pci: Add helper for implementing memory-mapped config space accesses

This sort of pattern for implementing memory-mapped PCI config space
accesses appears in U-Boot twice already, and a third user is coming up.
So add helper functions to avoid code duplication, similar to how Linux
has pci_generic_config_write and pci_generic_config_read.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/include/pci.h b/include/pci.h
index c8ef997d0d..7adc04301c 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -1086,6 +1086,57 @@ int pci_read_config32(pci_dev_t pcidev, int offset, u32 *valuep);
 int pci_read_config16(pci_dev_t pcidev, int offset, u16 *valuep);
 int pci_read_config8(pci_dev_t pcidev, int offset, u8 *valuep);
 
+/**
+ * pci_generic_mmap_write_config() - Generic helper for writing to
+ * memory-mapped PCI configuration space.
+ * @bus: Pointer to the PCI bus
+ * @addr_f: Callback for calculating the config space address
+ * @bdf: Identifies the PCI device to access
+ * @offset: The offset into the device's configuration space
+ * @value: The value to write
+ * @size: Indicates the size of access to perform
+ *
+ * Write the value @value of size @size from offset @offset within the
+ * configuration space of the device identified by the bus, device & function
+ * numbers in @bdf on the PCI bus @bus. The callback function @addr_f is
+ * responsible for calculating the CPU address of the respective configuration
+ * space offset.
+ *
+ * Return: 0 on success, else -EINVAL
+ */
+int pci_generic_mmap_write_config(
+	struct udevice *bus,
+	int (*addr_f)(struct udevice *bus, pci_dev_t bdf, uint offset, void **addrp),
+	pci_dev_t bdf,
+	uint offset,
+	ulong value,
+	enum pci_size_t size);
+
+/**
+ * pci_generic_mmap_read_config() - Generic helper for reading from
+ * memory-mapped PCI configuration space.
+ * @bus: Pointer to the PCI bus
+ * @addr_f: Callback for calculating the config space address
+ * @bdf: Identifies the PCI device to access
+ * @offset: The offset into the device's configuration space
+ * @valuep: A pointer at which to store the read value
+ * @size: Indicates the size of access to perform
+ *
+ * Read a value of size @size from offset @offset within the configuration
+ * space of the device identified by the bus, device & function numbers in @bdf
+ * on the PCI bus @bus. The callback function @addr_f is responsible for
+ * calculating the CPU address of the respective configuration space offset.
+ *
+ * Return: 0 on success, else -EINVAL
+ */
+int pci_generic_mmap_read_config(
+	struct udevice *bus,
+	int (*addr_f)(struct udevice *bus, pci_dev_t bdf, uint offset, void **addrp),
+	pci_dev_t bdf,
+	uint offset,
+	ulong *valuep,
+	enum pci_size_t size);
+
 #ifdef CONFIG_DM_PCI_COMPAT
 /* Compatibility with old naming */
 static inline int pci_write_config_dword(pci_dev_t pcidev, int offset,