Add support for the PCIe port present on the i.MX6 family of controllers. These use the Synopsis Designware core tied to their own PHY. Signed-off-by: Sean Cross <xobs@xxxxxxxxxx> --- .../devicetree/bindings/pci/designware-pcie.txt | 5 + arch/arm/boot/dts/imx6qdl.dtsi | 16 + arch/arm/mach-imx/Kconfig | 2 + arch/arm/mach-imx/clk-imx6q.c | 11 + drivers/pci/host/Kconfig | 6 + drivers/pci/host/Makefile | 1 + drivers/pci/host/pci-imx6.c | 482 ++++++++++++++++++++ 7 files changed, 523 insertions(+) create mode 100644 drivers/pci/host/pci-imx6.c diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt index eabcb4b..41d8419 100644 --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt @@ -21,6 +21,11 @@ Required properties: - num-lanes: number of lanes to use - reset-gpio: gpio pin number of power good signal +Optional properties for fsl,imx6-pcie +- power-on-gpio: gpio pin number of power-enable signal +- wake-up-gpio: gpio pin number of incoming wakeup signal +- disable-gpio: gpio pin number of outgoing rfkill/endpoint disable signal + Example: SoC specific DT Entry: diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi index ccd55c2..ec72271 100644 --- a/arch/arm/boot/dts/imx6qdl.dtsi +++ b/arch/arm/boot/dts/imx6qdl.dtsi @@ -116,6 +116,22 @@ arm,data-latency = <4 2 3>; }; + pcie: pcie@0x01000000 { + compatible = "fsl,imx6-pcie", "snps,dw-pcie"; + reg = <0x01ffc000 0x4000>; /* DBI */ + + #address-cells = <3>; + #size-cells = <2>; + device_type = "pci"; + ranges = <0x00000800 0 0x01f00000 0x01f00000 0 0x00080000 /* configuration space */ + 0x81000000 0 0 0x01f80000 0 0x00010000 /* downstream I/O */ + 0x82000000 0 0x01000000 0x01000000 0 0x00f00000>; /* non-prefetchable memory */ + + num-lanes = <1>; + interrupts = <0 123 0x04>; + status = "disabled"; + }; + pmu { compatible = "arm,cortex-a9-pmu"; interrupts = <0 94 0x04>; diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig index 29a8af6..e6ac281 100644 --- a/arch/arm/mach-imx/Kconfig +++ b/arch/arm/mach-imx/Kconfig @@ -801,6 +801,8 @@ config SOC_IMX6Q select HAVE_IMX_SRC select HAVE_SMP select MFD_SYSCON + select MIGHT_HAVE_PCI + select PCI_DOMAINS if PCI select PINCTRL select PINCTRL_IMX6Q select PL310_ERRATA_588369 if CACHE_PL310 diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c index 679d49a..0a2093c 100644 --- a/arch/arm/mach-imx/clk-imx6q.c +++ b/arch/arm/mach-imx/clk-imx6q.c @@ -622,6 +622,17 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node) if (ret) pr_warn("failed to set up CLKO: %d\n", ret); + /* + * All existing boards with PCIe run them off LVDS1 + */ + if (IS_ENABLED(CONFIG_PCI_IMX6)) { + clk_set_parent(clk[lvds1_sel], clk[sata_ref]); + clk_prepare_enable(clk[lvds1_gate]); + clk_prepare_enable(clk[pcie_ref_125m]); + clk_prepare_enable(clk[pcie_axi]); + } + + /* Set initial power mode */ imx6q_set_lpm(WAIT_CLOCKED); diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index 3d95048..efa24d9 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -15,6 +15,12 @@ config PCI_EXYNOS select PCIEPORTBUS select PCIE_DW +config PCI_IMX6 + bool "Freescale i.MX6 PCIe controller" + depends on SOC_IMX6Q + select PCIEPORTBUS + select PCIE_DW + config PCI_TEGRA bool "NVIDIA Tegra PCIe controller" depends on ARCH_TEGRA diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index c9a997b..287d6a0 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o +obj-$(CONFIG_PCI_IMX6) += pci-imx6.o obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c new file mode 100644 index 0000000..a3f9053 --- /dev/null +++ b/drivers/pci/host/pci-imx6.c @@ -0,0 +1,482 @@ +/* + * PCIe host controller driver for Freescale i.MX6 SoCs + * + * Copyright (C) 2013 Kosagi + * http://www.kosagi.com + * + * Author: Sean Cross <xobs@xxxxxxxxxx> + * + * 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/delay.h> +#include <linux/gpio.