fdt: Add several apis to decode pci device node

This commit adds several APIs to decode PCI device node according to
the Open Firmware PCI bus bindings, including:
- fdtdec_get_pci_addr() for encoded pci address
- fdtdec_get_pci_vendev() for vendor id and device id
- fdtdec_get_pci_bdf() for pci device bdf triplet
- fdtdec_get_pci_bar32() for pci device register bar

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
(Include <pci.h> in fdtdec.h and adjust tegra to fix build error)

3 files changed, 257 insertions, 26 deletions

diff --git a/drivers/pci/pci_tegra.c b/drivers/pci/pci_tegra.c
index a03ad5f..f9e05ad 100644
--- a/drivers/pci/pci_tegra.c
+++ b/drivers/pci/pci_tegra.c
@@ -458,6 +458,7 @@ static int tegra_pcie_parse_port_info(const void *fdt, int node,
 				      unsigned int *index,
 				      unsigned int *lanes)
 {
+	struct fdt_pci_addr addr;
 	pci_dev_t bdf;
 	int err;
 
@@ -469,7 +470,7 @@ static int tegra_pcie_parse_port_info(const void *fdt, int node,
 
 	*lanes = err;
 
-	err = fdtdec_pci_get_bdf(fdt, node, &bdf);
+	err = fdtdec_get_pci_bdf(fdt, node, &addr, &bdf);
 	if (err < 0) {
 		error("failed to parse \"reg\" property");
 		return err;
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 5effa24..75af750 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -15,6 +15,7 @@
  */
 
 #include <libfdt.h>
+#include <pci.h>
 
 /*
  * A typedef for a physical address. Note that fdt data is always big
@@ -50,6 +51,49 @@ struct fdt_resource {
 	fdt_addr_t end;
 };
 
+enum fdt_pci_space {
+	FDT_PCI_SPACE_CONFIG = 0,
+	FDT_PCI_SPACE_IO = 0x01000000,
+	FDT_PCI_SPACE_MEM32 = 0x02000000,
+	FDT_PCI_SPACE_MEM64 = 0x03000000,
+	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
+	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
+};
+
+#define FDT_PCI_ADDR_CELLS	3
+#define FDT_PCI_SIZE_CELLS	2
+#define FDT_PCI_REG_SIZE	\
+	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
+
+/*
+ * The Open Firmware spec defines PCI physical address as follows:
+ *
+ *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
+ *
+ * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
+ * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
+ * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
+ *
+ * where:
+ *
+ * n:        is 0 if the address is relocatable, 1 otherwise
+ * p:        is 1 if addressable region is prefetchable, 0 otherwise
+ * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
+ *           (for Memory), or below 64KB (for relocatable I/O)
+ * ss:       is the space code, denoting the address space
+ * bbbbbbbb: is the 8-bit Bus Number
+ * ddddd:    is the 5-bit Device Number
+ * fff:      is the 3-bit Function Number
+ * rrrrrrrr: is the 8-bit Register Number
+ * hhhhhhhh: is a 32-bit unsigned number
+ * llllllll: is a 32-bit unsigned number
+ */
+struct fdt_pci_addr {
+	u32	phys_hi;
+	u32	phys_mid;
+	u32	phys_lo;
+};
+
 /**
  * Compute the size of a resource.
  *
@@ -258,6 +302,60 @@ fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
 		const char *prop_name, fdt_size_t *sizep);
 
