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

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Amlogic DesignWare based PCIe host controller driver
  *
  * Copyright (c) 2021 BayLibre, SAS
  * Author: Neil Armstrong <narmstrong@baylibre.com>
  *
  * Based on pcie_dw_rockchip.c
  * Copyright (c) 2021 Rockchip, Inc.
  */

 #include <common.h>
 #include <clk.h>
 #include <dm.h>
 #include <generic-phy.h>
 #include <pci.h>
 #include <power-domain.h>
 #include <reset.h>
 #include <syscon.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
 #include <asm-generic/gpio.h>
 #include <dm/device_compat.h>
 #include <linux/iopoll.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
 #include <linux/bitfield.h>

 #include "pcie_dw_common.h"

 DECLARE_GLOBAL_DATA_PTR;

 /**
  * struct meson_pcie - Amlogic Meson DW PCIe controller state
  *
  * @pci: The common PCIe DW structure
  * @meson_cfg_base: The base address of vendor regs
  * @phy
  * @clk_port
  * @clk_general
  * @clk_pclk
  * @rsts
  * @rst_gpio: The #PERST signal for slot
  */
 struct meson_pcie {
 	/* Must be first member of the struct */
 	struct pcie_dw dw;
 	void *meson_cfg_base;
 	struct phy phy;
 	struct clk clk_port;
 	struct clk clk_general;
 	struct clk clk_pclk;
 	struct reset_ctl_bulk rsts;
 	struct gpio_desc rst_gpio;
 };

 #define PCI_EXP_DEVCTL_PAYLOAD	0x00e0	/* Max_Payload_Size */

 #define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
 #define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)

 /* PCIe specific config registers */
 #define PCIE_CFG0			0x0
 #define APP_LTSSM_ENABLE		BIT(7)

 #define PCIE_CFG_STATUS12		0x30
 #define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
 #define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
 #define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)

 #define PCIE_CFG_STATUS17		0x44
 #define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)

 #define WAIT_LINKUP_TIMEOUT		4000
 #define PORT_CLK_RATE			100000000UL
 #define MAX_PAYLOAD_SIZE		256
 #define MAX_READ_REQ_SIZE		256
 #define PCIE_RESET_DELAY		500
 #define PCIE_SHARED_RESET		1
 #define PCIE_NORMAL_RESET		0

 enum pcie_data_rate {
 	PCIE_GEN1,
 	PCIE_GEN2,
 	PCIE_GEN3,
 	PCIE_GEN4
 };

 /* Parameters for the waiting for #perst signal */
 #define PERST_WAIT_US			1000000

 static inline u32 meson_cfg_readl(struct meson_pcie *priv, u32 reg)
 {
 	return readl(priv->meson_cfg_base + reg);
 }

 static inline void meson_cfg_writel(struct meson_pcie *priv, u32 val, u32 reg)
 {
 	writel(val, priv->meson_cfg_base + reg);
 }

 /**
  * meson_pcie_configure() - Configure link
  *
  * @meson_pcie: Pointer to the PCI controller state
  *
  * Configure the link mode and width
  */
 static void meson_pcie_configure(struct meson_pcie *priv)
 {
 	u32 val;

 	dw_pcie_dbi_write_enable(&priv->dw, true);

 	val = readl(priv->dw.dbi_base + PCIE_PORT_LINK_CONTROL);
 	val &= ~PORT_LINK_FAST_LINK_MODE;
 	val |= PORT_LINK_DLL_LINK_EN;
 	val &= ~PORT_LINK_MODE_MASK;
 	val |= PORT_LINK_MODE_1_LANES;
 	writel(val, priv->dw.dbi_base + PCIE_PORT_LINK_CONTROL);

 	val = readl(priv->dw.dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);
 	val &= ~PORT_LOGIC_LINK_WIDTH_MASK;
 	val |= PORT_LOGIC_LINK_WIDTH_1_LANES;
 	writel(val, priv->dw.dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);

