From 8098310be5887bd5e80830f105b63ed59dc10421 Mon Sep 17 00:00:00 2001
From: Alexander Filippov <a.filippov@yadro.com>
Date: Fri, 22 May 2020 11:45:31 +0300
Subject: [PATCH] aspeed: add bmc position support

There are two Nicoles in one chassis in the Tatlin hardware.
The position is encoded by a pin, read by an MCU, and then translated
to the BMC via GPIO pin GPIOE1.

This reads the GPIO pin state and put is as a bootargs item.

Signed-off-by: Alexander Filippov <a.filippov@yadro.com>
---
 arch/arm/mach-aspeed/ast-late-init.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/arch/arm/mach-aspeed/ast-late-init.c b/arch/arm/mach-aspeed/ast-late-init.c
index 5646c0e882..7d36dc0d8a 100644
--- a/arch/arm/mach-aspeed/ast-late-init.c
+++ b/arch/arm/mach-aspeed/ast-late-init.c
@@ -7,6 +7,7 @@
 
 #include <asm/arch/ast_scu.h>
 #include <asm/arch/regs-scu.h>
+#include <asm/gpio.h>
 #include <malloc.h>
 
 static void update_bootargs_cmd(const char *key, const char *value)
@@ -106,9 +107,29 @@ static void set_reset_reason(void)
     }
 }
 
+static void set_bmc_position(void)
+{
+    unsigned gpio = ASPEED_GPIO(E, 1);
+
+    /* Init GPIO */
+    if (gpio_request(gpio, "bmcposition") == 0 &&
+        gpio_direction_input(gpio) == 0)
+    {
+        int position = gpio_get_value(gpio);
+        if (position >= 0)
+        {
+            printf("BMC Position: %d\n", position);
+            update_bootargs_cmd("bmcposition", position ? "1" : "0");
+        }
+    }
+
+    gpio_free(gpio);
+}
+
 int board_late_init(void)
 {
     set_reset_reason();
+    set_bmc_position();
 
     return 0;
 }
-- 
2.25.4