From 487a731517391bbc6e887ac242fc11d4f61088e8 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 21 Sep 2026 22:27:47 +0200 Subject: [PATCH] PCI: rcar-gen4: Handle PERST# via reset subsystem Handle PERST# via both GPIO and reset subsystem. On R-Car Gen4, the PERST# signal is operated as a GPIO, on R-Car Gen5 it might only be accessible via SCMI reset via reset subsystem. Support both options. This is a preparatory work for R-Car Gen5 support. Signed-off-by: Marek Vasut Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260921202823.72620-6-marek.vasut+renesas@mailbox.org --- drivers/pci/controller/dwc/pcie-rcar-gen4.c | 41 +++++++++++++++++++-- 1 file changed, 37 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c index c768a9c7b3b7..cf1f5de45182 100644 --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c @@ -99,6 +99,7 @@ struct rcar_gen4_pcie { void __iomem *base; void __iomem *phy_base; struct platform_device *pdev; + struct reset_control *perst; const struct rcar_gen4_pcie_drvdata *drvdata; }; #define to_rcar_gen4_pcie(_dw) container_of(_dw, struct rcar_gen4_pcie, dw) @@ -317,12 +318,25 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar) static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar) { + struct device *dev = rcar->dw.dev; + struct device_node *root_port; + rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy"); if (IS_ERR(rcar->phy_base)) return PTR_ERR(rcar->phy_base); + root_port = of_get_next_available_child(dev->of_node, NULL); + if (root_port) { + rcar->perst = of_reset_control_get_optional_exclusive(root_port, "perst"); + of_node_put(root_port); + if (IS_ERR(rcar->perst)) + return dev_err_probe(dev, PTR_ERR(rcar->perst), "Failed to get PERST#\n"); + } + /* Renesas-specific registers */ rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app"); + if (IS_ERR(rcar->base)) + reset_control_put(rcar->perst); return PTR_ERR_OR_ZERO(rcar->base); } @@ -494,6 +508,21 @@ static int rcar_gen4_pcie_enable_device(struct pci_host_bridge *bridge, return 0; } +static void rcar_gen4_pcie_host_perst_assert(struct dw_pcie_rp *pp, bool assert) +{ + struct dw_pcie *dw = to_dw_pcie_from_pp(pp); + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw); + + if (dw->pe_rst) { + gpiod_set_value_cansleep(dw->pe_rst, assert); + } else { + if (assert) + reset_control_assert(rcar->perst); + else + reset_control_deassert(rcar->perst); + } +} + /* Host mode */ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp) { @@ -504,7 +533,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp) if (pp->bridge) pp->bridge->enable_device = rcar_gen4_pcie_enable_device; - gpiod_set_value_cansleep(dw->pe_rst, 1); + rcar_gen4_pcie_host_perst_assert(pp, true); ret = rcar->drvdata->init(rcar); if (ret) @@ -525,7 +554,7 @@ static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp) msleep(PCIE_T_PVPERL_MS); /* pe_rst requires 100msec delay */ - gpiod_set_value_cansleep(dw->pe_rst, 0); + rcar_gen4_pcie_host_perst_assert(pp, false); return 0; @@ -539,7 +568,7 @@ static void rcar_gen4_pcie_host_deinit(struct dw_pcie_rp *pp) struct dw_pcie *dw = to_dw_pcie_from_pp(pp); struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw); - gpiod_set_value_cansleep(dw->pe_rst, 1); + rcar_gen4_pcie_host_perst_assert(pp, true); rcar->drvdata->deinit(rcar); } @@ -713,7 +742,7 @@ static int rcar_gen4_pcie_probe(struct platform_device *pdev) err = rcar_gen4_pcie_prepare(rcar); if (err) - return err; + goto err_prepare; err = rcar_gen4_add_dw_pcie(rcar); if (err) @@ -724,6 +753,9 @@ static int rcar_gen4_pcie_probe(struct platform_device *pdev) err_unprepare: rcar_gen4_pcie_unprepare(rcar); +err_prepare: + reset_control_put(rcar->perst); + return err; } @@ -747,6 +779,7 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev) rcar_gen4_remove_dw_pcie(rcar); rcar_gen4_pcie_unprepare(rcar); + reset_control_put(rcar->perst); } static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)