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

 static inline void meson_pcie_enable_ltssm(struct meson_pcie *priv)
 {
 	u32 val;

 	val = meson_cfg_readl(priv, PCIE_CFG0);
 	val |= APP_LTSSM_ENABLE;
 	meson_cfg_writel(priv, val, PCIE_CFG0);
 }

 static int meson_pcie_wait_link_up(struct meson_pcie *priv)
 {
 	u32 speed_okay = 0;
 	u32 cnt = 0;
 	u32 state12, state17, smlh_up, ltssm_up, rdlh_up;

 	do {
 		state12 = meson_cfg_readl(priv, PCIE_CFG_STATUS12);
 		state17 = meson_cfg_readl(priv, PCIE_CFG_STATUS17);
 		smlh_up = IS_SMLH_LINK_UP(state12);
 		rdlh_up = IS_RDLH_LINK_UP(state12);
 		ltssm_up = IS_LTSSM_UP(state12);

 		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
 			speed_okay = 1;

 		if (smlh_up)
 			debug("%s: smlh_link_up is on\n", __func__);
 		if (rdlh_up)
 			debug("%s: rdlh_link_up is on\n", __func__);
 		if (ltssm_up)
 			debug("%s: ltssm_up is on\n", __func__);
 		if (speed_okay)
 			debug("%s: speed_okay\n", __func__);

 		if (smlh_up && rdlh_up && ltssm_up && speed_okay)
 			return 0;

 		cnt++;

 		udelay(10);
 	} while (cnt < WAIT_LINKUP_TIMEOUT);

 	printf("%s: error: wait linkup timeout\n", __func__);
 	return -EIO;
 }

 /**
  * meson_pcie_link_up() - Wait for the link to come up
  *
  * @meson_pcie: Pointer to the PCI controller state
  * @cap_speed: Desired link speed
  *
  * Return: 1 (true) for active line and negative (false) for no link (timeout)
  */
 static int meson_pcie_link_up(struct meson_pcie *priv, u32 cap_speed)
 {
 	/* DW link configurations */
 	meson_pcie_configure(priv);

 	/* Reset the device */
 	if (dm_gpio_is_valid(&priv->rst_gpio)) {
 		dm_gpio_set_value(&priv->rst_gpio, 1);
 		/*
 		 * Minimal is 100ms from spec but we see
 		 * some wired devices need much more, such as 600ms.
 		 * Add a enough delay to cover all cases.
 		 */
 		udelay(PERST_WAIT_US);
 		dm_gpio_set_value(&priv->rst_gpio, 0);
 	}

 	/* Enable LTSSM */
 	meson_pcie_enable_ltssm(priv);

 	return meson_pcie_wait_link_up(priv);
 }

 static int meson_size_to_payload(int size)
 {
 	/*
 	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
 	 * So if input size is not 2^order alignment or less than 2^7 or bigger
 	 * than 2^12, just set to default size 2^(1+7).
 	 */
 	if (!is_power_of_2(size) || size < 128 || size > 4096) {
 		debug("%s: payload size %d, set to default 256\n", __func__, size);
 		return 1;
 	}

 	return fls(size) - 8;
 }

 static void meson_set_max_payload(struct meson_pcie *priv, int size)
 {
 	u32 val;
 	u16 offset = dm_pci_find_capability(priv->dw.dev, PCI_CAP_ID_EXP);
 	int max_payload_size = meson_size_to_payload(size);

 	dw_pcie_dbi_write_enable(&priv->dw, true);

 	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
 	val &= ~PCI_EXP_DEVCTL_PAYLOAD;
 	writel(val, priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);

 	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
 	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
 	writel(val, priv->dw.dbi_base + PCI_EXP_DEVCTL);

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

 static void meson_set_max_rd_req_size(struct meson_pcie *priv, int size)
 {
 	u32 val;
 	u16 offset = dm_pci_find_capability(priv->dw.dev, PCI_CAP_ID_EXP);
 	int max_rd_req_size = meson_size_to_payload(size);

 	dw_pcie_dbi_write_enable(&priv->dw, true);

