drm/ast: Add VGACRAA register constants

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>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250305163207.267650-3-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_mm.c b/drivers/gpu/drm/ast/ast_mm.c
index 20d833632a0144aedc65dc1528756e1715c0b50c..8d8aac8c0814a14d9a49d68e4433492568117f25 100644 (file)
--- 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 bb2cc1d8b84ea3fc2e2aad8d58c5f4c09e406f3f..039b93bed19e597a172afb1907b8858d35d66500 100644 (file)
--- 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 */