drm/ast: Fix open-coded scu_rev access

Replace all open-coded access to P2A and SCU registers in the device
detection with the appropriate calls to ast_moutdwm() and ast_mindwm().
Use P2A and MCR register constants. Name variables according to registers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20260327133532.79696-16-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index 6fe549f16309c11286e62e488da0e5ae81006826..ba6cf5fa901c97c2abe9d343504e49cc3d239842 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -242,7 +242,7 @@ static int ast_detect_chip(struct pci_dev *pdev,
        enum ast_config_mode config_mode = ast_use_defaults;
        uint32_t scu_rev = 0xffffffff;
        enum ast_chip chip;
-       u32 data;
+       u32 data, p2a04, scu07c;
        u8 vgacrd0, vgacrd1;
 
        /*
@@ -275,14 +275,13 @@ static int ast_detect_chip(struct pci_dev *pdev,
                        }
 
                        /* Double check that it's actually working */
-                       data = __ast_read32(regs, 0xf004);
-                       if ((data != 0xffffffff) && (data != 0x00)) {
+                       p2a04 = __ast_read32(regs, AST_REG_P2A04);
+                       if (p2a04 != 0xffffffff && p2a04 != 0x00000000) {
                                config_mode = ast_use_p2a;
 
-                               /* Read SCU7c (silicon revision register) */
-                               __ast_write32(regs, 0xf004, AST_REG_MCR00);
-                               __ast_write32(regs, 0xf000, 0x1);
-                               scu_rev = __ast_read32(regs, 0x1207c);
+                               /* Read SCU7C (silicon revision register) */
+                               scu07c = __ast_mindwm(regs, AST_REG_SCU07C);
+                               scu_rev = scu07c & AST_REG_SCU07C_CHIP_BONDING_MASK;
                        }
                }
        }

diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index 92cfa02b642f65d794690a4e88ab13652f99302b..ea7dc382aee7116a59bbd112ce7bbfef6556e37d 100644 (file)
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -191,6 +191,7 @@
 #define AST_REG_SCU040                         AST_REG_SCU(0x040)
 #define AST_REG_SCU070                         AST_REG_SCU(0x070)
 #define AST_REG_SCU07C                         AST_REG_SCU(0x07c)
+#define AST_REG_SCU07C_CHIP_BONDING_MASK       GENMASK(15, 8)
 #define AST_REG_SCU084                         AST_REG_SCU(0x084)
 #define AST_REG_SCU088                         AST_REG_SCU(0x088)
 #define AST_REG_SCU08C                         AST_REG_SCU(0x08c)