| /* |
| * PCIe host controller driver for Freescale i.MX6 SoCs |
| * |
| * Copyright (C) 2013 Kosagi |
| * http://www.kosagi.com |
| * |
| * Author: Sean Cross <xobs@kosagi.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/delay.h> |
| #include <linux/gpio.h> |
| #include <linux/kernel.h> |
| #include <linux/mfd/syscon.h> |
| #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> |
| #include <linux/module.h> |
| #include <linux/of_gpio.h> |
| #include <linux/pci.h> |
| #include <linux/platform_device.h> |
| #include <linux/regmap.h> |
| #include <linux/resource.h> |
| #include <linux/signal.h> |
| #include <linux/types.h> |
| #include <linux/interrupt.h> |
| |
| #include "pcie-designware.h" |
| |
| #define to_imx6_pcie(x) container_of(x, struct imx6_pcie, pp) |
| |
| struct imx6_pcie { |
| int reset_gpio; |
| struct clk *pcie_bus; |
| struct clk *pcie_phy; |
| struct clk *pcie; |
| struct pcie_port pp; |
| struct regmap *iomuxc_gpr; |
| void __iomem *mem_base; |
| }; |
| |
| /* PCIe Root Complex registers (memory-mapped) */ |
| #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_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29) |
| #define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4) |
| |
| #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(void __iomem *dbi_base, int exp_val) |
| { |
| u32 val; |
| u32 max_iterations = 10; |
| u32 wait_counter = 0; |
| |
| do { |
| val = readl(dbi_base + 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(void __iomem *dbi_base, int addr) |
| { |
| u32 val; |
| int ret; |
| |
| val = addr << PCIE_PHY_CTRL_DATA_LOC; |
| writel(val, dbi_base + PCIE_PHY_CTRL); |
| |
| val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC); |
| writel(val, dbi_base + PCIE_PHY_CTRL); |
| |
| ret = pcie_phy_poll_ack(dbi_base, 1); |
| if (ret) |
| return ret; |
| |
| val = addr << PCIE_PHY_CTRL_DATA_LOC; |
| writel(val, dbi_base + PCIE_PHY_CTRL); |
| |
| return pcie_phy_poll_ack(dbi_base, 0); |
| } |
| |
| /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */ |
| static int pcie_phy_read(void __iomem *dbi_base, int addr , int *data) |
| { |
| u32 val, phy_ctl; |
| int ret; |
| |
| ret = pcie_phy_wait_ack(dbi_base, addr); |
| if (ret) |
| return ret; |
| |
| /* assert Read signal */ |
| phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC; |
| writel(phy_ctl, dbi_base + PCIE_PHY_CTRL); |
| |
| ret = pcie_phy_poll_ack(dbi_base, 1); |
| if (ret) |
| return ret; |
| |
| val = readl(dbi_base + PCIE_PHY_STAT); |
| *data = val & 0xffff; |
| |
| /* deassert Read signal */ |
| writel(0x00, dbi_base + PCIE_PHY_CTRL); |
| |
| return pcie_phy_poll_ack(dbi_base, 0); |
| } |
| |
| static int pcie_phy_write(void __iomem *dbi_base, int addr, int data) |
| { |
| u32 var; |
| int ret; |
| |
| /* write addr */ |
| /* cap addr */ |
| ret = pcie_phy_wait_ack(dbi_base, addr); |
| if (ret) |
| return ret; |
| |
| var = data << PCIE_PHY_CTRL_DATA_LOC; |
| writel(var, dbi_base + PCIE_PHY_CTRL); |
| |
| /* capture data */ |
| var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC); |
| writel(var, dbi_base + PCIE_PHY_CTRL); |
| |
| ret = pcie_phy_poll_ack(dbi_base, 1); |
| if (ret) |
| return ret; |
| |
| /* deassert cap data */ |
| var = data << PCIE_PHY_CTRL_DATA_LOC; |
| writel(var, dbi_base + PCIE_PHY_CTRL); |
| |
| /* wait for ack de-assertion */ |
| ret = pcie_phy_poll_ack(dbi_base, 0); |
| if (ret) |
| return ret; |
| |
| /* assert wr signal */ |
| var = 0x1 << PCIE_PHY_CTRL_WR_LOC; |
| writel(var, dbi_base + PCIE_PHY_CTRL); |
| |
| /* wait for ack */ |
| ret = pcie_phy_poll_ack(dbi_base, 1); |
| if (ret) |
| return ret; |
| |
| /* deassert wr signal */ |
| var = data << PCIE_PHY_CTRL_DATA_LOC; |
| writel(var, dbi_base + PCIE_PHY_CTRL); |
| |
| /* wait for ack de-assertion */ |
| ret = pcie_phy_poll_ack(dbi_base, 0); |
| if (ret) |
| return ret; |
| |
| writel(0x0, dbi_base + PCIE_PHY_CTRL); |
| |
| return 0; |
| } |
| |
| /* Added for PCI abort handling */ |
| static int imx6q_pcie_abort_handler(unsigned long addr, |
| unsigned int fsr, struct pt_regs *regs) |
| { |
| return 0; |
| } |
| |
