hsu: driver for Medfield High Speed UART device

This is a PCI & UART driver, which suppors both PIO and DMA mode
UART operation. It has 3 identical UART ports and one internal
DMA controller.

Current FW will export 4 pci devices for hsu: 3 uart ports and 1
dma controller, each has one IRQ line. And we need to discuss the
device model, one PCI device covering whole HSU should be a better
model, but there is a problem of how to export the 4 IRQs info

Current driver set the highest baud rate to 2746800bps, which is
easy to scale down to 115200/230400.... To suport higher baud rate,
we need add special process, change DLAB/DLH/PS/DIV/MUL registers
all together.

921600 is the highest baud rate that has been tested with Bluetooth
modem connected to HSU port 0. Will test more when there is right
BT firmware.

Current version contains several work around for A0's Silicon bugs

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/serial/Kconfig

@@ -724,6 +724,16 @@ config MRST_MAX3110_IRQ
 	help
 	  This has to be enabled after Moorestown GPIO driver is loaded
 
+config SERIAL_MFD_HSU
+	tristate "Medfield High Speed UART support"
+	depends on PCI
+	select SERIAL_CORE
+
+config SERIAL_MFD_HSU_CONSOLE
+	boolean "Medfile HSU serial console support"
+	depends on SERIAL_MFD_HSU=y
+	select SERIAL_CORE_CONSOLE
+
 config SERIAL_BFIN
 	tristate "Blackfin serial port support"
 	depends on BLACKFIN

drivers/serial/Makefile

@@ -87,3 +87,4 @@ obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
 obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
 obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
+obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o