Re: [PATCH 2/4] MIPS: pci: Add driver for MT7621 PCIe controller
From: Sergio Paracuellos
Date: Mon Jun 07 2021 - 02:45:36 EST
Hi Rob,
On Sat, Jun 5, 2021 at 12:25 AM Sergio Paracuellos
<sergio.paracuellos@xxxxxxxxx> wrote:
>
> Hi Rob,
>
> Thanks for the review.
>
> On Fri, Jun 4, 2021 at 9:30 PM Rob Herring <robh@xxxxxxxxxx> wrote:
> >
> > On Sat, May 15, 2021 at 02:40:53PM +0200, Sergio Paracuellos wrote:
> > > This patch adds a driver for the PCIe controller of MT7621 SoC.
> > >
> > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
> > > ---
> > > arch/mips/pci/Makefile | 1 +
> > > arch/mips/pci/pci-mt7621.c | 624 +++++++++++++++++++++++++++++++++++++
> > > arch/mips/ralink/Kconfig | 9 +-
> > > 3 files changed, 633 insertions(+), 1 deletion(-)
> > > create mode 100644 arch/mips/pci/pci-mt7621.c
> > >
> > > diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
> > > index f3eecc065e5c..178c550739c4 100644
> > > --- a/arch/mips/pci/Makefile
> > > +++ b/arch/mips/pci/Makefile
> > > @@ -24,6 +24,7 @@ obj-$(CONFIG_PCI_AR2315) += pci-ar2315.o
> > > obj-$(CONFIG_SOC_AR71XX) += pci-ar71xx.o
> > > obj-$(CONFIG_PCI_AR724X) += pci-ar724x.o
> > > obj-$(CONFIG_PCI_XTALK_BRIDGE) += pci-xtalk-bridge.o
> > > +obj-$(CONFIG_PCI_MT7621) += pci-mt7621.o
> > > #
> > > # These are still pretty much in the old state, watch, go blind.
> > > #
> > > diff --git a/arch/mips/pci/pci-mt7621.c b/arch/mips/pci/pci-mt7621.c
> > > new file mode 100644
> > > index 000000000000..fe1945819d25
> > > --- /dev/null
> > > +++ b/arch/mips/pci/pci-mt7621.c
> > > @@ -0,0 +1,624 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * BRIEF MODULE DESCRIPTION
> > > + * PCI init for Ralink RT2880 solution
> > > + *
> > > + * Copyright 2007 Ralink Inc. (bruce_chang@xxxxxxxxxxxxxxxxx)
> > > + *
> > > + * May 2007 Bruce Chang
> > > + * Initial Release
> > > + *
> > > + * May 2009 Bruce Chang
> > > + * support RT2880/RT3883 PCIe
> > > + *
> > > + * May 2011 Bruce Chang
> > > + * support RT6855/MT7620 PCIe
> > > + */
> > > +
> > > +#include <linux/bitops.h>
> > > +#include <linux/clk.h>
> > > +#include <linux/delay.h>
> > > +#include <linux/gpio/consumer.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of.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/reset.h>
> > > +#include <linux/sys_soc.h>
> > > +
> > > +/* 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)
> > > +
> > > +/* Host-PCI bridge registers */
> > > +#define RALINK_PCI_PCICFG_ADDR 0x0000
> > > +#define RALINK_PCI_PCIMSK_ADDR 0x000C
> > > +#define RALINK_PCI_CONFIG_ADDR 0x0020
> > > +#define RALINK_PCI_CONFIG_DATA 0x0024
> > > +#define RALINK_PCI_MEMBASE 0x0028
> > > +#define RALINK_PCI_IOBASE 0x002C
> > > +
> > > +/* PCIe RC control registers */
> > > +#define MT7621_PCIE_OFFSET 0x2000
> > > +#define MT7621_NEXT_PORT 0x1000
> > > +
> > > +#define RALINK_PCI_BAR0SETUP_ADDR 0x0010
> >
> > Standard BAR0 register?
