Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved. |
| 3 | * Copyright 2008 Juergen Beisert, kernel@pengutronix.de |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License |
| 7 | * as published by the Free Software Foundation; either version 2 |
| 8 | * of the License, or (at your option) any later version. |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| 17 | * MA 02110-1301, USA. |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | * i.MX27 specific CPU detection code |
| 22 | */ |
| 23 | |
| 24 | #include <linux/io.h> |
| 25 | #include <linux/module.h> |
| 26 | |
Shawn Guo | 50f2de6 | 2012-09-14 14:14:45 +0800 | [diff] [blame] | 27 | #include "hardware.h" |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 28 | |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 29 | static int mx27_cpu_rev = -1; |
| 30 | static int mx27_cpu_partnumber; |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 31 | |
Sascha Hauer | edfcea8 | 2009-02-16 15:13:43 +0100 | [diff] [blame] | 32 | #define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */ |
| 33 | |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 34 | static int mx27_read_cpu_rev(void) |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 35 | { |
| 36 | u32 val; |
| 37 | /* |
| 38 | * now we have access to the IO registers. As we need |
| 39 | * the silicon revision very early we read it here to |
| 40 | * avoid any further hooks |
| 41 | */ |
Uwe Kleine-König | bc9ea6c | 2009-12-16 17:30:27 +0100 | [diff] [blame] | 42 | val = __raw_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR |
| 43 | + SYS_CHIP_ID)); |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 44 | |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 45 | mx27_cpu_partnumber = (int)((val >> 12) & 0xFFFF); |
| 46 | |
Dinh Nguyen | 9ab4650 | 2010-11-15 11:30:01 -0600 | [diff] [blame] | 47 | switch (val >> 28) { |
| 48 | case 0: |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 49 | return IMX_CHIP_REVISION_1_0; |
Dinh Nguyen | 9ab4650 | 2010-11-15 11:30:01 -0600 | [diff] [blame] | 50 | case 1: |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 51 | return IMX_CHIP_REVISION_2_0; |
Dinh Nguyen | 9ab4650 | 2010-11-15 11:30:01 -0600 | [diff] [blame] | 52 | case 2: |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 53 | return IMX_CHIP_REVISION_2_1; |
Dinh Nguyen | 9ab4650 | 2010-11-15 11:30:01 -0600 | [diff] [blame] | 54 | default: |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 55 | return IMX_CHIP_REVISION_UNKNOWN; |
Dinh Nguyen | 9ab4650 | 2010-11-15 11:30:01 -0600 | [diff] [blame] | 56 | } |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Returns: |
| 61 | * the silicon revision of the cpu |
| 62 | * -EINVAL - not a mx27 |
| 63 | */ |
| 64 | int mx27_revision(void) |
| 65 | { |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 66 | if (mx27_cpu_rev == -1) |
| 67 | mx27_cpu_rev = mx27_read_cpu_rev(); |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 68 | |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 69 | if (mx27_cpu_partnumber != 0x8821) |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 70 | return -EINVAL; |
| 71 | |
Jason Liu | 3f5492c | 2011-08-26 13:35:20 +0800 | [diff] [blame] | 72 | return mx27_cpu_rev; |
Juergen Beisert | f31405c | 2008-07-05 10:02:59 +0200 | [diff] [blame] | 73 | } |
| 74 | EXPORT_SYMBOL(mx27_revision); |