OxPCIe uart: Split PCI bridge control

None of the PCI bridge management here is specific to the PCI UART
device/function. Also the Kconfig variable defaults are not globally
valid, fill samsung/lumpy with working values.

Change-Id: Id22631412379af1d6bf62c996357d36d7ec47ca3
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5237
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

9 files changed, 183 insertions, 135 deletions

diff --git a/src/console/console.c b/src/console/console.c
index 9e9e4e2..348264d 100644
--- a/src/console/console.c
+++ b/src/console/console.c
@@ -28,6 +28,11 @@
 #include <arch/hlt.h>
 #include <arch/io.h>
 
+#if CONFIG_EARLY_PCI_BRIDGE
+/* FIXME: ROMCC chokes on PCI headers. */
+#include <device/pci.h>
+#endif
+
 #ifndef __PRE_RAM__
 #include <string.h>
 #include <types.h>
@@ -40,6 +45,9 @@ void console_init(void)
 	if(get_option(&console_loglevel, "debug_level") != CB_SUCCESS)
 		console_loglevel=CONFIG_DEFAULT_CONSOLE_LOGLEVEL;
 
+#if CONFIG_EARLY_PCI_BRIDGE
+	pci_early_bridge_init();
+#endif
 	for(driver = console_drivers; driver < econsole_drivers; driver++) {
 		if (!driver->init)
 			continue;
@@ -101,8 +109,8 @@ void console_init(void)
 #if defined(__BOOT_BLOCK__) && CONFIG_BOOTBLOCK_CONSOLE || \
     !defined(__BOOT_BLOCK__) && CONFIG_EARLY_CONSOLE
 
-#if CONFIG_DRIVERS_OXFORD_OXPCIE
-	oxford_init();
+#if CONFIG_EARLY_PCI_BRIDGE
+	pci_early_bridge_init();
 #endif
 #if CONFIG_CONSOLE_SERIAL
 	uart_init();
diff --git a/src/device/Kconfig b/src/device/Kconfig
index eaa0c04..932b4de 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -237,6 +237,35 @@ config PCIEXP_ASPM
 config PCI_BUS_SEGN_BITS
 	int
 	default 0
+
+config EARLY_PCI_BRIDGE
+	bool "Early PCI bridge"
+	depends on PCI
+	default n
+	help
+	  While coreboot is executing code from ROM, the coreboot resource
+	  allocator has not been running yet. Hence PCI devices living behind
+	  a bridge are not yet visible to the system.
+
+	  This option enables static configuration for a single pre-defined
+	  PCI bridge function on bus 0.
+
+if EARLY_PCI_BRIDGE
+
+config EARLY_PCI_BRIDGE_DEVICE
+	hex "bridge device"
+	default 0x0
+
+config EARLY_PCI_BRIDGE_FUNCTION
+	hex "bridge function"
+	default 0x0
+
+config EARLY_PCI_MMIO_BASE
+	hex "MMIO window base"
+	default 0x0
+
+endif # EARLY_PCI_BRIDGE
+
 endmenu
 
 menu "VGA BIOS"
diff --git a/src/device/Makefile.inc b/src/device/Makefile.inc
index ce412b7..bd41b12 100644
--- a/src/device/Makefile.inc
+++ b/src/device/Makefile.inc
@@ -11,6 +11,7 @@ ramstage-$(CONFIG_CARDBUS_PLUGIN_SUPPORT) += cardbus_device.c
 ramstage-$(CONFIG_AZALIA_PLUGIN_SUPPORT) += azalia_device.c
 ramstage-$(CONFIG_ARCH_X86) += pnp_device.c
 ramstage-$(CONFIG_PCI) += pci_ops.c
+ramstage-$(CONFIG_PCI) += pci_early.c
 ramstage-y += smbus_ops.c
 
 romstage-y += device_romstage.c
diff --git a/src/device/pci_early.c b/src/device/pci_early.c
index c15a4d0..e31287e 100644
--- a/src/device/pci_early.c
+++ b/src/device/pci_early.c
@@ -1,6 +1,8 @@
 /*
  * This file is part of the coreboot project.
  *
+ * Copyright (C) 2011 Google Inc
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; version 2 of the License.
@@ -15,9 +17,14 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
  */
 
