[U-Boot] [PATCH 1/4] Implement "pci enum" command for CONFIG_DM_PCI

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

With CONFIG_DM_PCI enabled, PCI buses are not enumerated at boot, as they
are without that config option enabled. No command exists to enumerate the
PCI buses. Hence, unless some board-specific code causes PCI enumeration,
PCI-based Ethernet devices are not detected, and network access is not
available.

This patch implements "pci enum" in the CONFIG_DM_PCI case, thus giving a
mechanism whereby PCI can be enumerated.

do_pci()'s handling of case 'e' is moved into a single location before the
dev variable is assigned, in order to skip calculation of dev. The enum
sub-command doesn't need the dev value, and skipping its calculation
avoids an irrelevant error being printed.

Using a command to initialize PCI like this has a disadvantage relative to
enumerating PCI at boot. In particular, Ethernet devices are not probed
during PCI enumeration, but only when used. This defers setting variables
such as ethact, ethaddr, etc. until the first network-related command is
executed. Hopefully this will not cause further issues. Perhaps in the
long term, we need a "net start/enum" command too?

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
This series naturally needs to be applied in order in a single branch.
This series depends on all previous applied test/py patches.

 common/cmd_pci.c         | 18 +++++-------------
 drivers/pci/pci-uclass.c | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/common/cmd_pci.c b/common/cmd_pci.c
index 8094d3380fbd..2f4978af9fe3 100644
--- a/common/cmd_pci.c
+++ b/common/cmd_pci.c
@@ -578,9 +578,10 @@ static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		if ((bdf = get_pci_dev(argv[2])) == -1)
 			return 1;
 		break;
-#ifdef CONFIG_CMD_PCI_ENUM
+#if defined(CONFIG_CMD_PCI_ENUM) || defined(CONFIG_DM_PCI)
 	case 'e':
-		break;
+		pci_init();
+		return 0;
 #endif
 	default:		/* scan bus */
 		value = 1; /* short listing */
@@ -621,15 +622,6 @@ static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		break;
 	case 'd':		/* display */
 		return pci_cfg_display(dev, addr, size, value);
-#ifdef CONFIG_CMD_PCI_ENUM
-	case 'e':
-# ifdef CONFIG_DM_PCI
-		printf("This command is not yet supported with driver model\n");
-# else
-		pci_init();
-# endif
-		break;
-#endif
 	case 'n':		/* next */
 		if (argc < 4)
 			goto usage;
@@ -665,9 +657,9 @@ static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 static char pci_help_text[] =
 	"[bus] [long]\n"
 	"    - short or long list of PCI devices on bus 'bus'\n"
-#ifdef CONFIG_CMD_PCI_ENUM
+#if defined(CONFIG_CMD_PCI_ENUM) || defined(CONFIG_DM_PCI)
 	"pci enum\n"
-	"    - re-enumerate PCI buses\n"
+	"    - Enumerate PCI buses\n"
 #endif
 	"pci header b.d.f\n"
 	"    - show header of PCI device 'bus.device.function'\n"
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 685df9d274e4..f51f08289d66 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1247,3 +1247,18 @@ U_BOOT_DRIVER(pci_generic_drv) = {
 	.id		= UCLASS_PCI_GENERIC,
 	.of_match	= pci_generic_ids,
 };
+
+void pci_init(void)
+{
+	struct udevice *bus;
+
+	/*
+	 * Enumerate all known controller devices. Enumeration has the side-
+	 * effect of probing them, so PCIe devices will be enumerated too.
+	 */
+	for (uclass_first_device(UCLASS_PCI, &bus);
+	     bus;
+	     uclass_next_device(&bus)) {
+		;
+	}
+}
-- 
2.7.0