>
> Ok, I will remove this and use 'PCI_BASE_ADDRESS_0' instead.
>
> >
> > > +#define RALINK_PCI_ID 0x0030
> > > +#define RALINK_PCI_CLASS 0x0034
> > > +#define RALINK_PCI_SUBID 0x0038
> > > +#define RALINK_PCI_STATUS 0x0050
> > > +
> > > +/* Some definition values */
> > > +#define PCIE_REVISION_ID BIT(0)
> > > +#define PCIE_CLASS_CODE (0x60400 << 8)
> > > +#define PCIE_BAR_MAP_MAX GENMASK(30, 16)
> > > +#define PCIE_BAR_ENABLE BIT(0)
> > > +#define PCIE_PORT_INT_EN(x) BIT(20 + (x))
> > > +#define PCIE_PORT_LINKUP BIT(0)
> > > +
> > > +#define PERST_DELAY_MS 100
> > > +
> > > +/**
> > > + * struct mt7621_pcie_port - PCIe port information
> > > + * @base: I/O mapped register base
> > > + * @list: port list
> > > + * @pcie: pointer to PCIe host info
> > > + * @clk: pointer to the port clock gate
> > > + * @phy: pointer to PHY control block
> > > + * @pcie_rst: pointer to port reset control
> > > + * @gpio_rst: gpio reset
> > > + * @slot: port slot
> > > + * @enabled: indicates if port is enabled
> > > + */
> > > +struct mt7621_pcie_port {
> > > + void __iomem *base;
> > > + struct list_head list;
> > > + struct mt7621_pcie *pcie;
> > > + struct clk *clk;
> > > + struct phy *phy;
> > > + struct reset_control *pcie_rst;
> > > + struct gpio_desc *gpio_rst;
> > > + u32 slot;
> > > + bool enabled;
> > > +};
> > > +
> > > +/**
> > > + * struct mt7621_pcie - PCIe host information
> > > + * @base: IO Mapped Register Base
> > > + * @io: IO resource
> > > + * @mem: pointer to non-prefetchable memory resource
> > > + * @dev: Pointer to PCIe device
> > > + * @io_map_base: virtual memory base address for io
> > > + * @ports: pointer to PCIe port information
> > > + * @resets_inverted: depends on chip revision
> > > + * reset lines are inverted.
> > > + */
> > > +struct mt7621_pcie {
> > > + void __iomem *base;
> > > + struct device *dev;
> >
> > > + struct resource io;
> > > + struct resource *mem;
> > > + unsigned long io_map_base;
> >
> > These are all stored in the host bridge struct, no need for you to store
> > them.
>
> IO resources must be requested and mapped manually (see my explanation
> below) and I use mem resource to also setup mips iocu regions, that is
> why I am storing it also here.
>
> >
> > > + struct list_head ports;
> >
> > A list is kind of an overkill for 3 entries and you know how many ports.
> > Just embed an array of struct mt7621_pcie_port. Then you only need 1
> > alloc.
>
> Since ports are at most three but can be one or two also depending on
> the board I ended up using a list instead of a fixed array of three
> ports. This list is dynamically updated depending on link status. If
> some of the ports are not present in the board nodes initially stored
> after device tree parsing are deleted for the list. If it is not a big
> problem I prefer to maintain this list as it is.
>
> >
> > > + bool resets_inverted;
> > > +};
> > > +
> > > +static inline u32 pcie_read(struct mt7621_pcie *pcie, u32 reg)
> > > +{
> > > + return readl(pcie->base + reg);
> >
> > Can use _relaxed variants here and through out.
>
> Ok will change into _relaxed variants if is preferred.
