X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=arch%2Fx86%2Fcpu%2Fqueensbay%2Ftnc.c;h=b226e4c5fd623694aeaeafc9387810cfec2554d9;hb=d19c90747d8975a523489f863984c521ae72ce39;hp=b46a7e996f8e5a0414b552f27edce514dc1131bc;hpb=1131d4e22cf8f13d0dabaad7f1b84d9baffdfbd6;p=u-boot

diff --git a/arch/x86/cpu/queensbay/tnc.c b/arch/x86/cpu/queensbay/tnc.c
index b46a7e996f..b226e4c5fd 100644
--- a/arch/x86/cpu/queensbay/tnc.c
+++ b/arch/x86/cpu/queensbay/tnc.c
@@ -5,49 +5,113 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <pci.h>
 #include <asm/io.h>
-#include <asm/pci.h>
+#include <asm/irq.h>
 #include <asm/post.h>
 #include <asm/arch/device.h>
-#include <asm/arch/irq.h>
+#include <asm/arch/tnc.h>
 #include <asm/fsp/fsp_support.h>
 #include <asm/processor.h>
 
-static void unprotect_spi_flash(void)
+static int __maybe_unused disable_igd(void)
 {
-	u32 bc;
+	struct udevice *igd, *sdvo;
+	int ret;
+
+	ret = dm_pci_bus_find_bdf(TNC_IGD, &igd);
+	if (ret)
+		return ret;
+	if (!igd)
+		return 0;
+
+	ret = dm_pci_bus_find_bdf(TNC_SDVO, &sdvo);
+	if (ret)
+		return ret;
+	if (!sdvo)
+		return 0;
+
+	/*
+	 * According to Atom E6xx datasheet, setting VGA Disable (bit17)
+	 * of Graphics Controller register (offset 0x50) prevents IGD
+	 * (D2:F0) from reporting itself as a VGA display controller
+	 * class in the PCI configuration space, and should also prevent
+	 * it from responding to VGA legacy memory range and I/O addresses.
+	 *
+	 * However test result shows that with just VGA Disable bit set and
+	 * a PCIe graphics card connected to one of the PCIe controllers on
+	 * the E6xx, accessing the VGA legacy space still causes system hang.
+	 * After a number of attempts, it turns out besides VGA Disable bit,
+	 * the SDVO (D3:F0) device should be disabled to make it work.
+	 *
+	 * To simplify, use the Function Disable register (offset 0xc4)
+	 * to disable both IGD (D2:F0) and SDVO (D3:F0) devices. Now these
+	 * two devices will be completely disabled (invisible in the PCI
+	 * configuration space) unless a system reset is performed.
+	 */
+	dm_pci_write_config32(igd, IGD_FD, FUNC_DISABLE);
+	dm_pci_write_config32(sdvo, IGD_FD, FUNC_DISABLE);
+
+	/*
+	 * After setting the function disable bit, IGD and SDVO devices will
+	 * disappear in the PCI configuration space. This however creates an
+	 * inconsistent state from a driver model PCI controller point of view,
+	 * as these two PCI devices are still attached to its parent's child
+	 * device list as maintained by the driver model. Some driver model PCI
+	 * APIs like dm_pci_find_class(), are referring to the list to speed up
+	 * the finding process instead of re-enumerating the whole PCI bus, so
+	 * it gets the stale cached data which is wrong.
+	 *
+	 * Note x86 PCI enueration normally happens twice, in pre-relocation
+	 * phase and post-relocation. One option might be to call disable_igd()
+	 * in one of the pre-relocation initialization hooks so that it gets
+	 * disabled in the first round, and when it comes to the second round
+	 * driver model PCI will construct a correct list. Unfortunately this
+	 * does not work as Intel FSP is used on this platform to perform low
+	 * level initialization, and fsp_init_phase_pci() is called only once
+	 * in the post-relocation phase. If we disable IGD and SDVO devices,
+	 * fsp_init_phase_pci() simply hangs and never returns.
+	 *
+	 * So the only option we have is to manually remove these two devices.
+	 */
+	ret = device_remove(igd);
+	if (ret)
+		return ret;
+	ret = device_unbind(igd);
+	if (ret)
+		return ret;
+	ret = device_remove(sdvo);
+	if (ret)
+		return ret;
+	ret = device_unbind(sdvo);
+	if (ret)
+		return ret;
 
-	bc = x86_pci_read_config32(TNC_LPC, 0xd8);
-	bc |= 0x1;	/* unprotect the flash */
-	x86_pci_write_config32(TNC_LPC, 0xd8, bc);
+	return 0;
 }
 
 int arch_cpu_init(void)
 {
-	struct pci_controller *hose;
 	int ret;
 
 	post_code(POST_CPU_INIT);
-#ifdef CONFIG_SYS_X86_TSC_TIMER
-	timer_set_base(rdtsc());
-#endif
 
 	ret = x86_cpu_init_f();
 	if (ret)
 		return ret;
 
-	ret = pci_early_init_hose(&hose);
-	if (ret)
-		return ret;
-
-	unprotect_spi_flash();
-
 	return 0;
 }
 
-int arch_misc_init(void)
+int arch_early_init_r(void)
 {
-	pirq_init();
+	int ret = 0;
 
-	return 0;
+#ifdef CONFIG_DISABLE_IGD
+	ret = disable_igd();
+#endif
+
+	return ret;
 }