Re: Re: [PATCH 1/2] PCI: mediatek: Add Mediatek PCIe host controller support
From: Ryder Lee
Date: Mon Apr 24 2017 - 22:15:00 EST
Hi,
On Mon, 2017-04-24 at 17:02 -0500, Bjorn Helgaas wrote:
> Hi Ryder,
>
> Looks good, but I have a few questions below.
>
> On Sun, Apr 23, 2017 at 04:19:02PM +0800, Ryder Lee wrote:
> > Add support for the Mediatek PCIe controller which can be found
> > on MT7623A/N, MT2701 and MT8521p platforms.
> >
> > Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
> > ---
> > drivers/pci/host/Kconfig | 11 +
> > drivers/pci/host/Makefile | 1 +
> > drivers/pci/host/pcie-mediatek.c | 611 +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 623 insertions(+)
> > create mode 100644 drivers/pci/host/pcie-mediatek.c
> >
> > diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> > index f7c1d4d..cf13b5d 100644
> > --- a/drivers/pci/host/Kconfig
> > +++ b/drivers/pci/host/Kconfig
> > @@ -174,6 +174,17 @@ config PCIE_ROCKCHIP
> > There is 1 internal PCIe port available to support GEN2 with
> > 4 slots.
> >
> > +config PCIE_MEDIATEK
> > + bool "Mediatek PCIe Controller for MT7623 SoCs families"
> > + depends on (ARM && ARCH_MEDIATEK) || COMPILE_TEST
> > + depends on OF
> > + depends on PCI
> > + select PCIEPORTBUS
> > + help
> > + Say Y here if you want to enable PCIe controller support on MT7623 A/N
> > + series SoCs. There is a one root complex with 3 root ports available.
> > + Each port supports Gen2 lane x1.
> > +
> > config VMD
> > depends on PCI_MSI && X86_64 && SRCU
> > tristate "Intel Volume Management Device Driver"
> > diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> > index 4d36866..265adff 100644
> > --- a/drivers/pci/host/Makefile
> > +++ b/drivers/pci/host/Makefile
> > @@ -17,6 +17,7 @@ obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
> > obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
> > obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
> > obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
> > +obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
> > obj-$(CONFIG_VMD) += vmd.o
> >
> > # The following drivers are for devices that use the generic ACPI
> > diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
> > new file mode 100644
> > index 0000000..98e84d9
> > --- /dev/null
> > +++ b/drivers/pci/host/pcie-mediatek.c
> > @@ -0,0 +1,611 @@
> > +/*
> > + * PCIe host controller driver for Mediatek MT7623 SoCs families
> > + *
> > + * Copyright (c) 2017 MediaTek Inc.
> > + * Author: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
> > + *
> > + * 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.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/delay.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_pci.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/pci.h>
> > +#include <linux/phy/phy.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/reset.h>
> > +
> > +/* PCIe shared registers */
> > +#define PCIE_SYS_CFG 0x00
> > +#define PCIE_INT_ENABLE 0x0c
> > +#define PCIE_CFG_ADDR 0x20
> > +#define PCIE_CFG_DATA 0x24
> > +
> > +/* PCIe per port registers */
> > +#define PCIE_BAR0_SETUP 0x10
> > +#define PCIE_BAR1_SETUP 0x14
> > +#define PCIE_BAR0_MEM_BASE 0x18
> > +#define PCIE_CLASS 0x34
> > +#define PCIE_LINK_STATUS 0x50
> > +
> > +#define PCIE_PORT_INT_EN(x) BIT(20 + (x))
> > +#define PCIE_PORT_PERST(x) BIT(1 + (x))
