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>

2 files changed, 33 insertions, 0 deletions

diff --git a/include/dm/fdtaddr.h b/include/dm/fdtaddr.h
index 57b326cb33..959d3bc2d6 100644
--- a/include/dm/fdtaddr.h
+++ b/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
diff --git a/include/dm/read.h b/include/dm/read.h
index 803daf7620..d37fcb504d 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -249,6 +249,26 @@ 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);