| static int imx6_pcie_assert_core_reset(struct pcie_port *pp) |
| { |
| struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); |
| u32 val, gpr1, gpr12; |
| |
| /* |
| * If the bootloader already enabled the link we need some special |
| * handling to get the core back into a state where it is safe to |
| * touch it for configuration. As there is no dedicated reset signal |
| * wired up for MX6QDL, we need to manually force LTSSM into "detect" |
| * state before completely disabling LTSSM, which is a prerequisite |
| * for core configuration. |
| * |
| * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong |
| * indication that the bootloader activated the link. |
| */ |
| regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); |
| regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); |
| |
| if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && |
| (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { |
| val = readl(pp->dbi_base + PCIE_PL_PFLR); |
| val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; |
| val |= PCIE_PL_PFLR_FORCE_LINK; |
| writel(val, pp->dbi_base + PCIE_PL_PFLR); |
| |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, |
| IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); |
| } |
| |
| 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); |
| |
| return 0; |
| } |
| |
| static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) |
| { |
| struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); |
| int ret; |
| |
| ret = clk_prepare_enable(imx6_pcie->pcie_phy); |
| if (ret) { |
| dev_err(pp->dev, "unable to enable pcie_phy clock\n"); |
| goto err_pcie_phy; |
| } |
| |
| ret = clk_prepare_enable(imx6_pcie->pcie_bus); |
| if (ret) { |
| dev_err(pp->dev, "unable to enable pcie_bus clock\n"); |
| goto err_pcie_bus; |
| } |
| |
| ret = clk_prepare_enable(imx6_pcie->pcie); |
| if (ret) { |
| dev_err(pp->dev, "unable to enable pcie clock\n"); |
| goto err_pcie; |
| } |
| |
| /* 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); |
| |
| /* 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(imx6_pcie->reset_gpio, 0); |
| msleep(100); |
| gpio_set_value(imx6_pcie->reset_gpio, 1); |
| } |
| return 0; |
| |
| err_pcie: |
| clk_disable_unprepare(imx6_pcie->pcie_bus); |
| err_pcie_bus: |
| clk_disable_unprepare(imx6_pcie->pcie_phy); |
| err_pcie_phy: |
| return ret; |
| |
| } |
| |
| static void imx6_pcie_init_phy(struct pcie_port *pp) |
| { |
| struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); |
| |
| 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_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12); |
| 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, 0 << 0); |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, |
| IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB, 0 << 6); |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, |
| IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB, 20 << 12); |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, |
| IMX6Q_GPR8_TX_SWING_FULL, 127 << 18); |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8, |
| IMX6Q_GPR8_TX_SWING_LOW, 127 << 25); |
| } |
| |
| static int imx6_pcie_wait_for_link(struct pcie_port *pp) |
| { |
| unsigned int retries; |
| |
| for (retries = 0; retries < 200; retries++) { |
| if (dw_pcie_link_up(pp)) |
| return 0; |
| usleep_range(100, 1000); |
| } |
| |
| dev_err(pp->dev, "phy link never came up\n"); |
| dev_dbg(pp->dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n", |
| readl(pp->dbi_base + PCIE_PHY_DEBUG_R0), |
| readl(pp->dbi_base + PCIE_PHY_DEBUG_R1)); |
| return -EINVAL; |
| } |
| |
| static int imx6_pcie_wait_for_speed_change(struct pcie_port *pp) |
| { |
| u32 tmp; |
| unsigned int retries; |
| |
| for (retries = 0; retries < 200; retries++) { |
| tmp = readl(pp->dbi_base + 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(pp->dev, "Speed change timeout\n"); |
| return -EINVAL; |
| } |
| |
| static irqreturn_t imx6_pcie_msi_handler(int irq, void *arg) |
| { |
| struct pcie_port *pp = arg; |
| |
| return dw_handle_msi_irq(pp); |
| } |
| |
