rockchip: rk3368: add DRAM controller driver with DRAM initialisation

This adds a DRAM controller driver for the RK3368 and places it in
drivers/ram/rockchip (where the other DM-enabled DRAM controller
drivers for rockchip devices should also be moved eventually).

At this stage, only the following feature-set is supported:
 - DDR3
 - 32-bit configuration (i.e. fully populated)
 - dual-rank (i.e. no auto-detection of ranks)
 - DDR3-1600K speed-bin

This driver expects to run from a TPL stage that will later return to
the RK3368 BROM.  It communicates with later stages through the
os_reg2 in the pmugrf (i.e. using the same mechanism as Rockchip's DDR
init code).

Unlike other DMC drivers for RK32xx and RK33xx parts, the required
timings are calculated within the driver based on a target frequency
and a DDR3 speed-bin (only the DDR3-1600K speed-bin is support at this
time).

The RK3368 also has the DDRC0_CON0 (DDR ch. 0, control-register 0)
register for controlling the operation of its (single-channel) DRAM
controller in the GRF block.  This provides for selecting DDR3, mobile
DDR modes, and control low-power operation.
As part of this change, DDRC0_CON0 is also added to the GRF structure
definition (at offset 0x600).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/doc/device-tree-bindings/clock/rockchip,rk3368-dmc.txt b/doc/device-tree-bindings/clock/rockchip,rk3368-dmc.txt
new file mode 100644
index 0000000000..8e7357d53d
--- /dev/null
+++ b/doc/device-tree-bindings/clock/rockchip,rk3368-dmc.txt
@@ -0,0 +1,67 @@
+RK3368 dynamic memory controller driver
+=======================================
+
+The RK3368 DMC (dynamic memory controller) driver supports setup/initialisation
+during TPL using configuration data from the DTS (i.e. OF_PLATDATA), based on
+the following key configuration data:
+  (a) a target-frequency (i.e. operating point) for the memory operation
+  (b) a speed-bin (as defined in JESD-79) for the DDR3 used in hardware
+  (c) a memory-schedule (i.e. mapping from physical addresses to the address
+      pins of the memory bus)
+
+Required properties
+-------------------
+
+- compatible: "rockchip,rk3368-dmc"
+- reg
+    protocol controller (PCTL) address and PHY controller (DDRPHY) address
+- rockchip,ddr-speed-bin
+    the DDR3 device's speed-bin (as specified according to JESD-79)
+        DDR3_800D (5-5-5)
+        DDR3_800E (6-6-6)
+        DDR3_1066E (6-6-6)
+        DDR3_1066F (7-7-7)
+        DDR3_1066G (8-8-8)
+        DDR3_1333F (7-7-7)
+        DDR3_1333G (8-8-8)
+        DDR3_1333H (9-9-9)
+        DDR3_1333J (10-10-10)
+        DDR3_1600G (8-8-8)
+        DDR3_1600H (9-9-9)
+        DDR3_1600J (10-10-10)
+        DDR3_1600K (11-11-11)
+        DDR3_1866J (10-10-10)
+        DDR3_1866K (11-11-11)
+        DDR3_1866L (12-12-12)
+        DDR3_1866M (13-13-13)
+        DDR3_2133K (11-11-11)
+        DDR3_2133L (12-12-12)
+        DDR3_2133M (13-13-13)
+        DDR3_2133N (14-14-14)
+- rockchip,ddr-frequency:
+    target DDR clock frequency in Hz (not all frequencies may be supported,
+    as there's some cooperation from the clock-driver required)
+- rockchip,memory-schedule:
+    controls the decoding of physical addresses to DRAM addressing (i.e. how
+    the physical address maps onto the address pins/chip-select of the device)
+	DMC_MSCH_CBDR: column -> bank -> device -> row
+	DMC_MSCH_CBRD: column -> band -> row -> device
+	DMC_MSCH_CRBD: column -> row -> band -> device
+
+Example (for DDR3-1600K and 800MHz)
+-----------------------------------
+
+	#include <dt-bindings/memory/rk3368-dmc.h>
+
+	dmc: dmc@ff610000 {
+	        u-boot,dm-pre-reloc;
+		compatible = "rockchip,rk3368-dmc";
+		reg = <0 0xff610000 0 0x400
+		       0 0xff620000 0 0x400>;
+	};
+
+	&dmc {
+		rockchip,ddr-speed-bin = <DDR3_1600K>;
+		rockchip,ddr-frequency = <800000000>;
+		rockchip,memory-schedule = <DMC_MSCH_CBRD>;
+	};