> > +#define PCIE_PORT_LINKUP BIT(0)
> > +#define PCIE_BAR_MAP_MAX GENMASK(31, 16)
> > +
> > +#define PCIE_BAR_ENABLE BIT(0)
> > +#define PCIE_REVISION_ID BIT(0)
> > +#define PCIE_CLASS_CODE (0x60400 << 8)
> > +#define PCIE_CONF_REG(regn) (((regn) & GENMASK(7, 2)) | \
> > + ((((regn) >> 8) & GENMASK(3, 0)) << 24))
> > +#define PCIE_CONF_FUN(fun) (((fun) << 8) & GENMASK(10, 8))
> > +#define PCIE_CONF_DEV(dev) (((dev) << 11) & GENMASK(15, 11))
> > +#define PCIE_CONF_BUS(bus) (((bus) << 16) & GENMASK(23, 16))
> > +#define PCIE_CONF_ADDR(regn, fun, dev, bus) \
> > + (PCIE_CONF_REG(regn) | PCIE_CONF_FUN(fun) | \
> > + PCIE_CONF_DEV(dev) | PCIE_CONF_BUS(bus))
> > +
> > +/* Mediatek specific configuration registers */
> > +#define PCIE_FTS_NUM 0x70c
> > +#define PCIE_FTS_NUM_MASK GENMASK(15, 8)
> > +#define PCIE_FTS_NUM_L0(x) ((x) & 0xff << 8)
> > +
> > +#define PCIE_FC_CREDIT 0x73c
> > +#define PCIE_FC_CREDIT_MASK (GENMASK(31, 31) | GENMASK(28, 16))
> > +#define PCIE_FC_CREDIT_VAL(x) ((x) << 16)
> > +
> > +/**
> > + * struct mtk_pcie_port - PCIe port information
> > + * @dev: pointer to root port device
> > + * @base: IO mapped register base
> > + * @list: port list
> > + * @pcie: pointer to PCIe host info
> > + * @reset: pointer to RC reset control
> > + * @regs: port memory region
> > + * @sys_ck: root port clock
> > + * @phy: pointer to phy control block
> > + * @irq: IRQ number
> > + * @lane: lane count
> > + * @index: port index
> > + */
> > +struct mtk_pcie_port {
> > + struct device *dev;
> > + void __iomem *base;
> > + struct list_head list;
> > + struct mtk_pcie *pcie;
> > + struct reset_control *reset;
> > + struct resource regs;
> > + struct clk *sys_ck;
> > + struct phy *phy;
> > + int irq;
> > + u32 lane;
> > + u32 index;
> > +};
> > +
> > +/**
> > + * struct mtk_pcie - PCIe host information
> > + * @dev: pointer to PCIe device
> > + * @base: IO mapped register Base
> > + * @free_ck: free-run reference clock
> > + * @resources: bus resources
> > + * @ports: pointer to PCIe port information
> > + */
> > +struct mtk_pcie {
> > + struct device *dev;
> > + void __iomem *base;
> > + struct clk *free_ck;
> > + struct list_head resources;
> > + struct list_head ports;
> > +};
> > +
> > +static inline bool mtk_pcie_link_is_up(struct mtk_pcie_port *port)
> > +{
> > + return !!(readl_relaxed(port->base + PCIE_LINK_STATUS) &
> > + PCIE_PORT_LINKUP);
> > +}
> > +
> > +static bool mtk_pcie_valid_device(struct mtk_pcie *pcie,
> > + struct pci_bus *bus, int devfn)
> > +{
> > + struct mtk_pcie_port *port;
> > + struct pci_dev *dev;
> > + struct pci_bus *pbus;
> > +
> > + /* if there is no link, then there is no device */
> > + list_for_each_entry(port, &pcie->ports, list) {
> > + if (bus->number == 0 && port->index == PCI_SLOT(devfn) &&
> > + mtk_pcie_link_is_up(port)) {
> > + return true;
> > + } else if (bus->number != 0) {
> > + pbus = bus;
> > + do {
> > + dev = pbus->self;
> > + if (port->index == PCI_SLOT(dev->devfn) &&
> > + mtk_pcie_link_is_up(port)) {
> > + return true;
> > + }
> > + pbus = dev->bus;
> > + } while (dev->bus->number != 0);
> > + }
> > + }
> > +
> > + return false;
> > +}
> > +
> > +static void mtk_pcie_port_free(struct mtk_pcie_port *port)
> > +{
> > + struct mtk_pcie *pcie = port->pcie;
> > + struct device *dev = pcie->dev;
> > +
> > + devm_iounmap(dev, port->base);
> > + devm_release_mem_region(dev, port->regs.start,
