fbdev: Add GXT4000P and GXT6500P support to the gxt4500 driver

I'm reviving an old patch from 2009 that adds support for GXT4000P and GXT6500P
adapter to the gxt4500 driver.

See threads at http://marc.info/?l=linux-fbdev-devel&m=124345080216952&w=2
and https://lists.ozlabs.org/pipermail/linuxppc-dev/2009-June/072672.html
for more details.

This patch adds support for GXT4000P and GXT6500P cards found on some
IBM pSeries machines.
GXT4000P/6000P and GXT4500P/6500P  couples are  identical from
software's point of view and are based on the same  Raster Engine
(RC1000), except for a different reference clock for the PLL.
GXT6x00P models are equipped with an additional Geometry Engine
(GT1000) but this driver doesn't use it.
Signed-off-by: Nico Macrionitis <acrux@cruxppc.org>
Signed-off-by: Giuseppe Coviello <cjg@cruxppc.org>
Tested-by: Dan Horák <dan@danny.cz>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/video/Kconfig

@@ -2140,14 +2140,16 @@ config FB_UDL
 	  To compile as a module, choose M here: the module name is udlfb.
 
 config FB_IBM_GXT4500
-	tristate "Framebuffer support for IBM GXT4500P adaptor"
+	tristate "Framebuffer support for IBM GXT4000P/4500P/6000P/6500P adaptors"
 	depends on FB && PPC
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
 	---help---
-	  Say Y here to enable support for the IBM GXT4500P display
-	  adaptor, found on some IBM System P (pSeries) machines.
+	  Say Y here to enable support for the IBM GXT4000P/6000P and
+	  GXT4500P/6500P display adaptor based on Raster Engine RC1000,
+	  found on some IBM System P (pSeries) machines. This driver
+	  doesn't use Geometry Engine GT1000.
 
 config FB_PS3
 	tristate "PS3 GPU framebuffer driver"

drivers/video/gxt4500.c

 /*
- * Frame buffer device for IBM GXT4500P and GXT6000P display adaptors
+ * Frame buffer device for IBM GXT4500P/6500P and GXT4000P/6000P
+ * display adaptors
  *
  * Copyright (C) 2006 Paul Mackerras, IBM Corp. <paulus@samba.org>
  */
@@ -14,6 +15,8 @@
 #include <linux/string.h>
 
 #define PCI_DEVICE_ID_IBM_GXT4500P	0x21c
+#define PCI_DEVICE_ID_IBM_GXT6500P	0x21b
+#define PCI_DEVICE_ID_IBM_GXT4000P	0x16e
 #define PCI_DEVICE_ID_IBM_GXT6000P	0x170
 
 /* GXT4500P registers */
@@ -173,6 +176,8 @@ static const struct fb_videomode defaultmode __devinitconst = {
 /* List of supported cards */
 enum gxt_cards {
 	GXT4500P,
+	GXT6500P,
+	GXT4000P,
 	GXT6000P
 };
 
@@ -182,6 +187,8 @@ static const struct cardinfo {
 	const char *cardname;
 } cardinfo[] = {
 	[GXT4500P] = { .refclk_ps = 9259, .cardname = "IBM GXT4500P" },
+	[GXT6500P] = { .refclk_ps = 9259, .cardname = "IBM GXT6500P" },
+	[GXT4000P] = { .refclk_ps = 40000, .cardname = "IBM GXT4000P" },
 	[GXT6000P] = { .refclk_ps = 40000, .cardname = "IBM GXT6000P" },
 };
 
@@ -736,6 +743,10 @@ static void __devexit gxt4500_remove(struct pci_dev *pdev)
 static const struct pci_device_id gxt4500_pci_tbl[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4500P),
 	  .driver_data = GXT4500P },
+	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6500P),
+	  .driver_data = GXT6500P },
+	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4000P),
+	  .driver_data = GXT4000P },
 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6000P),
 	  .driver_data = GXT6000P },
 	{ 0 }
@@ -768,7 +779,7 @@ static void __exit gxt4500_exit(void)
 module_exit(gxt4500_exit);
 
 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
-MODULE_DESCRIPTION("FBDev driver for IBM GXT4500P/6000P");
+MODULE_DESCRIPTION("FBDev driver for IBM GXT4500P/6500P and GXT4000P/6000P");
 MODULE_LICENSE("GPL");
 module_param(mode_option, charp, 0);
 MODULE_PARM_DESC(mode_option, "Specify resolution as \"<xres>x<yres>[-<bpp>][@<refresh>]\"");