+#define __SIMPLE_DEVICE__
+
 #include <arch/io.h>
 #include <device/pci.h>
 #include <device/pci_def.h>
+#include <delay.h>
+
+#ifdef __PRE_RAM__
 
 unsigned pci_find_next_capability(device_t dev, unsigned cap, unsigned last)
 {
@@ -66,3 +73,100 @@ unsigned pci_find_capability(device_t dev, unsigned cap)
 {
 	return pci_find_next_capability(dev, cap, 0);
 }
+#endif
+
+
+#if CONFIG_EARLY_PCI_BRIDGE
+
+static void pci_bridge_reset_secondary(device_t p2p_bridge)
+{
+	u16 reg16;
+
+	/* First we reset the secondary bus. */
+	reg16 = pci_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL);
+	reg16 |= (1 << 6); /* SRESET */
+	pci_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16);
+
+	/* Assume we don't have to wait here forever */
+
+	/* Read back and clear reset bit. */
+	reg16 = pci_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL);
+	reg16 &= ~(1 << 6); /* SRESET */
+	pci_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16);
+}
+
+static void pci_bridge_set_secondary(device_t p2p_bridge, u8 secondary)
+{
+	/* Disable config transaction forwarding. */
+	pci_write_config8(p2p_bridge, PCI_SECONDARY_BUS, 0x00);
+	pci_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, 0x00);
+	/* Enable config transaction forwarding. */
+	pci_write_config8(p2p_bridge, PCI_SECONDARY_BUS, secondary);
+	pci_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, secondary);
+}
+
+static void pci_bridge_set_mmio(device_t p2p_bridge, u32 base, u32 size)
+{
+	u16 reg16;
+
+	/* Disable MMIO window behind the bridge. */
+	reg16 = pci_read_config16(p2p_bridge, PCI_COMMAND);
+	reg16 &= ~PCI_COMMAND_MEMORY;
+	pci_write_config16(p2p_bridge, PCI_COMMAND, reg16);
+	pci_write_config32(p2p_bridge, PCI_MEMORY_BASE, 0x10);
+
+	if (!size)
+		return;
+
+	/* Enable MMIO window behind the bridge. */
+	pci_write_config32(p2p_bridge, PCI_MEMORY_BASE,
+		((base + size - 1) & 0xfff00000) | ((base >> 16) & 0xfff0));
+
+	reg16 = pci_read_config16(p2p_bridge, PCI_COMMAND);
+	reg16 |= PCI_COMMAND_MEMORY;
+	pci_write_config16(p2p_bridge, PCI_COMMAND, reg16);
+}
+
+void pci_early_bridge_init(void)
+{
+	int timeout, ret = -1;
+
+	/* No PCI-to-PCI bridges are enabled yet, so the one we try to
+	 * configure must have its primary on bus 0.
+	 */
+	pci_devfn_t p2p_bridge = PCI_DEV(0, CONFIG_EARLY_PCI_BRIDGE_DEVICE,
+		CONFIG_EARLY_PCI_BRIDGE_FUNCTION);
+
+	/* Secondary bus number is mostly irrelevant as we disable
+	 * configuration transactions right after the probe.
+	 */
+	u8 secondary = 15;
+	u8 dev = 0;
+	u32 mmio_base = CONFIG_EARLY_PCI_MMIO_BASE;
+
+	/* Enable configuration and MMIO over bridge. */
+	pci_bridge_reset_secondary(p2p_bridge);
+	pci_bridge_set_secondary(p2p_bridge, secondary);
+	pci_bridge_set_mmio(p2p_bridge, mmio_base, 0x4000);
+
+	for (timeout = 20000; timeout; timeout--) {
+		u32 id = pci_read_config32(PCI_DEV(secondary, dev, 0), PCI_VENDOR_ID);
+		if (id != 0 && id != 0xffffffff && id != 0xffff0001)
+			break;
+		udelay(10);
+	}
+
+	if (timeout != 0)
+		ret = pci_early_device_probe(secondary, dev, mmio_base);
+
+	/* Disable MMIO window if we found no suitable device. */
+	if (ret)
+		pci_bridge_set_mmio(p2p_bridge, 0, 0);
+
+	/* Resource allocator will reconfigure bridges and secondary bus
+	 * number may change. Thus early device cannot reliably use config
+	 * transactions from here on, so we may as well disable them.
+	 */
+	pci_bridge_set_secondary(p2p_bridge, 0);
+}
+#endif /* CONFIG_EARLY_PCI_BRIDGE */
diff --git a/src/drivers/oxford/oxpcie/Kconfig b/src/drivers/oxford/oxpcie/Kconfig