>
> >
> > > +}
> > > +
> > > +static inline void pcie_write(struct mt7621_pcie *pcie, u32 val, u32 reg)
> > > +{
> > > + writel(val, pcie->base + reg);
> > > +}
> > > +
> > > +static inline void pcie_rmw(struct mt7621_pcie *pcie, u32 reg, u32 clr, u32 set)
> > > +{
> > > + u32 val = readl(pcie->base + reg);
> > > +
> > > + val &= ~clr;
> > > + val |= set;
> > > + writel(val, pcie->base + reg);
> > > +}
> > > +
> > > +static inline u32 pcie_port_read(struct mt7621_pcie_port *port, u32 reg)
> > > +{
> > > + return readl(port->base + reg);
> > > +}
> > > +
> > > +static inline void pcie_port_write(struct mt7621_pcie_port *port,
> > > + u32 val, u32 reg)
> > > +{
> > > + writel(val, port->base + reg);
> > > +}
> > > +
> > > +static inline u32 mt7621_pci_get_cfgaddr(unsigned int bus, unsigned int slot,
> > > + unsigned int func, unsigned int where)
> > > +{
> > > + return (((where & 0xF00) >> 8) << 24) | (bus << 16) | (slot << 11) |
> > > + (func << 8) | (where & 0xfc) | 0x80000000;
> > > +}
> > > +
> > > +static void __iomem *mt7621_pcie_map_bus(struct pci_bus *bus,
> > > + unsigned int devfn, int where)
> > > +{
> > > + struct mt7621_pcie *pcie = bus->sysdata;
> > > + u32 address = mt7621_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
> > > + PCI_FUNC(devfn), where);
> > > +
> > > + writel(address, pcie->base + RALINK_PCI_CONFIG_ADDR);
> > > +
> > > + return pcie->base + RALINK_PCI_CONFIG_DATA + (where & 3);
> > > +}
> > > +
> > > +struct pci_ops mt7621_pci_ops = {
> > > + .map_bus = mt7621_pcie_map_bus,
> > > + .read = pci_generic_config_read,
> > > + .write = pci_generic_config_write,
> > > +};
> > > +
> > > +static u32 read_config(struct mt7621_pcie *pcie, unsigned int dev, u32 reg)
> > > +{
> > > + u32 address = mt7621_pci_get_cfgaddr(0, dev, 0, reg);
> > > +
> > > + pcie_write(pcie, address, RALINK_PCI_CONFIG_ADDR);
> > > + return pcie_read(pcie, RALINK_PCI_CONFIG_DATA);
> > > +}
> > > +
> > > +static void write_config(struct mt7621_pcie *pcie, unsigned int dev,
> > > + u32 reg, u32 val)
> > > +{
> > > + u32 address = mt7621_pci_get_cfgaddr(0, dev, 0, reg);
> > > +
> > > + pcie_write(pcie, address, RALINK_PCI_CONFIG_ADDR);
> > > + pcie_write(pcie, val, RALINK_PCI_CONFIG_DATA);
> > > +}
> > > +
> > > +static inline void mt7621_rst_gpio_pcie_assert(struct mt7621_pcie_port *port)
> > > +{
> > > + if (port->gpio_rst)
> >
> > Don't need the if. gpiod_set_value should work with NULL.
>
> Gpio resets can be optional. Some boards use one gpio reset pin for
> each port but others only one for all of them. So if no reset is not
> requested for a port I don't want to do anything. Hence, the check.
