spi: rockchip: support "sleep" pin configuration

In the pattern of many other devices, support a system-sleep pin
configuration.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/spi-rockchip.txt

@@ -31,6 +31,10 @@ Optional Properties:
 - rx-sample-delay-ns: nanoseconds to delay after the SCLK edge before sampling
 		Rx data (may need to be fine tuned for high capacitance lines).
 		No delay (0) by default.
+- pinctrl-names: Names for the pin configuration(s); may be "default" or
+		"sleep", where the "sleep" configuration may describe the state
+		the pins should be in during system suspend. See also
+		pinctrl/pinctrl-bindings.txt.
 
 
 Example:
@@ -46,4 +50,7 @@ Example:
 		interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&cru SCLK_SPI0>, <&cru PCLK_SPI0>;
 		clock-names = "spiclk", "apb_pclk";
+		pinctrl-0 = <&spi1_pins>;
+		pinctrl-1 = <&spi1_sleep>;
+		pinctrl-names = "default", "sleep";
 	};

drivers/spi/spi-rockchip.c

@@ -17,6 +17,7 @@
 #include <linux/dmaengine.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
 #include <linux/pm_runtime.h>
@@ -843,6 +844,8 @@ static int rockchip_spi_suspend(struct device *dev)
 		clk_disable_unprepare(rs->apb_pclk);
 	}
 
+	pinctrl_pm_select_sleep_state(dev);
+
 	return ret;
 }
 
@@ -852,6 +855,8 @@ static int rockchip_spi_resume(struct device *dev)
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct rockchip_spi *rs = spi_master_get_devdata(master);
 
+	pinctrl_pm_select_default_state(dev);
+
 	if (!pm_runtime_suspended(dev)) {
 		ret = clk_prepare_enable(rs->apb_pclk);
 		if (ret < 0)