[PATCH v5 3/6] PCI: Add pci_lnkctl2_bus_speed() to convert lnkctl2speed to pci_bus_speed

Add a exported function to convert lnkctl2speed to enum pci_bus_speed,
so that other kernel drivers can use it.

Signed-off-by: Krishna Chaitanya Chundru <[email protected]>
---
 drivers/pci/pci.c   | 15 +++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 77b17b13ee61..cda7d210ddbf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5939,6 +5939,21 @@ int pcie_link_speed_mbps(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL(pcie_link_speed_mbps);
 
+/**
+ * pci_lnkctl2_bus_speed - convert Link Control 2 Target Link Speed to pci_bus_speed
+ * @speed: Target Link Speed (TLS) value from Link Control 2 register (0-4 for Gen1-Gen5)
+ *
+ * Convert the Target Link Speed (TLS) field value from the Link Control 2 register
+ * to the corresponding enum pci_bus_speed.
+ *
+ * Return: pci_bus_speed corresponding to the TLS value
+ */
+enum pci_bus_speed pci_lnkctl2_bus_speed(u32 speed)
+{
+	return pcie_link_speed[speed];
+}
+EXPORT_SYMBOL(pci_lnkctl2_bus_speed);
+
 /**
  * pcie_bandwidth_available - determine minimum link settings of a PCIe
  *			      device and its bandwidth limitation
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d1f2d382189d..244c145af04f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1727,6 +1727,7 @@ int pci_cfg_space_size(struct pci_dev *dev);
 unsigned char pci_bus_max_busnr(struct pci_bus *bus);
 resource_size_t pcibios_window_alignment(struct pci_bus *bus,
 					 unsigned long type);
+enum pci_bus_speed pci_lnkctl2_bus_speed(u32 speed);
 
 #define PCI_VGA_STATE_CHANGE_BRIDGE (1 << 0)
 #define PCI_VGA_STATE_CHANGE_DECODES (1 << 1)

-- 
2.34.1