| static int imx6_pcie_establish_link(struct pcie_port *pp) |
| { |
| struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); |
| 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 = readl(pp->dbi_base + PCIE_RC_LCR); |
| tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; |
| tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1; |
| writel(tmp, pp->dbi_base + PCIE_RC_LCR); |
| |
| /* Start LTSSM. */ |
| regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, |
| IMX6Q_GPR12_PCIE_CTL_2, 1 << 10); |
| |
| ret = imx6_pcie_wait_for_link(pp); |
| if (ret) |
| return ret; |
| |
| /* Allow Gen2 mode after the link is up. */ |
| tmp = readl(pp->dbi_base + PCIE_RC_LCR); |
| tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; |
| tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2; |
| writel(tmp, pp->dbi_base + PCIE_RC_LCR); |
| |
| /* |
| * Start Directed Speed Change so the best possible speed both link |
| * partners support can be negotiated. |
| */ |
| tmp = readl(pp->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL); |
| tmp |= PORT_LOGIC_SPEED_CHANGE; |
| writel(tmp, pp->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL); |
| |
| ret = imx6_pcie_wait_for_speed_change(pp); |
| if (ret) { |
| dev_err(pp->dev, "Failed to bring link up!\n"); |
| return ret; |
| } |
| |
| /* Make sure link training is finished as well! */ |
| ret = imx6_pcie_wait_for_link(pp); |
| if (ret) { |
| dev_err(pp->dev, "Failed to bring link up!\n"); |
| return ret; |
| } |
| |
| tmp = readl(pp->dbi_base + PCIE_RC_LCSR); |
| dev_dbg(pp->dev, "Link up, Gen=%i\n", (tmp >> 16) & 0xf); |
| return 0; |
| } |
| |
| static void imx6_pcie_host_init(struct pcie_port *pp) |
| { |
| imx6_pcie_assert_core_reset(pp); |
| |
| imx6_pcie_init_phy(pp); |
| |
| imx6_pcie_deassert_core_reset(pp); |
| |
| dw_pcie_setup_rc(pp); |
| |
| imx6_pcie_establish_link(pp); |
| |
| if (IS_ENABLED(CONFIG_PCI_MSI)) |
| dw_pcie_msi_init(pp); |
| } |
| |
| static void imx6_pcie_reset_phy(struct pcie_port *pp) |
| { |
| u32 tmp; |
| |
| pcie_phy_read(pp->dbi_base, 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(pp->dbi_base, PHY_RX_OVRD_IN_LO, tmp); |
| |
| usleep_range(2000, 3000); |
| |
| pcie_phy_read(pp->dbi_base, 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(pp->dbi_base, PHY_RX_OVRD_IN_LO, tmp); |
| } |
| |
| static int imx6_pcie_link_up(struct pcie_port *pp) |
| { |
| u32 rc, debug_r0, rx_valid; |
| int count = 5; |
| |
| /* |
| * Test if the PHY reports that the link is up and also that the LTSSM |
| * training finished. There are three possible states of the link when |
| * this code is called: |
| * 1) The link is DOWN (unlikely) |
| * The link didn't come up yet for some reason. This usually means |
| * we have a real problem somewhere. Reset the PHY and exit. This |
| * state calls for inspection of the DEBUG registers. |
| * 2) The link is UP, but still in LTSSM training |
| * Wait for the training to finish, which should take a very short |
| * time. If the training does not finish, we have a problem and we |
| * need to inspect the DEBUG registers. If the training does finish, |
| * the link is up and operating correctly. |
| * 3) The link is UP and no longer in LTSSM training |
| * The link is up and operating correctly. |
| */ |
| while (1) { |
| rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1); |
| if (!(rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_UP)) |
| break; |
| if (!(rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING)) |
| return 1; |
| if (!count--) |
| break; |
| dev_dbg(pp->dev, "Link is up, but still in training\n"); |
| /* |
| * Wait a little bit, then re-check if the link finished |
| * the training. |
| */ |
| usleep_range(1000, 2000); |
| } |
| /* |
| * From L0, initiate MAC entry to gen2 if EP/RC supports gen2. |
| * Wait 2ms (LTSSM timeout is 24ms, PHY lock is ~5us in gen2). |
| * If (MAC/LTSSM.state == Recovery.RcvrLock) |
| * && (PHY/rx_valid==0) then pulse PHY/rx_reset. Transition |
| * to gen2 is stuck |
| */ |
| pcie_phy_read(pp->dbi_base, PCIE_PHY_RX_ASIC_OUT, &rx_valid); |
