// SPDX-License-Identifier: GPL-2.0 /* * PCIe host controller driver for Freescale i.MX6 SoCs * * Copyright (C) 2013 Kosagi * http://www.kosagi.com * * Author: Sean Cross */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pcie-designware.h" #define to_imx6_pcie(x) dev_get_drvdata((x)->dev) enum imx6_pcie_variants { IMX6Q, IMX6SX, IMX6QP, IMX7D, }; struct imx6_pcie { struct dw_pcie *pci; int reset_gpio; bool gpio_active_high; struct clk *pcie_bus; struct clk *pcie_phy; struct clk *pcie_inbound_axi; struct clk *pcie; struct regmap *iomuxc_gpr; struct reset_control *pciephy_reset; struct reset_control *apps_reset; enum imx6_pcie_variants variant; u32 tx_deemph_gen1; u32 tx_deemph_gen2_3p5db; u32 tx_deemph_gen2_6db; u32 tx_swing_full; u32 tx_swing_low; int link_gen; struct regulator *vpcie; }; /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */ #define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000 #define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50 #define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200 /* PCIe Root Complex registers (memory-mapped) */ #define PCIE_RC_IMX6_MSI_CAP 0x50 #define PCIE_RC_LCR 0x7c #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK 0xf #define PCIE_RC_LCSR 0x80 /* PCIe Port Logic registers (memory-mapped) */ #define PL_OFFSET 0x700 #define PCIE_PL_PFLR (PL_OFFSET + 0x08) #define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16) #define PCIE_PL_PFLR_FORCE_LINK (1 << 15) #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28) #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c) #define PCIE_PHY_CTRL (PL_OFFSET + 0x114) #define PCIE_PHY_CTRL_DATA_LOC 0 #define PCIE_PHY_CTRL_CAP_ADR_LOC 16 #define PCIE_PHY_CTRL_CAP_DAT_LOC 17 #define PCIE_PHY_CTRL_WR_LOC 18 #define PCIE_PHY_CTRL_RD_LOC 19 #define PCIE_PHY_STAT (PL_OFFSET + 0x110) #define PCIE_PHY_STAT_ACK_LOC 16 #define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C #define PORT_LOGIC_SPEED_CHANGE (0x1 << 17) /* PHY registers (not memory-mapped) */ #define PCIE_PHY_RX_ASIC_OUT 0x100D #define PCIE_PHY_RX_ASIC_OUT_VALID (1 << 0) #define PHY_RX_OVRD_IN_LO 0x1005 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5) #define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3) static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, int exp_val) { struct dw_pcie *pci = imx6_pcie->pci; u32 val; u32 max_iterations = 10; u32 wait_counter = 0; do { val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT); val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1; wait_counter++; if (val == exp_val) return 0; udelay(1); } while (wait_counter < max_iterations); return -ETIMEDOUT; } static int pcie_phy_wait_ack(struct imx6_pcie *imx6_pcie, int addr) { struct dw_pcie *pci = imx6_pcie->pci; u32 val; int ret; val = addr << PCIE_PHY_CTRL_DATA_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val); val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC); dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val); ret = pcie_phy_poll_ack(imx6_pcie, 1); if (ret) return ret; val = addr << PCIE_PHY_CTRL_DATA_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val); return pcie_phy_poll_ack(imx6_pcie, 0); } /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */ static int pcie_phy_read(struct imx6_pcie *imx6_pcie, int addr, int *data) { struct dw_pcie *pci = imx6_pcie->pci; u32 val, phy_ctl; int ret; ret = pcie_phy_wait_ack(imx6_pcie, addr); if (ret) return ret; /* assert Read signal */ phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, phy_ctl); ret = pcie_phy_poll_ack(imx6_pcie, 1); if (ret) return ret; val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT); *data = val & 0xffff; /* deassert Read signal */ dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x00); return pcie_phy_poll_ack(imx6_pcie, 0); } static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, int data) { struct dw_pcie *pci = imx6_pcie->pci; u32 var; int ret; /* write addr */ /* cap addr */ ret = pcie_phy_wait_ack(imx6_pcie, addr); if (ret) return ret; var = data << PCIE_PHY_CTRL_DATA_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var); /* capture