drm/ast: Enable VGA without ast device instance

We'll have to enable the VGA functionality for detecting the ast
device type. Make this work without an instance of the ast device.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116100240.22975-6-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 026ef89..82fcee9 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -35,22 +35,17 @@
 
 #include "ast_drv.h"
 
-static bool ast_is_vga_enabled(struct drm_device *dev)
+static bool ast_is_vga_enabled(void __iomem *ioregs)
 {
-       struct ast_device *ast = to_ast_device(dev);
-       u8 ch;
-
-       ch = ast_io_read8(ast, AST_IO_VGAER);
+       u8 vgaer = __ast_read8(ioregs, AST_IO_VGAER);
 
-       return !!(ch & 0x01);
+       return vgaer & AST_IO_VGAER_VGA_ENABLE;
 }
 
-static void ast_enable_vga(struct drm_device *dev)
+static void ast_enable_vga(void __iomem *ioregs)
 {
-       struct ast_device *ast = to_ast_device(dev);
-
-       ast_io_write8(ast, AST_IO_VGAER, 0x01);
-       ast_io_write8(ast, AST_IO_VGAMR_W, 0x01);
+       __ast_write8(ioregs, AST_IO_VGAER, AST_IO_VGAER_VGA_ENABLE);
+       __ast_write8(ioregs, AST_IO_VGAMR_W, AST_IO_VGAMR_IOSEL);
 }
 
 /*
@@ -74,9 +69,9 @@ static int ast_enable_mmio(struct ast_device *ast)
        return devm_add_action_or_reset(dev->dev, ast_enable_mmio_release, ast);
 }
 
-static void ast_open_key(struct ast_device *ast)
+static void ast_open_key(void __iomem *ioregs)
 {
-       ast_set_index_reg(ast, AST_IO_VGACRI, 0x80, 0xA8);
+       __ast_write8_i(ioregs, AST_IO_VGACRI, 0x80, AST_IO_VGACR80_PASSWORD);
 }
 
 static int ast_device_config_init(struct ast_device *ast)
@@ -487,7 +482,7 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
        ast->regs = regs;
        ast->ioregs = ioregs;
 
-       if (!ast_is_vga_enabled(dev)) {
+       if (!ast_is_vga_enabled(ioregs)) {
                drm_info(dev, "VGA not enabled on entry, requesting chip POST\n");
                need_post = true;
        }
@@ -497,10 +492,10 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
         * access to the scratch registers will fail.
         */
        if (need_post)
-               ast_enable_vga(dev);
-
+               ast_enable_vga(ioregs);
        /* Enable extended register access */
-       ast_open_key(ast);
+       ast_open_key(ioregs);
+
        ret = ast_enable_mmio(ast);
        if (ret)
                return ERR_PTR(ret);

diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index 05bab94..5258a84 100644 (file)
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -13,8 +13,14 @@
 #define AST_IO_MM_LENGTH               (128)
 
 #define AST_IO_VGAARI_W                        (0x40)
+
 #define AST_IO_VGAMR_W                 (0x42)
+#define AST_IO_VGAMR_R                 (0x4c)
+#define AST_IO_VGAMR_IOSEL             BIT(0)
+
 #define AST_IO_VGAER                   (0x43)
+#define AST_IO_VGAER_VGA_ENABLE                BIT(0)
+
 #define AST_IO_VGASRI                  (0x44)
 #define AST_IO_VGADRR                  (0x47)
 #define AST_IO_VGADWR                  (0x48)
@@ -22,14 +28,13 @@
 #define AST_IO_VGAGRI                  (0x4E)
 
 #define AST_IO_VGACRI                  (0x54)
+#define AST_IO_VGACR80_PASSWORD                (0xa8)
 #define AST_IO_VGACRCB_HWC_16BPP       BIT(0) /* set: ARGB4444, cleared: 2bpp palette */
 #define AST_IO_VGACRCB_HWC_ENABLED     BIT(1)
 
 #define AST_IO_VGAIR1_R                        (0x5A)
 #define AST_IO_VGAIR1_VREFRESH         BIT(3)
 
-#define AST_IO_VGAMR_R                 (0x4C)
-
 /*
  * Display Transmitter Type
  */