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_gpio.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/resource.h> +#include <linux/signal.h> +#include <linux/types.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> + +#include "pcie-designware.h" + +#define to_imx6_pcie(x) container_of(x, struct imx6_pcie, pp) + +struct imx6_pcie { + int reset_gpio; + int power_on_gpio; + int wake_up_gpio; + int disable_gpio; + struct pcie_port pp; + struct regmap *iomuxc_gpr; + void __iomem *mem_base; +}; + +/* PCIe Port Logic registers (memory-mapped) */ +#define PL_OFFSET 0x700 +#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_DATA_LOC 0 +#define PCIE_PHY_STAT_ACK_LOC 16 + +/* PHY registers (not memory-mapped) */ +#define PCIE_PHY_RX_ASIC_OUT 0x100D + +#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++; + udelay(1); + } while ((wait_counter < max_iterations) && (val != exp_val)); + + if (val != exp_val) + return -ETIMEDOUT; + + return 0; +} + +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); + + ret = pcie_phy_poll_ack(dbi_base, 0); + if (ret) + return ret; + + return 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 << PCIE_PHY_STAT_DATA_LOC)); + + /* deassert Read signal */ + writel(0x00, dbi_base + PCIE_PHY_CTRL); + + ret = pcie_phy_poll_ack(dbi_base, 0); + if (ret) + return ret; + + return 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-assetion */ + 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-assetion */ + ret = pcie_phy_poll_ack(dbi_base, 0); + if (ret) + return ret; + + writel(0x0, dbi_base + PCIE_PHY_CTRL); + + return 0; +} + +static int imx6_pcie_assert_core_reset(struct pcie_port *pp) +{ + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6Q_GPR12_PCIE_CTL_2, 1 << 10); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); + + gpio_set_value(imx6_pcie->reset_gpio, 0); + msleep(100); + gpio_set_value(imx6_pcie->reset_gpio, 1); + + return 0; +} + +static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) +{ + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + + if (gpio_is_valid(imx6_pcie->power_on_gpio)) + gpio_set_value(imx6_pcie->power_on_gpio, 1); + + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); + + /* allow the clocks to stabilize */ + usleep_range(100, 200); + + return 0; +} + +static void imx6_pcie_init_phy(struct pcie_port *pp) +{ + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + + /* FIXME the field name should be aligned to RM */ + 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 void imx6_pcie_host_init(struct pcie_port *pp) +{ + int count = 0; + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + + imx6_pcie_assert_core_reset(pp); + + imx6_pcie_init_phy(pp); + + imx6_pcie_deassert_core_reset(pp); + + dw_pcie_setup_rc(pp); + + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6Q_GPR12_PCIE_CTL_2, 1 << 10); + + while (!dw_pcie_link_up(pp)) { + usleep_range(100, 1000); + count++; + if (count >= 10) { + 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)); + break; + } + } + + return; +} + +static int imx6_pcie_link_up(struct pcie_port *pp) +{ + u32 rc, ltssm, rx_valid, temp; + + /* link is debug bit 36, debug register 1 starts at bit 32 */ + rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1) & (0x1 << (36 - 32)); + if (rc) + return -EAGAIN; + + /* 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); + ltssm = readl(pp->dbi_base + PCIE_PHY_DEBUG_R0) & 0x3F; + + if (rx_valid & 0x01) + return 0; + + if (ltssm != 0x0d) + return 0; + + dev_err(pp->dev, + "transition to gen2 is stuck, reset PHY!