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[75.72.117.212]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-94359efe149sm604118039f.13.2025.10.30.15.03.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Oct 2025 15:03:12 -0700 (PDT) From: Alex Elder To: lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org, robh@kernel.org, bhelgaas@google.com Cc: dlan@gentoo.org, aurelien@aurel32.net, johannes@erdfelt.com, p.zabel@pengutronix.de, christian.bruel@foss.st.com, thippeswamy.havalige@amd.com, krishna.chundru@oss.qualcomm.com, mayank.rana@oss.qualcomm.com, qiang.yu@oss.qualcomm.com, shradha.t@samsung.com, inochiama@gmail.com, guodong@riscstar.com, linux-pci@vger.kernel.org, spacemit@lists.linux.dev, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver Date: Thu, 30 Oct 2025 17:02:56 -0500 Message-ID: <20251030220259.1063792-6-elder@riscstar.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20251030220259.1063792-1-elder@riscstar.com> References: <20251030220259.1063792-1-elder@riscstar.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce a driver for the PCIe host controller found in the SpacemiT K1 SoC. The hardware is derived from the Synopsys DesignWare PCIe IP. The driver supports three PCIe ports that operate at PCIe gen2 transfer rates (5 GT/sec). The first port uses a combo PHY, which may be configured for use for USB 3 instead. Signed-off-by: Alex Elder --- drivers/pci/controller/dwc/Kconfig | 11 + drivers/pci/controller/dwc/Makefile | 1 + drivers/pci/controller/dwc/pcie-spacemit-k1.c | 349 ++++++++++++++++++ 3 files changed, 361 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-spacemit-k1.c diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index 349d4657393c9..d229260f0337e 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig @@ -509,6 +509,17 @@ config PCI_KEYSTONE_EP on DesignWare hardware and therefore the driver re-uses the DesignWare core functions to implement the driver. +config PCIE_SPACEMIT_K1 + tristate "SpacemiT K1 PCIe controller (host mode)" + depends on ARCH_SPACEMIT || COMPILE_TEST + depends on PCI && OF && HAS_IOMEM + select PCIE_DW_HOST + select PCI_PWRCTRL_SLOT + default ARCH_SPACEMIT + help + Enables support for the PCIe controller in the K1 SoC operating + in host mode. + config PCIE_VISCONTI_HOST bool "Toshiba Visconti PCIe controller" depends on ARCH_VISCONTI || COMPILE_TEST diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile index 7ae28f3b0fb39..662b0a219ddc4 100644 --- a/drivers/pci/controller/dwc/Makefile +++ b/drivers/pci/controller/dwc/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o +obj-$(CONFIG_PCIE_SPACEMIT_K1) += pcie-spacemit-k1.o obj-$(CONFIG_PCIE_STM32_HOST) += pcie-stm32.o obj-$(CONFIG_PCIE_STM32_EP) += pcie-stm32-ep.o diff --git a/drivers/pci/controller/dwc/pcie-spacemit-k1.c b/drivers/pci/controller/dwc/pcie-spacemit-k1.c new file mode 100644 index 0000000000000..2efb92ef948f2 --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-spacemit-k1.c @@ -0,0 +1,349 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SpacemiT K1 PCIe host driver + * + * Copyright (C) 2025 by RISCstar Solutions Corporation. All rights reserved. + * Copyright (c) 2023, spacemit Corporation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pcie-designware.h" + +#define PCI_VENDOR_ID_SPACEMIT 0x201f +#define PCI_DEVICE_ID_SPACEMIT_K1 0x0001 + +/* Offsets and field definitions for link management registers */ +#define K1_PHY_AHB_IRQ_EN 0x0000 +#define PCIE_INTERRUPT_EN BIT(0) + +#define K1_PHY_AHB_LINK_STS 0x0004 +#define SMLH_LINK_UP BIT(1) +#define RDLH_LINK_UP BIT(12) + +#define INTR_ENABLE 0x0014 +#define MSI_CTRL_INT BIT(11) + +/* Some controls require APMU regmap access */ +#define SYSCON_APMU "spacemit,apmu" + +/* Offsets and field definitions for APMU