>
> >
> > > + gpiod_set_value(port->gpio_rst, 1);
> > > +}
> > > +
> > > +static inline void mt7621_rst_gpio_pcie_deassert(struct mt7621_pcie_port *port)
> > > +{
> > > + if (port->gpio_rst)
> > > + gpiod_set_value(port->gpio_rst, 0);
> > > +}
> > > +
> > > +static inline bool mt7621_pcie_port_is_linkup(struct mt7621_pcie_port *port)
> > > +{
> > > + return (pcie_port_read(port, RALINK_PCI_STATUS) & PCIE_PORT_LINKUP) != 0;
> > > +}
> > > +
> > > +static inline void mt7621_control_assert(struct mt7621_pcie_port *port)
> > > +{
> > > + struct mt7621_pcie *pcie = port->pcie;
> > > +
> > > + if (pcie->resets_inverted)
> > > + reset_control_assert(port->pcie_rst);
> > > + else
> > > + reset_control_deassert(port->pcie_rst);
> > > +}
> > > +
> > > +static inline void mt7621_control_deassert(struct mt7621_pcie_port *port)
> > > +{
> > > + struct mt7621_pcie *pcie = port->pcie;
> > > +
> > > + if (pcie->resets_inverted)
> > > + reset_control_deassert(port->pcie_rst);
> > > + else
> > > + reset_control_assert(port->pcie_rst);
> > > +}
> > > +
> > > +static void setup_cm_memory_region(struct mt7621_pcie *pcie)
> > > +{
> > > + struct resource *mem_resource = pcie->mem;
> > > + struct device *dev = pcie->dev;
> > > + resource_size_t mask;
> > > +
> > > + if (mips_cps_numiocu(0)) {
> > > + /*
> > > + * FIXME: hardware doesn't accept mask values with 1s after
> > > + * 0s (e.g. 0xffef), so it would be great to warn if that's
> > > + * about to happen
> > > + */
> > > + mask = ~(mem_resource->end - mem_resource->start);
> > > +
> > > + write_gcr_reg1_base(mem_resource->start);
> > > + write_gcr_reg1_mask(mask | CM_GCR_REGn_MASK_CMTGT_IOCU0);
> > > + dev_info(dev, "PCI coherence region base: 0x%08llx, mask/settings: 0x%08llx\n",
> > > + (unsigned long long)read_gcr_reg1_base(),
> > > + (unsigned long long)read_gcr_reg1_mask());
> > > + }
> > > +}
> > > +
> > > +static int mt7621_pci_parse_request_of_pci_ranges(struct pci_host_bridge *host)
> > > +{
> > > + struct mt7621_pcie *pcie = pci_host_bridge_priv(host);
> > > + struct device *dev = pcie->dev;
> > > + struct device_node *node = dev->of_node;
> > > + struct of_pci_range_parser parser;
> > > + struct resource_entry *entry;
> > > + struct of_pci_range range;
> > > + LIST_HEAD(res);
> > > +
> > > + if (of_pci_range_parser_init(&parser, node)) {
> > > + dev_err(dev, "missing \"ranges\" property\n");
> > > + return -EINVAL;
> > > + }
> > > +
> > > + /*
> > > + * IO_SPACE_LIMIT for MIPS is 0xffff but this platform uses IO at
> > > + * upper address 0x001e160000. of_pci_range_to_resource does not work
> >
> > I think that's normal...
>
> No, pci_address_to_pio will fail and io resources are not properly
> assigned at all.
>
> >
> > > + * well for MIPS platforms that don't define PCI_IOBASE, so set the IO
> > > + * resource manually instead.
> >
> > Can't this be fixed?
>
> This is the way the current PCI architecture is in mips... Maybe
> Thomas has a strong opinion on this.
>
> >
> > > + */
> > > + for_each_of_pci_range(&parser, &range) {
> > > + switch (range.flags & IORESOURCE_TYPE_BITS) {
> >
> > The core code already parses ranges for you. Try not to do it again.
> > (Use the resource instead)
>
> See below...
>
> >
> > > + case IORESOURCE_IO:
> > > + pcie->io_map_base =
> > > + (unsigned long)ioremap(range.cpu_addr,
> > > + range.size);
> > > + pcie->io.name = node->full_name;
> > > + pcie->io.flags = range.flags;
> > > + pcie->io.start = range.cpu_addr;
> > > + pcie->io.end = range.cpu_addr + range.size - 1;
> > > + pcie->io.parent = pcie->io.child = pcie->io.sibling = NULL;
> > > + set_io_port_base(pcie->io_map_base);
> > > + break;
> > > + }
> > > + }
> > > +
> > > + entry = resource_list_first_type(&host->windows, IORESOURCE_MEM);
> > > + if (!entry) {
> > > + dev_err(dev, "Cannot get memory resource");
> > > + return -EINVAL;
> > > + }
> > > +
> > > + pcie->mem = entry->res;
> > > + pci_add_resource(&res, &pcie->io);
> > > + pci_add_resource(&res, entry->res);
> > > + list_splice_init(&res, &host->windows);
> >
> > This should already be done for you.
