From 3f5492c51367ed7bf39eaf9f86ba5b4f8a27a111 Mon Sep 17 00:00:00 2001 From: Jason Liu Date: Fri, 26 Aug 2011 13:35:20 +0800 Subject: ARM: mx27: Print silicon revision on boot Silicon revision is useful information to have during kernel boot. Print the MX27 silicon revision. Signed-off-by: Fabio Estevam Signed-off-by: Jason Liu Cc: Sascha Hauer Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/cpu-imx27.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'arch/arm/mach-imx/cpu-imx27.c') diff --git a/arch/arm/mach-imx/cpu-imx27.c b/arch/arm/mach-imx/cpu-imx27.c index 3b117be37bd2..ff38e1505f67 100644 --- a/arch/arm/mach-imx/cpu-imx27.c +++ b/arch/arm/mach-imx/cpu-imx27.c @@ -26,12 +26,12 @@ #include -static int cpu_silicon_rev = -1; -static int cpu_partnumber; +static int mx27_cpu_rev = -1; +static int mx27_cpu_partnumber; #define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */ -static void query_silicon_parameter(void) +static int mx27_read_cpu_rev(void) { u32 val; /* @@ -42,20 +42,18 @@ static void query_silicon_parameter(void) val = __raw_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR + SYS_CHIP_ID)); + mx27_cpu_partnumber = (int)((val >> 12) & 0xFFFF); + switch (val >> 28) { case 0: - cpu_silicon_rev = IMX_CHIP_REVISION_1_0; - break; + return IMX_CHIP_REVISION_1_0; case 1: - cpu_silicon_rev = IMX_CHIP_REVISION_2_0; - break; + return IMX_CHIP_REVISION_2_0; case 2: - cpu_silicon_rev = IMX_CHIP_REVISION_2_1; - break; + return IMX_CHIP_REVISION_2_1; default: - cpu_silicon_rev = IMX_CHIP_REVISION_UNKNOWN; + return IMX_CHIP_REVISION_UNKNOWN; } - cpu_partnumber = (int)((val >> 12) & 0xFFFF); } /* @@ -65,12 +63,12 @@ static void query_silicon_parameter(void) */ int mx27_revision(void) { - if (cpu_silicon_rev == -1) - query_silicon_parameter(); + if (mx27_cpu_rev == -1) + mx27_cpu_rev = mx27_read_cpu_rev(); - if (cpu_partnumber != 0x8821) + if (mx27_cpu_partnumber != 0x8821) return -EINVAL; - return cpu_silicon_rev; + return mx27_cpu_rev; } EXPORT_SYMBOL(mx27_revision); -- cgit v1.2.3