diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-stm32.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-stm32.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-stm32.c b/drivers/pci/controller/dwc/pcie-stm32.c new file mode 100644 index 000000000000..96a5fb893af4 --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-stm32.c @@ -0,0 +1,358 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * STMicroelectronics STM32MP25 PCIe root complex driver. + * + * Copyright (C) 2025 STMicroelectronics + * Author: Christian Bruel <christian.bruel@foss.st.com> + */ + +#include <linux/clk.h> +#include <linux/mfd/syscon.h> +#include <linux/of_platform.h> +#include <linux/phy/phy.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/pm_wakeirq.h> +#include <linux/regmap.h> +#include <linux/reset.h> +#include "pcie-designware.h" +#include "pcie-stm32.h" +#include "../../pci.h" + +struct stm32_pcie { + struct dw_pcie pci; + struct regmap *regmap; + struct reset_control *rst; + struct phy *phy; + struct clk *clk; + struct gpio_desc *perst_gpio; + struct gpio_desc *wake_gpio; +}; + +static void stm32_pcie_deassert_perst(struct stm32_pcie *stm32_pcie) +{ + if (stm32_pcie->perst_gpio) { + msleep(PCIE_T_PVPERL_MS); + gpiod_set_value(stm32_pcie->perst_gpio, 0); + } + + msleep(PCIE_RESET_CONFIG_WAIT_MS); +} + +static void stm32_pcie_assert_perst(struct stm32_pcie *stm32_pcie) +{ + gpiod_set_value(stm32_pcie->perst_gpio, 1); +} + +static int stm32_pcie_start_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + + return regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_LTSSM_EN, + STM32MP25_PCIECR_LTSSM_EN); +} + +static void stm32_pcie_stop_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_LTSSM_EN, 0); +} + +static int stm32_pcie_suspend_noirq(struct device *dev) +{ + struct stm32_pcie *stm32_pcie = dev_get_drvdata(dev); + int ret; + + ret = dw_pcie_suspend_noirq(&stm32_pcie->pci); + if (ret) + return ret; + + stm32_pcie_assert_perst(stm32_pcie); + + clk_disable_unprepare(stm32_pcie->clk); + + if (!device_wakeup_path(dev)) + phy_exit(stm32_pcie->phy); + + return pinctrl_pm_select_sleep_state(dev); +} + +static int stm32_pcie_resume_noirq(struct device *dev) +{ + struct stm32_pcie *stm32_pcie = dev_get_drvdata(dev); + int ret; + + /* + * The core clock is gated with CLKREQ# from the COMBOPHY REFCLK, + * thus if no device is present, must deassert it with a GPIO from + * pinctrl pinmux before accessing the DBI registers. + */ + ret = pinctrl_pm_select_init_state(dev); + if (ret) { + dev_err(dev, "Failed to activate pinctrl pm state: %d\n", ret); + return ret; + } + + if (!device_wakeup_path(dev)) { + ret = phy_init(stm32_pcie->phy); + if (ret) { + pinctrl_pm_select_default_state(dev); + return ret; + } + } + + ret = clk_prepare_enable(stm32_pcie->clk); + if (ret) + goto err_phy_exit; + + stm32_pcie_deassert_perst(stm32_pcie); + + ret = dw_pcie_resume_noirq(&stm32_pcie->pci); + if (ret) + goto err_disable_clk; + + pinctrl_pm_select_default_state(dev); + + return 0; + +err_disable_clk: + stm32_pcie_assert_perst(stm32_pcie); + clk_disable_unprepare(stm32_pcie->clk); + +err_phy_exit: + phy_exit(stm32_pcie->phy); + pinctrl_pm_select_default_state(dev); + + return ret; +} + +static const struct dev_pm_ops stm32_pcie_pm_ops = { + NOIRQ_SYSTEM_SLEEP_PM_OPS(stm32_pcie_suspend_noirq, + stm32_pcie_resume_noirq) +}; + +static const struct dw_pcie_host_ops stm32_pcie_host_ops = { +}; + +static const struct dw_pcie_ops dw_pcie_ops = { + .start_link = stm32_pcie_start_link, + .stop_link = stm32_pcie_stop_link +}; + +static int stm32_add_pcie_port(struct stm32_pcie *stm32_pcie) +{ + struct device *dev = stm32_pcie->pci.dev; + unsigned int wake_irq; + int ret; + + ret = phy_set_mode(stm32_pcie->phy, PHY_MODE_PCIE); + if (ret) + return ret; + + ret = phy_init(stm32_pcie->phy); + if (ret) + return ret; + + ret = regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_TYPE_MASK, + STM32MP25_PCIECR_RC); + if (ret) + goto err_phy_exit; + + stm32_pcie_deassert_perst(stm32_pcie); + + if (stm32_pcie->wake_gpio) { + wake_irq = gpiod_to_irq(stm32_pcie->wake_gpio); + ret = dev_pm_set_dedicated_wake_irq(dev, wake_irq); + if (ret) { + dev_err(dev, "Failed to enable wakeup irq %d\n", ret); + goto err_assert_perst; + } + irq_set_irq_type(wake_irq, IRQ_TYPE_EDGE_FALLING); + } + + return 0; + +err_assert_perst: + stm32_pcie_assert_perst(stm32_pcie); + +err_phy_exit: + phy_exit(stm32_pcie->phy); + + return ret; +} + +static void stm32_remove_pcie_port(struct stm32_pcie *stm32_pcie) +{ + dev_pm_clear_wake_irq(stm32_pcie->pci.dev); + + stm32_pcie_assert_perst(stm32_pcie); + + phy_exit(stm32_pcie->phy); +} + +static int stm32_pcie_parse_port(struct stm32_pcie *stm32_pcie) +{ + struct device *dev = stm32_pcie->pci.dev; + struct device_node *root_port; + + root_port = of_get_next_available_child(dev->of_node, NULL); + + stm32_pcie->phy = devm_of_phy_get(dev, root_port, NULL); + if (IS_ERR(stm32_pcie->phy)) { + of_node_put(root_port); + return dev_err_probe(dev, PTR_ERR(stm32_pcie->phy), + "Failed to get pcie-phy\n"); + } + + stm32_pcie->perst_gpio = devm_fwnode_gpiod_get(dev, of_fwnode_handle(root_port), + "reset", GPIOD_OUT_HIGH, NULL); + if (IS_ERR(stm32_pcie->perst_gpio)) { + if (PTR_ERR(stm32_pcie->perst_gpio) != -ENOENT) { + of_node_put(root_port); + return dev_err_probe(dev, PTR_ERR(stm32_pcie->perst_gpio), + "Failed to get reset GPIO\n"); + } + stm32_pcie->perst_gpio = NULL; + } + + stm32_pcie->wake_gpio = devm_fwnode_gpiod_get(dev, of_fwnode_handle(root_port), + "wake", GPIOD_IN, NULL); + + if (IS_ERR(stm32_pcie->wake_gpio)) { + if (PTR_ERR(stm32_pcie->wake_gpio) != -ENOENT) { + of_node_put(root_port); + return dev_err_probe(dev, PTR_ERR(stm32_pcie->wake_gpio), + "Failed to get wake GPIO\n"); + } + stm32_pcie->wake_gpio = NULL; + } + + of_node_put(root_port); + + return 0; +} + +static int stm32_pcie_probe(struct platform_device *pdev) +{ + struct stm32_pcie *stm32_pcie; + struct device *dev = &pdev->dev; + int ret; + + stm32_pcie = devm_kzalloc(dev, sizeof(*stm32_pcie), GFP_KERNEL); + if (!stm32_pcie) + return -ENOMEM; + + stm32_pcie->pci.dev = dev; + stm32_pcie->pci.ops = &dw_pcie_ops; + stm32_pcie->pci.pp.ops = &stm32_pcie_host_ops; + + stm32_pcie->regmap = syscon_regmap_lookup_by_compatible("st,stm32mp25-syscfg"); + if (IS_ERR(stm32_pcie->regmap)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->regmap), + "No syscfg specified\n"); + + stm32_pcie->clk = devm_clk_get(dev, NULL); + if (IS_ERR(stm32_pcie->clk)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->clk), + "Failed to get PCIe clock source\n"); + + stm32_pcie->rst = devm_reset_control_get_exclusive(dev, NULL); + if (IS_ERR(stm32_pcie->rst)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->rst), + "Failed to get PCIe reset\n"); + + ret = stm32_pcie_parse_port(stm32_pcie); + if (ret) + return ret; + + platform_set_drvdata(pdev, stm32_pcie); + + ret = stm32_add_pcie_port(stm32_pcie); + if (ret) + return ret; + + reset_control_assert(stm32_pcie->rst); + reset_control_deassert(stm32_pcie->rst); + + ret = clk_prepare_enable(stm32_pcie->clk); + if (ret) { + dev_err(dev, "Core clock enable failed %d\n", ret); + goto err_remove_port; + } + + ret = pm_runtime_set_active(dev); + if (ret < 0) { + dev_err_probe(dev, ret, "Failed to activate runtime PM\n"); + goto err_disable_clk; + } + + pm_runtime_no_callbacks(dev); + + ret = devm_pm_runtime_enable(dev); + if (ret < 0) { + dev_err_probe(dev, ret, "Failed to enable runtime PM\n"); + goto err_disable_clk; + } + + ret = dw_pcie_host_init(&stm32_pcie->pci.pp); + if (ret) + goto err_disable_clk; + + if (stm32_pcie->wake_gpio) + device_init_wakeup(dev, true); + + return 0; + +err_disable_clk: + clk_disable_unprepare(stm32_pcie->clk); + +err_remove_port: + stm32_remove_pcie_port(stm32_pcie); + + return ret; +} + +static void stm32_pcie_remove(struct platform_device *pdev) +{ + struct stm32_pcie *stm32_pcie = platform_get_drvdata(pdev); + struct dw_pcie_rp *pp = &stm32_pcie->pci.pp; + + if (stm32_pcie->wake_gpio) + device_init_wakeup(&pdev->dev, false); + + dw_pcie_host_deinit(pp); + + clk_disable_unprepare(stm32_pcie->clk); + + stm32_remove_pcie_port(stm32_pcie); + + pm_runtime_put_noidle(&pdev->dev); +} + +static const struct of_device_id stm32_pcie_of_match[] = { + { .compatible = "st,stm32mp25-pcie-rc" }, + {}, +}; + +static struct platform_driver stm32_pcie_driver = { + .probe = stm32_pcie_probe, + .remove = stm32_pcie_remove, + .driver = { + .name = "stm32-pcie", + .of_match_table = stm32_pcie_of_match, + .pm = &stm32_pcie_pm_ops, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; + +module_platform_driver(stm32_pcie_driver); + +MODULE_AUTHOR("Christian Bruel <christian.bruel@foss.st.com>"); +MODULE_DESCRIPTION("STM32MP25 PCIe Controller driver"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(of, stm32_pcie_of_match); |