 	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
 	val &= ~PCI_EXP_DEVCTL_PAYLOAD;
 	writel(val, priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);

 	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
 	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
 	writel(val, priv->dw.dbi_base + PCI_EXP_DEVCTL);

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

 static int meson_pcie_init_port(struct udevice *dev)
 {
 	int ret;
 	struct meson_pcie *priv = dev_get_priv(dev);

 	ret = generic_phy_init(&priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to init phy (ret=%d)\n", ret);
 		return ret;
 	}

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

 	ret = generic_phy_reset(&priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to reset phy (ret=%d)\n", ret);
 		goto err_exit_phy;
 	}

 	ret = reset_assert_bulk(&priv->rsts);
 	if (ret) {
 		dev_err(dev, "failed to assert resets (ret=%d)\n", ret);
 		goto err_power_off_phy;
 	}

 	udelay(PCIE_RESET_DELAY);

 	ret = reset_deassert_bulk(&priv->rsts);
 	if (ret) {
 		dev_err(dev, "failed to deassert resets (ret=%d)\n", ret);
 		goto err_power_off_phy;
 	}

 	udelay(PCIE_RESET_DELAY);

 	ret = clk_set_rate(&priv->clk_port, PORT_CLK_RATE);
 	if (ret) {
 		dev_err(dev, "failed to set port clk rate (ret=%d)\n", ret);
 		goto err_deassert_bulk;
 	}

 	ret = clk_enable(&priv->clk_general);
 	if (ret) {
 		dev_err(dev, "failed to enable clk general (ret=%d)\n", ret);
 		goto err_deassert_bulk;
 	}

 	ret = clk_enable(&priv->clk_pclk);
 	if (ret) {
 		dev_err(dev, "failed to enable pclk (ret=%d)\n", ret);
 		goto err_deassert_bulk;
 	}

 	meson_set_max_payload(priv, MAX_PAYLOAD_SIZE);
 	meson_set_max_rd_req_size(priv, MAX_READ_REQ_SIZE);

 	pcie_dw_setup_host(&priv->dw);

 	meson_pcie_link_up(priv, LINK_SPEED_GEN_2);

 	return 0;
 err_deassert_bulk:
 	reset_assert_bulk(&priv->rsts);
 err_power_off_phy:
 	generic_phy_power_off(&priv->phy);
 err_exit_phy:
 	generic_phy_exit(&priv->phy);

 	return ret;
 }

 static int meson_pcie_parse_dt(struct udevice *dev)
 {
 	struct meson_pcie *priv = dev_get_priv(dev);
 	int ret;

 	priv->dw.dbi_base = (void *)dev_read_addr_index(dev, 0);
 	if (!priv->dw.dbi_base)
 		return -ENODEV;

 	dev_dbg(dev, "ELBI address is 0x%p\n", priv->dw.dbi_base);

 	priv->meson_cfg_base = (void *)dev_read_addr_index(dev, 1);
 	if (!priv->meson_cfg_base)
 		return -ENODEV;

 	dev_dbg(dev, "CFG address is 0x%p\n", priv->meson_cfg_base);

 	ret = gpio_request_by_name(dev, "reset-gpios", 0,
 				   &priv->rst_gpio, GPIOD_IS_OUT);
 	if (ret) {
 		dev_err(dev, "failed to find reset-gpios property\n");
 		return ret;
 	}

 	ret = reset_get_bulk(dev, &priv->rsts);
 	if (ret) {
 		dev_err(dev, "Can't get reset: %d\n", ret);
 		return ret;
 	}

 	ret = clk_get_by_name(dev, "port", &priv->clk_port);
 	if (ret) {
 		dev_err(dev, "Can't get port clock: %d\n", ret);
 		return ret;
 	}

 	ret = clk_get_by_name(dev, "general", &priv->clk_general);
 	if (ret) {
 		dev_err(dev, "Can't get port clock: %d\n", ret);
 		return ret;
 	}

