[RFC v2] ARM: memory: da8xx-ddrctl: new driver

Kevin Hilman [off-list ref] writes:

Bartosz Golaszewski [off-list ref] writes:

quoted

Create a new driver for the da8xx DDR2/mDDR controller and implement
support for writing to the Peripheral Bus Burst Priority Register.

Signed-off-by: Bartosz Golaszewski <redacted>
---
 .../memory-controllers/ti-da8xx-ddrctl.txt         |  20 +++
 drivers/memory/Kconfig                             |   8 +
 drivers/memory/Makefile                            |   1 +
 drivers/memory/da8xx-ddrctl.c                      | 175 +++++++++++++++++++++
 4 files changed, 204 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
 create mode 100644 drivers/memory/da8xx-ddrctl.c

diff --git
a/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
new file mode 100644
index 0000000..7e271dd

--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt

@@ -0,0 +1,20 @@
+* Device tree bindings for Texas Instruments da8xx DDR2/mDDR memory controller
+
+The DDR2/mDDR memory controller present on Texas Instruments da8xx SoCs features
+a set of registers which allow to tweak the controller's behavior.
+
+Documentation:
+OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
+
+Required properties:
+
+- compatible:		"ti,da850-ddr-controller" - for da850 SoC based boards
+- reg:			a tuple containing the base address of the memory
+			controller and the size of the memory area to map
+
+Example for da850 shown below.
+
+ddrctl {
+	compatible = "ti,da850-ddr-controller";
+	reg = <0xB0000000 0x100>;
+};

Axel's series for the USB PHY reminded me that the PHY also has some
config registers in this same area, and his series creates a syscon for
a similar range of registers.

Could you create a syscon for the SYSCFG0 registers, which would then
be used by ths driver and your other drivers/bus driver?  Then the
binding  would just reference the sysconf via phandle, and your driver
can use syscon_regmap_lookup_by_phandle()

Nevermind. I though that the config register in this driver was also in
SYSCFG0, but I see now that it's in the reg region of the DDR controller
itself, so no syscon is needed.

Kevin