Resurrect IT8172 IDE controller driver

Support for the IT8172 IDE controller was removed from the kernel sometime after 2.6.18. Support for the only boards that used the IT8172 was removed from the kernel after 2.6.18, as they had never compiled since 2.6.0. However, there are a couple of platforms that use this
chip: the PMC-Sierra Xiao Hu thin-client computer, which is no longer in production, and the Linksys NSS4000 Network Attached Storage box, which is based on the Xiao Hu board. I am attempting to add support for the Xiao Hu to the kernel, and this IT8172 IDE controller is the first bit of code in this effort.

This patch resurrects the IT8172 IDE controller code. I began with the 2.6.18 version of the it8172.c file, and have moved it forward so that it works with the latest version of the kernel. I have run this driver on a PMC-Sierra Xiao Hu board with the 2.6.28-rc7 kernel, and I have had no problems with it in my configuration. The attached patch applies cleanly against 2.6.28-rc7.

---
 drivers/ide/Kconfig     |    7 +
 drivers/ide/Makefile    |    1 
 drivers/ide/it8172.c    |  177 ++++++++++++++++++++++++++++++++++++++
 include/linux/pci_ids.h |    1 
 4 files changed, 186 insertions(+)

diff -uprN a/drivers/ide/Kconfig b/drivers/ide/Kconfig
@@ -524,6 +524,13 @@ config BLK_DEV_PIIX
 	  This allows the kernel to change PIO, DMA and UDMA speeds and to
 	  configure the chip to optimum performance.
 
+config BLK_DEV_IT8172
+	tristate "IT8172 IDE support"
+	select BLK_DEV_IDEDMA_PCI
+	help
+	  This driver adds support for the IDE controller on the
+	  IT8172 System Controller.
+
 config BLK_DEV_IT8213
 	tristate "IT8213 IDE support"
 	select BLK_DEV_IDEDMA_PCI

diff -uprN a/drivers/ide/Makefile b/drivers/ide/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_BLK_DEV_SC1200)		+= sc1200.
 obj-$(CONFIG_BLK_DEV_CY82C693)		+= cy82c693.o
 obj-$(CONFIG_BLK_DEV_DELKIN)		+= delkin_cb.o
 obj-$(CONFIG_BLK_DEV_HPT366)		+= hpt366.o
+obj-$(CONFIG_BLK_DEV_IT8172)		+= it8172.o
 obj-$(CONFIG_BLK_DEV_IT8213)		+= it8213.o
 obj-$(CONFIG_BLK_DEV_IT821X)		+= it821x.o
 obj-$(CONFIG_BLK_DEV_JMICRON)		+= jmicron.o

diff -uprN a/include/linux/pci_ids.h b/include/linux/pci_ids.h
@@ -1658,6 +1658,7 @@
 #define PCI_VENDOR_ID_ROCKWELL		0x127A
 
 #define PCI_VENDOR_ID_ITE		0x1283
+#define PCI_DEVICE_ID_ITE_8172		0x8172
 #define PCI_DEVICE_ID_ITE_8211		0x8211
 #define PCI_DEVICE_ID_ITE_8212		0x8212
 #define PCI_DEVICE_ID_ITE_8213		0x8213