Re: [v4,2/3] PCI: mediatek: Add new generation controller support

Bjorn Helgaas
2020-11-19T20:28:55Z

"Add new generation" really contains no information. And "mediatek"
is already used for the pcie-mediatek.c driver, so we should have a
new tag for this new driver. Include useful information in the
subject, e.g.,

PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192

On Wed, Nov 18, 2020 at 04:29:34PM +0800, Jianjun Wang wrote:
> MediaTek's PCIe host controller has three generation HWs, the new
> generation HW is an individual bridge, it supoorts Gen3 speed and
> up to 256 MSI interrupt numbers for multi-function devices.

s/supoorts/supports/

> Add support for new Gen3 controller which can be found on MT8192.
>
> Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
> Acked-by: Ryder Lee <ryder.lee@mediatek.com>
> ---
> drivers/pci/controller/Kconfig | 14 +
> drivers/pci/controller/Makefile | 1 +
> drivers/pci/controller/pcie-mediatek-gen3.c | 1031 +++++++++++++++++++
> 3 files changed, 1046 insertions(+)
> create mode 100644 drivers/pci/controller/pcie-mediatek-gen3.c
>
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index f18c3725ef80..83daa772595b 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -239,6 +239,20 @@ config PCIE_MEDIATEK
> Say Y here if you want to enable PCIe controller support on
> MediaTek SoCs.
>
> +config PCIE_MEDIATEK_GEN3
> + tristate "MediaTek GEN3 PCIe controller"

s/GEN3/Gen3/

> + depends on ARCH_MEDIATEK || COMPILE_TEST
> + depends on OF

Do you really need "depends on OF"? There are stubs to cover most
interfaces even when CONFIG_OF is not set. Depending on OF reduces
compile-test coverage.

> + depends on PCI_MSI_IRQ_DOMAIN
> + help
> + Adds support for PCIe Gen3 MAC controller for MediaTek SoCs.
> + This PCIe controller provides the capable of Gen3, Gen2 and

"provides the capable of" doesn't parse.

> + Gen1 speed, and support up to 256 MSI interrupt numbers for
> + multi-function devices.
> +
> + Say Y here if you want to enable Gen3 PCIe controller support on
> + MediaTek SoCs.
> +
> config PCIE_TANGO_SMP8759
> bool "Tango SMP8759 PCIe controller (DANGEROUS)"
> depends on ARCH_TANGO && PCI_MSI && OF
> diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> index bcdbf49ab1e4..9c1b96777597 100644
> --- a/drivers/pci/controller/Makefile
> +++ b/drivers/pci/controller/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
> obj-$(CONFIG_PCIE_ROCKCHIP_EP) += pcie-rockchip-ep.o
> obj-$(CONFIG_PCIE_ROCKCHIP_HOST) += pcie-rockchip-host.o
> obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
> +obj-$(CONFIG_PCIE_MEDIATEK_GEN3) += pcie-mediatek-gen3.o
> obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
> obj-$(CONFIG_VMD) += vmd.o
> obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> new file mode 100644
> index 000000000000..dd454cfee373
> --- /dev/null
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -0,0 +1,1031 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * MediaTek PCIe host controller driver.
> + *
> + * Copyright (c) 2020 MediaTek Inc.
> + * Author: Jianjun Wang <jianjun.wang@mediatek.com>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/iopoll.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/of_address.h>
> +#include <linux/of_clk.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_domain.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +
> +#include "../pci.h"
> +
> +#define PCIE_SETTING_REG 0x80
> +#define PCIE_PCI_IDS_1 0x9c
> +#define PCI_CLASS(class) (class << 8)
> +#define PCIE_RC_MODE BIT(0)
> +
> +#define PCIE_CFGNUM_REG 0x140
> +#define PCIE_CFG_DEVFN(devfn) ((devfn) & GENMASK(7, 0))
> +#define PCIE_CFG_BUS(bus) (((bus) << 8) & GENMASK(15, 8))
> +#define PCIE_CFG_BYTE_EN(bytes) (((bytes) << 16) & GENMASK(19, 16))
> +#define PCIE_CFG_FORCE_BYTE_EN BIT(20)
> +#define PCIE_CFG_OFFSET_ADDR 0x1000
> +#define PCIE_CFG_HEADER(devfn, bus) \
> + (PCIE_CFG_DEVFN(devfn) | PCIE_CFG_BUS(bus))

This should be:

(PCIE_CFG_BUS(bus) | PCIE_CFG_DEVFN(devfn))

to match the order of the bits in the address you're constructing.

> +#define PCIE_CFG_HEADER_FORCE_BE(devfn, bus, bytes) \
> + (PCIE_CFG_HEADER(devfn, bus) | PCIE_CFG_BYTE_EN(bytes) \
> + | PCIE_CFG_FORCE_BYTE_EN)

Reorder similarly.