>
> Most MIPS platforms do not define PCI_IOBASE, nor implement
> pci_address_to_pio(). Moreover, IO_SPACE_LIMIT is 0xffff for most MIPS
> platforms. of_pci_range_to_resource passes the _start address_ of the
> IO range into pci_address_to_pio, which then checks it against
> IO_SPACE_LIMIT and fails. So I have to do this manually or nothing
> will work properly...
>
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int mt7621_pcie_parse_port(struct mt7621_pcie *pcie,
> > > + int slot)
> > > +{
> > > + struct mt7621_pcie_port *port;
> > > + struct device *dev = pcie->dev;
> > > + struct platform_device *pdev = to_platform_device(dev);
> > > + char name[10];
> > > +
> > > + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> > > + if (!port)
> > > + return -ENOMEM;
> > > +
> > > + port->base = devm_platform_ioremap_resource(pdev, slot + 1);
> > > + if (IS_ERR(port->base))
> > > + return PTR_ERR(port->base);
> > > +
> > > + snprintf(name, sizeof(name), "pcie%d", slot);
> > > + port->clk = devm_clk_get(dev, name);
> > > + if (IS_ERR(port->clk)) {
> > > + dev_err(dev, "failed to get pcie%d clock\n", slot);
> > > + return PTR_ERR(port->clk);
> > > + }
> > > +
> > > + snprintf(name, sizeof(name), "pcie%d", slot);
> > > + port->pcie_rst = devm_reset_control_get_exclusive(dev, name);
> > > + if (PTR_ERR(port->pcie_rst) == -EPROBE_DEFER) {
> > > + dev_err(dev, "failed to get pcie%d reset control\n", slot);
> > > + return PTR_ERR(port->pcie_rst);
> > > + }
> > > +
> > > + snprintf(name, sizeof(name), "pcie-phy%d", slot);
> > > + port->phy = devm_phy_get(dev, name);
> > > + if (IS_ERR(port->phy) && slot != 1)
> > > + return PTR_ERR(port->phy);
> > > +
> > > + port->gpio_rst = devm_gpiod_get_index_optional(dev, "reset", slot,
> > > + GPIOD_OUT_LOW);
> > > + if (IS_ERR(port->gpio_rst)) {
> > > + dev_err(dev, "Failed to get GPIO for PCIe%d\n", slot);
> > > + return PTR_ERR(port->gpio_rst);
> > > + }
> > > +
> > > + port->slot = slot;
> > > + port->pcie = pcie;
> > > +
> > > + INIT_LIST_HEAD(&port->list);
> > > + list_add_tail(&port->list, &pcie->ports);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
> > > +{
> > > + struct device *dev = pcie->dev;
> > > + struct platform_device *pdev = to_platform_device(dev);
> > > + struct device_node *node = dev->of_node, *child;
> > > + int err;
> > > +
> > > + pcie->base = devm_platform_ioremap_resource(pdev, 0);
> > > + if (IS_ERR(pcie->base))
> > > + return PTR_ERR(pcie->base);
> > > +
> > > + for_each_available_child_of_node(node, child) {
> > > + int slot;
> > > +
> > > + err = of_pci_get_devfn(child);
> > > + if (err < 0) {
> > > + of_node_put(child);
> > > + dev_err(dev, "failed to parse devfn: %d\n", err);
> > > + return err;
> > > + }
> > > +
> > > + slot = PCI_SLOT(err);
> > > +
> > > + err = mt7621_pcie_parse_port(pcie, slot);
> > > + if (err) {
> > > + of_node_put(child);
> > > + return err;
> > > + }
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int mt7621_pcie_init_port(struct mt7621_pcie_port *port)
> > > +{
> > > + struct mt7621_pcie *pcie = port->pcie;
> > > + struct device *dev = pcie->dev;
> > > + u32 slot = port->slot;