 	ret = clk_get_by_name(dev, "pclk", &priv->clk_pclk);
 	if (ret) {
 		dev_err(dev, "Can't get port clock: %d\n", ret);
 		return ret;
 	}

 	ret = generic_phy_get_by_index(dev, 0, &priv->phy);
 	if (ret) {
 		dev_err(dev, "failed to get pcie phy (ret=%d)\n", ret);
 		return ret;
 	}

 	return 0;
 }

 /**
  * meson_pcie_probe() - Probe the PCIe bus for active link
  *
  * @dev: A pointer to the device being operated on
  *
  * Probe for an active link on the PCIe bus and configure the controller
  * to enable this port.
  *
  * Return: 0 on success, else -ENODEV
  */
 static int meson_pcie_probe(struct udevice *dev)
 {
 	struct meson_pcie *priv = dev_get_priv(dev);
 	struct udevice *ctlr = pci_get_controller(dev);
 	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
 	int ret = 0;

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

 	ret = meson_pcie_parse_dt(dev);
 	if (ret)
 		return ret;

 	ret = meson_pcie_init_port(dev);
 	if (ret) {
 		dm_gpio_free(dev, &priv->rst_gpio);
 		return ret;
 	}

 	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);

 	return 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);
 }

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

 static const struct udevice_id meson_pcie_ids[] = {
 	{ .compatible = "amlogic,axg-pcie" },
 	{ .compatible = "amlogic,g12a-pcie" },
 	{ }
 };

 U_BOOT_DRIVER(meson_dw_pcie) = {
 	.name			= "pcie_dw_meson",
 	.id			= UCLASS_PCI,
 	.of_match		= meson_pcie_ids,
 	.ops			= &meson_pcie_ops,
 	.probe			= meson_pcie_probe,
 	.priv_auto		= sizeof(struct meson_pcie),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Amlogic DesignWare based PCIe host controller driver
	*
	* Copyright (c) 2021 BayLibre, SAS
	* Author: Neil Armstrong <narmstrong@baylibre.com>
	*
	* Based on pcie_dw_rockchip.c
	* Copyright (c) 2021 Rockchip, Inc.
	*/

	#include <common.h>
	#include <clk.h>
	#include <dm.h>
	#include <generic-phy.h>
	#include <pci.h>
	#include <power-domain.h>
	#include <reset.h>
	#include <syscon.h>
	#include <asm/global_data.h>
	#include <asm/io.h>
	#include <asm-generic/gpio.h>
	#include <dm/device_compat.h>
	#include <linux/iopoll.h>
	#include <linux/delay.h>
	#include <linux/log2.h>
	#include <linux/bitfield.h>

	#include "pcie_dw_common.h"

	DECLARE_GLOBAL_DATA_PTR;

	/**
	* struct meson_pcie - Amlogic Meson DW PCIe controller state
	*
	* @pci: The common PCIe DW structure
	* @meson_cfg_base: The base address of vendor regs
	* @phy
	* @clk_port
	* @clk_general
	* @clk_pclk
	* @rsts
	* @rst_gpio: The #PERST signal for slot
	*/
	struct meson_pcie {
	/* Must be first member of the struct */
	struct pcie_dw dw;
	void *meson_cfg_base;
	struct phy phy;
	struct clk clk_port;
	struct clk clk_general;
	struct clk clk_pclk;
	struct reset_ctl_bulk rsts;
	struct gpio_desc rst_gpio;
	};

	#define PCI_EXP_DEVCTL_PAYLOAD 0x00e0 /* Max_Payload_Size */

	#define PCIE_CAP_MAX_PAYLOAD_SIZE(x) ((x) << 5)
	#define PCIE_CAP_MAX_READ_REQ_SIZE(x) ((x) << 12)

	/* PCIe specific config registers */
	#define PCIE_CFG0 0x0
	#define APP_LTSSM_ENABLE BIT(7)