data */ var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC); dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var); ret = pcie_phy_poll_ack(imx6_pcie, 1); if (ret) return ret; /* deassert cap data */ var = data << PCIE_PHY_CTRL_DATA_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var); /* wait for ack de-assertion */ ret = pcie_phy_poll_ack(imx6_pcie, 0); if (ret) return ret; /* assert wr signal */ var = 0x1 << PCIE_PHY_CTRL_WR_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var); /* wait for ack */ ret = pcie_phy_poll_ack(imx6_pcie, 1); if (ret) return ret; /* deassert wr signal */ var = data << PCIE_PHY_CTRL_DATA_LOC; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var); /* wait for ack de-assertion */ ret = pcie_phy_poll_ack(imx6_pcie, 0); if (ret) return ret; dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x0); return 0; } static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie) { u32 tmp; pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp); tmp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN); pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp); usleep_range(2000, 3000); pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp); tmp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN); pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp); } /* Added for PCI abort handling */ static int imx6q_pcie_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); unsigned long instr = *(unsigned long *)pc; int reg = (instr >> 12) & 15; /* * If the instruction being executed was a read, * make it look like it read all-ones. */ if ((instr & 0x0c100000) == 0x04100000) { unsigned long val; if (instr & 0x00400000) val = 255; else val = -1; regs->uregs[reg] = val; regs->ARM_pc += 4; return 0; } if ((instr & 0x0e100090) == 0x00100090) { regs->uregs[reg] = -1; regs->ARM_pc += 4; return 0; } return 1; } static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie) { struct device *dev = imx6_pcie->pci->dev; switch (imx6_pcie->variant) { case IMX7D: reset_control_assert(imx6_pcie->pciephy_reset); reset_control_assert(imx6_pcie->apps_reset); break; case IMX6SX: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_TEST_POWERDOWN, IMX6SX_GPR12_PCIE_TEST_POWERDOWN); /* Force PCIe PHY reset */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, IMX6SX_GPR5_PCIE_BTNRST_RESET, IMX6SX_GPR5_PCIE_BTNRST_RESET); break; case IMX6QP: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_SW_RST, IMX6Q_GPR1_PCIE_SW_RST); break; case IMX6Q: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); break; } if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { int ret = regulator_disable(imx6_pcie->vpcie); if (ret) dev_err(dev, "failed to disable vpcie regulator: %d\n", ret); } } static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) { struct dw_pcie *pci = imx6_pcie->pci; struct device *dev = pci->dev; int ret = 0; switch (imx6_pcie->variant) { case IMX6SX: ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi); if (ret) { dev_err(dev, "unable to enable pcie_axi clock\n"); break; } regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0); break; case IMX6QP: /* FALLTHROUGH */ case IMX6Q: /* power up core phy and enable ref clock */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); /* * the async reset input need ref clock to sync internally, * when the ref clock comes after reset, internal synced * reset time is too short, cannot meet the requirement. * add one ~10us delay here. */ udelay(10); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); break; case IMX7D: break; } return ret; } static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie) { u32 val; unsigned int retries; struct device *dev = imx6_pcie->pci->dev; for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) { regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val); if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED) return; usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN, PHY_PLL_LOCK_WAIT_USLEEP_MAX); } dev_err(dev, "PCIe PLL lock timeout\n"); } static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) { struct dw_pcie *pci = imx6_pcie->pci; struct device *dev = pci->dev; int ret; if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) { ret = regulator_enable(imx6_pcie->vpcie); if (ret) { dev_err(dev, "failed to enable vpcie regulator: %d\n", ret); return; } } ret = clk_prepare_enable(imx6_pcie->pcie_phy); if (ret) { dev_err(dev, "unable to enable pcie_phy clock\n"); goto err_pcie_phy; } ret = clk_prepare_enable(imx6_pcie->pcie_bus); if (ret) { dev_err(dev, "unable to enable pcie_bus clock\n"); goto err_pcie_bus; } ret = clk_prepare_enable(imx6_pcie->pcie); if (ret) { dev_err(dev, "unable to enable pcie clock\n"); goto err_pcie; } ret = imx6_pcie_enable_ref_clk(imx6_pcie); if (ret) { dev_err(dev, "unable to enable pcie ref clock\n"); goto err_ref_clk; } /* allow the clocks to stabilize */ usleep_range(200, 500); /* Some boards don't have PCIe reset GPIO. */ if (gpio_is_valid(imx6_pcie->reset_gpio)) { gpio_set_value_cansleep(imx6_pcie->reset_gpio, imx6_pcie->gpio_active_high); msleep(100); gpio_set_value_cansleep(imx6_pcie->reset_gpio, !imx6_pcie->gpio_active_high); } switch (imx6_pcie->variant) { case IMX7D: reset_control_deassert(imx6_pcie->pciephy_reset); imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie); break; case IMX6SX: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, IMX6SX_GPR5_PCIE_BTNRST_RESET, 0); break; case IMX6QP: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_SW_RST, 0); usleep_range(200, 500); break; case IMX6Q: /* Nothing to do */ break; } return; err_ref_clk: clk_disable_unprepare(imx6_pcie->pcie); err_pcie: clk_disable_unprepare(imx6_pcie->pcie_bus); err_pcie_bus: clk_disable_unprepare(imx6_pcie->pcie_phy); err_pcie_phy: if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { ret = regulator_disable(imx6_pcie->vpcie); if (ret) dev_err(dev, "failed to disable vpcie regulator: %d\n", ret); } } static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie) { switch (imx6_pcie->variant) { case IMX7D: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0); break; case IMX6SX: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_RX_EQ_MASK, IMX6SX_GPR12_PCIE_RX_EQ_2); /* FALLTHROUGH */ default: regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); /* configure constant input signal to the pcie ctrl and phy */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_LOS_LEVEL, 9 << 4); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, IMX6Q_GPR8_TX_DEEMPH_GEN1, imx6_pcie->tx_deemph_gen1 << 0); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB, imx6_pcie->tx_deemph_gen2_3p5db << 6); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB, imx6_pcie->tx_deemph_gen2_6db << 12); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, IMX6Q_GPR8_TX_SWING_FULL, imx6_pcie->tx_swing_full << 18); regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, IMX6Q_GPR8_TX_SWING_LOW, imx6_pcie->tx_swing_low << 25); break; } regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12); } static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie) { struct dw_pcie *pci = imx6_pcie->pci; struct device *dev = pci->dev; /* check if the link is up or not */ if (!dw_pcie_wait_for_link(pci)) return 0; dev_dbg(dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n", dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0), dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1)); return -ETIMEDOUT; } static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie) { struct dw_pcie *pci = imx6_pcie->pci; struct device *dev = pci->dev; u32 tmp; unsigned int retries; for (retries = 0; retries < 200; retries++) { tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); /* Test if the speed change finished. */ if (!