drivers/pci/pcie_dw_imx.c - u-boot - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2024 Linaro Ltd.
  *
  * Author: Sumit Garg <sumit.garg@linaro.org>
  */

 #include <asm/io.h>
 #include <asm-generic/gpio.h>
 #include <clk.h>
 #include <dm.h>
 #include <dm/device_compat.h>
 #include <generic-phy.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/iopoll.h>
 #include <log.h>
 #include <pci.h>
 #include <power/regulator.h>
 #include <regmap.h>
 #include <reset.h>
 #include <syscon.h>
 #include <time.h>

 #include "pcie_dw_common.h"

 #define PCIE_LINK_CAPABILITY		0x7c
 #define TARGET_LINK_SPEED_MASK		0xf
 #define LINK_SPEED_GEN_1		0x1
 #define LINK_SPEED_GEN_2		0x2
 #define LINK_SPEED_GEN_3		0x3

 #define PCIE_MISC_CONTROL_1_OFF		0x8bc
 #define PCIE_DBI_RO_WR_EN		BIT(0)

 #define PCIE_PORT_DEBUG0			0x728
 #define PCIE_PORT_DEBUG1			0x72c
 #define PCIE_PORT_DEBUG1_LINK_UP		BIT(4)
 #define PCIE_PORT_DEBUG1_LINK_IN_TRAINING	BIT(29)

 #define PCIE_LINK_UP_TIMEOUT_MS		100

 #define IOMUXC_GPR14_OFFSET			0x38
 #define IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN	BIT(10)
 #define IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE		BIT(11)

 struct pcie_dw_imx {
 	/* Must be first member of the struct */
 	struct pcie_dw			dw;
 	struct regmap			*iomuxc_gpr;
 	struct clk_bulk			clks;
 	struct gpio_desc		reset_gpio;
 	struct reset_ctl		apps_reset;
 	struct phy			phy;
 	struct udevice			*vpcie;
 };

 struct pcie_chip_info {
 	const char *gpr;
 };

 static const struct pcie_chip_info imx8mm_chip_info = {
 	.gpr = "fsl,imx8mm-iomuxc-gpr",
 };

 static const struct pcie_chip_info imx8mp_chip_info = {
 	.gpr = "fsl,imx8mp-iomuxc-gpr",
 };

 static void pcie_dw_configure(struct pcie_dw_imx *priv, u32 cap_speed)
 {
 	dw_pcie_dbi_write_enable(&priv->dw, true);

 	clrsetbits_le32(priv->dw.dbi_base + PCIE_LINK_CAPABILITY,
 			TARGET_LINK_SPEED_MASK, cap_speed);

 	dw_pcie_dbi_write_enable(&priv->dw, false);
 }

 static void imx_pcie_ltssm_enable(struct pcie_dw_imx *priv)
 {
 	reset_deassert(&priv->apps_reset);
 }

 static void imx_pcie_ltssm_disable(struct pcie_dw_imx *priv)
 {
 	reset_assert(&priv->apps_reset);
 }

 static bool is_link_up(u32 val)
 {
 	return ((val & PCIE_PORT_DEBUG1_LINK_UP) &&
 		(!(val & PCIE_PORT_DEBUG1_LINK_IN_TRAINING)));
 }

 static int wait_link_up(struct pcie_dw_imx *priv)
 {
 	u32 val;

 	return readl_poll_sleep_timeout(priv->dw.dbi_base + PCIE_PORT_DEBUG1,
 					val, is_link_up(val), 10000, 100000);
 }

 static int pcie_link_up(struct pcie_dw_imx *priv, u32 cap_speed)
 {
 	int ret;

 	/* DW pre link configurations */
 	pcie_dw_configure(priv, cap_speed);

 	/* Initiate link training */
 	imx_pcie_ltssm_enable(priv);

