diff options
| author | Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com> | 2025-03-28 15:58:31 +0530 |
|---|---|---|
| committer | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2025-04-19 19:42:38 +0530 |
| commit | f9eb654fb194e7c404d4984481a18edb9b1c1d7c (patch) | |
| tree | a2f5ffc52d4e4bef818b128a7097311d05b7c2bc | |
| parent | 57a4591df70900252265ecfd6eeba95ce2021504 (diff) | |
PCI: dwc: Update pci->num_lanes to maximum supported link width
If the num-lanes property is not present in the devicetree, update
pci->num_lanes with the hardware supported maximum link width using
the newly introduced dw_pcie_link_get_max_link_width() API.
The API is used to get the Maximum Link Width (MLW) of the controller.
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
[mani: reworded commit message a bit]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250328-preset_v6-v9-3-22cfa0490518@oss.qualcomm.com
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-host.c | 3 | ||||
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 8 | ||||
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.h | 1 |
3 files changed, 12 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index ecc33f6789e3..e8eccf6a1b2f 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -523,6 +523,9 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) dw_pcie_iatu_detect(pci); + if (pci->num_lanes < 1) + pci->num_lanes = dw_pcie_link_get_max_link_width(pci); + /* * Allocate the resource for MSG TLP before programming the iATU * outbound window in dw_pcie_setup_rc(). Since the allocation depends diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 97d76d3dc066..cafe91bd9c34 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -781,6 +781,14 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci) } +int dw_pcie_link_get_max_link_width(struct dw_pcie *pci) +{ + u8 cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + u32 lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); + + return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap); +} + static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) { u32 lnkcap, lwsc, plc; diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 56aafdbcdaca..dda788e3bd24 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -540,6 +540,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val); int dw_pcie_link_up(struct dw_pcie *pci); void dw_pcie_upconfig_setup(struct dw_pcie *pci); int dw_pcie_wait_for_link(struct dw_pcie *pci); +int dw_pcie_link_get_max_link_width(struct dw_pcie *pci); int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, const struct dw_pcie_ob_atu_cfg *atu); int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type, |