> > + resource_size(&port->regs));
> > + list_del(&port->list);
> > + devm_kfree(dev, port);
> > +}
> > +
> > +static int mtk_pcie_hw_rd_cfg(struct mtk_pcie *pcie, u32 bus, u32 devfn,
> > + int where, int size, u32 *val)
> > +{
> > + writel(PCIE_CONF_ADDR(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
> > + pcie->base + PCIE_CFG_ADDR);
> > +
> > + *val = 0;
> > +
> > + switch (size) {
> > + case 1:
> > + *val = readb(pcie->base + PCIE_CFG_DATA + (where & 3));
> > + break;
> > + case 2:
> > + *val = readw(pcie->base + PCIE_CFG_DATA + (where & 2));
> > + break;
> > + case 4:
> > + *val = readl(pcie->base + PCIE_CFG_DATA);
> > + break;
> > + }
> > +
> > + return PCIBIOS_SUCCESSFUL;
> > +}
> > +
> > +static int mtk_pcie_hw_wr_cfg(struct mtk_pcie *pcie, u32 bus, u32 devfn,
> > + int where, int size, u32 val)
> > +
> > +{
> > + writel(PCIE_CONF_ADDR(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
> > + pcie->base + PCIE_CFG_ADDR);
> > +
> > + switch (size) {
> > + case 1:
> > + writeb(val, pcie->base + PCIE_CFG_DATA + (where & 3));
> > + break;
> > + case 2:
> > + writew(val, pcie->base + PCIE_CFG_DATA + (where & 2));
> > + break;
> > + case 4:
> > + writel(val, pcie->base + PCIE_CFG_DATA);
> > + break;
> > + }
> > +
> > + return PCIBIOS_SUCCESSFUL;
> > +}
> > +
> > +static int mtk_pcie_read_config(struct pci_bus *bus, u32 devfn,
> > + int where, int size, u32 *val)
> > +{
> > + struct mtk_pcie *pcie = bus->sysdata;
> > + u32 bn = bus->number;
> > +
> > + if (!mtk_pcie_valid_device(pcie, bus, devfn)) {
> > + *val = 0xffffffff;
> > + return PCIBIOS_DEVICE_NOT_FOUND;
> > + }
>
> I know there are some other drivers with the *_valid_device() pattern
> in their config accessors, but I don't like it because it's racy.
> It's possible for the link to be up for the test above, then go down
> before the actual config access below.
>
> Your hardware *should* do something sensible if we try to read config
> space when the link is down, and ideally that would be enough that we
> don't need this "valid_device()" check.
>
Yup,it's unnecessary, will remove it.
> > + return mtk_pcie_hw_rd_cfg(pcie, bn, devfn, where, size, val);
> > +}
> > +
> > +static int mtk_pcie_write_config(struct pci_bus *bus, u32 devfn,
> > + int where, int size, u32 val)
> > +{
> > + struct mtk_pcie *pcie = bus->sysdata;
> > + u32 bn = bus->number;
> > +
> > + if (!mtk_pcie_valid_device(pcie, bus, devfn))
> > + return PCIBIOS_DEVICE_NOT_FOUND;
> > +
> > + return mtk_pcie_hw_wr_cfg(pcie, bn, devfn, where, size, val);
> > +}
> > +
> > +static struct pci_ops mtk_pcie_ops = {
> > + .read = mtk_pcie_read_config,
> > + .write = mtk_pcie_write_config,
> > +};
> > +
> > +static void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
> > +{
> > + struct mtk_pcie *pcie = port->pcie;
> > + u32 val;
> > +
> > + /* enable interrupt */
> > + val = readl(pcie->base + PCIE_INT_ENABLE);
> > + val |= PCIE_PORT_INT_EN(port->index);
> > + writel(val, pcie->base + PCIE_INT_ENABLE);
> > +
> > + /* map to all DDR region. We need to set it before cfg operation. */
> > + writel(PCIE_BAR_MAP_MAX | PCIE_BAR_ENABLE,
> > + port->base + PCIE_BAR0_SETUP);
> > +
> > + /* configure class Code and revision ID */
> > + writel(PCIE_CLASS_CODE | PCIE_REVISION_ID,
> > + port->base + PCIE_CLASS);
> > +
> > + /* configure FC credit */
> > + mtk_pcie_hw_rd_cfg(pcie, 0, (port->index << 3),