	#define PCIE_CFG_STATUS12 0x30
	#define IS_SMLH_LINK_UP(x) ((x) & (1 << 6))
	#define IS_RDLH_LINK_UP(x) ((x) & (1 << 16))
	#define IS_LTSSM_UP(x) ((((x) >> 10) & 0x1f) == 0x11)

	#define PCIE_CFG_STATUS17 0x44
	#define PM_CURRENT_STATE(x) (((x) >> 7) & 0x1)

	#define WAIT_LINKUP_TIMEOUT 4000
	#define PORT_CLK_RATE 100000000UL
	#define MAX_PAYLOAD_SIZE 256
	#define MAX_READ_REQ_SIZE 256
	#define PCIE_RESET_DELAY 500
	#define PCIE_SHARED_RESET 1
	#define PCIE_NORMAL_RESET 0

	enum pcie_data_rate {
	PCIE_GEN1,
	PCIE_GEN2,
	PCIE_GEN3,
	PCIE_GEN4
	};

	/* Parameters for the waiting for #perst signal */
	#define PERST_WAIT_US 1000000

	static inline u32 meson_cfg_readl(struct meson_pcie *priv, u32 reg)
	{
	return readl(priv->meson_cfg_base + reg);
	}

	static inline void meson_cfg_writel(struct meson_pcie *priv, u32 val, u32 reg)
	{
	writel(val, priv->meson_cfg_base + reg);
	}

	/**
	* meson_pcie_configure() - Configure link
	*
	* @meson_pcie: Pointer to the PCI controller state
	*
	* Configure the link mode and width
	*/
	static void meson_pcie_configure(struct meson_pcie *priv)
	{
	u32 val;

	dw_pcie_dbi_write_enable(&priv->dw, true);

	val = readl(priv->dw.dbi_base + PCIE_PORT_LINK_CONTROL);
	val &= ~PORT_LINK_FAST_LINK_MODE;
	val \|= PORT_LINK_DLL_LINK_EN;
	val &= ~PORT_LINK_MODE_MASK;
	val \|= PORT_LINK_MODE_1_LANES;
	writel(val, priv->dw.dbi_base + PCIE_PORT_LINK_CONTROL);

	val = readl(priv->dw.dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);
	val &= ~PORT_LOGIC_LINK_WIDTH_MASK;
	val \|= PORT_LOGIC_LINK_WIDTH_1_LANES;
	writel(val, priv->dw.dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);

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

	static inline void meson_pcie_enable_ltssm(struct meson_pcie *priv)
	{
	u32 val;

	val = meson_cfg_readl(priv, PCIE_CFG0);
	val \|= APP_LTSSM_ENABLE;
	meson_cfg_writel(priv, val, PCIE_CFG0);
	}

	static int meson_pcie_wait_link_up(struct meson_pcie *priv)
	{
	u32 speed_okay = 0;
	u32 cnt = 0;
	u32 state12, state17, smlh_up, ltssm_up, rdlh_up;

	do {
	state12 = meson_cfg_readl(priv, PCIE_CFG_STATUS12);
	state17 = meson_cfg_readl(priv, PCIE_CFG_STATUS17);
	smlh_up = IS_SMLH_LINK_UP(state12);
	rdlh_up = IS_RDLH_LINK_UP(state12);
	ltssm_up = IS_LTSSM_UP(state12);

	if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
	speed_okay = 1;

	if (smlh_up)
	debug("%s: smlh_link_up is on\n", __func__);
	if (rdlh_up)
	debug("%s: rdlh_link_up is on\n", __func__);
	if (ltssm_up)
	debug("%s: ltssm_up is on\n", __func__);
	if (speed_okay)
	debug("%s: speed_okay\n", __func__);

	if (smlh_up && rdlh_up && ltssm_up && speed_okay)
	return 0;

	cnt++;

	udelay(10);
	} while (cnt < WAIT_LINKUP_TIMEOUT);

	printf("%s: error: wait linkup timeout\n", __func__);
	return -EIO;
	}

	/**
	* meson_pcie_link_up() - Wait for the link to come up
	*
	* @meson_pcie: Pointer to the PCI controller state
	* @cap_speed: Desired link speed
	*
	* Return: 1 (true) for active line and negative (false) for no link (timeout)
	*/
	static int meson_pcie_link_up(struct meson_pcie *priv, u32 cap_speed)
	{
	/* DW link configurations */
	meson_pcie_configure(priv);