 /**
+ * Look at an address property in a node and return the pci address which
+ * corresponds to the given type in the form of fdt_pci_addr.
+ * The property must hold one fdt_pci_addr with a lengh.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param type		pci address type (FDT_PCI_SPACE_xxx)
+ * @param prop_name	name of property to find
+ * @param addr		returns pci address in the form of fdt_pci_addr
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
+		const char *prop_name, struct fdt_pci_addr *addr);
+
+/**
+ * Look at the compatible property of a device node that represents a PCI
+ * device and extract pci vendor id and device id from it.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param vendor	vendor id of the pci device
+ * @param device	device id of the pci device
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_vendev(const void *blob, int node,
+		u16 *vendor, u16 *device);
+
+/**
+ * Look at the pci address of a device node that represents a PCI device
+ * and parse the bus, device and function number from it.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param addr		pci address in the form of fdt_pci_addr
+ * @param bdf		returns bus, device, function triplet
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_bdf(const void *blob, int node,
+		struct fdt_pci_addr *addr, pci_dev_t *bdf);
+
+/**
+ * Look at the pci address of a device node that represents a PCI device
+ * and return base address of the pci device's registers.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param addr		pci address in the form of fdt_pci_addr
+ * @param bar		returns base address of the pci device's registers
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_bar32(const void *blob, int node,
+		struct fdt_pci_addr *addr, u32 *bar);
+
+/**
  * Look up a 32-bit integer property in a node and return it. The property
  * must have at least 4 bytes of data. The value of the first cell is
  * returned.
@@ -683,17 +781,6 @@ int fdt_get_named_resource(const void *fdt, int node, const char *property,
 			   struct fdt_resource *res);
 
 /**
- * Look at the reg property of a device node that represents a PCI device
- * and parse the bus, device and function number from it.
- *
- * @param fdt		FDT blob
- * @param node		node to examine
- * @param bdf		returns bus, device, function triplet
- * @return 0 if ok, negative on error
- */
-int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
-
-/**
  * Decode a named region within a memory bank of a given type.
  *
  * This function handles selection of a memory region. The region is
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 745b390..487122e 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -126,6 +126,163 @@ fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 	return fdtdec_get_addr_size(blob, node, prop_name, NULL);
 }
 