> +#define PCIE_RST_CTRL_REG 0x148
> +#define PCIE_MAC_RSTB BIT(0)
> +#define PCIE_PHY_RSTB BIT(1)
> +#define PCIE_BRG_RSTB BIT(2)
> +#define PCIE_PE_RSTB BIT(3)
> +
> +#define PCIE_MISC_STATUS_REG 0x14C
> +#define PCIE_LTR_MSG_RECEIVED BIT(0)
> +#define PCIE_PCIE_MSG_RECEIVED BIT(1)

Unused, please remove.

> +#define PCIE_LTSSM_STATUS_REG 0x150
> +#define PCIE_LTSSM_STATE_MASK GENMASK(28, 24)
> +#define PCIE_LTSSM_STATE(val) ((val & PCIE_LTSSM_STATE_MASK) >> 24)

> +#define PCIE_LTSSM_STATE_L0 0x10
> +#define PCIE_LTSSM_STATE_L1_IDLE 0x13

Unused, please remove.

> +#define PCIE_LTSSM_STATE_L2_IDLE 0x14
> +
> +#define PCIE_LINK_STATUS_REG 0x154
> +#define PCIE_PORT_LINKUP BIT(8)
> +
> +#define PCIE_MSI_SET_NUM 8
> +#define PCIE_MSI_IRQS_PER_SET 32
> +#define PCIE_MSI_IRQS_NUM \
> + (PCIE_MSI_IRQS_PER_SET * (PCIE_MSI_SET_NUM))
> +
> +#define PCIE_INT_ENABLE_REG 0x180
> +#define PCIE_MSI_MASK GENMASK(PCIE_MSI_SET_NUM + 8 - 1, 8)
> +#define PCIE_MSI_SHIFT 8
> +#define PCIE_INTX_SHIFT 24
> +#define PCIE_INTX_MASK GENMASK(27, 24)

> +#define PCIE_MSG_MASK BIT(28)
> +#define PCIE_AER_MASK BIT(29)
> +#define PCIE_PM_MASK BIT(30)

Unused, please remove.

> +#define PCIE_INT_STATUS_REG 0x184
> +#define PCIE_MSI_SET_ENABLE_REG 0x190
> +
> +#define PCIE_LOW_POWER_CTRL_REG 0x194
> +#define PCIE_DIS_LOWPWR_MASK GENMASK(3, 0)
> +#define PCIE_DIS_L0S_MASK BIT(0)
> +#define PCIE_DIS_L1_MASK BIT(1)
> +#define PCIE_DIS_L11_MASK BIT(2)
> +#define PCIE_DIS_L12_MASK BIT(3)
> +#define PCIE_FORCE_DIS_LOWPWR GENMASK(11, 8)
> +#define PCIE_FORCE_DIS_L0S BIT(8)
> +#define PCIE_FORCE_DIS_L1 BIT(9)
> +#define PCIE_FORCE_DIS_L11 BIT(10)
> +#define PCIE_FORCE_DIS_L12 BIT(11)

Unused, please remove.

