/*
 * cpuinfo.c - Show information about cp15 registers
 *
 * Copyright (c) 2009 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * 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.
 */

#include <common.h>
#include <command.h>
#include <complete.h>

#define CPU_ARCH_UNKNOWN	0
#define CPU_ARCH_ARMv3		1
#define CPU_ARCH_ARMv4		2
#define CPU_ARCH_ARMv4T		3
#define CPU_ARCH_ARMv5		4
#define CPU_ARCH_ARMv5T		5
#define CPU_ARCH_ARMv5TE	6
#define CPU_ARCH_ARMv5TEJ	7
#define CPU_ARCH_ARMv6		8
#define CPU_ARCH_ARMv7		9

static void decode_cache(unsigned long size)
{
	int linelen = 1 << ((size & 0x3) + 3);
	int mult = 2 + ((size >> 2) & 1);
	int cache_size = mult << (((size >> 6) & 0x7) + 8);

	if (((size >> 2) & 0xf) == 1)
		printf("no cache\n");
	else
		printf("%d bytes (linelen = %d)\n", cache_size, linelen);
}

static char *crbits[] = {"M", "A", "C", "W", "P", "D", "L", "B", "S", "R",
	"F", "Z", "I", "V", "RR", "L4", "DT", "", "IT", "ST", "", "FI", "U", "XP",
	"VE", "EE", "L2", "", "TRE", "AFE", "TE"};

static int do_cpuinfo(int argc, char *argv[])
{
	unsigned long mainid, cache, cr;
	char *architecture, *implementer;
	int i;
	int cpu_arch;

	__asm__ __volatile__(
		"mrc    p15, 0, %0, c0, c0, 0   @ read control reg\n"
		: "=r" (mainid)
		:
		: "memory");

	__asm__ __volatile__(
		"mrc    p15, 0, %0, c0, c0, 1   @ read control reg\n"
		: "=r" (cache)
		:
		: "memory");

	__asm__ __volatile__(
		"mrc    p15, 0, %0, c1, c0, 0   @ read control reg\n"
			: "=r" (cr)
			:
			: "memory");

	switch (mainid >> 24) {
	case 0x41:
		implementer = "ARM";
		break;
	case 0x44:
		implementer = "Digital Equipment Corp.";
		break;
	case 0x40:
		implementer = "Motorola - Freescale Semiconductor Inc.";
		break;
	case 0x56:
		implementer = "Marvell Semiconductor Inc.";
		break;
	case 0x69:
		implementer = "Intel Corp.";
		break;
	default:
		implementer = "Unknown";
	}

	if ((mainid & 0x0008f000) == 0) {
		cpu_arch = CPU_ARCH_UNKNOWN;
	} else if ((mainid & 0x0008f000) == 0x00007000) {
		cpu_arch = (mainid & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
	} else if ((mainid & 0x00080000) == 0x00000000) {
		cpu_arch = (mainid >> 16) & 7;
		if (cpu_arch)
			cpu_arch += CPU_ARCH_ARMv3;
	} else if ((mainid & 0x000f0000) == 0x000f0000) {
		unsigned int mmfr0;

		/* Revised CPUID format. Read the Memory Model Feature
		 * Register 0 and check for VMSAv7 or PMSAv7 */
		asm("mrc	p15, 0, %0, c0, c1, 4"
		    : "=r" (mmfr0));
		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
		    (mmfr0 & 0x000000f0) >= 0x00000030)
			cpu_arch = CPU_ARCH_ARMv7;
		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
			 (mmfr0 & 0x000000f0) == 0x00000020)
			cpu_arch = CPU_ARCH_ARMv6;
		else
			cpu_arch = CPU_ARCH_UNKNOWN;
	} else
		cpu_arch = CPU_ARCH_UNKNOWN;

	switch (cpu_arch) {
	case CPU_ARCH_ARMv3:
		architecture = "v3";
		break;
	case CPU_ARCH_ARMv4:
		architecture = "v4";
		break;
	case CPU_ARCH_ARMv4T:
		architecture = "v4T";
		break;
	case CPU_ARCH_ARMv5:
		architecture = "v5";
		break;
	case CPU_ARCH_ARMv5T:
		architecture = "v5T";
		break;
	case CPU_ARCH_ARMv5TE:
		architecture = "v5TE";
		break;
	case CPU_ARCH_ARMv5TEJ:
		architecture = "v5TEJ";
		break;
	case CPU_ARCH_ARMv6:
		architecture = "v6";
		break;
	case CPU_ARCH_ARMv7:
		architecture = "v7";
		break;
	case CPU_ARCH_UNKNOWN:
	default:
		architecture = "Unknown";
	}

	printf("implementer: %s\narchitecture: %s\n",
			implementer, architecture);

	if (cache & (1 << 24)) {
		/* seperate I/D cache */
		printf("I-cache: ");
		decode_cache(cache & 0xfff);
		printf("D-cache: ");
		decode_cache((cache >> 12) & 0xfff);
	} else {
		/* unified I/D cache */
		printf("cache: ");
		decode_cache(cache & 0xfff);
	}

	printf("Control register: ");
	for (i = 0; i < ARRAY_SIZE(crbits); i++)
		if (cr & (1 << i))
			printf("%s ", crbits[i]);
	printf("\n");

	return 0;
}

BAREBOX_CMD_START(cpuinfo)
	.cmd            = do_cpuinfo,
	.usage          = "Show info about CPU",
	BAREBOX_CMD_COMPLETE(empty_complete)
BAREBOX_CMD_END