[PATCH v2 3/7] drm/ast: Add VGACR99 register constants

[Thomas Zimmermann <tzimmermann@suse.de>]

Add register constants for VGACR99 and use them when detecting the
size of the VGA memory. Aligns the code with the programming manual.
Also replace literal size values with Linux' SZ_ size constants.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/ast/ast_mm.c  | 13 ++++++-------
 drivers/gpu/drm/ast/ast_reg.h |  1 +
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_mm.c b/drivers/gpu/drm/ast/ast_mm.c
index 8d8aac8c0814..3d03ef556d0a 100644
--- a/drivers/gpu/drm/ast/ast_mm.c
+++ b/drivers/gpu/drm/ast/ast_mm.c
@@ -35,9 +35,8 @@
 
 static u32 ast_get_vram_size(struct ast_device *ast)
 {
-	u8 jreg;
 	u32 vram_size;
-	u8 vgacraa;
+	u8 vgacr99, vgacraa;
 
 	vgacraa = ast_get_index_reg(ast, AST_IO_VGACRI, 0xaa);
 	switch (vgacraa & AST_IO_VGACRAA_VGAMEM_SIZE_MASK) {
@@ -55,16 +54,16 @@ static u32 ast_get_vram_size(struct ast_device *ast)
 		break;
 	}
 
-	jreg = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0x99, 0xff);
-	switch (jreg & 0x03) {
+	vgacr99 = ast_get_index_reg(ast, AST_IO_VGACRI, 0x99);
+	switch (vgacr99 & AST_IO_VGACR99_VGAMEM_RSRV_MASK) {
 	case 1:
-		vram_size -= 0x100000;
+		vram_size -= SZ_1M;
 		break;
 	case 2:
-		vram_size -= 0x200000;
+		vram_size -= SZ_2M;
 		break;
 	case 3:
-		vram_size -= 0x400000;
+		vram_size -= SZ_4M;
 		break;
 	}
 
diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index 039b93bed19e..e15adaf3a80e 100644
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -30,6 +30,7 @@
 
 #define AST_IO_VGACRI			(0x54)
 #define AST_IO_VGACR80_PASSWORD		(0xa8)
+#define AST_IO_VGACR99_VGAMEM_RSRV_MASK	GENMASK(1, 0)
 #define AST_IO_VGACRA1_VGAIO_DISABLED	BIT(1)
 #define AST_IO_VGACRA1_MMIO_ENABLED	BIT(2)
 #define AST_IO_VGACRA3_DVO_ENABLED	BIT(7)
-- 
2.48.1