spi: tegra114: add spi driver

Add spi driver for NVIDIA's Tegra114 spi controller. This controller
is different than the older SoCs spi controller and there is a change
in register interface also.

This driver supports the:
- non DMA based transfer for smaller transfer i.e. less than FIFO depth.
- APB DMA based transfer for lager transfer i.e. more than FIFO depth.
- Runtime PM for clock gating.
- registration through DT and platform board files.

Change-Id: I30ab59a29d80b191843878994227945261ae8e17
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/202032
Reviewed-by: Nitin Kumbhar <nkumbhar@nvidia.com>
Tested-by: Nitin Kumbhar <nkumbhar@nvidia.com>
(cherry picked from commit 8b21af40fc68e280a1e7f0168928d1b97b61b6ba)

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/spi/nvidia,spi-tegra114.txt b/Documentation/devicetree/bindings/spi/nvidia,spi-tegra114.txt
new file mode 100644
index 000000000000..8a93aacd8d86
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/nvidia,spi-tegra114.txt
@@ -0,0 +1,29 @@
+NVIDIA Tegra114 SPI controller.
+
+Required properties:
+- compatible : should be "nvidia,tegra114-spi".
+- reg: Should contain SPI registers location and length.
+- interrupts: Should contain SPI interrupts.
+- nvidia,dma-request-selector : The Tegra DMA controller's phandle and
+  request selector for this SPI controller.
+
+Recommended properties:
+- spi-max-frequency: Definition as per
+                     Documentation/devicetree/bindings/spi/spi-bus.txt
+Optional properties:
+- nvidia,clock-always-on: Enable clock of spi always.
+
+Example:
+
+spi@7000d600 {
+	compatible = "nvidia,tegra114-spi";
+	reg = <0x7000d600 0x200>;
+	interrupts = <0 82 0x04>;
+	nvidia,dma-request-selector = <&apbdma 16>;
+	spi-max-frequency = <25000000>;
+	nvidia,clock-always-on;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "disabled";
+};
+