pci: Add functions to update PCI configuration registers

It is common to read a config register value, clear and set some bits, then
write back the updated value. Add functions to do this in one step, for
convenience.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/pci.h b/include/pci.h
index 68548b00d94..db84744571e 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -1027,6 +1027,21 @@ int pci_bus_write_config(struct udevice *bus, pci_dev_t bdf, int offset,
 			 unsigned long value, enum pci_size_t size);
 
 /**
+ * pci_bus_clrset_config32() - Update a configuration value for a device
+ *
+ * The register at @offset is updated to (oldvalue & ~clr) | set.
+ *
+ * @bus:	Bus to access
+ * @bdf:	PCI device address: bus, device and function -see PCI_BDF()
+ * @offset:	Register offset to update
+ * @clr:	Bits to clear
+ * @set:	Bits to set
+ * @return 0 if OK, -ve on error
+ */
+int pci_bus_clrset_config32(struct udevice *bus, pci_dev_t bdf, int offset,
+			    u32 clr, u32 set);
+
+/**
  * Driver model PCI config access functions. Use these in preference to others
  * when you have a valid device
  */
@@ -1044,6 +1059,14 @@ int dm_pci_write_config8(struct udevice *dev, int offset, u8 value);
 int dm_pci_write_config16(struct udevice *dev, int offset, u16 value);
 int dm_pci_write_config32(struct udevice *dev, int offset, u32 value);
 
+/**
+ * These permit convenient read/modify/write on PCI configuration. The
+ * register is updated to (oldvalue & ~clr) | set.
+ */
+int dm_pci_clrset_config8(struct udevice *dev, int offset, u32 clr, u32 set);
+int dm_pci_clrset_config16(struct udevice *dev, int offset, u32 clr, u32 set);
+int dm_pci_clrset_config32(struct udevice *dev, int offset, u32 clr, u32 set);
+
 /*
  * The following functions provide access to the above without needing the
  * size parameter. We are trying to encourage the use of the 8/16/32-style