dm: pci: Add a function to read a PCI BAR

At present PCI address transaction is not supported so drivers must
manually read the correct BAR after reading the device tree info. The
ns16550 has a suitable implementation, so move this code into the core
DM support.

Note that there is no live-tree equivalent at present.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: correct the unclear comments in test.dts]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

arch/sandbox/dts/test.dts

@@ -456,12 +456,15 @@
 		};
 		pci@1,0 {
 			compatible = "pci-generic";
-			reg = <0x0800 0 0 0 0>;
+			/* reg 0 is at 0x14, using FDT_PCI_SPACE_MEM32 */
+			reg = <0x02000814 0 0 0 0
+			       0x01000810 0 0 0 0>;
 			sandbox,emul = <&swap_case_emul0_1>;
 		};
 		pci@1f,0 {
 			compatible = "pci-generic";
-			reg = <0xf800 0 0 0 0>;
+			/* reg 0 is at 0x10, using FDT_PCI_SPACE_IO */
+			reg = <0x0100f810 0 0 0 0>;
 			sandbox,emul = <&swap_case_emul0_1f>;
 		};
 	};

drivers/core/fdtaddr.c

@@ -190,3 +190,36 @@ void *devfdt_map_physmem(struct udevice *dev, unsigned long size)
 
 	return map_physmem(addr, size, MAP_NOCACHE);
 }
+
+fdt_addr_t devfdt_get_addr_pci(struct udevice *dev)
+{
+	ulong addr;
+
+	addr = devfdt_get_addr(dev);
+	if (CONFIG_IS_ENABLED(PCI) && IS_ENABLED(CONFIG_DM_PCI) &&
+	    addr == FDT_ADDR_T_NONE) {
+		struct fdt_pci_addr pci_addr;
+		u32 bar;
+		int ret;
+
+		ret = fdtdec_get_pci_addr(gd->fdt_blob,
+					  dev_of_offset(dev),
+					  FDT_PCI_SPACE_MEM32, "reg",
+					  &pci_addr);
+		if (ret) {
+			/* try if there is any i/o-mapped register */
+			ret = fdtdec_get_pci_addr(gd->fdt_blob,
+						  dev_of_offset(dev),
+						  FDT_PCI_SPACE_IO, "reg",
+						  &pci_addr);
+			if (ret)
+				return FDT_ADDR_T_NONE;
+		}
+		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
+		if (ret)
+			return FDT_ADDR_T_NONE;
+		addr = bar;
+	}
+
+	return addr;
+}

drivers/core/read.c

@@ -307,3 +307,14 @@ int dev_read_alias_highest_id(const char *stem)
 
 	return fdtdec_get_alias_highest_id(gd->fdt_blob, stem);
 }
+
+fdt_addr_t dev_read_addr_pci(struct udevice *dev)
+{
+	ulong addr;
+
+	addr = dev_read_addr(dev);
+	if (addr == FDT_ADDR_T_NONE && !of_live_active())
+		addr = devfdt_get_addr_pci(dev);
+
+	return addr;
+}

drivers/serial/ns16550.c

@@ -440,36 +440,7 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 	int err;
 
 	/* try Processor Local Bus device first */
-	addr = dev_read_addr(dev);
+	addr = dev_read_addr_pci(dev);
-#if CONFIG_IS_ENABLED(PCI) && defined(CONFIG_DM_PCI)
-	if (addr == FDT_ADDR_T_NONE) {
-		/* then try pci device */
-		struct fdt_pci_addr pci_addr;
-		u32 bar;
-		int ret;
-
-		/* we prefer to use a memory-mapped register */
-		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev_of_offset(dev),
-					  FDT_PCI_SPACE_MEM32, "reg",
-					  &pci_addr);
-		if (ret) {
-			/* try if there is any i/o-mapped register */
-			ret = fdtdec_get_pci_addr(gd->fdt_blob,
-						  dev_of_offset(dev),
-						  FDT_PCI_SPACE_IO,
-						  "reg", &pci_addr);
-			if (ret)
-				return ret;
-		}
-
-		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
-		if (ret)
-			return ret;
-
-		addr = bar;
-	}
-#endif
-
 	if (addr == FDT_ADDR_T_NONE)
 		return -EINVAL;
 

include/dm/fdtaddr.h

@@ -138,4 +138,12 @@ fdt_addr_t devfdt_get_addr_name(struct udevice *dev, const char *name);
 fdt_addr_t devfdt_get_addr_size_name(struct udevice *dev, const char *name,
 				     fdt_size_t *size);
 
