cmd: pci: add option to parse and display BAR information

Currently the PCI command only allows to see the BAR register
values but not the size and actual base address.
This little extension parses the BAR registers and displays
the base, size and type of each BAR.

Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/pci.c

@@ -92,6 +92,77 @@ static void pci_show_regs(pci_dev_t dev, struct pci_reg_info *regs)
 }
 #endif
 
+#ifdef CONFIG_DM_PCI
+int pci_bar_show(struct udevice *dev)
+{
+	u8 header_type;
+	int bar_cnt, bar_id, mem_type;
+	bool is_64, is_io;
+	u32 base_low, base_high;
+	u32 size_low, size_high;
+	u64 base, size;
+	u32 reg_addr;
+	int prefetchable;
+
+	dm_pci_read_config8(dev, PCI_HEADER_TYPE, &header_type);
+
+	if (header_type == PCI_HEADER_TYPE_CARDBUS) {
+		printf("CardBus doesn't support BARs\n");
+		return -ENOSYS;
+	}
+
+	bar_cnt = (header_type == PCI_HEADER_TYPE_NORMAL) ? 6 : 2;
+
+	printf("ID   Base                Size                Width  Type\n");
+	printf("----------------------------------------------------------\n");
+
+	bar_id = 0;
+	reg_addr = PCI_BASE_ADDRESS_0;
+	while (bar_cnt) {
+		dm_pci_read_config32(dev, reg_addr, &base_low);
+		dm_pci_write_config32(dev, reg_addr, 0xffffffff);
+		dm_pci_read_config32(dev, reg_addr, &size_low);
+		dm_pci_write_config32(dev, reg_addr, base_low);
+		reg_addr += 4;
+
+		base = base_low & ~0xf;
+		size = size_low & ~0xf;
+		base_high = 0x0;
+		size_high = 0xffffffff;
+		is_64 = 0;
+		prefetchable = base_low & PCI_BASE_ADDRESS_MEM_PREFETCH;
+		is_io = base_low & PCI_BASE_ADDRESS_SPACE_IO;
+		mem_type = base_low & PCI_BASE_ADDRESS_MEM_TYPE_MASK;
+
+		if (mem_type == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+			dm_pci_read_config32(dev, reg_addr, &base_high);
+			dm_pci_write_config32(dev, reg_addr, 0xffffffff);
+			dm_pci_read_config32(dev, reg_addr, &size_high);
+			dm_pci_write_config32(dev, reg_addr, base_high);
+			bar_cnt--;
+			reg_addr += 4;
+			is_64 = 1;
+		}
+
+		base = base | ((u64)base_high << 32);
+		size = size | ((u64)size_high << 32);
+
+		if ((!is_64 && size_low) || (is_64 && size)) {
+			size = ~size + 1;
+			printf(" %d   %#016llx  %#016llx  %d     %s   %s\n",
+			       bar_id, base, size, is_64 ? 64 : 32,
+			       is_io ? "I/O" : "MEM",
+			       prefetchable ? "Prefetchable" : "");
+		}
+
+		bar_id++;
+		bar_cnt--;
+	}
+
+	return 0;
+}
+#endif
+
 static struct pci_reg_info regs_start[] = {
 	{ "vendor ID", PCI_SIZE_16, PCI_VENDOR_ID },
 	{ "device ID", PCI_SIZE_16, PCI_DEVICE_ID },
@@ -573,6 +644,9 @@ static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		if (argc > 4)
 			value = simple_strtoul(argv[4], NULL, 16);
 	case 'h':		/* header */
+#ifdef CONFIG_DM_PCI
+	case 'b':		/* bars */
+#endif
 		if (argc < 3)
 			goto usage;
 		if ((bdf = get_pci_dev(argv[2])) == -1)
@@ -641,6 +715,11 @@ static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		ret = pci_cfg_write(dev, addr, size, value);
 #endif
 		break;
+#ifdef CONFIG_DM_PCI
+
+	case 'b':		/* bars */
+		return pci_bar_show(dev);
+#endif
 	default:
 		ret = CMD_RET_USAGE;
 		break;
@@ -663,6 +742,10 @@ static char pci_help_text[] =
 #endif
 	"pci header b.d.f\n"
 	"    - show header of PCI device 'bus.device.function'\n"
+#ifdef CONFIG_DM_PCI
+	"pci bar b.d.f\n"
+	"    - show BARs base and size for device b.d.f'\n"
+#endif
 	"pci display[.b, .w, .l] b.d.f [address] [# of objects]\n"
 	"    - display PCI configuration space (CFG)\n"
 	"pci next[.b, .w, .l] b.d.f address\n"