diff options
Diffstat (limited to 'arch/arm/mach-mx5/cpu.c')
| -rw-r--r-- | arch/arm/mach-mx5/cpu.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/arm/mach-mx5/cpu.c b/arch/arm/mach-mx5/cpu.c index 41c769f08c4d..2d37785e3857 100644 --- a/arch/arm/mach-mx5/cpu.c +++ b/arch/arm/mach-mx5/cpu.c @@ -14,9 +14,62 @@ #include <linux/types.h> #include <linux/kernel.h> #include <linux/init.h> +#include <linux/module.h> #include <mach/hardware.h> #include <asm/io.h> +static int cpu_silicon_rev = -1; + +#define SI_REV 0x48 + +static void query_silicon_parameter(void) +{ + void __iomem *rom = ioremap(MX51_IROM_BASE_ADDR, MX51_IROM_SIZE); + u32 rev; + + if (!rom) { + cpu_silicon_rev = -EINVAL; + return; + } + + rev = readl(rom + SI_REV); + switch (rev) { + case 0x1: + cpu_silicon_rev = MX51_CHIP_REV_1_0; + break; + case 0x2: + cpu_silicon_rev = MX51_CHIP_REV_1_1; + break; + case 0x10: + cpu_silicon_rev = MX51_CHIP_REV_2_0; + break; + case 0x20: + cpu_silicon_rev = MX51_CHIP_REV_3_0; + break; + default: + cpu_silicon_rev = 0; + } + + iounmap(rom); +} + +/* + * Returns: + * the silicon revision of the cpu + * -EINVAL - not a mx51 + */ +int mx51_revision(void) +{ + if (!cpu_is_mx51()) + return -EINVAL; + + if (cpu_silicon_rev == -1) + query_silicon_parameter(); + + return cpu_silicon_rev; +} +EXPORT_SYMBOL(mx51_revision); + static int __init post_cpu_init(void) { unsigned int reg; |