 	/* Check that link was established */
 	ret = wait_link_up(priv);
 	if (ret)
 		imx_pcie_ltssm_disable(priv);

 	return ret;
 }

 static int imx_pcie_assert_core_reset(struct pcie_dw_imx *priv)
 {
 	if (dm_gpio_is_valid(&priv->reset_gpio)) {
 		dm_gpio_set_value(&priv->reset_gpio, 1);
 		mdelay(20);
 	}

 	return reset_assert(&priv->apps_reset);
 }

 static int imx_pcie_clk_enable(struct pcie_dw_imx *priv)
 {
 	int ret;

 	ret = clk_enable_bulk(&priv->clks);
 	if (ret)
 		return ret;

 	/*
 	 * Set the over ride low and enabled make sure that
 	 * REF_CLK is turned on.
 	 */
 	regmap_update_bits(priv->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
 			   IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE, 0);
 	regmap_update_bits(priv->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
 			   IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN,
 			   IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN);

 	/* allow the clocks to stabilize */
 	udelay(500);

 	return 0;
 }

 static void imx_pcie_deassert_core_reset(struct pcie_dw_imx *priv)
 {
 	if (!dm_gpio_is_valid(&priv->reset_gpio))
 		return;

 	mdelay(100);
 	dm_gpio_set_value(&priv->reset_gpio, 0);
 	/* Wait for 100ms after PERST# deassertion (PCIe r5.0, 6.6.1) */
 	mdelay(100);
 }

 static int pcie_dw_imx_probe(struct udevice *dev)
 {
 	struct pcie_dw_imx *priv = dev_get_priv(dev);
 	struct udevice *ctlr = pci_get_controller(dev);
 	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
 	int ret;

 	if (priv->vpcie) {
 		ret = regulator_set_enable(priv->vpcie, true);
 		if (ret) {
 			dev_err(dev, "failed to enable vpcie regulator\n");
 			return ret;
 		}
 	}

 	ret = imx_pcie_assert_core_reset(priv);
 	if (ret) {
 		dev_err(dev, "failed to assert core reset\n");
 		return ret;
 	}

 	ret = imx_pcie_clk_enable(priv);
 	if (ret) {
 		dev_err(dev, "failed to enable clocks\n");
 		goto err_clk;
 	}

 	ret = generic_phy_init(&priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to initialize PHY\n");
 		goto err_phy_init;
 	}

 	ret = generic_phy_power_on(&priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to power on PHY\n");
 		goto err_phy_power;
 	}

 	imx_pcie_deassert_core_reset(priv);

 	priv->dw.first_busno = dev_seq(dev);
 	priv->dw.dev = dev;
 	pcie_dw_setup_host(&priv->dw);

 	if (pcie_link_up(priv, LINK_SPEED_GEN_1)) {
 		printf("PCIE-%d: Link down\n", dev_seq(dev));
 		ret = -ENODEV;
 		goto err_link;
 	}

 	printf("PCIE-%d: Link up (Gen%d-x%d, Bus%d)\n", dev_seq(dev),
 	       pcie_dw_get_link_speed(&priv->dw),
 	       pcie_dw_get_link_width(&priv->dw),
 	       hose->first_busno);

 	pcie_dw_prog_outbound_atu_unroll(&priv->dw, PCIE_ATU_REGION_INDEX0,
 					 PCIE_ATU_TYPE_MEM,
 					 priv->dw.mem.phys_start,
 					 priv->dw.mem.bus_start, priv->dw.mem.size);

 	return 0;

 err_link:
 	generic_shutdown_phy(&priv->phy);
 err_phy_power:
 	generic_phy_exit(&priv->phy);
 err_phy_init:
 	clk_disable_bulk(&priv->clks);
 err_clk:
 	imx_pcie_deassert_core_reset(priv);

 	return ret;
 }

 static int pcie_dw_imx_remove(struct udevice *dev)
 {
 	struct pcie_dw_imx *priv = dev_get_priv(dev);

 	generic_shutdown_phy(&priv->phy);
 	dm_gpio_free(dev, &priv->reset_gpio);
 	reset_free(&priv->apps_reset);
 	clk_release_bulk(&priv->clks);

 	return 0;
 }

 static int pcie_dw_imx_of_to_plat(struct udevice *dev)
 {
 	struct pcie_chip_info *info = (void *)dev_get_driver_data(dev);
 	struct pcie_dw_imx *priv = dev_get_priv(dev);
 	ofnode gpr;
 	int ret;