\n"); + + pcie_phy_read(pp->dbi_base, + PHY_RX_OVRD_IN_LO, &temp); + temp |= (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, temp); + + usleep_range(2000, 3000); + + pcie_phy_read(pp->dbi_base, + PHY_RX_OVRD_IN_LO, &temp); + temp &= ~(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, temp); + + 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 add_pcie_port(struct pcie_port *pp, struct platform_device *pdev) +{ + int ret; + + pp->irq = platform_get_irq(pdev, 0); + if (!pp->irq) { + dev_err(&pdev->dev, "failed to get irq\n"); + return -ENODEV; + } + + pp->root_bus_nr = -1; + pp->ops = &imx6_pcie_host_ops; + + spin_lock_init(&pp->conf_lock); + 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; + + dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!dbi_base) { + dev_err(&pdev->dev, "dbi_base memory resource not found\n"); + return -ENODEV; + } + + pp->dbi_base = devm_request_and_ioremap(&pdev->dev, dbi_base); + if (IS_ERR(pp->dbi_base)) { + dev_err(&pdev->dev, "unable to remap dbi_base\n"); + ret = PTR_ERR(pp->dbi_base); + goto err; + } + + /* 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"); + goto err; + } + } + + imx6_pcie->power_on_gpio = of_get_named_gpio(np, "power-on-gpio", 0); + if (gpio_is_valid(imx6_pcie->power_on_gpio)) { + ret = devm_gpio_request_one(&pdev->dev, + imx6_pcie->power_on_gpio, + GPIOF_OUT_INIT_LOW, + "PCIe power enable"); + if (ret) { + dev_err(&pdev->dev, "unable to get power-on gpio\n"); + goto err; + } + } + + imx6_pcie->wake_up_gpio = of_get_named_gpio(np, "wake-up-gpio", 0); + if (gpio_is_valid(imx6_pcie->wake_up_gpio)) { + ret = devm_gpio_request_one(&pdev->dev, + imx6_pcie->wake_up_gpio, + GPIOF_IN, + "PCIe wake up"); + if (ret) { + dev_err(&pdev->dev, "unable to get wake-up gpio\n"); + goto err; + } + } + + imx6_pcie->disable_gpio = of_get_named_gpio(np, "disable-gpio", 0); + if (gpio_is_valid(imx6_pcie->disable_gpio)) { + ret = devm_gpio_request_one(&pdev->dev, + imx6_pcie->disable_gpio, + GPIOF_OUT_INIT_HIGH, + "PCIe disable endpoint"); + if (ret) { + dev_err(&pdev->dev, "unable to get disable-ep gpio\n"); + goto err; + } + } + + /* 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"); + ret = PTR_ERR(imx6_pcie->iomuxc_gpr); + goto err; + } + + ret = add_pcie_port(pp, pdev); + if (ret < 0) + goto err; + + platform_set_drvdata(pdev, imx6_pcie); + return 0; + +err: + return ret; +} + +static const struct of_device_id imx6_pcie_of_match[] = { + { .compatible = "fsl,imx6-pcie", }, + {}, +}; +MODULE_DEVICE_TABLE(of, imx6_pcie_of_match); + +static struct platform_driver imx6_pcie_driver = { + .driver = { + .name = "imx6-pcie", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(imx6_pcie_of_match), + }, +}; + +/* Freescale PCIe driver does not allow module unload */ + +static int __init pcie_init(void) +{ + return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe); +} +subsys_initcall(pcie_init); + +MODULE_AUTHOR("Sean Cross <xobs@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Freescale i.MX6 PCIe host controller driver"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html