x86: Access the VGA ROM when needed

Add code to the generic pci_rom file to access the VGA ROM in PCI space
when needed.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/pci/pci_auto.c

@@ -11,7 +11,7 @@
  */
 
 #include <common.h>
-
+#include <errno.h>
 #include <pci.h>
 
 #undef DEBUG
@@ -191,6 +191,32 @@ void pciauto_setup_device(struct pci_controller *hose,
 	pci_hose_write_config_byte(hose, dev, PCI_LATENCY_TIMER, 0x80);
 }
 
+int pciauto_setup_rom(struct pci_controller *hose, pci_dev_t dev)
+{
+	pci_addr_t bar_value;
+	pci_size_t bar_size;
+	u32 bar_response;
+	u16 cmdstat = 0;
+
+	pci_hose_write_config_dword(hose, dev, PCI_ROM_ADDRESS, 0xfffffffe);
+	pci_hose_read_config_dword(hose, dev, PCI_ROM_ADDRESS, &bar_response);
+	if (!bar_response)
+		return -ENOENT;
+
+	bar_size = -(bar_response & ~1);
+	DEBUGF("PCI Autoconfig: ROM, size=%#x, ", bar_size);
+	if (pciauto_region_allocate(hose->pci_mem, bar_size, &bar_value) == 0) {
+		pci_hose_write_config_dword(hose, dev, PCI_ROM_ADDRESS,
+					    bar_value);
+	}
+	DEBUGF("\n");
+	pci_hose_read_config_word(hose, dev, PCI_COMMAND, &cmdstat);
+	cmdstat |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
+	pci_hose_write_config_word(hose, dev, PCI_COMMAND, cmdstat);
+
+	return 0;
+}
+
 void pciauto_prescan_setup_bridge(struct pci_controller *hose,
 					 pci_dev_t dev, int sub_bus)
 {

drivers/pci/pci_rom.c

@@ -81,7 +81,12 @@ static int pci_rom_probe(pci_dev_t dev, uint class,
 #ifdef CONFIG_X86_OPTION_ROM_ADDR
 	rom_address = CONFIG_X86_OPTION_ROM_ADDR;
 #else
-	pci_write_config_dword(dev, PCI_ROM_ADDRESS, (u32)PCI_ROM_ADDRESS_MASK);
+
+	if (pciauto_setup_rom(pci_bus_to_hose(PCI_BUS(dev)), dev)) {
+		debug("Cannot find option ROM\n");
+		return -ENOENT;
+	}
+
 	pci_read_config_dword(dev, PCI_ROM_ADDRESS, &rom_address);
 	if (rom_address == 0x00000000 || rom_address == 0xffffffff) {
 		debug("%s: rom_address=%x\n", __func__, rom_address);

include/pci.h

@@ -697,5 +697,14 @@ void pci_write_bar32(struct pci_controller *hose, pci_dev_t dev, int barnum,
  * */
 u32 pci_read_bar32(struct pci_controller *hose, pci_dev_t dev, int barnum);
 
+/**
+ * pciauto_setup_rom() - Set up access to a device ROM
+ *
+ * @hose:	PCI hose to use
+ * @dev:	PCI device to adjust
+ * @return 0 if done, -ve on error
+ */
+int pciauto_setup_rom(struct pci_controller *hose, pci_dev_t dev);
+
 #endif /* __ASSEMBLY__ */
 #endif /* _PCI_H */