 	/* Get the controller base address */
 	priv->dw.dbi_base = (void *)dev_read_addr_name(dev, "dbi");
 	if ((fdt_addr_t)priv->dw.dbi_base == FDT_ADDR_T_NONE) {
 		dev_err(dev, "failed to get dbi_base address\n");
 		return -EINVAL;
 	}

 	/* Get the config space base address and size */
 	priv->dw.cfg_base = (void *)dev_read_addr_size_name(dev, "config",
 							    &priv->dw.cfg_size);
 	if ((fdt_addr_t)priv->dw.cfg_base == FDT_ADDR_T_NONE) {
 		dev_err(dev, "failed to get cfg_base address\n");
 		return -EINVAL;
 	}

 	ret = clk_get_bulk(dev, &priv->clks);
 	if (ret) {
 		dev_err(dev, "failed to get PCIe clks\n");
 		return ret;
 	}

 	ret = reset_get_by_name(dev, "apps", &priv->apps_reset);
 	if (ret) {
 		dev_err(dev,
 			"Failed to get PCIe apps reset control\n");
 		goto err_reset;
 	}

 	ret = gpio_request_by_name(dev, "reset-gpio", 0, &priv->reset_gpio,
 				   GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
 	if (ret) {
 		dev_err(dev, "unable to get reset-gpio\n");
 		goto err_gpio;
 	}

 	ret = generic_phy_get_by_name(dev, "pcie-phy", &priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to get pcie phy\n");
 		goto err_phy;
 	}

 	gpr = ofnode_by_compatible(ofnode_null(), info->gpr);
 	if (ofnode_equal(gpr, ofnode_null())) {
 		dev_err(dev, "unable to find GPR node\n");
 		ret = -ENODEV;
 		goto err_phy;
 	}

 	priv->iomuxc_gpr = syscon_node_to_regmap(gpr);
 	if (IS_ERR(priv->iomuxc_gpr)) {
 		dev_err(dev, "unable to find iomuxc registers\n");
 		ret = PTR_ERR(priv->iomuxc_gpr);
 		goto err_phy;
 	}

 	/* vpcie-supply regulator is optional */
 	device_get_supply_regulator(dev, "vpcie-supply", &priv->vpcie);

 	return 0;

 err_phy:
 	dm_gpio_free(dev, &priv->reset_gpio);
 err_gpio:
 	reset_free(&priv->apps_reset);
 err_reset:
 	clk_release_bulk(&priv->clks);

 	return ret;
 }

 static const struct dm_pci_ops pcie_dw_imx_ops = {
 	.read_config	= pcie_dw_read_config,
 	.write_config	= pcie_dw_write_config,
 };

 static const struct udevice_id pcie_dw_imx_ids[] = {
 	{ .compatible = "fsl,imx8mm-pcie", .data = (ulong)&imx8mm_chip_info, },
 	{ .compatible = "fsl,imx8mp-pcie", .data = (ulong)&imx8mp_chip_info, },
 	{ }
 };

 U_BOOT_DRIVER(pcie_dw_imx) = {
 	.name		= "pcie_dw_imx",
 	.id		= UCLASS_PCI,
 	.of_match	= pcie_dw_imx_ids,
 	.ops		= &pcie_dw_imx_ops,
 	.of_to_plat	= pcie_dw_imx_of_to_plat,
 	.probe		= pcie_dw_imx_probe,
 	.remove		= pcie_dw_imx_remove,
 	.priv_auto	= sizeof(struct pcie_dw_imx),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2024 Linaro Ltd.
	*
	* Author: Sumit Garg <sumit.garg@linaro.org>
	*/

