xref: /openbmc/linux/arch/arm/mach-imx/cpu-imx31.c (revision 615c36f5)
1 /*
2  * MX31 CPU type detection
3  *
4  * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/io.h>
14 #include <mach/hardware.h>
15 #include <mach/iim.h>
16 #include <mach/common.h>
17 
18 static int mx31_cpu_rev = -1;
19 
20 static struct {
21 	u8 srev;
22 	const char *name;
23 	unsigned int rev;
24 } mx31_cpu_type[] = {
25 	{ .srev = 0x00, .name = "i.MX31(L)", .rev = IMX_CHIP_REVISION_1_0 },
26 	{ .srev = 0x10, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
27 	{ .srev = 0x11, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
28 	{ .srev = 0x12, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
29 	{ .srev = 0x13, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
30 	{ .srev = 0x14, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_2 },
31 	{ .srev = 0x15, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_2 },
32 	{ .srev = 0x28, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_2_0 },
33 	{ .srev = 0x29, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_2_0 },
34 };
35 
36 static int mx31_read_cpu_rev(void)
37 {
38 	u32 i, srev;
39 
40 	/* read SREV register from IIM module */
41 	srev = __raw_readl(MX31_IO_ADDRESS(MX31_IIM_BASE_ADDR + MXC_IIMSREV));
42 	srev &= 0xff;
43 
44 	for (i = 0; i < ARRAY_SIZE(mx31_cpu_type); i++)
45 		if (srev == mx31_cpu_type[i].srev) {
46 			imx_print_silicon_rev(mx31_cpu_type[i].name,
47 						mx31_cpu_type[i].rev);
48 			return mx31_cpu_type[i].rev;
49 		}
50 
51 	imx_print_silicon_rev("i.MX31", IMX_CHIP_REVISION_UNKNOWN);
52 	return IMX_CHIP_REVISION_UNKNOWN;
53 }
54 
55 int mx31_revision(void)
56 {
57 	if (mx31_cpu_rev == -1)
58 		mx31_cpu_rev = mx31_read_cpu_rev();
59 
60 	return mx31_cpu_rev;
61 }
62 EXPORT_SYMBOL(mx31_revision);
63