> > + PCIE_FC_CREDIT, 4, &val);
> > + val &= ~PCIE_FC_CREDIT_MASK;
> > + val |= PCIE_FC_CREDIT_VAL(0x806c);
> > + mtk_pcie_hw_wr_cfg(pcie, 0, (port->index << 3),
> > + PCIE_FC_CREDIT, 4, val);
> > +
> > + /* configure RC FTS number to 250 when it leaves L0s */
> > + mtk_pcie_hw_rd_cfg(pcie, 0, (port->index << 3),
> > + PCIE_FTS_NUM, 4, &val);
> > + val &= ~PCIE_FTS_NUM_MASK;
> > + val |= PCIE_FTS_NUM_L0(0x50);
> > + mtk_pcie_hw_wr_cfg(pcie, 0, (port->index << 3),
> > + PCIE_FTS_NUM, 4, val);
> > +}
> > +
> > +static void mtk_pcie_assert_ports(struct mtk_pcie_port *port)
> > +{
> > + struct mtk_pcie *pcie = port->pcie;
> > + u32 val;
> > +
> > + /* assert port PERST_N */
> > + val = readl(pcie->base + PCIE_SYS_CFG);
> > + val |= PCIE_PORT_PERST(port->index);
> > + writel(val, pcie->base + PCIE_SYS_CFG);
> > +
> > + /* de-assert port PERST_N */
> > + val = readl(pcie->base + PCIE_SYS_CFG);
> > + val &= ~PCIE_PORT_PERST(port->index);
> > + writel(val, pcie->base + PCIE_SYS_CFG);
> > +
> > + /*
> > + * at least 100ms delay because PCIe v2.0 need more time to
> > + * train from Gen1 to Gen2
> > + */
> > + msleep(100);
> > +}
> > +
> > +static int mtk_pcie_enable_ports(struct mtk_pcie *pcie)
> > +{
> > + struct device *dev = pcie->dev;
> > + struct mtk_pcie_port *port, *tmp;
> > + int err, linkup = 0;
> > +
> > + list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
> > + err = clk_prepare_enable(port->sys_ck);
> > + if (err) {
> > + dev_err(dev, "failed to enable port%d clock\n",
> > + port->index);
> > + continue;
> > + }
> > +
> > + /* assert RC */
> > + reset_control_assert(port->reset);
> > + /* de-assert RC */
> > + reset_control_deassert(port->reset);
> > +
> > + /* power on PHY */
> > + err = phy_power_on(port->phy);
> > + if (err) {
> > + dev_err(dev, "failed to power on port%d phy\n",
> > + port->index);
> > + goto err_phy_on;
> > + }
> > +
> > + mtk_pcie_assert_ports(port);
> > +
> > + /* if link up, then setup root port configuration space */
> > + if (mtk_pcie_link_is_up(port)) {
> > + mtk_pcie_configure_rc(port);
> > + linkup++;
> > + continue;
> > + }
> > +
> > + dev_info(dev, "Port%d link down\n", port->index);
> > +
> > + phy_power_off(port->phy);
> > +err_phy_on:
> > + clk_disable_unprepare(port->sys_ck);
> > + mtk_pcie_port_free(port);
> > + }
> > +
> > + return linkup;
> > +}
> > +
> > +static int mtk_pcie_get_port_resource(struct mtk_pcie_port *port,
> > + struct device_node *node)
> > +{
> > + struct device *dev = port->pcie->dev;
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct platform_device *plat_dev;
> > + char name[10];
> > + int err;
> > +
> > + err = of_address_to_resource(node, 0, &port->regs);
> > + if (err) {
> > + dev_err(dev, "failed to parse address: %d\n", err);
> > + return err;
> > + }
> > +
> > + port->base = devm_ioremap_resource(dev, &port->regs);
> > + if (IS_ERR(port->base)) {
> > + dev_err(dev, "failed to map port%d base\n", port->index);
> > + return PTR_ERR(port->base);
> > + }
> > +
> > + plat_dev = of_find_device_by_node(node);
> > + if (!plat_dev) {
> > + plat_dev = of_platform_device_create(
> > + node, NULL,
> > + platform_bus_type.dev_root);
> > + if (!plat_dev)
> > + return -EPROBE_DEFER;
> > + }
> > +
> > + port->dev = &plat_dev->dev;
> > +
> > + port->irq = platform_get_irq(pdev, port->index);
> > + if (!port->irq) {
> > + dev_err(dev, "failed to get irq\n");
