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

[Jocelyn Falempe]

On 05/03/2025 14:35, Thomas Zimmermann wrote:
> 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.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>

> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at 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)