+#ifdef CONFIG_PCI
+int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
+		const char *prop_name, struct fdt_pci_addr *addr)
+{
+	const u32 *cell;
+	int len;
+	int ret = -ENOENT;
+
+	debug("%s: %s: ", __func__, prop_name);
+
+	/*
+	 * If we follow the pci bus bindings strictly, we should check
+	 * the value of the node's parent node's #address-cells and
+	 * #size-cells. They need to be 3 and 2 accordingly. However,
+	 * for simplicity we skip the check here.
+	 */
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (!cell)
+		goto fail;
+
+	if ((len % FDT_PCI_REG_SIZE) == 0) {
+		int num = len / FDT_PCI_REG_SIZE;
+		int i;
+
+		for (i = 0; i < num; i++) {
+			debug("pci address #%d: %08lx %08lx %08lx\n", i,
+			      (ulong)fdt_addr_to_cpu(cell[0]),
+			      (ulong)fdt_addr_to_cpu(cell[1]),
+			      (ulong)fdt_addr_to_cpu(cell[2]));
+			if ((fdt_addr_to_cpu(*cell) & type) == type) {
+				addr->phys_hi = fdt_addr_to_cpu(cell[0]);
+				addr->phys_mid = fdt_addr_to_cpu(cell[1]);
+				addr->phys_lo = fdt_addr_to_cpu(cell[2]);
+				break;
+			} else {
+				cell += (FDT_PCI_ADDR_CELLS +
+					 FDT_PCI_SIZE_CELLS);
+			}
+		}
+
+		if (i == num)
+			goto fail;
+
+		return 0;
+	} else {
+		ret = -EINVAL;
+	}
+
+fail:
+	debug("(not found)\n");
+	return ret;
+}
+
+int fdtdec_get_pci_vendev(const void *blob, int node, u16 *vendor, u16 *device)
+{
+	const char *list, *end;
+	int len;
+
+	list = fdt_getprop(blob, node, "compatible", &len);
+	if (!list)
+		return -ENOENT;
+
+	end = list + len;
+	while (list < end) {
+		char *s;
+
+		len = strlen(list);
+		if (len >= strlen("pciVVVV,DDDD")) {
+			s = strstr(list, "pci");
+
+			/*
+			 * check if the string is something like pciVVVV,DDDD.RR
+			 * or just pciVVVV,DDDD
+			 */
+			if (s && s[7] == ',' &&
+			    (s[12] == '.' || s[12] == 0)) {
+				s += 3;
+				*vendor = simple_strtol(s, NULL, 16);
+
+				s += 5;
+				*device = simple_strtol(s, NULL, 16);
+
+				return 0;
+			}
+		} else {
+			list += (len + 1);
+		}
+	}
+
+	return -ENOENT;
+}
+
+int fdtdec_get_pci_bdf(const void *blob, int node,
+		struct fdt_pci_addr *addr, pci_dev_t *bdf)
+{
+	u16 dt_vendor, dt_device, vendor, device;
+	int ret;
+
+	/* get vendor id & device id from the compatible string */
+	ret = fdtdec_get_pci_vendev(blob, node, &dt_vendor, &dt_device);
+	if (ret)
+		return ret;
+
+	/* extract the bdf from fdt_pci_addr */
+	*bdf = addr->phys_hi & 0xffff00;
+
+	/* read vendor id & device id based on bdf */
+	pci_read_config_word(*bdf, PCI_VENDOR_ID, &vendor);
+	pci_read_config_word(*bdf, PCI_DEVICE_ID, &device);
+
+	/*
+	 * Note there are two places in the device tree to fully describe
+	 * a pci device: one is via compatible string with a format of
+	 * "pciVVVV,DDDD" and the other one is the bdf numbers encoded in
+	 * the device node's reg address property. We read the vendor id
+	 * and device id based on bdf and compare the values with the
+	 * "VVVV,DDDD". If they are the same, then we are good to use bdf
+	 * to read device's bar. But if they are different, we have to rely
+	 * on the vendor id and device id extracted from the compatible
+	 * string and locate the real bdf by pci_find_device(). This is
+	 * because normally we may only know device's device number and
+	 * function number when writing device tree. The bus number is
+	 * dynamically assigned during the pci enumeration process.
+	 */
+	if ((dt_vendor != vendor) || (dt_device != device)) {
+		*bdf = pci_find_device(dt_vendor, dt_device, 0);
+		if (*bdf == -1)
+			return -ENODEV;
+	}
+
+	return 0;
+}
+
+int fdtdec_get_pci_bar32(const void *blob, int node,
+		struct fdt_pci_addr *addr, u32 *bar)
+{
+	pci_dev_t bdf;
+	int barnum;
+	int ret;
+
+	/* get pci devices's bdf */
+	ret = fdtdec_get_pci_bdf(blob, node, addr, &bdf);
+	if (ret)
+		return ret;
+
+	/* extract the bar number from fdt_pci_addr */
+	barnum = addr->phys_hi & 0xff;
+	if ((barnum < PCI_BASE_ADDRESS_0) || (barnum > PCI_CARDBUS_CIS))
+		return -EINVAL;
+
+	barnum = (barnum - PCI_BASE_ADDRESS_0) / 4;
+	*bar = pci_read_bar32(pci_bus_to_hose(PCI_BUS(bdf)), bdf, barnum);
+
+	return 0;
+}
+#endif
+
 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 		uint64_t default_val)
 {
@@ -795,20 +952,6 @@ int fdt_get_named_resource(const void *fdt, int node, const char *property,
 	return fdt_get_resource(fdt, node, property, index, res);
 }
 
-int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf)
-{
-	const fdt32_t *prop;
-	int len;
-
-	prop = fdt_getprop(fdt, node, "reg", &len);
-	if (!prop)
-		return len;
-
-	*bdf = fdt32_to_cpu(*prop) & 0xffffff;
-
-	return 0;
-}
-
 int fdtdec_decode_memory_region(const void *blob, int config_node,
 				const char *mem_type, const char *suffix,
 				fdt_addr_t *basep, fdt_size_t *sizep)