	#include <asm/io.h>
	#include <asm-generic/gpio.h>
	#include <clk.h>
	#include <dm.h>
	#include <dm/device_compat.h>
	#include <generic-phy.h>
	#include <linux/bitops.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/iopoll.h>
	#include <log.h>
	#include <pci.h>
	#include <power/regulator.h>
	#include <regmap.h>
	#include <reset.h>
	#include <syscon.h>
	#include <time.h>

	#include "pcie_dw_common.h"

	#define PCIE_LINK_CAPABILITY 0x7c
	#define TARGET_LINK_SPEED_MASK 0xf
	#define LINK_SPEED_GEN_1 0x1
	#define LINK_SPEED_GEN_2 0x2
	#define LINK_SPEED_GEN_3 0x3

	#define PCIE_MISC_CONTROL_1_OFF 0x8bc
	#define PCIE_DBI_RO_WR_EN BIT(0)

	#define PCIE_PORT_DEBUG0 0x728
	#define PCIE_PORT_DEBUG1 0x72c
	#define PCIE_PORT_DEBUG1_LINK_UP BIT(4)
	#define PCIE_PORT_DEBUG1_LINK_IN_TRAINING BIT(29)

	#define PCIE_LINK_UP_TIMEOUT_MS 100

	#define IOMUXC_GPR14_OFFSET 0x38
	#define IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
	#define IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)

	struct pcie_dw_imx {
	/* Must be first member of the struct */
	struct pcie_dw dw;
	struct regmap *iomuxc_gpr;
	struct clk_bulk clks;
	struct gpio_desc reset_gpio;
	struct reset_ctl apps_reset;
	struct phy phy;
	struct udevice *vpcie;
	};

	struct pcie_chip_info {
	const char *gpr;
	};

	static const struct pcie_chip_info imx8mm_chip_info = {
	.gpr = "fsl,imx8mm-iomuxc-gpr",
	};

	static const struct pcie_chip_info imx8mp_chip_info = {
	.gpr = "fsl,imx8mp-iomuxc-gpr",
	};

	static void pcie_dw_configure(struct pcie_dw_imx *priv, u32 cap_speed)
	{
	dw_pcie_dbi_write_enable(&priv->dw, true);

	clrsetbits_le32(priv->dw.dbi_base + PCIE_LINK_CAPABILITY,
	TARGET_LINK_SPEED_MASK, cap_speed);

	dw_pcie_dbi_write_enable(&priv->dw, false);
	}

	static void imx_pcie_ltssm_enable(struct pcie_dw_imx *priv)
	{
	reset_deassert(&priv->apps_reset);
	}

	static void imx_pcie_ltssm_disable(struct pcie_dw_imx *priv)
	{
	reset_assert(&priv->apps_reset);
	}

	static bool is_link_up(u32 val)
	{
	return ((val & PCIE_PORT_DEBUG1_LINK_UP) &&
	(!(val & PCIE_PORT_DEBUG1_LINK_IN_TRAINING)));
	}

	static int wait_link_up(struct pcie_dw_imx *priv)
	{
	u32 val;

	return readl_poll_sleep_timeout(priv->dw.dbi_base + PCIE_PORT_DEBUG1,
	val, is_link_up(val), 10000, 100000);
	}

	static int pcie_link_up(struct pcie_dw_imx *priv, u32 cap_speed)
	{
	int ret;

	/* DW pre link configurations */
	pcie_dw_configure(priv, cap_speed);

	/* Initiate link training */
	imx_pcie_ltssm_enable(priv);

