openwrtv4/target/linux/sunxi/patches-4.4/100-clk-sunxi-add-dram-gates-support.patch

From 6d3a47c29186aa8d26ff05a6209c94291ace0696 Mon Sep 17 00:00:00 2001
From: Chen-Yu Tsai <wens@csie.org>
Date: Sat, 5 Dec 2015 21:16:42 +0800
Subject: [PATCH] clk: sunxi: Add DRAM gates support for sun4i-a10

The A10/A20 share the same set of DRAM clock gates, which controls
direct memory access for some peripherals.

On the A10, bit 15 controls the system's DRAM clock output (possibly
to the DRAM chips), which we need to keep on.

On the A20 this has been moved to the DRAM controller, becoming a no-op.
However it is still listed in the user manual, so add it anyway.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/clk-simple-gates.c              | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 153ac72..ef0b452 100644
diff --git a/drivers/clk/sunxi/clk-simple-gates.c b/drivers/clk/sunxi/clk-simple-gates.c
index c8acc06..f4da52b 100644
--- a/drivers/clk/sunxi/clk-simple-gates.c
+++ b/drivers/clk/sunxi/clk-simple-gates.c
@@ -160,3 +160,15 @@ CLK_OF_DECLARE(sun5i_a13_ahb, "allwinner,sun5i-a13-ahb-gates-clk",
 	       sun4i_a10_ahb_init);
 CLK_OF_DECLARE(sun7i_a20_ahb, "allwinner,sun7i-a20-ahb-gates-clk",
 	       sun4i_a10_ahb_init);
+
+static const int sun4i_a10_dram_critical_clocks[] __initconst = {
+	15,	/* dram_output */
+};
+
+static void __init sun4i_a10_dram_init(struct device_node *node)
+{
+	sunxi_simple_gates_setup(node, sun4i_a10_dram_critical_clocks,
+				 ARRAY_SIZE(sun4i_a10_dram_critical_clocks));
+}
+CLK_OF_DECLARE(sun4i_a10_dram, "allwinner,sun4i-a10-dram-gates-clk",
+	       sun4i_a10_dram_init);