// SPDX-License-Identifier: GPL-2.0-only /* * PCIe controller driver for Intel Keem Bay * Copyright (C) 2020 Intel Corporation */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pcie-designware.h" /* PCIE_REGS_APB_SLV Registers */ #define PCIE_REGS_PCIE_CFG 0x0004 #define PCIE_DEVICE_TYPE BIT(8) #define PCIE_RSTN BIT(0) #define PCIE_REGS_PCIE_APP_CNTRL 0x0008 #define APP_LTSSM_ENABLE BIT(0) #define PCIE_REGS_INTERRUPT_ENABLE 0x0028 #define MSI_CTRL_INT_EN BIT(8) #define EDMA_INT_EN GENMASK(7, 0) #define PCIE_REGS_INTERRUPT_STATUS 0x002c #define MSI_CTRL_INT BIT(8) #define PCIE_REGS_PCIE_SII_PM_STATE 0x00b0 #define SMLH_LINK_UP BIT(19) #define RDLH_LINK_UP BIT(8) #define PCIE_REGS_PCIE_SII_LINK_UP (SMLH_LINK_UP | RDLH_LINK_UP) #define PCIE_REGS_PCIE_PHY_CNTL 0x0164 #define PHY0_SRAM_BYPASS BIT(8) #define PCIE_REGS_PCIE_PHY_STAT 0x0168 #define PHY0_MPLLA_STATE BIT(1) #define PCIE_REGS_LJPLL_STA 0x016c #define LJPLL_LOCK BIT(0) #define PCIE_REGS_LJPLL_CNTRL_0 0x0170 #define LJPLL_EN BIT(29) #define LJPLL_FOUT_EN GENMASK(24, 21) #define PCIE_REGS_LJPLL_CNTRL_2 0x0178 #define LJPLL_REF_DIV GENMASK(17, 12) #define LJPLL_FB_DIV GENMASK(11, 0) #define PCIE_REGS_LJPLL_CNTRL_3 0x017c #define LJPLL_POST_DIV3A GENMASK(24, 22) #define LJPLL_POST_DIV2A GENMASK(18, 16) #define PERST_DELAY_US 1000 #define AUX_CLK_RATE_HZ 24000000 struct keembay_pcie { struct dw_pcie pci; void __iomem *apb_base; enum dw_pcie_device_mode mode; struct clk *clk_master; struct clk *clk_aux; struct gpio_desc *reset; }; struct keembay_pcie_of_data { enum dw_pcie_device_mode mode; }; static void keembay_ep_reset_assert(struct keembay_pcie *pcie) { gpiod_set_value_cansleep(pcie->reset, 1); usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500); } static void keembay_ep_reset_deassert(struct keembay_pcie *pcie) { /* * Ensure that PERST# is asserted for a minimum of 100ms. * * For more details, refer to PCI Express Card Electromechanical * Specification Revision 1.1, Table-2.4. */ msleep(100); gpiod_set_value_cansleep(pcie->reset, 0); usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500); } static void keembay_pcie_ltssm_set(struct keembay_pcie *pcie, bool enable) { u32 val; val = readl(pcie->apb_base + PCIE_REGS_PCIE_APP_CNTRL); if (enable) val |= APP_LTSSM_ENABLE; else val &= ~APP_LTSSM_ENABLE; writel(val, pcie->apb_base + PCIE_REGS_PCIE_APP_CNTRL); } static int keembay_pcie_link_up(struct dw_pcie *pci) { struct keembay_pcie *pcie = dev_get_drvdata(pci->dev); u32 val; val = readl(pcie->apb_base + PCIE_REGS_PCIE_SII_PM_STATE); return (val & PCIE_REGS_PCIE_SII_LINK_UP) == PCIE_REGS_PCIE_SII_LINK_UP; } static int keembay_pcie_start_link(struct dw_pcie *pci) { struct keembay_pcie *pcie = dev_get_drvdata(pci->dev); u32 val; int ret; if (pcie->mode == DW_PCIE_EP_TYPE) return 0; keembay_pcie_ltssm_set(pcie, false); ret = readl_poll_timeout(pcie->apb_base + PCIE_REGS_PCIE_PHY_STAT, val, val & PHY0_MPLLA_STATE, 20, 500 * USEC_PER_MSEC); if (ret) { dev_err(pci->dev, "MPLLA is not locked\n"); return ret; } keembay_pcie_ltssm_set(pcie, true); return 0; } static void keembay_pcie_stop_link(struct dw_pcie *pci) { struct keembay_pcie *pcie = dev_get_drvdata(pci->dev); keembay_pcie_ltssm_set(pcie, false); } static const struct dw_pcie_ops keembay_pcie_ops = { .link_up = keembay_pcie_link_up, .start_link = keembay_pcie_start_link, .stop_link = keembay_pcie_stop_link, }; static inline void keembay_pcie_disable_clock(void *data) { struct clk *clk = data; clk_disable_unprepare(clk); } static inline struct clk *keembay_pcie_probe_clock(struct device *dev, const char *id, u64 