This is a preparation before adding the Max-Link-width capability setup which would in its turn complete the max-link-width setup procedure defined by Synopsys in the HW-manual. Seeing there is a max-link-speed setup method defined in the DW PCIe core driver it would be good to have a similar function for the link width setup. That's why we need to define a dedicated function first from already implemented but incomplete link-width setting up code. [kwilczynski: commit log] Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-7-yoshihiro.shimoda.uh@xxxxxxxxxxx Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx> Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware.c | 86 ++++++++++---------- 1 file changed, 41 insertions(+), 45 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 1c1c7348972b..da4aba4aee62 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -732,6 +732,46 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) } +static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) +{ + u32 lwsc, plc; + + if (!num_lanes) + return; + + /* Set the number of lanes */ + plc = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL); + plc &= ~PORT_LINK_FAST_LINK_MODE; + plc &= ~PORT_LINK_MODE_MASK; + + /* Set link width speed control register */ + lwsc = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); + lwsc &= ~PORT_LOGIC_LINK_WIDTH_MASK; + switch (num_lanes) { + case 1: + plc |= PORT_LINK_MODE_1_LANES; + lwsc |= PORT_LOGIC_LINK_WIDTH_1_LANES; + break; + case 2: + plc |= PORT_LINK_MODE_2_LANES; + lwsc |= PORT_LOGIC_LINK_WIDTH_2_LANES; + break; + case 4: + plc |= PORT_LINK_MODE_4_LANES; + lwsc |= PORT_LOGIC_LINK_WIDTH_4_LANES; + break; + case 8: + plc |= PORT_LINK_MODE_8_LANES; + lwsc |= PORT_LOGIC_LINK_WIDTH_8_LANES; + break; + default: + dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes); + return; + } + dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc); + dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc); +} + void dw_pcie_iatu_detect(struct dw_pcie *pci) { int max_region, ob, ib; @@ -1013,49 +1053,5 @@ void dw_pcie_setup(struct dw_pcie *pci) val |= PORT_LINK_DLL_LINK_EN; dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val); - if (!pci->num_lanes) { - dev_dbg(pci->dev, "Using h/w default number of lanes\n"); - return; - } - - /* Set the number of lanes */ - val &= ~PORT_LINK_FAST_LINK_MODE; - val &= ~PORT_LINK_MODE_MASK; - switch (pci->num_lanes) { - case 1: - val |= PORT_LINK_MODE_1_LANES; - break; - case 2: - val |= PORT_LINK_MODE_2_LANES; - break; - case 4: - val |= PORT_LINK_MODE_4_LANES; - break; - case 8: - val |= PORT_LINK_MODE_8_LANES; - break; - default: - dev_err(pci->dev, "num-lanes %u: invalid value\n", pci->num_lanes); - return; - } - dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val); - - /* Set link width speed control register */ - val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); - val &= ~PORT_LOGIC_LINK_WIDTH_MASK; - switch (pci->num_lanes) { - case 1: - val |= PORT_LOGIC_LINK_WIDTH_1_LANES; - break; - case 2: - val |= PORT_LOGIC_LINK_WIDTH_2_LANES; - break; - case 4: - val |= PORT_LOGIC_LINK_WIDTH_4_LANES; - break; - case 8: - val |= PORT_LOGIC_LINK_WIDTH_8_LANES; - break; - } - dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val); + dw_pcie_link_set_max_link_width(pci, pci->num_lanes); } -- 2.25.1