index 5ad42aa..c2ea7b6 100644
--- a/src/drivers/oxford/oxpcie/Kconfig
+++ b/src/drivers/oxford/oxpcie/Kconfig
@@ -1,68 +1,10 @@
 config DRIVERS_OXFORD_OXPCIE
 	bool "Oxford OXPCIe952"
 	default n
+	depends on PCI
 	select DRIVERS_UART_8250MEM
+	select EARLY_PCI_BRIDGE
 	help
 	  Support for Oxford OXPCIe952 serial port PCIe cards.
 	  Currently only devices with the vendor ID 0x1415 and device ID
-	  0xc158 will work.
-	  NOTE: Right now you have to set the base address of your OXPCIe952
-	  card to exactly the value that the device allocator would set them
-	  later on, or serial console functionality will stop as soon as the
-	  resource allocator assigns a new base address to the device.
-
-config OXFORD_OXPCIE_BRIDGE_BUS
-	hex "OXPCIe's PCIe bridge bus number"
-	default 0x0
-	depends on DRIVERS_OXFORD_OXPCIE
-	help
-	  While coreboot is executing code from ROM, the coreboot resource
-	  allocator has not been running yet. Hence PCI devices living behind
-	  a bridge are not yet visible to the system. In order to use an
-	  OXPCIe952 based PCIe card, coreboot has to set up the PCIe bridge
-	  that controls the OXPCIe952 controller first.
-
-config OXFORD_OXPCIE_BRIDGE_DEVICE
-	hex "OXPCIe's PCIe bridge device number"
-	default 0x1c
-	depends on DRIVERS_OXFORD_OXPCIE
-	help
-	  While coreboot is executing code from ROM, the coreboot resource
-	  allocator has not been running yet. Hence PCI devices living behind
-	  a bridge are not yet visible to the system. In order to use an
-	  OXPCIe952 based PCIe card, coreboot has to set up the PCIe bridge
-	  that controls the OXPCIe952 controller first.
-
-config OXFORD_OXPCIE_BRIDGE_FUNCTION
-	hex "OXPCIe's PCIe bridge function number"
-	default 0x2
-	depends on DRIVERS_OXFORD_OXPCIE
-	help
-	  While coreboot is executing code from ROM, the coreboot resource
-	  allocator has not been running yet. Hence PCI devices living behind
-	  a bridge are not yet visible to the system. In order to use an
-	  OXPCIe952 based PCIe card, coreboot has to set up the PCIe bridge
-	  that controls the OXPCIe952 controller first.
-
-config OXFORD_OXPCIE_BRIDGE_SUBORDINATE
-	hex "OXPCIe's PCIe bridge subordinate bus"
-	default 0x3
-	depends on DRIVERS_OXFORD_OXPCIE
-	help
-	  While coreboot is executing code from ROM, the coreboot resource
-	  allocator has not been running yet. Hence PCI devices living behind
-	  a bridge are not yet visible to the system. In order to use an
-	  OXPCIe952 based PCIe card, coreboot has to set up the PCIe bridge
-	  that controls the OXPCIe952 controller first.
-
-config OXFORD_OXPCIE_BASE_ADDRESS
-	hex "Base address for rom stage console"
-	default 0xe0400000
-	depends on DRIVERS_OXFORD_OXPCIE
-	help
-	  While coreboot is executing code from ROM, the coreboot resource
-	  allocator has not been running yet. Hence PCI devices living behind
-	  a bridge are not yet visible to the system. In order to use an
-	  OXPCIe952 based PCIe card, coreboot has to set up a temporary address
-	  for the OXPCIe952 controller.
-
+	  0xc158 or 0xc11b will work.
diff --git a/src/drivers/oxford/oxpcie/oxpcie_early.c b/src/drivers/oxford/oxpcie/oxpcie_early.c
index 7de9da6..b81fa89 100644
--- a/src/drivers/oxford/oxpcie/oxpcie_early.c
+++ b/src/drivers/oxford/oxpcie/oxpcie_early.c
@@ -23,101 +23,53 @@
 #include <stddef.h>
 #include <arch/io.h>
 #include <arch/early_variables.h>
-#include <delay.h>
 #include <boot/coreboot_tables.h>
 #include <console/uart.h>
 #include <device/pci.h>
 #include <device/pci_def.h>
 
