENTRY; i++) {
+		if (!adam2_env[i].name) {
+			adam2_env[i].name = name;
+			adam2_env[i].value = value;
+			return;
+		} else if (!strcmp(adam2_env[i].name, name)) {
+			adam2_env[i].value = value;
+			return;
+		}
+	}
+}
+
+static int __init parse_psp_env(void *psp_env_base)
+{
+	int i, n;
+	char *name, *value;
+	struct psp_env_chunk *chunks = (struct psp_env_chunk *)psp_env_data;
+
+	memcpy_fromio(chunks, psp_env_base, PSP_ENV_SIZE);
+
+	i = 1;
+	n = PSP_ENV_SIZE / sizeof(struct psp_env_chunk);
+	while (i < n) {
+		if ((chunks[i].num == 0xff) || ((i + chunks[i].len) > n))
+			break;
+		value = chunks[i].data;
+		if (chunks[i].num) {
+			name = lookup_psp_var_map(chunks[i].num);
+		} else {
+			name = value;
+			value += strlen(name) + 1;
+		}
+		if (name)
+			add_adam2_var(name, value);
+		i += chunks[i].len;
+	}
+	return 0;
+}
+
+static void __init ar7_init_env(struct env_var *env)
+{
+	int i;
+	struct psbl_rec *psbl = (struct psbl_rec *)(KSEG1ADDR(0x14000300));
+	void *psp_env = (void *)KSEG1ADDR(psbl->env_base);
+
+	if (strcmp(psp_env, psp_env_version) == 0) {
+		parse_psp_env(psp_env);
+	} else {
+		for (i = 0; i < MAX_ENTRY; i++, env++)
+			if (env->name)
+				add_adam2_var(env->name, env->value);
+	}
+}
+
+static void __init console_config(void)
+{
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+	char console_string[40];
+	int baud = 0;
+	char parity = '\0', bits = '\0', flow = '\0';
+	char *s, *p;
+
+	if (strstr(prom_getcmdline(), "console="))
+		return;
+
+#ifdef CONFIG_KGDB
+	if (!strstr(prom_getcmdline(), "nokgdb")) {
+		strcat(prom_getcmdline(), " console=kgdb");
+		kgdb_enabled = 1;
+		return;
+	}
+#endif
+
+	s = prom_getenv("modetty0");
+	if (s) {
+		baud = simple_strtoul(s, &p, 10);
+		s = p;
+		if (*s == ',')
+			s++;
+		if (*s)
+			parity = *s++;
+		if (*s == ',')
+			s++;
+		if (*s)
+			bits = *s++;
+		if (*s == ',')
+			s++;
+		if (*s == 'h')
+			flow = 'r';
+	}
+
+	if (baud == 0)
+		baud = 38400;
+	if (parity != 'n' && parity != 'o' && parity != 'e')
+		parity = 'n';
+	if (bits != '7' && bits != '8')
+		bits = '8';
+
+	if (flow == 'r')
+		sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,
+			parity, bits, flow);
+	else
+		sprintf(console_string, " console=ttyS0,%d%c%c", baud, parity,
+			bits);
+	strcat(prom_getcmdline(), console_string);
+#endif
+}
+
+void __init prom_init(void)
+{
+	ar7_init_cmdline(fw_arg0, (char **)fw_arg1);
+	ar7_init_env((struct env_var *)fw_arg2);
+	console_config();
+}
+
+#define PORT(offset) (KSEG1ADDR(AR7_REGS_UART0 + (offset * 4)))
+static inline unsigned int serial_in(int offset)
+{
+	return readl((void *)PORT(offset));
+}
+
+static inline void serial_out(int offset, int value)
+{
+	writel(value, (void *)PORT(offset));
+}
+
+char prom_getchar(void)
+{
+	while (!(serial_in(UART_LSR) & UART_LSR_DR))
+		;
+	return serial_in(UART_RX);
+}
+
+int prom_putchar(char c)
+{
+	while ((serial_in(UART_LSR) & UART_LSR_TEMT) == 0)
+		;
+	serial_out(UART_TX, c);
+	return 1;
+}
+