	/* Check that link was established */
	ret = wait_link_up(priv);
	if (ret)
	imx_pcie_ltssm_disable(priv);

	return ret;
	}

	static int imx_pcie_assert_core_reset(struct pcie_dw_imx *priv)
	{
	if (dm_gpio_is_valid(&priv->reset_gpio)) {
	dm_gpio_set_value(&priv->reset_gpio, 1);
	mdelay(20);
	}

	return reset_assert(&priv->apps_reset);
	}

	static int imx_pcie_clk_enable(struct pcie_dw_imx *priv)
	{
	int ret;

	ret = clk_enable_bulk(&priv->clks);
	if (ret)
	return ret;

	/*
	* Set the over ride low and enabled make sure that
	* REF_CLK is turned on.
	*/
	regmap_update_bits(priv->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
	IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE, 0);
	regmap_update_bits(priv->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
	IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN,
	IMX8M_GPR_PCIE_CLK_REQ_OVERRIDE_EN);

	/* allow the clocks to stabilize */
	udelay(500);

	return 0;
	}

	static void imx_pcie_deassert_core_reset(struct pcie_dw_imx *priv)
	{
	if (!dm_gpio_is_valid(&priv->reset_gpio))
	return;

	mdelay(100);
	dm_gpio_set_value(&priv->reset_gpio, 0);
	/* Wait for 100ms after PERST# deassertion (PCIe r5.0, 6.6.1) */
	mdelay(100);
	}

	static int pcie_dw_imx_probe(struct udevice *dev)
	{
	struct pcie_dw_imx *priv = dev_get_priv(dev);
	struct udevice *ctlr = pci_get_controller(dev);
	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
	int ret;

	if (priv->vpcie) {
	ret = regulator_set_enable(priv->vpcie, true);
	if (ret) {
	dev_err(dev, "failed to enable vpcie regulator\n");
	return ret;
	}
	}

	ret = imx_pcie_assert_core_reset(priv);
	if (ret) {
	dev_err(dev, "failed to assert core reset\n");
	return ret;
	}

	ret = imx_pcie_clk_enable(priv);
	if (ret) {
	dev_err(dev, "failed to enable clocks\n");
	goto err_clk;
	}

	ret = generic_phy_init(&priv->phy);
	if (ret) {
	dev_err(dev, "failed to initialize PHY\n");
	goto err_phy_init;
	}

	ret = generic_phy_power_on(&priv->phy);
	if (ret) {
	dev_err(dev, "failed to power on PHY\n");
	goto err_phy_power;
	}

	imx_pcie_deassert_core_reset(priv);

	priv->dw.first_busno = dev_seq(dev);
	priv->dw.dev = dev;
	pcie_dw_setup_host(&priv->dw);

	if (pcie_link_up(priv, LINK_SPEED_GEN_1)) {
	printf("PCIE-%d: Link down\n", dev_seq(dev));
	ret = -ENODEV;
	goto err_link;
	}

	printf("PCIE-%d: Link up (Gen%d-x%d, Bus%d)\n", dev_seq(dev),
	pcie_dw_get_link_speed(&priv->dw),
	pcie_dw_get_link_width(&priv->dw),
	hose->first_busno);

	pcie_dw_prog_outbound_atu_unroll(&priv->dw, PCIE_ATU_REGION_INDEX0,
	PCIE_ATU_TYPE_MEM,
	priv->dw.mem.phys_start,
	priv->dw.mem.bus_start, priv->dw.mem.size);

	return 0;

	err_link:
	generic_shutdown_phy(&priv->phy);
	err_phy_power:
	generic_phy_exit(&priv->phy);
	err_phy_init:
	clk_disable_bulk(&priv->clks);
	err_clk:
	imx_pcie_deassert_core_reset(priv);

	return ret;
	}

	static int pcie_dw_imx_remove(struct udevice *dev)
	{
	struct pcie_dw_imx *priv = dev_get_priv(dev);

	generic_shutdown_phy(&priv->phy);
	dm_gpio_free(dev, &priv->reset_gpio);
	reset_free(&priv->apps_reset);
	clk_release_bulk(&priv->clks);

	return 0;
	}

	static int pcie_dw_imx_of_to_plat(struct udevice *dev)
	{
	struct pcie_chip_info info = (void )dev_get_driver_data(dev);
	struct pcie_dw_imx *priv = dev_get_priv(dev);
	ofnode gpr;
	int ret;