rate) { struct clk *clk; int ret; clk = devm_clk_get(dev, id); if (IS_ERR(clk)) return clk; if (rate) { ret = clk_set_rate(clk, rate); if (ret) return ERR_PTR(ret); } ret = clk_prepare_enable(clk); if (ret) return ERR_PTR(ret); ret = devm_add_action_or_reset(dev, keembay_pcie_disable_clock, clk); if (ret) return ERR_PTR(ret); return clk; } static int keembay_pcie_probe_clocks(struct keembay_pcie *pcie) { struct dw_pcie *pci = &pcie->pci; struct device *dev = pci->dev; pcie->clk_master = keembay_pcie_probe_clock(dev, "master", 0); if (IS_ERR(pcie->clk_master)) return dev_err_probe(dev, PTR_ERR(pcie->clk_master), "Failed to enable master clock"); pcie->clk_aux = keembay_pcie_probe_clock(dev, "aux", AUX_CLK_RATE_HZ); if (IS_ERR(pcie->clk_aux)) return dev_err_probe(dev, PTR_ERR(pcie->clk_aux), "Failed to enable auxiliary clock"); return 0; } /* * Initialize the internal PCIe PLL in Host mode. * See the following sections in Keem Bay data book, * (1) 6.4.6.1 PCIe Subsystem Example Initialization, * (2) 6.8 PCIe Low Jitter PLL for Ref Clk Generation. */ static int keembay_pcie_pll_init(struct keembay_pcie *pcie) { struct dw_pcie *pci = &pcie->pci; u32 val; int ret; val = FIELD_PREP(LJPLL_REF_DIV, 0) | FIELD_PREP(LJPLL_FB_DIV, 0x32); writel(val, pcie->apb_base + PCIE_REGS_LJPLL_CNTRL_2); val = FIELD_PREP(LJPLL_POST_DIV3A, 0x2) | FIELD_PREP(LJPLL_POST_DIV2A, 0x2); writel(val, pcie->apb_base + PCIE_REGS_LJPLL_CNTRL_3); val = FIELD_PREP(LJPLL_EN, 0x1) | FIELD_PREP(LJPLL_FOUT_EN, 0xc); writel(val, pcie->apb_base + PCIE_REGS_LJPLL_CNTRL_0); ret = readl_poll_timeout(pcie->apb_base + PCIE_REGS_LJPLL_STA, val, val & LJPLL_LOCK, 20, 500 * USEC_PER_MSEC); if (ret) dev_err(pci->dev, "Low jitter PLL is not locked\n"); return ret; } static void keembay_pcie_msi_irq_handler(struct irq_desc *desc) { struct keembay_pcie *pcie = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); u32 val, mask, status; struct dw_pcie_rp *pp; /* * Keem Bay PCIe Controller provides an additional IP logic on top of * standard DWC IP to clear MSI IRQ by writing '1' to the respective * bit of the status register. * * So, a chained irq handler is defined to handle this additional * IP logic. */ chained_irq_enter(chip, desc); pp = &pcie->pci.pp; val = readl(pcie->apb_base + PCIE_REGS_INTERRUPT_STATUS); mask = readl(pcie->apb_base + PCIE_REGS_INTERRUPT_ENABLE); status = val & mask; if (status & MSI_CTRL_INT) { dw_handle_msi_irq(pp); writel(status, pcie->apb_base + PCIE_REGS_INTERRUPT_STATUS); } chained_irq_exit(chip, desc); } static int keembay_pcie_setup_msi_irq(struct keembay_pcie *pcie) { struct dw_pcie *pci = &pcie->pci; struct device *dev = pci->dev; struct platform_device *pdev = to_platform_device(dev); int irq; irq = platform_get_irq_byname(pdev, "pcie"); if (irq < 0) return irq; irq_set_chained_handler_and_data(irq, keembay_pcie_msi_irq_handler, pcie); return 0; } static void keembay_pcie_ep_init(struct dw_pcie_ep *ep) { struct dw_pcie *pci = to_dw_pcie_from_ep(ep); struct keembay_pcie *pcie = dev_get_drvdata(pci->dev); writel(EDMA_INT_EN, pcie->apb_base + PCIE_REGS_INTERRUPT_ENABLE); } static int keembay_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no, unsigned int type, u16 interrupt_num) { struct dw_pcie *pci = to_dw_pcie_from_ep(ep); switch (type) { case PCI_IRQ_INTX: /* INTx interrupts are not supported in Keem Bay */ dev_err(pci->dev, "INTx IRQ is not supported\n"); return -EINVAL; case PCI_IRQ_MSI: return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num); case PCI_IRQ_MSIX: return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num); default: dev_err(pci->dev, "Unknown IRQ type %d\n", type); return -EINVAL; } } static const struct pci_epc_features keembay_pcie_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = true, .reserved_bar = BIT(BAR_1) | BIT(BAR_3) | BIT(BAR_5), .