projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| f31405cc JB |
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 | ||
| a09e64fb | 27 | #include <mach/hardware.h> |
| f31405cc | 28 | |
| f31405cc JB |
29 | static int cpu_silicon_rev = -1; |
| 30 | static int cpu_partnumber; | |
| 31 | ||
| edfcea80 SH |
32 | #define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */ |
| 33 | ||
| f31405cc JB |
34 | static void query_silicon_parameter(void) |
| 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 | */ | |
| bc9ea6c7 UKK |
42 | val = __raw_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR |
| 43 | + SYS_CHIP_ID)); | |
| f31405cc | 44 | |
| 9ab4650f DN |
45 | switch (val >> 28) { |
| 46 | case 0: | |
| 47 | cpu_silicon_rev = IMX_CHIP_REVISION_1_0; | |
| 48 | break; | |
| 49 | case 1: | |
| 50 | cpu_silicon_rev = IMX_CHIP_REVISION_2_0; | |
| 51 | break; | |
| 52 | case 2: | |
| 53 | cpu_silicon_rev = IMX_CHIP_REVISION_2_1; | |
| 54 | break; | |
| 55 | default: | |
| 56 | cpu_silicon_rev = IMX_CHIP_REVISION_UNKNOWN; | |
| 57 | } | |
| f31405cc JB |
58 | cpu_partnumber = (int)((val >> 12) & 0xFFFF); |
| 59 | } | |
| 60 | ||
| 61 | /* | |
| 62 | * Returns: | |
| 63 | * the silicon revision of the cpu | |
| 64 | * -EINVAL - not a mx27 | |
| 65 | */ | |
| 66 | int mx27_revision(void) | |
| 67 | { | |
| 68 | if (cpu_silicon_rev == -1) | |
| 69 | query_silicon_parameter(); | |
| 70 | ||
| 71 | if (cpu_partnumber != 0x8821) | |
| 72 | return -EINVAL; | |
| 73 | ||
| 74 | return cpu_silicon_rev; | |
| 75 | } | |
| 76 | EXPORT_SYMBOL(mx27_revision); |