	/* Get the controller base address */
	priv->dw.dbi_base = (void *)dev_read_addr_name(dev, "dbi");
	if ((fdt_addr_t)priv->dw.dbi_base == FDT_ADDR_T_NONE) {
	dev_err(dev, "failed to get dbi_base address\n");
	return -EINVAL;
	}

	/* Get the config space base address and size */
	priv->dw.cfg_base = (void *)dev_read_addr_size_name(dev, "config",
	&priv->dw.cfg_size);
	if ((fdt_addr_t)priv->dw.cfg_base == FDT_ADDR_T_NONE) {
	dev_err(dev, "failed to get cfg_base address\n");
	return -EINVAL;
	}

	ret = clk_get_bulk(dev, &priv->clks);
	if (ret) {
	dev_err(dev, "failed to get PCIe clks\n");
	return ret;
	}

	ret = reset_get_by_name(dev, "apps", &priv->apps_reset);
	if (ret) {
	dev_err(dev,
	"Failed to get PCIe apps reset control\n");
	goto err_reset;
	}

	ret = gpio_request_by_name(dev, "reset-gpio", 0, &priv->reset_gpio,
	GPIOD_IS_OUT \| GPIOD_IS_OUT_ACTIVE);
	if (ret) {
	dev_err(dev, "unable to get reset-gpio\n");
	goto err_gpio;
	}

	ret = generic_phy_get_by_name(dev, "pcie-phy", &priv->phy);
	if (ret) {
	dev_err(dev, "failed to get pcie phy\n");
	goto err_phy;
	}

	gpr = ofnode_by_compatible(ofnode_null(), info->gpr);
	if (ofnode_equal(gpr, ofnode_null())) {
	dev_err(dev, "unable to find GPR node\n");
	ret = -ENODEV;
	goto err_phy;
	}

	priv->iomuxc_gpr = syscon_node_to_regmap(gpr);
	if (IS_ERR(priv->iomuxc_gpr)) {
	dev_err(dev, "unable to find iomuxc registers\n");
	ret = PTR_ERR(priv->iomuxc_gpr);
	goto err_phy;
	}

	/* vpcie-supply regulator is optional */
	device_get_supply_regulator(dev, "vpcie-supply", &priv->vpcie);

	return 0;

	err_phy:
	dm_gpio_free(dev, &priv->reset_gpio);
	err_gpio:
	reset_free(&priv->apps_reset);
	err_reset:
	clk_release_bulk(&priv->clks);

	return ret;
	}

	static const struct dm_pci_ops pcie_dw_imx_ops = {
	.read_config = pcie_dw_read_config,
	.write_config = pcie_dw_write_config,
	};

	static const struct udevice_id pcie_dw_imx_ids[] = {
	{ .compatible = "fsl,imx8mm-pcie", .data = (ulong)&imx8mm_chip_info, },
	{ .compatible = "fsl,imx8mp-pcie", .data = (ulong)&imx8mp_chip_info, },
	{ }
	};

	U_BOOT_DRIVER(pcie_dw_imx) = {
	.name = "pcie_dw_imx",
	.id = UCLASS_PCI,
	.of_match = pcie_dw_imx_ids,
	.ops = &pcie_dw_imx_ops,
	.of_to_plat = pcie_dw_imx_of_to_plat,
	.probe = pcie_dw_imx_probe,
	.remove = pcie_dw_imx_remove,
	.priv_auto = sizeof(struct pcie_dw_imx),
	};