> > + return -ENODEV;
> > + }
> > +
> > + port->sys_ck = devm_clk_get(port->dev, "sys_ck");
> > + if (IS_ERR(port->sys_ck)) {
> > + dev_err(port->dev, "failed to get port%d clock\n", port->index);
> > + return PTR_ERR(port->sys_ck);
> > + }
> > +
> > + port->reset = devm_reset_control_get(port->dev, "pcie-reset");
> > + if (IS_ERR(port->reset)) {
> > + dev_err(port->dev, "failed to get port%d reset control\n",
> > + port->index);
> > + return PTR_ERR(port->reset);
> > + }
> > +
> > + snprintf(name, sizeof(name), "pcie-phy%d", port->index);
> > + port->phy = devm_of_phy_get(port->dev, node, name);
> > + if (IS_ERR(port->phy)) {
> > + dev_err(port->dev, "failed to get port%d phy\n", port->index);
> > + return PTR_ERR(port->phy);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_pcie_parse_and_add_res(struct mtk_pcie *pcie)
> > +{
> > + struct device *dev = pcie->dev;
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct device_node *node = dev->of_node, *child;
> > + struct resource_entry *win, *tmp;
> > + struct resource *regs;
> > + resource_size_t iobase;
> > + int err;
> > +
> > + /* parse shared resources */
> > + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + pcie->base = devm_ioremap_resource(dev, regs);
> > + if (IS_ERR(pcie->base)) {
> > + dev_err(dev, "failed to get PCIe base\n");
> > + return PTR_ERR(pcie->base);
> > + }
> > +
> > + pcie->free_ck = devm_clk_get(dev, "free_ck");
> > + if (IS_ERR(pcie->free_ck)) {
> > + dev_err(dev, "failed to get free_ck\n");
> > + return PTR_ERR(pcie->free_ck);
> > + }
> > +
> > + err = of_pci_get_host_bridge_resources(node, 0, 0xff, &pcie->resources,
> > + &iobase);
> > + if (err)
> > + return err;
> > +
> > + err = devm_request_pci_bus_resources(dev, &pcie->resources);
> > + if (err)
> > + return err;
> > +
> > + resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
> > + struct resource *res = win->res;
> > +
> > + switch (resource_type(res)) {
> > + case IORESOURCE_IO:
> > + err = pci_remap_iospace(res, iobase);
> > + if (err) {
> > + dev_warn(dev, "failed to map resource %pR\n",
> > + res);
> > + resource_list_destroy_entry(win);
> > + }
> > + break;
> > + }
> > + }
> > +
> > + /* parse port resources */
> > + for_each_child_of_node(node, child) {
> > + struct mtk_pcie_port *port;
> > + int index;
> > +
> > + err = of_pci_get_devfn(child);
> > + if (err < 0) {
> > + dev_err(pcie->dev, "failed to parse devfn: %d\n", err);
>
> dev_err(dev, ...)
OK.
> > + return err;
> > + }
> > +
> > + index = PCI_SLOT(err);
> > + if (index < 1) {
> > + dev_err(dev, "invalid port number: %d\n", index);
> > + return -EINVAL;
> > + }
> > +
> > + index--;
> > +
> > + if (!of_device_is_available(child))
> > + continue;
> > +
> > + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> > + if (!port)
> > + return -ENOMEM;
> > +
> > + err = of_property_read_u32(child, "num-lanes", &port->lane);
> > + if (err) {
> > + dev_err(dev, "missing num-lanes property\n");
> > + return err;
> > + }
> > +
> > + port->index = index;
> > + port->pcie = pcie;
> > +
> > + err = mtk_pcie_get_port_resource(port, child);
> > + if (err)
> > + return err;
> > +
> > + INIT_LIST_HEAD(&port->list);
> > + list_add_tail(&port->list, &pcie->ports);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * This IP lacks interrupt status register to check or map INTx from
> > + * different devices at the same time.