+/**
+ * devfdt_get_addr_pci() - Read an address and handle PCI address translation
+ *
+ * @dev: Device to read from
+ * @return address or FDT_ADDR_T_NONE if not found
+ */
+fdt_addr_t devfdt_get_addr_pci(struct udevice *dev);
+
 #endif

include/dm/read.h

@@ -248,6 +248,26 @@ fdt_addr_t dev_read_addr(struct udevice *dev);
  */
 void *dev_read_addr_ptr(struct udevice *dev);
 
+/**
+ * dev_read_addr_pci() - Read an address and handle PCI address translation
+ *
+ * At present U-Boot does not have address translation logic for PCI in the
+ * livetree implementation (of_addr.c). This special function supports this for
+ * the flat tree implementation.
+ *
+ * This function should be removed (and code should use dev_read() instead)
+ * once:
+ *
+ * 1. PCI address translation is added; and either
+ * 2. everything uses livetree where PCI translation is used (which is feasible
+ *    in SPL and U-Boot proper) or PCI address translation is added to
+ *    fdtdec_get_addr() and friends.
+ *
+ * @dev: Device to read from
+ * @return address or FDT_ADDR_T_NONE if not found
+ */
+fdt_addr_t dev_read_addr_pci(struct udevice *dev);
+
 /**
  * dev_remap_addr() - Get the reg property of a device as a
  *                         memory-mapped I/O pointer
@@ -691,6 +711,11 @@ static inline void *dev_read_addr_ptr(struct udevice *dev)
 	return devfdt_get_addr_ptr(dev);
 }
 
+static inline fdt_addr_t dev_read_addr_pci(struct udevice *dev)
+{
+	return devfdt_get_addr_pci(dev);
+}
+
 static inline void *dev_remap_addr(struct udevice *dev)
 {
 	return devfdt_remap_addr(dev);

test/dm/pci.c

@@ -294,3 +294,48 @@ static int dm_test_pci_ea(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_pci_ea, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test the dev_read_addr_pci() function */
+static int dm_test_pci_addr_flat(struct unit_test_state *uts)
+{
+	struct udevice *swap1f, *swap1;
+	ulong io_addr, mem_addr;
+
+	ut_assertok(dm_pci_bus_find_bdf(PCI_BDF(0, 0x1f, 0), &swap1f));
+	io_addr = dm_pci_read_bar32(swap1f, 0);
+	ut_asserteq(io_addr, dev_read_addr_pci(swap1f));
+
+	/*
+	 * This device has both I/O and MEM spaces but the MEM space appears
+	 * first
+	 */
+	ut_assertok(dm_pci_bus_find_bdf(PCI_BDF(0, 0x1, 0), &swap1));
+	mem_addr = dm_pci_read_bar32(swap1, 1);
+	ut_asserteq(mem_addr, dev_read_addr_pci(swap1));
+
+	return 0;
+}
+DM_TEST(dm_test_pci_addr_flat, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT |
+		DM_TESTF_FLAT_TREE);
+
+/*
+ * Test the dev_read_addr_pci() function with livetree. That function is
+ * not currently fully implemented, in that it fails to return the BAR address.
+ * Once that is implemented this test can be removed and dm_test_pci_addr_flat()
+ * can be used for both flattree and livetree by removing the DM_TESTF_FLAT_TREE
+ * flag above.
+ */
+static int dm_test_pci_addr_live(struct unit_test_state *uts)
+{
+	struct udevice *swap1f, *swap1;
+
+	ut_assertok(dm_pci_bus_find_bdf(PCI_BDF(0, 0x1f, 0), &swap1f));
+	ut_asserteq(FDT_ADDR_T_NONE, dev_read_addr_pci(swap1f));
+
+	ut_assertok(dm_pci_bus_find_bdf(PCI_BDF(0, 0x1, 0), &swap1));
+	ut_asserteq(FDT_ADDR_T_NONE, dev_read_addr_pci(swap1));
+
+	return 0;
+}
+DM_TEST(dm_test_pci_addr_live, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT |
+		DM_TESTF_LIVE_TREE);