diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2026-03-27 14:33:00 +0100 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2026-04-08 11:04:49 +0200 |
| commit | 5da1fcb9cb69a3274b77747ffcc3f0a2223e253d (patch) | |
| tree | 80243c3a154afe68c1d1eed9c307055e5acc22ed /drivers/gpu | |
| parent | a0320ef5a99090d5c5ee1f5fd40409b0c0035430 (diff) | |
drm/ast: Use constants for SDRAM registers
Aspeed hardware allows for acceessing the SDRAM from the host. SDRAM
registers are located at the memory range at [0x80000000, 0xffffffff].
Refer to memory access with the macro AST_SDRAM(). Also add a TODO item
for the nonsensical documentation next to its caller.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20260327133532.79696-9-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_2500.c | 17 | ||||
| -rw-r--r-- | drivers/gpu/drm/ast/ast_reg.h | 7 |
2 files changed, 17 insertions, 7 deletions
diff --git a/drivers/gpu/drm/ast/ast_2500.c b/drivers/gpu/drm/ast/ast_2500.c index f0639f1ef062..39f401dd1f47 100644 --- a/drivers/gpu/drm/ast/ast_2500.c +++ b/drivers/gpu/drm/ast/ast_2500.c @@ -225,6 +225,9 @@ static void ddr_phy_init_2500(struct ast_device *ast) } /* + * TODO: Review and fix the comments. The function below only detects + * up to 1 GiB of SDRAM. + * * Check DRAM Size * 1Gb : 0x80000000 ~ 0x87FFFFFF * 2Gb : 0x80000000 ~ 0x8FFFFFFF @@ -238,21 +241,21 @@ static void check_dram_size_2500(struct ast_device *ast, u32 tRFC) reg_04 = ast_mindwm(ast, AST_REG_MCR04) & 0xfffffffc; reg_14 = ast_mindwm(ast, AST_REG_MCR14) & 0xffffff00; - ast_moutdwm(ast, 0xA0100000, 0x41424344); - ast_moutdwm(ast, 0x90100000, 0x35363738); - ast_moutdwm(ast, 0x88100000, 0x292A2B2C); - ast_moutdwm(ast, 0x80100000, 0x1D1E1F10); + ast_moutdwm(ast, AST_SDRAM(0x20100000), 0x41424344); + ast_moutdwm(ast, AST_SDRAM(0x10100000), 0x35363738); + ast_moutdwm(ast, AST_SDRAM(0x08100000), 0x292A2B2C); + ast_moutdwm(ast, AST_SDRAM(0x00100000), 0x1D1E1F10); /* Check 8Gbit */ - if (ast_mindwm(ast, 0xA0100000) == 0x41424344) { + if (ast_mindwm(ast, AST_SDRAM(0x20100000)) == 0x41424344) { reg_04 |= 0x03; reg_14 |= (tRFC >> 24) & 0xFF; /* Check 4Gbit */ - } else if (ast_mindwm(ast, 0x90100000) == 0x35363738) { + } else if (ast_mindwm(ast, AST_SDRAM(0x10100000)) == 0x35363738) { reg_04 |= 0x02; reg_14 |= (tRFC >> 16) & 0xFF; /* Check 2Gbit */ - } else if (ast_mindwm(ast, 0x88100000) == 0x292A2B2C) { + } else if (ast_mindwm(ast, AST_SDRAM(0x08100000)) == 0x292A2B2C) { reg_04 |= 0x01; reg_14 |= (tRFC >> 8) & 0xFF; } else { diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h index 5effe6897b51..78fabe2a9c81 100644 --- a/drivers/gpu/drm/ast/ast_reg.h +++ b/drivers/gpu/drm/ast/ast_reg.h @@ -209,4 +209,11 @@ #define AST_REG_WDT1C(__n) AST_REG_WDT((__n), 0x1c) #define AST_REG_WDT2C(__n) AST_REG_WDT((__n), 0x2c) +/* + * SDRAM (0x80000000 - 0xffffffff) + */ + +#define AST_SDRAM_BASE (0x80000000) +#define AST_SDRAM(__offset) (AST_SDRAM_BASE + (__offset)) + #endif |