> > + */
> > +static int __init mtk_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
> > +{
> > + struct mtk_pcie *pcie = dev->bus->sysdata;
> > + struct mtk_pcie_port *port;
> > +
> > + list_for_each_entry(port, &pcie->ports, list)
> > + if (port->index == slot)
> > + return port->irq;
> > +
> > + return -1;
> > +}
> > +
> > +static int mtk_pcie_register_ports(struct mtk_pcie *pcie)
> > +{
> > + struct pci_bus *bus, *child;
> > +
> > + bus = pci_scan_root_bus(pcie->dev, 0, &mtk_pcie_ops, pcie,
> > + &pcie->resources);
> > + if (!bus) {
> > + dev_err(pcie->dev, "failed to create root bus\n");
> > + return -ENOMEM;
> > + }
> > +
> > + if (!pci_has_flag(PCI_PROBE_ONLY)) {
> > + pci_fixup_irqs(pci_common_swizzle, mtk_pcie_map_irq);
> > + pci_bus_size_bridges(bus);
> > + pci_bus_assign_resources(bus);
> > +
> > + list_for_each_entry(child, &bus->children, node)
> > + pcie_bus_configure_settings(child);
>
> Do you actually need the functionality of PCI_PROBE_ONLY? We're
> trying to get rid of this, so if you don't need it, please omit it.
>
> If you *do* need it, can you include a note about why?
>
> If you do need it, I don't think PCI_PROBE_ONLY should control
> pci_fixup_irqs() or pcie_bus_configure_settings(). I know there is
> some other similar code that does this, but I think PCI_PROBE_ONLY
> should only influence resource assignment, i.e., BARs and bridge
> windows. I don't want it to influence IRQs or the MPS/MRRS settings
> done by pcie_bus_configure_settings() if we can avoid it.
I will remove it, thanks.
> > + }
> > +
> > + pci_bus_add_devices(bus);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_pcie_probe(struct platform_device *pdev)
> > +{
> > + struct mtk_pcie *pcie;
> > + int err;
> > +
> > + pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
> > + if (!pcie)
> > + return -ENOMEM;
> > +
> > + pcie->dev = &pdev->dev;
> > + platform_set_drvdata(pdev, pcie);
> > +
> > + /*
> > + * parse PCI ranges, configuration bus range and
> > + * request their resources
> > + */
> > + INIT_LIST_HEAD(&pcie->ports);
> > + INIT_LIST_HEAD(&pcie->resources);
> > +
> > + err = mtk_pcie_parse_and_add_res(pcie);
> > + if (err)
> > + goto err_parse;
> > +
> > + pm_runtime_enable(pcie->dev);
> > + err = pm_runtime_get_sync(pcie->dev);
> > + if (err)
> > + goto err_pm;
> > +
> > + err = clk_prepare_enable(pcie->free_ck);
> > + if (err) {
> > + dev_err(pcie->dev, "failed to enable free_ck\n");
> > + goto err_free_ck;
> > + }
> > +
> > + /* power on PCIe ports */
> > + err = mtk_pcie_enable_ports(pcie);
> > + if (!err)
> > + goto err_enable;
> > +
> > + /* register PCIe ports */
> > + err = mtk_pcie_register_ports(pcie);
> > + if (err)
> > + goto err_enable;
> > +
> > + return 0;
> > +
> > +err_enable:
> > + clk_disable_unprepare(pcie->free_ck);
> > +err_free_ck:
> > + pm_runtime_put_sync(pcie->dev);
> > +err_pm:
> > + pm_runtime_disable(pcie->dev);
> > +err_parse:
> > + pci_free_resource_list(&pcie->resources);
> > +
> > + return err;
> > +}
> > +
> > +static const struct of_device_id mtk_pcie_ids[] = {
> > + { .compatible = "mediatek,mt7623-pcie"},
> > + { .compatible = "mediatek,mt2701-pcie"},
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, mtk_pcie_ids);
> > +
> > +static struct platform_driver mtk_pcie_driver = {
> > + .probe = mtk_pcie_probe,
> > + .driver = {
> > + .name = "mtk-pcie",
> > + .of_match_table = mtk_pcie_ids,
>
> Per [1], I think you should have ".suppress_bind_attrs = true," here.
> Without it, apparently you can easily crash the system by unbinding
> the driver, as in [2].
>
> [1] https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/commit/?id=65e0527b933a
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git/commit/?id=073d3dbe9a7c
OK!
> > + },
> > +};
> > +
> > +builtin_platform_driver(mtk_pcie_driver);
> > +
> > +MODULE_DESCRIPTION("Mediatek PCIe host driver for MT7623 SoCs families");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 1.9.1
> >
Thanks for your review!
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
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