> > > + int err;
> > > +
> > > + err = phy_init(port->phy);
> > > + if (err) {
> > > + dev_err(dev, "failed to initialize port%d phy\n", slot);
> > > + return err;
> > > + }
> > > +
> > > + err = phy_power_on(port->phy);
> > > + if (err) {
> > > + dev_err(dev, "failed to power on port%d phy\n", slot);
> > > + phy_exit(port->phy);
> > > + return err;
> > > + }
> > > +
> > > + port->enabled = true;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void mt7621_pcie_reset_assert(struct mt7621_pcie *pcie)
> > > +{
> > > + struct mt7621_pcie_port *port;
> > > +
> > > + list_for_each_entry(port, &pcie->ports, list) {
> > > + /* PCIe RC reset assert */
> > > + mt7621_control_assert(port);
> > > +
> > > + /* PCIe EP reset assert */
> > > + mt7621_rst_gpio_pcie_assert(port);
> > > + }
> > > +
> > > + msleep(PERST_DELAY_MS);
> > > +}
> > > +
> > > +static void mt7621_pcie_reset_rc_deassert(struct mt7621_pcie *pcie)
> > > +{
> > > + struct mt7621_pcie_port *port;
> > > +
> > > + list_for_each_entry(port, &pcie->ports, list)
> > > + mt7621_control_deassert(port);
> > > +}
> > > +
> > > +static void mt7621_pcie_reset_ep_deassert(struct mt7621_pcie *pcie)
> > > +{
> > > + struct mt7621_pcie_port *port;
> > > +
> > > + list_for_each_entry(port, &pcie->ports, list)
> > > + mt7621_rst_gpio_pcie_deassert(port);
> > > +
> > > + msleep(PERST_DELAY_MS);
> > > +}
> > > +
> > > +static void mt7621_pcie_init_ports(struct mt7621_pcie *pcie)
> > > +{
> > > + struct device *dev = pcie->dev;
> > > + struct mt7621_pcie_port *port, *tmp;
> > > + int err;
> > > +
> > > + mt7621_pcie_reset_assert(pcie);
> > > + mt7621_pcie_reset_rc_deassert(pcie);
> > > +
> > > + list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
> > > + u32 slot = port->slot;
> > > +
> > > + if (slot == 1) {
> > > + port->enabled = true;
> > > + continue;
> > > + }
> > > +
> > > + err = mt7621_pcie_init_port(port);
> > > + if (err) {
> > > + dev_err(dev, "Initiating port %d failed\n", slot);
> > > + list_del(&port->list);
> > > + }
> > > + }
> > > +
> > > + mt7621_pcie_reset_ep_deassert(pcie);
> > > +
> > > + tmp = NULL;
> > > + list_for_each_entry(port, &pcie->ports, list) {
> > > + u32 slot = port->slot;
> > > +
> > > + if (!mt7621_pcie_port_is_linkup(port)) {
> > > + dev_err(dev, "pcie%d no card, disable it (RST & CLK)\n",
> > > + slot);
> > > + mt7621_control_assert(port);
> > > + clk_disable_unprepare(port->clk);
> > > + port->enabled = false;
> > > +
> > > + if (slot == 0) {
> > > + tmp = port;
> > > + continue;
> > > + }
> > > +
> > > + if (slot == 1 && tmp && !tmp->enabled)
> > > + phy_power_off(tmp->phy)
> > > + }
> > > + }
> > > +}
> > > +
> > > +static void mt7621_pcie_enable_port(struct mt7621_pcie_port *port)
> > > +{
> > > + struct mt7621_pcie *pcie = port->pcie;
> > > + u32 slot = port->slot;
> > > + u32 offset = MT7621_PCIE_OFFSET + (slot * MT7621_NEXT_PORT);
> >
> > I don't see how this works unless the ports happen to be at the same VA
> > offset. The writes below are to the 'common' registers which are 0x100
> > bytes long based on the DT example, but the offset lines up with the
> > port offsets.