	/* Reset the device */
	if (dm_gpio_is_valid(&priv->rst_gpio)) {
	dm_gpio_set_value(&priv->rst_gpio, 1);
	/*
	* Minimal is 100ms from spec but we see
	* some wired devices need much more, such as 600ms.
	* Add a enough delay to cover all cases.
	*/
	udelay(PERST_WAIT_US);
	dm_gpio_set_value(&priv->rst_gpio, 0);
	}

	/* Enable LTSSM */
	meson_pcie_enable_ltssm(priv);

	return meson_pcie_wait_link_up(priv);
	}

	static int meson_size_to_payload(int size)
	{
	/*
	* dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
	* So if input size is not 2^order alignment or less than 2^7 or bigger
	* than 2^12, just set to default size 2^(1+7).
	*/
	if (!is_power_of_2(size) \|\| size < 128 \|\| size > 4096) {
	debug("%s: payload size %d, set to default 256\n", __func__, size);
	return 1;
	}

	return fls(size) - 8;
	}

	static void meson_set_max_payload(struct meson_pcie *priv, int size)
	{
	u32 val;
	u16 offset = dm_pci_find_capability(priv->dw.dev, PCI_CAP_ID_EXP);
	int max_payload_size = meson_size_to_payload(size);

	dw_pcie_dbi_write_enable(&priv->dw, true);

	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
	val &= ~PCI_EXP_DEVCTL_PAYLOAD;
	writel(val, priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);

	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
	val \|= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
	writel(val, priv->dw.dbi_base + PCI_EXP_DEVCTL);

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

	static void meson_set_max_rd_req_size(struct meson_pcie *priv, int size)
	{
	u32 val;
	u16 offset = dm_pci_find_capability(priv->dw.dev, PCI_CAP_ID_EXP);
	int max_rd_req_size = meson_size_to_payload(size);

	dw_pcie_dbi_write_enable(&priv->dw, true);

	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
	val &= ~PCI_EXP_DEVCTL_PAYLOAD;
	writel(val, priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);

	val = readl(priv->dw.dbi_base + offset + PCI_EXP_DEVCTL);
	val \|= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
	writel(val, priv->dw.dbi_base + PCI_EXP_DEVCTL);

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

	static int meson_pcie_init_port(struct udevice *dev)
	{
	int ret;
	struct meson_pcie *priv = dev_get_priv(dev);

	ret = generic_phy_init(&priv->phy);
	if (ret) {
	dev_err(dev, "failed to init phy (ret=%d)\n", ret);
	return ret;
	}

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

	ret = generic_phy_reset(&priv->phy);
	if (ret) {
	dev_err(dev, "failed to reset phy (ret=%d)\n", ret);
	goto err_exit_phy;
	}

	ret = reset_assert_bulk(&priv->rsts);
	if (ret) {
	dev_err(dev, "failed to assert resets (ret=%d)\n", ret);
	goto err_power_off_phy;
	}

	udelay(PCIE_RESET_DELAY);

	ret = reset_deassert_bulk(&priv->rsts);
	if (ret) {
	dev_err(dev, "failed to deassert resets (ret=%d)\n", ret);
	goto err_power_off_phy;
	}

	udelay(PCIE_RESET_DELAY);

	ret = clk_set_rate(&priv->clk_port, PORT_CLK_RATE);
	if (ret) {
	dev_err(dev, "failed to set port clk rate (ret=%d)\n", ret);
	goto err_deassert_bulk;
	}

	ret = clk_enable(&priv->clk_general);
	if (ret) {
	dev_err(dev, "failed to enable clk general (ret=%d)\n", ret);
	goto err_deassert_bulk;
	}