registers */ +#define PCIE_CLK_RESET_CONTROL 0x0000 +#define LTSSM_EN BIT(6) +#define PCIE_AUX_PWR_DET BIT(9) +#define PCIE_RC_PERST BIT(12) /* 1: assert PERST# */ +#define APP_HOLD_PHY_RST BIT(30) +#define DEVICE_TYPE_RC BIT(31) /* 0: endpoint; 1: RC */ + +#define PCIE_CONTROL_LOGIC 0x0004 +#define PCIE_SOFT_RESET BIT(0) + +struct k1_pcie { + struct dw_pcie pci; + struct phy *phy; + void __iomem *link; + struct regmap *pmu; /* Errors ignored; MMIO-backed regmap */ + u32 pmu_off; +}; + +#define to_k1_pcie(dw_pcie) \ + platform_get_drvdata(to_platform_device((dw_pcie)->dev)) + +static void k1_pcie_toggle_soft_reset(struct k1_pcie *k1) +{ + u32 offset; + u32 val; + + /* + * Write, then read back to guarantee it has reached the device + * before we start the delay. + */ + offset = k1->pmu_off + PCIE_CONTROL_LOGIC; + regmap_set_bits(k1->pmu, offset, PCIE_SOFT_RESET); + regmap_read(k1->pmu, offset, &val); + + mdelay(2); + + regmap_clear_bits(k1->pmu, offset, PCIE_SOFT_RESET); +} + +/* Enable app clocks, deassert resets */ +static int k1_pcie_enable_resources(struct k1_pcie *k1) +{ + struct dw_pcie *pci = &k1->pci; + int ret; + + ret = clk_bulk_prepare_enable(ARRAY_SIZE(pci->app_clks), pci->app_clks); + if (ret) + return ret; + + ret = reset_control_bulk_deassert(ARRAY_SIZE(pci->app_rsts), + pci->app_rsts); + if (ret) + goto err_disable_clks; + + return 0; + +err_disable_clks: + clk_bulk_disable_unprepare(ARRAY_SIZE(pci->app_clks), pci->app_clks); + + return ret; +} + +/* Assert resets, disable app clocks */ +static void k1_pcie_disable_resources(struct k1_pcie *k1) +{ + struct dw_pcie *pci = &k1->pci; + + reset_control_bulk_assert(ARRAY_SIZE(pci->app_rsts), pci->app_rsts); + clk_bulk_disable_unprepare(ARRAY_SIZE(pci->app_clks), pci->app_clks); +} + +static int k1_pcie_init(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct k1_pcie *k1 = to_k1_pcie(pci); + u32 offset; + u32 mask; + u32 val; + int ret; + + k1_pcie_toggle_soft_reset(k1); + + ret = k1_pcie_enable_resources(k1); + if (ret) + return ret; + + ret = phy_init(k1->phy); + if (ret) { + k1_pcie_disable_resources(k1); + + return ret; + } + + /* Set the PCI vendor and device ID */ + dw_pcie_dbi_ro_wr_en(pci); + dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, PCI_VENDOR_ID_SPACEMIT); + dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, PCI_DEVICE_ID_SPACEMIT_K1); + dw_pcie_dbi_ro_wr_dis(pci); + + /* + * Assert fundamental reset (drive PERST# low). Put the controller + * in root complex mode, and indicate that Vaux (3.3v) is present. + */ + mask = PCIE_RC_PERST; + mask |= DEVICE_TYPE_RC | PCIE_AUX_PWR_DET; + + /* + * Write, then read back to guarantee it has reached the device + * before we start the delay. + */ + offset = k1->pmu_off + PCIE_CLK_RESET_CONTROL; + regmap_set_bits(k1->pmu, offset, mask); + regmap_read(k1->pmu, offset, &val); + + mdelay(PCIE_T_PVPERL_MS); + + /* Deassert fundamental reset (drive PERST# high) */ + regmap_clear_bits(k1->pmu, offset, PCIE_RC_PERST); + + return 0; +} + +/* Disable ASPM L1 for now, until reported errors can be reproduced */ +static void k1_pcie_post_init(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + u8 offset; + u32 val; + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + + dw_pcie_dbi_ro_wr_en(pci); + + /* Turn off ASPM L1 for the link */ + val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP); + val &= ~PCI_EXP_LNKCAP_ASPM_L1; + writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP); + + dw_pcie_dbi_ro_wr_dis(pci); +} + +static void k1_pcie_deinit(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct k1_pcie *k1 = to_k1_pcie(pci); + + /* Assert fundamental reset (drive PERST# low) */ + regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL, + PCIE_RC_PERST); + + phy_exit(k1->phy); + + k1_pcie_disable_resources(k1); +} + +static