>
> RC registers for port 0 start at physical address 0x1e142000, for port
> 1 0x1e143000 and for port 2 0x1e144000. We are using
> 'pcie_write' which internally uses pcie->base which is 0x1e140000, but
> all the previous ones have been already requested and mapped for each
> port so we calculate the offset from this 0x1e140000 and write there.
>
> >
> > > + u32 val;
> > > +
> > > + /* enable pcie interrupt */
> > > + val = pcie_read(pcie, RALINK_PCI_PCIMSK_ADDR);
> > > + val |= PCIE_PORT_INT_EN(slot);
> > > + pcie_write(pcie, val, RALINK_PCI_PCIMSK_ADDR);
> > > +
> > > + /* map 2G DDR region */
> > > + pcie_write(pcie, PCIE_BAR_MAP_MAX | PCIE_BAR_ENABLE,
> > > + offset + RALINK_PCI_BAR0SETUP_ADDR);
> > > +
> > > + /* configure class code and revision ID */
> > > + pcie_write(pcie, PCIE_CLASS_CODE | PCIE_REVISION_ID,
> > > + offset + RALINK_PCI_CLASS);
> > > +}
> > > +
> > > +static int mt7621_pcie_enable_ports(struct mt7621_pcie *pcie)
> > > +{
> > > + struct device *dev = pcie->dev;
> > > + struct mt7621_pcie_port *port;
> > > + u8 num_slots_enabled = 0;
> > > + u32 slot;
> > > + u32 val;
> > > + int err;
> > > +
> > > + /* Setup MEMWIN and IOWIN */
> > > + pcie_write(pcie, 0xffffffff, RALINK_PCI_MEMBASE);
> > > + pcie_write(pcie, pcie->io.start, RALINK_PCI_IOBASE);
> > > +
> > > + list_for_each_entry(port, &pcie->ports, list) {
> > > + if (port->enabled) {
> > > + err = clk_prepare_enable(port->clk);
> > > + if (err) {
> > > + dev_err(dev, "enabling clk pcie%d\n", slot);
> > > + return err;
> > > + }
> > > +
> > > + mt7621_pcie_enable_port(port);
> > > + dev_info(dev, "PCIE%d enabled\n", port->slot);
> > > + num_slots_enabled++;
> > > + }
> > > + }
> > > +
> > > + for (slot = 0; slot < num_slots_enabled; slot++) {
> > > + val = read_config(pcie, slot, PCI_COMMAND);
> > > + val |= PCI_COMMAND_MASTER;
> > > + write_config(pcie, slot, PCI_COMMAND, val);
> > > + /* configure RC FTS number to 250 when it leaves L0s */
> > > + val = read_config(pcie, slot, PCIE_FTS_NUM);
> > > + val &= ~PCIE_FTS_NUM_MASK;
> > > + val |= PCIE_FTS_NUM_L0(0x50);
> > > + write_config(pcie, slot, PCIE_FTS_NUM, val);
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int mt7621_pcie_register_host(struct pci_host_bridge *host)
> > > +{
> > > + struct mt7621_pcie *pcie = pci_host_bridge_priv(host);
> > > +
> > > + host->ops = &mt7621_pci_ops;
> > > + host->sysdata = pcie;
> > > + return pci_host_probe(host);
> > > +}
> > > +
> > > +static const struct soc_device_attribute mt7621_pci_quirks_match[] = {
> > > + { .soc_id = "mt7621", .revision = "E2" }
> > > +};
> > > +
> > > +static int mt7621_pci_probe(struct platform_device *pdev)
> > > +{
> > > + struct device *dev = &pdev->dev;
> > > + const struct soc_device_attribute *attr;
> > > + struct mt7621_pcie *pcie;
> > > + struct pci_host_bridge *bridge;
> > > + int err;
> > > +
> > > + if (!dev->of_node)
> > > + return -ENODEV;
> > > +
> > > + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> > > + if (!bridge)
> > > + return -ENOMEM;
> > > +
> > > + pcie = pci_host_bridge_priv(bridge);
> > > + pcie->dev = dev;
> > > + platform_set_drvdata(pdev, pcie);
> > > + INIT_LIST_HEAD(&pcie->ports);
> > > +
> > > + attr = soc_device_match(mt7621_pci_quirks_match);
> > > + if (attr)
> > > + pcie->resets_inverted = true;
> > > +
> > > + err = mt7621_pcie_parse_dt(pcie);
> > > + if (err) {
> > > + dev_err(dev, "Parsing DT failed\n");
> > > + return err;
> > > + }
> > > +
> > > + err = mt7621_pci_parse_request_of_pci_ranges(bridge);
> > > + if (err) {
> > > + dev_err(dev, "Error requesting pci resources from ranges");
> > > + return err;
> > > + }
> > > +
> > > + /* set resources limits */
> > > + ioport_resource.start = pcie->io.start;
> > > + ioport_resource.end = pcie->io.end;
> > > +
> > > + mt7621_pcie_init_ports(pcie);
> > > +
> > > + err = mt7621_pcie_enable_ports(pcie);
> >
> > Really need 2 functions here?
