From: Sherry Sun Date: Wed, 22 Apr 2026 09:35:41 +0000 (+0800) Subject: PCI: imx6: Parse 'reset-gpios' in Root Port nodes X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=250eea5c06f5291603612cdf0c60326db4e19141;p=thirdparty%2Fkernel%2Flinux.git PCI: imx6: Parse 'reset-gpios' in Root Port nodes The current DT binding for pci-imx6 specifies the 'reset-gpios' property in the host bridge node. However, the PERST# signal logically belongs to individual Root Ports rather than the host bridge itself. This becomes important when supporting PCIe Key E connector and the PCI power control framework for pci-imx6 driver, which requires properties to be specified in Root Port nodes. Parse 'reset-gpios' from Root Port nodes and the PCIe bridge nodes under the Root Port using the common helper pci_host_common_parse_ports(), and update the reset GPIO handling to use the parsed port list from bridge->ports. To maintain DT backwards compatibility, fall back to the legacy method of parsing the host bridge node if the reset property is not present in the Root Port nodes. Since now the reset GPIO is obtained with GPIOD_ASIS flag, it may be in input mode, so use gpiod_direction_output() instead of gpiod_set_value_cansleep() to ensure the reset GPIO is properly configured as output before setting its value. Signed-off-by: Sherry Sun Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Acked-by: Richard Zhu Link: https://patch.msgid.link/20260422093549.407022-5-sherry.sun@nxp.com --- diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 5335c2b140fb5..773ab65b2afac 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -34,6 +34,7 @@ #include #include "../../pci.h" +#include "../pci-host-common.h" #include "pcie-designware.h" #define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9) @@ -152,7 +153,6 @@ struct imx_lut_data { struct imx_pcie { struct dw_pcie *pci; - struct gpio_desc *reset_gpiod; struct clk_bulk_data *clks; int num_clks; bool supports_clkreq; @@ -1219,6 +1219,41 @@ static void imx_pcie_disable_device(struct pci_host_bridge *bridge, imx_pcie_remove_lut(imx_pcie, pci_dev_id(pdev)); } +static int imx_pcie_parse_legacy_binding(struct imx_pcie *pcie) +{ + struct device *dev = pcie->pci->dev; + struct pci_host_bridge *bridge = pcie->pci->pp.bridge; + struct pci_host_port *port; + struct pci_host_perst *perst; + struct gpio_desc *reset; + + reset = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS); + if (IS_ERR(reset)) + return PTR_ERR(reset); + + if (!reset) + return 0; + + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + perst = devm_kzalloc(dev, sizeof(*perst), GFP_KERNEL); + if (!perst) + return -ENOMEM; + + INIT_LIST_HEAD(&port->perst); + perst->desc = reset; + INIT_LIST_HEAD(&perst->list); + list_add_tail(&perst->list, &port->perst); + + INIT_LIST_HEAD(&port->list); + list_add_tail(&port->list, &bridge->ports); + + return devm_add_action_or_reset(dev, pci_host_common_delete_ports, + &bridge->ports); +} + static void imx_pcie_vpcie_aux_disable(void *data) { struct regulator *vpcie_aux = data; @@ -1228,14 +1263,26 @@ static void imx_pcie_vpcie_aux_disable(void *data) static void imx_pcie_assert_perst(struct imx_pcie *imx_pcie, bool assert) { + struct dw_pcie *pci = imx_pcie->pci; + struct pci_host_bridge *bridge = pci->pp.bridge; + struct pci_host_perst *perst; + struct pci_host_port *port; + + if (!bridge || list_empty(&bridge->ports)) + return; + if (assert) { - gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 1); + list_for_each_entry(port, &bridge->ports, list) { + list_for_each_entry(perst, &port->perst, list) + gpiod_direction_output(perst->desc, 1); + } } else { - if (imx_pcie->reset_gpiod) { - msleep(PCIE_T_PVPERL_MS); - gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 0); - msleep(PCIE_RESET_CONFIG_WAIT_MS); + mdelay(PCIE_T_PVPERL_MS); + list_for_each_entry(port, &bridge->ports, list) { + list_for_each_entry(perst, &port->perst, list) + gpiod_direction_output(perst->desc, 0); } + mdelay(PCIE_RESET_CONFIG_WAIT_MS); } } @@ -1244,8 +1291,28 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp) struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct device *dev = pci->dev; struct imx_pcie *imx_pcie = to_imx_pcie(pci); + struct pci_host_bridge *bridge = pp->bridge; int ret; + if (bridge && list_empty(&bridge->ports)) { + /* Parse Root Port nodes if present */ + ret = pci_host_common_parse_ports(dev, bridge); + if (ret) { + if (ret != -ENODEV) { + dev_err(dev, "Failed to parse Root Port nodes: %d\n", ret); + return ret; + } + + /* + * Fall back to legacy binding for DT backwards + * compatibility + */ + ret = imx_pcie_parse_legacy_binding(imx_pcie); + if (ret) + return ret; + } + } + imx_pcie_assert_perst(imx_pcie, true); /* Keep 3.3Vaux supply enabled for entire PCIe controller lifecycle */ @@ -1699,13 +1766,6 @@ static int imx_pcie_probe(struct platform_device *pdev) return PTR_ERR(imx_pcie->phy_base); } - /* Fetch GPIOs */ - imx_pcie->reset_gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); - if (IS_ERR(imx_pcie->reset_gpiod)) - return dev_err_probe(dev, PTR_ERR(imx_pcie->reset_gpiod), - "unable to get reset gpio\n"); - gpiod_set_consumer_name(imx_pcie->reset_gpiod, "PCIe reset"); - /* Fetch clocks */ imx_pcie->num_clks = devm_clk_bulk_get_all(dev, &imx_pcie->clks); if (imx_pcie->num_clks < 0)