[3/8] PCI: dwc: Implement .pre_scale_bus_bw() & .post_scale_bus_bw hook

Commit Message

Krishna Chaitanya Chundru Feb. 17, 2025, 6:34 a.m. UTC

Add support for pre_scale_bus_bw() & post_scale_bus_bw() function op's.
Add support for DWC glue drivers to register for these ops.

Signed-off-by: Krishna Chaitanya Chundru <[e-mail]>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 21 +++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h      |  2 ++
 2 files changed, 23 insertions(+)

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index ffaded8f2df7..4da4df62c3f8 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -697,10 +697,31 @@  void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn,
 }
 EXPORT_SYMBOL_GPL(dw_pcie_own_conf_map_bus);
 
+static int dw_pcie_pre_scale_bus_bw(struct pci_bus *bus, int target_speed)
+{
+	struct dw_pcie_rp *pp = bus->sysdata;
+	int ret = 0;
+
+	if (pp->ops->pre_scale_bus_bw)
+		ret = pp->ops->pre_scale_bus_bw(pp, target_speed);
+
+	return ret;
+}
+
+static void dw_pcie_post_scale_bus_bw(struct pci_bus *bus, int current_speed)
+{
+	struct dw_pcie_rp *pp = bus->sysdata;
+
+	if (pp->ops->pre_scale_bus_bw)
+		pp->ops->post_scale_bus_bw(pp, current_speed);
+}
+
 static struct pci_ops dw_pcie_ops = {
 	.map_bus = dw_pcie_own_conf_map_bus,
 	.read = pci_generic_config_read,
 	.write = pci_generic_config_write,
+	.pre_scale_bus_bw = dw_pcie_pre_scale_bus_bw,
+	.post_scale_bus_bw = dw_pcie_post_scale_bus_bw,
 };
 
 static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp)
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 501d9ddfea16..16e02646a8b4 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -354,6 +354,8 @@  struct dw_pcie_host_ops {
 	void (*post_init)(struct dw_pcie_rp *pp);
 	int (*msi_init)(struct dw_pcie_rp *pp);
 	void (*pme_turn_off)(struct dw_pcie_rp *pp);
+	int (*pre_scale_bus_bw)(struct dw_pcie_rp *pp, int target_speed);
+	void (*post_scale_bus_bw)(struct dw_pcie_rp *pp, int current_speed);
 };
 
 struct dw_pcie_rp {