From 03dcf584823b8b7db7d437257dbb45bd4b7f95b4 Mon Sep 17 00:00:00 2001
From: Chanh Nguyen <chnguyen@amperecomputing.com>
Date: Mon, 21 Dec 2020 07:01:14 +0000
Subject: [PATCH] aspeed/scu : Switch PWM pin to GPIO input mode

In hardware design, the PWM pins will be at a high level if they are
configured in GPIO Input mode. This commit configures all PWM function
pins to input GPIO mode. This will allow fans to run at full speed when BMC resets or in U-boot.

Signed-off-by: Chanh Nguyen <chnguyen@amperecomputing.com>
---
 arch/arm/include/asm/arch-aspeed/ast_scu.h |  1 +
 arch/arm/mach-aspeed/ast-scu.c             | 12 ++++++++++++
 board/aspeed/ast-g5/ast-g5.c               | 10 ++++++++++
 include/configs/ast-g5-phy.h               |  3 +++
 4 files changed, 26 insertions(+)

diff --git a/arch/arm/include/asm/arch-aspeed/ast_scu.h b/arch/arm/include/asm/arch-aspeed/ast_scu.h
index dcbc6730d4..d2c010a0dc 100644
--- a/arch/arm/include/asm/arch-aspeed/ast_scu.h
+++ b/arch/arm/include/asm/arch-aspeed/ast_scu.h
@@ -45,5 +45,6 @@ extern u32 ast_scu_get_vga_memsize(void);
 extern void ast_scu_init_eth(u8 num);
 extern void ast_scu_multi_func_eth(u8 num);
 extern void ast_scu_multi_func_romcs(u8 num);
+extern void ast_scu_switch_pwm_to_gpio_mode(void);
 
 #endif
diff --git a/arch/arm/mach-aspeed/ast-scu.c b/arch/arm/mach-aspeed/ast-scu.c
index 12de9b8036..ef90ef3805 100644
--- a/arch/arm/mach-aspeed/ast-scu.c
+++ b/arch/arm/mach-aspeed/ast-scu.c
@@ -443,6 +443,18 @@ void ast_scu_multi_func_eth(u8 num)
 	}
 }
 
+void ast_scu_switch_pwm_to_gpio_mode(void)
+{
+	ast_scu_write(ast_scu_read(AST_SCU_FUN_PIN_CTRL3) &
+			~SCU_FUN_PIN_VPIG2 &
+			~SCU_FUN_PIN_VPIG3 &
+			~SCU_FUN_PIN_VPIG4 &
+			~SCU_FUN_PIN_VPIG5 &
+			~SCU_FUN_PIN_VPIG6 &
+			~SCU_FUN_PIN_VPIG7,
+			AST_SCU_FUN_PIN_CTRL3);
+}
+
 void ast_scu_multi_func_romcs(u8 num)
 {
 	ast_scu_write(ast_scu_read(AST_SCU_FUN_PIN_CTRL3) |
diff --git a/board/aspeed/ast-g5/ast-g5.c b/board/aspeed/ast-g5/ast-g5.c
index e67a4bf8b2..fba22a728e 100644
--- a/board/aspeed/ast-g5/ast-g5.c
+++ b/board/aspeed/ast-g5/ast-g5.c
@@ -24,6 +24,16 @@ int board_init(void)
 	return 0;
 }
 
+#ifdef CONFIG_BOARD_LATE_INIT
+int board_late_init(void)
+{
+	/* Switch PWM to GPIO mode to make FAN run in max speed */
+	ast_scu_switch_pwm_to_gpio_mode();
+
+	return 0;
+}
+#endif
+
 int dram_init(void)
 {
 	u32 vga = ast_scu_get_vga_memsize();
diff --git a/include/configs/ast-g5-phy.h b/include/configs/ast-g5-phy.h
index 62ddb841e5..5443a26cab 100644
--- a/include/configs/ast-g5-phy.h
+++ b/include/configs/ast-g5-phy.h
@@ -30,4 +30,7 @@
 /* platform.S */
 #define	CONFIG_DRAM_ECC_SIZE		0x10000000
 
+/* Call board_late_init */
+#define CONFIG_BOARD_LATE_INIT		1
+
 #endif	/* __AST_G5_PHY_CONFIG_H */
-- 
2.25.1