 static unsigned int oxpcie_present CAR_GLOBAL;
-static ROMSTAGE_CONST u32 uart0_base = CONFIG_OXFORD_OXPCIE_BASE_ADDRESS + 0x1000;
-static ROMSTAGE_CONST u32 uart1_base = CONFIG_OXFORD_OXPCIE_BASE_ADDRESS + 0x2000;
+static ROMSTAGE_CONST u32 uart0_base = CONFIG_EARLY_PCI_MMIO_BASE + 0x1000;
+static ROMSTAGE_CONST u32 uart1_base = CONFIG_EARLY_PCI_MMIO_BASE + 0x2000;
 
-#define PCIE_BRIDGE \
-	PCI_DEV(CONFIG_OXFORD_OXPCIE_BRIDGE_BUS, \
-		CONFIG_OXFORD_OXPCIE_BRIDGE_DEVICE, \
-		CONFIG_OXFORD_OXPCIE_BRIDGE_FUNCTION)
-
-#define OXPCIE_DEVICE \
-	PCI_DEV(CONFIG_OXFORD_OXPCIE_BRIDGE_SUBORDINATE, 0, 0)
-
-#define OXPCIE_DEVICE_3 \
-	PCI_DEV(CONFIG_OXFORD_OXPCIE_BRIDGE_SUBORDINATE, 0, 3)
-
-static void oxpcie_init_bridge(void)
+int pci_early_device_probe(u8 bus, u8 dev, u32 mmio_base)
 {
-	u16 reg16;
-
-	/* First we reset the secondary bus */
-	reg16 = pci_read_config16(PCIE_BRIDGE, PCI_BRIDGE_CONTROL);
-	reg16 |= (1 << 6); /* SRESET */
-	pci_write_config16(PCIE_BRIDGE, PCI_BRIDGE_CONTROL, reg16);
-
-	/* Assume we don't have to wait here forever */
+	pci_devfn_t device = PCI_DEV(bus, dev, 0);
 
-	/* Read back and clear reset bit. */
-	reg16 = pci_read_config16(PCIE_BRIDGE, PCI_BRIDGE_CONTROL);
-	reg16 &= ~(1 << 6); /* SRESET */
-	pci_write_config16(PCIE_BRIDGE, PCI_BRIDGE_CONTROL, reg16);
-
-	/* Set up subordinate bus number */
-	pci_write_config8(PCIE_BRIDGE, PCI_SECONDARY_BUS, 0x00);
-	pci_write_config8(PCIE_BRIDGE, PCI_SUBORDINATE_BUS, 0x00);
-	pci_write_config8(PCIE_BRIDGE, PCI_SECONDARY_BUS,
-			CONFIG_OXFORD_OXPCIE_BRIDGE_SUBORDINATE);
-	pci_write_config8(PCIE_BRIDGE, PCI_SUBORDINATE_BUS,
-			CONFIG_OXFORD_OXPCIE_BRIDGE_SUBORDINATE);
-
-	/* Memory window for the OXPCIe952 card */
-	// XXX is the calculation of base and limit correct?
-	pci_write_config32(PCIE_BRIDGE, PCI_MEMORY_BASE,
-			((CONFIG_OXFORD_OXPCIE_BASE_ADDRESS & 0xffff0000) |
-			((CONFIG_OXFORD_OXPCIE_BASE_ADDRESS >> 16) & 0xff00)));
-
-	/* Enable memory access through bridge */
-	reg16 = pci_read_config16(PCIE_BRIDGE, PCI_COMMAND);
-	reg16 |= PCI_COMMAND_MEMORY;
-	pci_write_config16(PCIE_BRIDGE, PCI_COMMAND, reg16);
-
-	u32 timeout = 20000; // Timeout in 10s of microseconds.
-	u32 id = 0;
-	for (;;) {
-		id = pci_read_config32(OXPCIE_DEVICE, PCI_VENDOR_ID);
-		if (!timeout-- || (id != 0 && id != 0xffffffff))
-			break;
-		udelay(10);
-	}
-
-	u32 device = OXPCIE_DEVICE; /* unknown default */
+	u32 id = pci_read_config32(device, PCI_VENDOR_ID);
 	switch (id) {
-	case 0xc1181415: /* e.g. Startech PEX1S1PMINI */
+	case 0xc1181415: /* e.g. Startech PEX1S1PMINI function 0 */
 		/* On this device function 0 is the parallel port, and
 		 * function 3 is the serial port. So let's go look for
 		 * the UART.
 		 */
-		id = pci_read_config32(OXPCIE_DEVICE_3, PCI_VENDOR_ID);
+		device = PCI_DEV(bus, dev, 3);
+		id = pci_read_config32(device, PCI_VENDOR_ID);
 		if (id != 0xc11b1415)
-			return;
-		device = OXPCIE_DEVICE_3;
+			return -1;
 		break;
+	case 0xc11b1415: /* e.g. Startech PEX1S1PMINI function 3 */
 	case 0xc1581415: /* e.g. Startech MPEX2S952 */
-		device = OXPCIE_DEVICE;
 		break;
 	default:
 		/* No UART here. */
-		return;
+		return -1;
 	}
 