const struct dw_pcie_host_ops k1_pcie_host_ops = { + .init = k1_pcie_init, + .post_init = k1_pcie_post_init, + .deinit = k1_pcie_deinit, +}; + +static bool k1_pcie_link_up(struct dw_pcie *pci) +{ + struct k1_pcie *k1 = to_k1_pcie(pci); + u32 val; + + val = readl_relaxed(k1->link + K1_PHY_AHB_LINK_STS); + + return (val & RDLH_LINK_UP) && (val & SMLH_LINK_UP); +} + +static int k1_pcie_start_link(struct dw_pcie *pci) +{ + struct k1_pcie *k1 = to_k1_pcie(pci); + u32 val; + + /* Stop holding the PHY in reset, and enable link training */ + regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL, + APP_HOLD_PHY_RST | LTSSM_EN, LTSSM_EN); + + /* Enable the MSI interrupt */ + writel_relaxed(MSI_CTRL_INT, k1->link + INTR_ENABLE); + + /* Top-level interrupt enable */ + val = readl_relaxed(k1->link + K1_PHY_AHB_IRQ_EN); + val |= PCIE_INTERRUPT_EN; + writel_relaxed(val, k1->link + K1_PHY_AHB_IRQ_EN); + + return 0; +} + +static void k1_pcie_stop_link(struct dw_pcie *pci) +{ + struct k1_pcie *k1 = to_k1_pcie(pci); + u32 val; + + /* Disable interrupts */ + val = readl_relaxed(k1->link + K1_PHY_AHB_IRQ_EN); + val &= ~PCIE_INTERRUPT_EN; + writel_relaxed(val, k1->link + K1_PHY_AHB_IRQ_EN); + + writel_relaxed(0, k1->link + INTR_ENABLE); + + /* Disable the link and hold the PHY in reset */ + regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL, + APP_HOLD_PHY_RST | LTSSM_EN, APP_HOLD_PHY_RST); +} + +static const struct dw_pcie_ops k1_pcie_ops = { + .link_up = k1_pcie_link_up, + .start_link = k1_pcie_start_link, + .stop_link = k1_pcie_stop_link, +}; + +static int k1_pcie_parse_port(struct k1_pcie *k1) +{ + struct device *dev = k1->pci.dev; + struct device_node *root_port; + struct phy *phy; + + /* We assume only one root port */ + root_port = of_get_next_available_child(dev_of_node(dev), NULL); + if (!root_port) + return -EINVAL; + + phy = devm_of_phy_get(dev, root_port, NULL); + + of_node_put(root_port); + + if (IS_ERR(phy)) + return PTR_ERR(phy); + + k1->phy = phy; + + return 0; +} + +static int k1_pcie_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct k1_pcie *k1; + int ret; + + k1 = devm_kzalloc(dev, sizeof(*k1), GFP_KERNEL); + if (!k1) + return -ENOMEM; + + k1->pmu = syscon_regmap_lookup_by_phandle_args(dev_of_node(dev), + SYSCON_APMU, 1, + &k1->pmu_off); + if (IS_ERR(k1->pmu)) + return dev_err_probe(dev, PTR_ERR(k1->pmu), + "failed to lookup PMU registers\n"); + + k1->link = devm_platform_ioremap_resource_byname(pdev, "link"); + if (!k1->link) + return dev_err_probe(dev, -ENOMEM, + "failed to map \"link\" registers\n"); + + k1->pci.dev = dev; + k1->pci.ops = &k1_pcie_ops; + dw_pcie_cap_set(&k1->pci, REQ_RES); + + k1->pci.pp.ops = &k1_pcie_host_ops; + + /* Hold the PHY in reset until we start the link */ + regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL, + APP_HOLD_PHY_RST); + + pm_runtime_set_active(dev); + pm_runtime_no_callbacks(dev); + devm_pm_runtime_enable(dev); + + platform_set_drvdata(pdev, k1); + + ret = k1_pcie_parse_port(k1); + if (ret) + return dev_err_probe(dev, ret, "failed to parse root port\n"); + + ret = dw_pcie_host_init(&k1->pci.pp); + if (ret) + return dev_err_probe(dev, ret, "failed to initialize host\n"); + + return 0; +} + +static void k1_pcie_remove(struct platform_device *pdev) +{ + struct k1_pcie *k1 = platform_get_drvdata(pdev); + + dw_pcie_host_deinit(&k1->pci.pp); +} + +static const struct of_device_id k1_pcie_of_match_table[] = { + { .compatible = "spacemit,k1-pcie", }, + { }, +}; + +static struct platform_driver k1_pcie_driver = { + .probe = k1_pcie_probe, + .remove = k1_pcie_remove, + .driver = { + .name = "spacemit-k1-pcie", + .of_match_table = k1_pcie_of_match_table, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_platform_driver(k1_pcie_driver); -- 2.48.1