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-rw-r--r--include/linux/cs5535.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index 39e93e8ed95d..eb34108a608b 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -36,6 +36,38 @@
#define LBAR_ACPI_SIZE 0x40
#define LBAR_PMS_SIZE 0x80
+/* 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_VR_MEM_SIZE 0x0200
+#define AMD_VSA_SIG 0x4132 /* signature is ascii 'VSA2' */
+#define GSW_VSA_SIG 0x534d /* General Software signature */
+
+#include <linux/io.h>
+
+static inline int cs5535_has_vsa2(void)
+{
+ static int has_vsa2 = -1;
+
+ if (has_vsa2 == -1) {
+ uint16_t val;
+
+ /*
+ * The VSA has virtual registers that we can query for a
+ * signature.
+ */
+ outw(VSA_VR_UNLOCK, VSA_VRC_INDEX);
+ outw(VSA_VR_SIGNATURE, VSA_VRC_INDEX);
+
+ val = inw(VSA_VRC_DATA);
+ has_vsa2 = (val == AMD_VSA_SIG || val == GSW_VSA_SIG);
+ }
+
+ return has_vsa2;
+}
+
/* GPIOs */
#define GPIO_OUTPUT_VAL 0x00
#define GPIO_OUTPUT_ENABLE 0x04
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