(tmp & PORT_LOGIC_SPEED_CHANGE)) return 0; usleep_range(100, 1000); } dev_err(dev, "Speed change timeout\n"); return -EINVAL; } static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie) { struct dw_pcie *pci = imx6_pcie->pci; struct device *dev = pci->dev; u32 tmp; int ret; /* * Force Gen1 operation when starting the link. In case the link is * started in Gen2 mode, there is a possibility the devices on the * bus will not be detected at all. This happens with PCIe switches. */ tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR); tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1; dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); /* Start LTSSM. */ if (imx6_pcie->variant == IMX7D) reset_control_deassert(imx6_pcie->apps_reset); else regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_PCIE_CTL_2, 1 << 10); ret = imx6_pcie_wait_for_link(imx6_pcie); if (ret) goto err_reset_phy; if (imx6_pcie->link_gen == 2) { /* Allow Gen2 mode after the link is up. */ tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR); tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2; dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); /* * Start Directed Speed Change so the best possible * speed both link partners support can be negotiated. */ tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); tmp |= PORT_LOGIC_SPEED_CHANGE; dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp); if (imx6_pcie->variant != IMX7D) { /* * On i.MX7, DIRECT_SPEED_CHANGE behaves differently * from i.MX6 family when no link speed transition * occurs and we go Gen1 -> yep, Gen1. The difference * is that, in such case, it will not be cleared by HW * which will cause the following code to report false * failure. */ ret = imx6_pcie_wait_for_speed_change(imx6_pcie); if (ret) { dev_err(dev, "Failed to bring link up!\n"); goto err_reset_phy; } } /* Make sure link training is finished as well! */ ret = imx6_pcie_wait_for_link(imx6_pcie); if (ret) { dev_err(dev, "Failed to bring link up!\n"); goto err_reset_phy; } } else { dev_info(dev, "Link: Gen2 disabled\n"); } tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR); dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf); return 0; err_reset_phy: dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0), dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1)); imx6_pcie_reset_phy(imx6_pcie); return ret; } static int imx6_pcie_host_init(struct pcie_port *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci); imx6_pcie_assert_core_reset(imx6_pcie); imx6_pcie_init_phy(imx6_pcie); imx6_pcie_deassert_core_reset(imx6_pcie); dw_pcie_setup_rc(pp); imx6_pcie_establish_link(imx6_pcie); if (IS_ENABLED(CONFIG_PCI_MSI)) dw_pcie_msi_init(pp); return 0; } static const struct dw_pcie_host_ops imx6_pcie_host_ops = { .host_init = imx6_pcie_host_init, }; static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, struct platform_device *pdev) { struct dw_pcie *pci = imx6_pcie->pci; struct pcie_port *pp = &pci->pp; struct device *dev = &pdev->dev; int ret; if (IS_ENABLED(CONFIG_PCI_MSI)) { pp->msi_irq = platform_get_irq_byname(pdev, "msi"); if (pp->msi_irq <= 0) { dev_err(dev, "failed to get MSI irq\n"); return -ENODEV; } } pp->ops = &imx6_pcie_host_ops; ret = dw_pcie_host_init(pp); if (ret) { dev_err(dev, "failed to initialize host\n"); return ret; } return 0; } static const struct dw_pcie_ops dw_pcie_ops = { /* No special ops needed, but pcie-designware still expects this struct */ }; static int imx6_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct dw_pcie *pci; struct imx6_pcie *imx6_pcie; struct resource *dbi_base; struct device_node *node = dev->of_node; int ret; u16 val; imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL); if (!imx6_pcie) return -ENOMEM; pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); if (!pci) return -ENOMEM; pci->dev = dev; pci->ops = &dw_pcie_ops; imx6_pcie->pci = pci; imx6_pcie->variant = (enum imx6_pcie_variants)of_device_get_match_data(dev); dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0); pci->dbi_base = devm_ioremap_resource(dev, dbi_base); if (IS_ERR(pci->dbi_base)) return PTR_ERR(pci->dbi_base); /* Fetch GPIOs */ imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0); imx6_pcie->gpio_active_high = of_property_read_bool(node, "reset-gpio-active-high"); if (gpio_is_valid(imx6_pcie->reset_gpio)) { ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio, imx6_pcie->gpio_active_high ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, "PCIe reset"); if (ret) { dev_err(dev, "unable to get reset gpio\n"); return