| debug_r0 = readl(pp->dbi_base + PCIE_PHY_DEBUG_R0); |
| |
| if (rx_valid & PCIE_PHY_RX_ASIC_OUT_VALID) |
| return 0; |
| |
| if ((debug_r0 & 0x3f) != 0x0d) |
| return 0; |
| |
| dev_err(pp->dev, "transition to gen2 is stuck, reset PHY!\n"); |
| dev_dbg(pp->dev, "debug_r0=%08x debug_r1=%08x\n", debug_r0, rc); |
| |
| imx6_pcie_reset_phy(pp); |
| |
| return 0; |
| } |
| |
| static struct pcie_host_ops imx6_pcie_host_ops = { |
| .link_up = imx6_pcie_link_up, |
| .host_init = imx6_pcie_host_init, |
| }; |
| |
| static int __init imx6_add_pcie_port(struct pcie_port *pp, |
| struct platform_device *pdev) |
| { |
| int ret; |
| |
| if (IS_ENABLED(CONFIG_PCI_MSI)) { |
| pp->msi_irq = platform_get_irq_byname(pdev, "msi"); |
| if (pp->msi_irq <= 0) { |
| dev_err(&pdev->dev, "failed to get MSI irq\n"); |
| return -ENODEV; |
| } |
| |
| ret = devm_request_irq(&pdev->dev, pp->msi_irq, |
| imx6_pcie_msi_handler, |
| IRQF_SHARED, "mx6-pcie-msi", pp); |
| if (ret) { |
| dev_err(&pdev->dev, "failed to request MSI irq\n"); |
| return ret; |
| } |
| } |
| |
| pp->root_bus_nr = -1; |
| pp->ops = &imx6_pcie_host_ops; |
| |
| ret = dw_pcie_host_init(pp); |
| if (ret) { |
| dev_err(&pdev->dev, "failed to initialize host\n"); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int __init imx6_pcie_probe(struct platform_device *pdev) |
| { |
| struct imx6_pcie *imx6_pcie; |
| struct pcie_port *pp; |
| struct device_node *np = pdev->dev.of_node; |
| struct resource *dbi_base; |
| int ret; |
| |
| imx6_pcie = devm_kzalloc(&pdev->dev, sizeof(*imx6_pcie), GFP_KERNEL); |
| if (!imx6_pcie) |
| return -ENOMEM; |
| |
| pp = &imx6_pcie->pp; |
| pp->dev = &pdev->dev; |
| |
| /* Added for PCI abort handling */ |
| hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, |
| "imprecise external abort"); |
| |
| dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| pp->dbi_base = devm_ioremap_resource(&pdev->dev, dbi_base); |
| if (IS_ERR(pp->dbi_base)) |
| return PTR_ERR(pp->dbi_base); |
| |
| /* Fetch GPIOs */ |
| imx6_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0); |
| if (gpio_is_valid(imx6_pcie->reset_gpio)) { |
| ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio, |
| GPIOF_OUT_INIT_LOW, "PCIe reset"); |
| if (ret) { |
| dev_err(&pdev->dev, "unable to get reset gpio\n"); |
| return ret; |
| } |
| } |
| |
| /* Fetch clocks */ |
| imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy"); |
| if (IS_ERR(imx6_pcie->pcie_phy)) { |
| dev_err(&pdev->dev, |
| "pcie_phy clock source missing or invalid\n"); |
| return PTR_ERR(imx6_pcie->pcie_phy); |
| } |
| |
| imx6_pcie->pcie_bus = devm_clk_get(&pdev->dev, "pcie_bus"); |
| if (IS_ERR(imx6_pcie->pcie_bus)) { |
| dev_err(&pdev->dev, |
| "pcie_bus clock source missing or invalid\n"); |
| return PTR_ERR(imx6_pcie->pcie_bus); |
| } |
| |
| imx6_pcie->pcie = devm_clk_get(&pdev->dev, "pcie"); |
| if (IS_ERR(imx6_pcie->pcie)) { |
| dev_err(&pdev->dev, |
| "pcie clock source missing or invalid\n"); |
| return PTR_ERR(imx6_pcie->pcie); |
| } |
| |
| /* 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(&pdev->dev, "unable to find iomuxc registers\n"); |
| return PTR_ERR(imx6_pcie->iomuxc_gpr); |
| } |
| |
| ret = imx6_add_pcie_port(pp, pdev); |
| if (ret < 0) |
| return ret; |
| |
| platform_set_drvdata(pdev, imx6_pcie); |
| 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->pp); |
| } |
| |
| static const struct of_device_id imx6_pcie_of_match[] = { |
| { .compatible = "fsl,imx6q-pcie", }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, imx6_pcie_of_match); |
| |
| static struct platform_driver imx6_pcie_driver = { |
| .driver = { |
| .name = "imx6q-pcie", |
| .of_match_table = imx6_pcie_of_match, |
| }, |
| .shutdown = imx6_pcie_shutdown, |
| }; |
| |
| /* Freescale PCIe driver does not allow module unload */ |
| |
| static int __init imx6_pcie_init(void) |
| { |
| return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe); |
| } |
| module_init(imx6_pcie_init); |
| |
| MODULE_AUTHOR("Sean Cross <xobs@kosagi.com>"); |
| MODULE_DESCRIPTION("Freescale i.MX6 PCIe host controller driver"); |
| MODULE_LICENSE("GPL v2"); |