From e9338364e6989ca2707638c7c70ae22975b0bb6c Mon Sep 17 00:00:00 2001 From: Andres Salomon Date: Mon, 28 Apr 2008 02:14:54 -0700 Subject: [PATCH] x86: GEODE: add Virtual Systems Architecture detection This is generic VSA2 detection. It's used by OLPC to determine whether or not the BIOS contains VSA2, but since other BIOSes are coming out that don't use the VSA (ie, tinybios), it might end up being useful for others. Signed-off-by: Andres Salomon Acked-by: Alan Cox Cc: Jordan Crouse Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-x86/geode.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/asm-x86/geode.h b/include/asm-x86/geode.h index b1bdf637856..3978200f126 100644 --- a/include/asm-x86/geode.h +++ b/include/asm-x86/geode.h @@ -103,6 +103,14 @@ extern int geode_get_dev_base(unsigned int dev); #define PM_AWKD 0x50 #define PM_SSC 0x54 +/* VSA2 magic values */ + +#define VSA_VRC_INDEX 0xAC1C +#define VSA_VRC_DATA 0xAC1E +#define VSA_VR_UNLOCK 0xFC53 /* unlock virtual register */ +#define VSA_VR_SIGNATURE 0x0003 +#define VSA_SIG 0x4132 /* signature is ascii 'VSA2' */ + /* GPIO */ #define GPIO_OUTPUT_VAL 0x00 @@ -174,6 +182,17 @@ static inline int is_geode(void) return (is_geode_gx() || is_geode_lx()); } +/* + * The VSA has virtual registers that we can query for a signature. + */ +static inline int geode_has_vsa2(void) +{ + outw(VSA_VR_UNLOCK, VSA_VRC_INDEX); + outw(VSA_VR_SIGNATURE, VSA_VRC_INDEX); + + return (inw(VSA_VRC_DATA) == VSA_SIG); +} + /* MFGPTs */ #define MFGPT_MAX_TIMERS 8 -- 2.20.1