[PATCH linux dev-4.10 v4] ARM: aspeed: Add Mellanox MSN machine (aspeed arch)

[Mykola Kostenok]

Initial introduction of Mellanox switches of MSNXXXX family equipped
with Aspeed 2520 BMC SoC. This adds the platform early initialization.

Signed-off-by: Mykola Kostenok <c_mykolak at mellanox.com>
---
v1->v2
Fixed issues pointed out by Joel:
- Make commit title shorter.
- Replace flash layout from separate dtsi to dts.
- Change compatible = "mellanox,msnxxxx-bmc" to "mellanox,msn-bmc".
- Remove no-hw-checksum from dts.
- Add comments.
- Remove WD2 disable from aspeed.c
- Add wdt2 to dts.

v2->v3
- Split v2 patch into three separate.

v3->v4
Fixed issues pointed by Andrew:
- Fix comment.
- Fix UART1 reset disable sequence(read/modify/write).
---
 arch/arm/mach-aspeed/aspeed.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/arch/arm/mach-aspeed/aspeed.c b/arch/arm/mach-aspeed/aspeed.c
index 0f1a536ba1b2..5c88286c96fd 100644
--- a/arch/arm/mach-aspeed/aspeed.c
+++ b/arch/arm/mach-aspeed/aspeed.c
@@ -188,6 +188,31 @@ static void __init do_lanyang_setup(void)
 	writel(reg & ~BIT(4), AST_IO(AST_BASE_LPC | 0x98));
 }
 
+static void __init do_mellanox_setup(void)
+{
+	unsigned long reg;
+
+	do_common_setup();
+
+	/* Set strapping for MAC1 to RMII/NCSI and MAC2 to RGMII. */
+	reg = readl(AST_IO(AST_BASE_SCU | 0x70));
+	reg |= BIT(7);
+	reg &= ~BIT(6);
+	writel(reg, AST_IO(AST_BASE_SCU | 0x70));
+
+	/* Disable default behavior of UART1 being held in reset by LPCRST#.
+	 * By releasing UART1 from being controlled by LPC reset, it becomes
+	 * immediately available regardless of the host being up. */
+	reg = readl(AST_IO(AST_BASE_LPC | 0x98));
+	/* Clear "Enable UART1 reset source from LPC" */
+	writel(reg & ~BIT(4), AST_IO(AST_BASE_LPC | 0x98));
+
+	/* Enable RMII1 50MHz RCLK output. */
+	reg = readl(AST_IO(AST_BASE_SCU | 0x48));
+	reg |= BIT(29);
+	writel(reg, AST_IO(AST_BASE_SCU | 0x48));
+}
+
 #define SCU_PASSWORD	0x1688A8A8
 
 static void __init aspeed_init_early(void)
@@ -227,6 +252,8 @@ static void __init aspeed_init_early(void)
 		do_romulus_setup();
 	if (of_machine_is_compatible("inventec,lanyang-bmc"))
 		do_lanyang_setup();
+	if (of_machine_is_compatible("mellanox,msn-bmc"))
+		do_mellanox_setup();
 }
 
 static void __init aspeed_map_io(void)
-- 
2.11.0