ret; } } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) { return imx6_pcie->reset_gpio; } /* Fetch clocks */ imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy"); if (IS_ERR(imx6_pcie->pcie_phy)) { dev_err(dev, "pcie_phy clock source missing or invalid\n"); return PTR_ERR(imx6_pcie->pcie_phy); } imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus"); if (IS_ERR(imx6_pcie->pcie_bus)) { dev_err(dev, "pcie_bus clock source missing or invalid\n"); return PTR_ERR(imx6_pcie->pcie_bus); } imx6_pcie->pcie = devm_clk_get(dev, "pcie"); if (IS_ERR(imx6_pcie->pcie)) { dev_err(dev, "pcie clock source missing or invalid\n"); return PTR_ERR(imx6_pcie->pcie); } switch (imx6_pcie->variant) { case IMX6SX: imx6_pcie->pcie_inbound_axi = devm_clk_get(dev, "pcie_inbound_axi"); if (IS_ERR(imx6_pcie->pcie_inbound_axi)) { dev_err(dev, "pcie_inbound_axi clock missing or invalid\n"); return PTR_ERR(imx6_pcie->pcie_inbound_axi); } break; case IMX7D: imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev, "pciephy"); if (IS_ERR(imx6_pcie->pciephy_reset)) { dev_err(dev, "Failed to get PCIEPHY reset control\n"); return PTR_ERR(imx6_pcie->pciephy_reset); } imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev, "apps"); if (IS_ERR(imx6_pcie->apps_reset)) { dev_err(dev, "Failed to get PCIE APPS reset control\n"); return PTR_ERR(imx6_pcie->apps_reset); } break; default: break; } /* Grab GPR config register range */ imx6_pcie->iomuxc_gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); if (IS_ERR(imx6_pcie->iomuxc_gpr)) { dev_err(dev, "unable to find iomuxc registers\n"); return PTR_ERR(imx6_pcie->iomuxc_gpr); } /* Grab PCIe PHY Tx Settings */ if (of_property_read_u32(node, "fsl,tx-deemph-gen1", &imx6_pcie->tx_deemph_gen1)) imx6_pcie->tx_deemph_gen1 = 0; if (of_property_read_u32(node, "fsl,tx-deemph-gen2-3p5db", &imx6_pcie->tx_deemph_gen2_3p5db)) imx6_pcie->tx_deemph_gen2_3p5db = 0; if (of_property_read_u32(node, "fsl,tx-deemph-gen2-6db", &imx6_pcie->tx_deemph_gen2_6db)) imx6_pcie->tx_deemph_gen2_6db = 20; if (of_property_read_u32(node, "fsl,tx-swing-full", &imx6_pcie->tx_swing_full)) imx6_pcie->tx_swing_full = 127; if (of_property_read_u32(node, "fsl,tx-swing-low", &imx6_pcie->tx_swing_low)) imx6_pcie->tx_swing_low = 127; /* Limit link speed */ ret = of_property_read_u32(node, "fsl,max-link-speed", &imx6_pcie->link_gen); if (ret) imx6_pcie->link_gen = 1; imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie"); if (IS_ERR(imx6_pcie->vpcie)) { if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER) return -EPROBE_DEFER; imx6_pcie->vpcie = NULL; } platform_set_drvdata(pdev, imx6_pcie); ret = imx6_add_pcie_port(imx6_pcie, pdev); if (ret < 0) return ret; if (pci_msi_enabled()) { val = dw_pcie_readw_dbi(pci, PCIE_RC_IMX6_MSI_CAP + PCI_MSI_FLAGS); val |= PCI_MSI_FLAGS_ENABLE; dw_pcie_writew_dbi(pci, PCIE_RC_IMX6_MSI_CAP + PCI_MSI_FLAGS, val); } return 0; } static void imx6_pcie_shutdown(struct platform_device *pdev) { struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev); /* bring down link, so bootloader gets clean state in case of reboot */ imx6_pcie_assert_core_reset(imx6_pcie); } static const struct of_device_id imx6_pcie_of_match[] = { { .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, }, { .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, }, { .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, }, { .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, }, {}, }; static struct platform_driver imx6_pcie_driver = { .driver = { .name = "imx6q-pcie", .of_match_table = imx6_pcie_of_match, .suppress_bind_attrs = true, }, .probe = imx6_pcie_probe, .shutdown = imx6_pcie_shutdown, }; static int __init imx6_pcie_init(void) { /* * Since probe() can be deferred we need to make sure that * hook_fault_code is not called after __init memory is freed * by kernel and since imx6q_pcie_abort_handler() is a no-op, * we can install the handler here without risking it * accessing some uninitialized driver state. */ hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0, "external abort on non-linefetch"); return platform_driver_register(&imx6_pcie_driver); } device_initcall(imx6_pcie_init);