>
> mt7621_pcie_init_ports is in charge of power on the phy and checks for
> link status to see which ports are in use and mt7621_pcie_enable_ports
> just enable all the stuff to be ready to be used.
>
> >
> > > + if (err) {
> > > + dev_err(dev, "Error enabling pcie ports\n");
> > > + return err;
> > > + }
> > > +
> > > + setup_cm_memory_region(pcie);
> > > +
> > > + return mt7621_pcie_register_host(bridge);
> > > +}
> > > +
> > > +static const struct of_device_id mt7621_pci_ids[] = {
> > > + { .compatible = "mediatek,mt7621-pci" },
> > > + {},
> > > +};
> > > +MODULE_DEVICE_TABLE(of, mt7621_pci_ids);
> > > +
> > > +static struct platform_driver mt7621_pci_driver = {
> > > + .probe = mt7621_pci_probe,
> > > + .driver = {
> > > + .name = "mt7621-pci",
> > > + .of_match_table = of_match_ptr(mt7621_pci_ids),
> > > + },
> > > +};
> > > +builtin_platform_driver(mt7621_pci_driver);
> > > diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
> > > index ec4daa63c5e3..50e5a54f7d9e 100644
> > > --- a/arch/mips/ralink/Kconfig
> > > +++ b/arch/mips/ralink/Kconfig
> > > @@ -56,7 +56,7 @@ choice
> > > select MIPS_GIC
> > > select COMMON_CLK
> > > select CLKSRC_MIPS_GIC
> > > - select HAVE_PCI if PCI_MT7621
> > > + select HAVE_PCI
> > > select SOC_BUS
> > > endchoice
> > >
> > > @@ -101,4 +101,11 @@ choice
> > >
> > > endchoice
> > >
> > > +config PCI_MT7621
> > > + bool "MediaTek MT7621 PCI Controller"
> > > + depends on RALINK && SOC_MT7621
> >
> > Ideally this should also have (|| COMPILE_TEST), but looks like there
> > are a few MIPS dependencies in here. So maybe (|| (MIPS &&
> > COMPILE_TEST)? If it's not built by allmodconfig or defconfig, it's hard
> > for people to compile test it.
>
> Ok, I will add (|| (MIPS && COMPILE_TEST) here.
>
> Best regards,
> Sergio Paracuellos
>
> >
> >
> > > + select PCI_DRIVERS_GENERIC
> > > + help
> > > + This selects a driver for the MediaTek MT7621 PCI Controller.
> > > +
> > > endif
> > > --
> > > 2.25.1
I have already sent to staging this patchset[0] regarding your
comments before moving this driver to 'drivers/pci/controller' and
sending v2:
[0]: https://lore.kernel.org/linux-staging/20210606161358.7114-1-sergio.paracuellos@xxxxxxxxx/T/#t
Thanks,
Sergio Paracuellos