[PATCH v2 2/7] drm/ast: Add VGACRAA register constants

[Thomas Zimmermann <tzimmermann@suse.de>]

Add register constants for VGACRAA and use them when detecting the
size of the VGA memory. Aligns the code with the programming manual.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/ast/ast_mm.c  | 5 +++--
 drivers/gpu/drm/ast/ast_reg.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_mm.c b/drivers/gpu/drm/ast/ast_mm.c
index 20d833632a01..8d8aac8c0814 100644
--- a/drivers/gpu/drm/ast/ast_mm.c
+++ b/drivers/gpu/drm/ast/ast_mm.c
@@ -37,9 +37,10 @@ static u32 ast_get_vram_size(struct ast_device *ast)
 {
 	u8 jreg;
 	u32 vram_size;
+	u8 vgacraa;
 
-	jreg = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xaa, 0xff);
-	switch (jreg & 3) {
+	vgacraa = ast_get_index_reg(ast, AST_IO_VGACRI, 0xaa);
+	switch (vgacraa & AST_IO_VGACRAA_VGAMEM_SIZE_MASK) {
 	case 0:
 		vram_size = SZ_8M;
 		break;
diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index bb2cc1d8b84e..039b93bed19e 100644
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -33,6 +33,7 @@
 #define AST_IO_VGACRA1_VGAIO_DISABLED	BIT(1)
 #define AST_IO_VGACRA1_MMIO_ENABLED	BIT(2)
 #define AST_IO_VGACRA3_DVO_ENABLED	BIT(7)
+#define AST_IO_VGACRAA_VGAMEM_SIZE_MASK	GENMASK(1, 0)
 #define AST_IO_VGACRB6_HSYNC_OFF	BIT(0)
 #define AST_IO_VGACRB6_VSYNC_OFF	BIT(1)
 #define AST_IO_VGACRCB_HWC_16BPP	BIT(0) /* set: ARGB4444, cleared: 2bpp palette */
-- 
2.48.1