	ret = clk_enable(&priv->clk_pclk);
	if (ret) {
	dev_err(dev, "failed to enable pclk (ret=%d)\n", ret);
	goto err_deassert_bulk;
	}

	meson_set_max_payload(priv, MAX_PAYLOAD_SIZE);
	meson_set_max_rd_req_size(priv, MAX_READ_REQ_SIZE);

	pcie_dw_setup_host(&priv->dw);

	meson_pcie_link_up(priv, LINK_SPEED_GEN_2);

	return 0;
	err_deassert_bulk:
	reset_assert_bulk(&priv->rsts);
	err_power_off_phy:
	generic_phy_power_off(&priv->phy);
	err_exit_phy:
	generic_phy_exit(&priv->phy);

	return ret;
	}

	static int meson_pcie_parse_dt(struct udevice *dev)
	{
	struct meson_pcie *priv = dev_get_priv(dev);
	int ret;

	priv->dw.dbi_base = (void *)dev_read_addr_index(dev, 0);
	if (!priv->dw.dbi_base)
	return -ENODEV;

	dev_dbg(dev, "ELBI address is 0x%p\n", priv->dw.dbi_base);

	priv->meson_cfg_base = (void *)dev_read_addr_index(dev, 1);
	if (!priv->meson_cfg_base)
	return -ENODEV;

	dev_dbg(dev, "CFG address is 0x%p\n", priv->meson_cfg_base);

	ret = gpio_request_by_name(dev, "reset-gpios", 0,
	&priv->rst_gpio, GPIOD_IS_OUT);
	if (ret) {
	dev_err(dev, "failed to find reset-gpios property\n");
	return ret;
	}

	ret = reset_get_bulk(dev, &priv->rsts);
	if (ret) {
	dev_err(dev, "Can't get reset: %d\n", ret);
	return ret;
	}

	ret = clk_get_by_name(dev, "port", &priv->clk_port);
	if (ret) {
	dev_err(dev, "Can't get port clock: %d\n", ret);
	return ret;
	}

	ret = clk_get_by_name(dev, "general", &priv->clk_general);
	if (ret) {
	dev_err(dev, "Can't get port clock: %d\n", ret);
	return ret;
	}

	ret = clk_get_by_name(dev, "pclk", &priv->clk_pclk);
	if (ret) {
	dev_err(dev, "Can't get port clock: %d\n", ret);
	return ret;
	}

	ret = generic_phy_get_by_index(dev, 0, &priv->phy);
	if (ret) {
	dev_err(dev, "failed to get pcie phy (ret=%d)\n", ret);
	return ret;
	}

	return 0;
	}

	/**
	* meson_pcie_probe() - Probe the PCIe bus for active link
	*
	* @dev: A pointer to the device being operated on
	*
	* Probe for an active link on the PCIe bus and configure the controller
	* to enable this port.
	*
	* Return: 0 on success, else -ENODEV
	*/
	static int meson_pcie_probe(struct udevice *dev)
	{
	struct meson_pcie *priv = dev_get_priv(dev);
	struct udevice *ctlr = pci_get_controller(dev);
	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
	int ret = 0;

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

	ret = meson_pcie_parse_dt(dev);
	if (ret)
	return ret;

	ret = meson_pcie_init_port(dev);
	if (ret) {
	dm_gpio_free(dev, &priv->rst_gpio);
	return ret;
	}

	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);

	return 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);
	}

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

	static const struct udevice_id meson_pcie_ids[] = {
	{ .compatible = "amlogic,axg-pcie" },
	{ .compatible = "amlogic,g12a-pcie" },
	{ }
	};

	U_BOOT_DRIVER(meson_dw_pcie) = {
	.name = "pcie_dw_meson",
	.id = UCLASS_PCI,
	.of_match = meson_pcie_ids,
	.ops = &meson_pcie_ops,
	.probe = meson_pcie_probe,
	.priv_auto = sizeof(struct meson_pcie),
	};