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4), .align = SZ_16K, }; static const struct pci_epc_features * keembay_pcie_get_features(struct dw_pcie_ep *ep) { return &keembay_pcie_epc_features; } static const struct dw_pcie_ep_ops keembay_pcie_ep_ops = { .init = keembay_pcie_ep_init, .raise_irq = keembay_pcie_ep_raise_irq, .get_features = keembay_pcie_get_features, }; static const struct dw_pcie_host_ops keembay_pcie_host_ops = { }; static int keembay_pcie_add_pcie_port(struct keembay_pcie *pcie, struct platform_device *pdev) { struct dw_pcie *pci = &pcie->pci; struct dw_pcie_rp *pp = &pci->pp; struct device *dev = &pdev->dev; u32 val; int ret; pp->ops = &keembay_pcie_host_ops; pp->msi_irq[0] = -ENODEV; ret = keembay_pcie_setup_msi_irq(pcie); if (ret) return ret; pcie->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(pcie->reset)) return PTR_ERR(pcie->reset); ret = keembay_pcie_probe_clocks(pcie); if (ret) return ret; val = readl(pcie->apb_base + PCIE_REGS_PCIE_PHY_CNTL); val |= PHY0_SRAM_BYPASS; writel(val, pcie->apb_base + PCIE_REGS_PCIE_PHY_CNTL); writel(PCIE_DEVICE_TYPE, pcie->apb_base + PCIE_REGS_PCIE_CFG); ret = keembay_pcie_pll_init(pcie); if (ret) return ret; val = readl(pcie->apb_base + PCIE_REGS_PCIE_CFG); writel(val | PCIE_RSTN, pcie->apb_base + PCIE_REGS_PCIE_CFG); keembay_ep_reset_deassert(pcie); ret = dw_pcie_host_init(pp); if (ret) { keembay_ep_reset_assert(pcie); dev_err(dev, "Failed to initialize host: %d\n", ret); return ret; } val = readl(pcie->apb_base + PCIE_REGS_INTERRUPT_ENABLE); if (IS_ENABLED(CONFIG_PCI_MSI)) val |= MSI_CTRL_INT_EN; writel(val, pcie->apb_base + PCIE_REGS_INTERRUPT_ENABLE); return 0; } static int keembay_pcie_probe(struct platform_device *pdev) { const struct keembay_pcie_of_data *data; struct device *dev = &pdev->dev; struct keembay_pcie *pcie; struct dw_pcie *pci; enum dw_pcie_device_mode mode; data = device_get_match_data(dev); if (!data) return -ENODEV; mode = (enum dw_pcie_device_mode)data->mode; pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); if (!pcie) return -ENOMEM; pci = &pcie->pci; pci->dev = dev; pci->ops = &keembay_pcie_ops; pcie->mode = mode; pcie->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb"); if (IS_ERR(pcie->apb_base)) return PTR_ERR(pcie->apb_base); platform_set_drvdata(pdev, pcie); switch (pcie->mode) { case DW_PCIE_RC_TYPE: if (!IS_ENABLED(CONFIG_PCIE_KEEMBAY_HOST)) return -ENODEV; return keembay_pcie_add_pcie_port(pcie, pdev); case DW_PCIE_EP_TYPE: if (!IS_ENABLED(CONFIG_PCIE_KEEMBAY_EP)) return -ENODEV; pci->ep.ops = &keembay_pcie_ep_ops; return dw_pcie_ep_init(&pci->ep); default: dev_err(dev, "Invalid device type %d\n", pcie->mode); return -ENODEV; } } static const struct keembay_pcie_of_data keembay_pcie_rc_of_data = { .mode = DW_PCIE_RC_TYPE, }; static const struct keembay_pcie_of_data keembay_pcie_ep_of_data = { .mode = DW_PCIE_EP_TYPE, }; static const struct of_device_id keembay_pcie_of_match[] = { { .compatible = "intel,keembay-pcie", .data = &keembay_pcie_rc_of_data, }, { .compatible = "intel,keembay-pcie-ep", .data = &keembay_pcie_ep_of_data, }, {} }; static struct platform_driver keembay_pcie_driver = { .driver = { .name = "keembay-pcie", .of_match_table = keembay_pcie_of_match, .suppress_bind_attrs = true, }, .probe = keembay_pcie_probe, }; builtin_platform_driver(keembay_pcie_driver);