imx-drm: Add mx6 hdmi transmitter support

Add mx6 hdmi transmitter support.

Original work has been done by Sascha Hauer and Tony Prisk.
Special thanks to Russell King for his carefully review, many bug fixes and
testing of the mx6 HDMI driver.

Tested on the following boards:
- mx6q sabresd
- mx6dl sabresd
- mx6solo wandboard
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/imx-drm/Kconfig

@@ -53,3 +53,9 @@ config DRM_IMX_IPUV3
 	depends on DRM_IMX_IPUV3_CORE
 	help
 	  Choose this if you have a i.MX5 or i.MX6 processor.
+
+config DRM_IMX_HDMI
+	tristate "Freescale i.MX DRM HDMI"
+	depends on DRM_IMX
+	help
+	  Choose this if you want to use HDMI on i.MX6.

drivers/staging/imx-drm/Makefile

@@ -11,3 +11,4 @@ obj-$(CONFIG_DRM_IMX_IPUV3_CORE) += ipu-v3/
 
 imx-ipuv3-crtc-objs  := ipuv3-crtc.o ipuv3-plane.o
 obj-$(CONFIG_DRM_IMX_IPUV3)	+= imx-ipuv3-crtc.o
+obj-$(CONFIG_DRM_IMX_HDMI) += imx-hdmi.o

include/linux/mfd/syscon/imx6q-iomuxc-gpr.h

@@ -212,6 +212,7 @@
 #define IMX6Q_GPR3_MIPI_MUX_CTL_IPU1_DI1	(0x1 << 4)
 #define IMX6Q_GPR3_MIPI_MUX_CTL_IPU2_DI0	(0x2 << 4)
 #define IMX6Q_GPR3_MIPI_MUX_CTL_IPU2_DI1	(0x3 << 4)
+#define IMX6Q_GPR3_HDMI_MUX_CTL_SHIFT		2
 #define IMX6Q_GPR3_HDMI_MUX_CTL_MASK		(0x3 << 2)
 #define IMX6Q_GPR3_HDMI_MUX_CTL_IPU1_DI0	(0x0 << 2)
 #define IMX6Q_GPR3_HDMI_MUX_CTL_IPU1_DI1	(0x1 << 2)