+	/* Sanity-check, we assume fixed location. */
+	if (mmio_base != CONFIG_EARLY_PCI_MMIO_BASE)
+		return -1;
+
 	/* Setup base address on device */
-	pci_write_config32(device, PCI_BASE_ADDRESS_0,
-				CONFIG_OXFORD_OXPCIE_BASE_ADDRESS);
+	pci_write_config32(device, PCI_BASE_ADDRESS_0, mmio_base);
 
 	/* Enable memory on device */
-	reg16 = pci_read_config16(device, PCI_COMMAND);
+	u16 reg16 = pci_read_config16(device, PCI_COMMAND);
 	reg16 |= PCI_COMMAND_MEMORY;
 	pci_write_config16(device, PCI_COMMAND, reg16);
 
 	car_set_var(oxpcie_present, 1);
+	return 0;
 }
 
 static int oxpcie_uart_active(void)
@@ -157,8 +109,3 @@ unsigned int uart_platform_refclk(void)
 {
 	return 62500000;
 }
-
-void oxford_init(void)
-{
-	oxpcie_init_bridge();
-}
diff --git a/src/include/console/uart.h b/src/include/console/uart.h
index ed922f1..68abf6f 100644
--- a/src/include/console/uart.h
+++ b/src/include/console/uart.h
@@ -54,7 +54,6 @@ static inline void *uart_platform_baseptr(int idx)
 }
 #endif
 
-void oxford_init(void);
 void oxford_remap(unsigned int new_base);
 
 #endif /* CONSOLE_UART_H */
diff --git a/src/include/device/pci.h b/src/include/device/pci.h
index 29d988f..f729c27 100644
--- a/src/include/device/pci.h
+++ b/src/include/device/pci.h
@@ -102,6 +102,8 @@ static inline const struct pci_operations *ops_pci(device_t dev)
 
 unsigned pci_find_next_capability(device_t dev, unsigned cap, unsigned last);
 unsigned pci_find_capability(device_t dev, unsigned cap);
+void pci_early_bridge_init(void);
+int pci_early_device_probe(u8 bus, u8 dev, u32 mmio_base);
 
 #endif /* CONFIG_PCI */
 
diff --git a/src/mainboard/samsung/lumpy/Kconfig b/src/mainboard/samsung/lumpy/Kconfig
index 032b4b5..500427a 100644
--- a/src/mainboard/samsung/lumpy/Kconfig
+++ b/src/mainboard/samsung/lumpy/Kconfig
@@ -46,4 +46,20 @@ config MAINBOARD_POWER_ON_AFTER_POWER_FAIL
 	bool
 	default n
 
+if EARLY_PCI_BRIDGE
+
+config EARLY_PCI_BRIDGE_DEVICE
+	hex
+	default 0x1c
+
+config EARLY_PCI_BRIDGE_FUNCTION
+	hex
+	default 0x0
+
+config EARLY_PCI_MMIO_BASE
+	hex
+	default 0xe0400000
+
+endif
+
 endif # BOARD_SAMSUNG_LUMPY