From: Frank Li <Frank.Li@xxxxxxx> Return the offset from CPU physical address to the parent bus address of the specified element of the devicetree 'reg' property. [bhelgaas: return offset, split .cpu_addr_fixup() checking and debug to separate patch] Link: https://lore.kernel.org/r/20250313-pci_fixup_addr-v11-5-01d2313502ab@xxxxxxx Signed-off-by: Frank Li <Frank.Li@xxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware.c | 23 ++++++++++++++++++++ drivers/pci/controller/dwc/pcie-designware.h | 3 +++ 2 files changed, 26 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 9d0a5f75effc..0a35e36da703 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -16,6 +16,7 @@ #include <linux/gpio/consumer.h> #include <linux/ioport.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/sizes.h> #include <linux/types.h> @@ -1105,3 +1106,25 @@ void dw_pcie_setup(struct dw_pcie *pci) dw_pcie_link_set_max_link_width(pci, pci->num_lanes); } + +resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci, + const char *reg_name, + resource_size_t cpu_phy_addr) +{ + struct device *dev = pci->dev; + struct device_node *np = dev->of_node; + int index; + u64 reg_addr; + + /* Look up reg_name address on parent bus */ + index = of_property_match_string(np, "reg-names", reg_name); + + if (index < 0) { + dev_err(dev, "No %s in devicetree \"reg\" property\n", reg_name); + return 0; + } + + of_property_read_reg(np, index, ®_addr, NULL); + + return cpu_phy_addr - reg_addr; +} diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index d0d8c622a6e8..16548b01347d 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -500,6 +500,9 @@ void dw_pcie_setup(struct dw_pcie *pci); void dw_pcie_iatu_detect(struct dw_pcie *pci); int dw_pcie_edma_detect(struct dw_pcie *pci); void dw_pcie_edma_remove(struct dw_pcie *pci); +resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci, + const char *reg_name, + resource_size_t cpu_phy_addr); static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val) { -- 2.34.1