> +#define PCIE_ICMD_PM_REG 0x198
> +#define PCIE_TURN_OFF_LINK BIT(4)
> +
> +#define PCIE_MSI_ADDR_BASE_REG 0xc00
> +#define PCIE_MSI_SET_OFFSET 0x10
> +#define PCIE_MSI_STATUS_OFFSET 0x04
> +#define PCIE_MSI_ENABLE_OFFSET 0x08
> +
> +#define PCIE_TRANS_TABLE_BASE_REG 0x800
> +#define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
> +#define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8
> +#define PCIE_ATR_TRSL_ADDR_MSB_OFFSET 0xc
> +#define PCIE_ATR_TRSL_PARAM_OFFSET 0x10
> +#define PCIE_ATR_TLB_SET_OFFSET 0x20
> +
> +#define PCIE_MAX_TRANS_TABLES 8
> +#define ATR_EN BIT(0)
> +#define ATR_SIZE(size) ((((size) - 1) << 1) & GENMASK(6, 1))
> +#define ATR_ID(id) (id & GENMASK(3, 0))
> +#define ATR_PARAM(param) (((param) << 16) & GENMASK(27, 16))
> +
> +/**
> + * struct mtk_pcie_msi - MSI information for each set
> + * @base: IO mapped register base
> + * @irq: MSI set Interrupt number
> + * @index: MSI set number
> + * @msg_addr: MSI message address
> + * @domain: IRQ domain
> + */
> +struct mtk_pcie_msi {
> + void __iomem *base;
> + unsigned int irq;
> + int index;
> + phys_addr_t msg_addr;
> + struct irq_domain *domain;
> +};
> +
> +/**
> + * struct mtk_pcie_port - PCIe port information
> + * @dev: PCIe device
> + * @base: IO mapped register base
> + * @reg_base: Physical register base
> + * @mac_reset: mac reset control
> + * @phy_reset: phy reset control
> + * @phy: PHY controller block
> + * @clks: PCIe clocks
> + * @num_clks: PCIe clocks count for this port
> + * @is_suspended: device suspend state
> + * @irq: PCIe controller interrupt number
> + * @intx_domain: legacy INTx IRQ domain
> + * @msi_domain: MSI IRQ domain
> + * @msi_top_domain: MSI IRQ top domain
> + * @msi_info: MSI sets information
> + * @lock: lock protecting IRQ bit map
> + * @msi_irq_in_use: bit map for assigned MSI IRQ
> + */
> +struct mtk_pcie_port {
> + struct device *dev;
> + void __iomem *base;
> + phys_addr_t reg_base;
> + struct reset_control *mac_reset;
> + struct reset_control *phy_reset;
> + struct phy *phy;
> + struct clk_bulk_data *clks;
> + int num_clks;
> + bool is_suspended;
> +
> + int irq;
> + struct irq_domain *intx_domain;
> + struct irq_domain *msi_domain;
> + struct irq_domain *msi_top_domain;
> + struct mtk_pcie_msi **msi_info;
> + struct mutex lock;
> + DECLARE_BITMAP(msi_irq_in_use, PCIE_MSI_IRQS_NUM);
> +};
> +
> +static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 *val)
> +{
> + struct mtk_pcie_port *port = bus->sysdata;
> + int bytes;
> +
> + bytes = ((1 << size) - 1) << (where & 0x3);

This seems like some unusual bit twiddling; at least, I don't remember
seeing this before. Can you skim other drivers and see if others do
the same thing, and adopt a common style if they do?

> + writel(PCIE_CFG_HEADER_FORCE_BE(devfn, bus->number, bytes),
> + port->base + PCIE_CFGNUM_REG);
> +
> + *val = readl(port->base + PCIE_CFG_OFFSET_ADDR + (where & ~0x3));

These look like they need to be atomic, since you need a writel()
followed by a readl().

pci_lock_config() (used in pci_bus_read_config_*(), etc) uses the
global pci_lock for this unless CONFIG_PCI_LOCKLESS_CONFIG is set.

But I would like to eventually move away from this implicit dependency
on pci_lock. If you need to make this atomic, can you add the
explicit locking here, so there's a clear connection between the lock
and the things it protects?

> + if (size <= 2)
> + *val = (*val >> (8 * (where & 0x3))) & ((1 << (size * 8)) - 1);
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 val)
> +{
> + struct mtk_pcie_port *port = bus->sysdata;
> + int bytes;
> +
> + bytes = ((1 << size) - 1) << (where & 0x3);
> + writel(PCIE_CFG_HEADER_FORCE_BE(devfn, bus->number, bytes),
> + port->base + PCIE_CFGNUM_REG);
> +
> + if (size <= 2)
> + val = (val & ((1 << (size * 8)) - 1)) << ((where & 0x3) * 8);
> +
> + writel(val, port->base + PCIE_CFG_OFFSET_ADDR + (where & ~0x3));
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static struct pci_ops mtk_pcie_ops = {
> + .read = mtk_pcie_config_read,
> + .write = mtk_pcie_config_write,
> +};
> +
> +static void mtk_pcie_set_trans_window(void __iomem *reg,
> + resource_size_t cpu_addr,
> + resource_size_t pci_addr, size_t size)
> +{
> + writel(lower_32_bits(cpu_addr) | ATR_SIZE(fls(size) - 1) | ATR_EN, reg);
> + writel(upper_32_bits(cpu_addr), reg + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
> + writel(lower_32_bits(pci_addr), reg + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
> + writel(upper_32_bits(pci_addr), reg + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);
> + writel(ATR_ID(0) | ATR_PARAM(0), reg + PCIE_ATR_TRSL_PARAM_OFFSET);
> +}
> +
> +static int mtk_pcie_set_trans_table(void __iomem *reg,
> + resource_size_t cpu_addr,
> + resource_size_t pci_addr, size_t size,
> + int num)
> +{
> + void __iomem *table_base;
> +
> + if (num > PCIE_MAX_TRANS_TABLES)
> + return -ENODEV;
> +
> + table_base = reg + num * PCIE_ATR_TLB_SET_OFFSET;
> + mtk_pcie_set_trans_window(table_base, cpu_addr, pci_addr, size);
> +
> + return 0;
> +}
> +
> +static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
> +{
> + struct resource_entry *entry;
> + struct pci_host_bridge *host = pci_host_bridge_from_priv(port);
> + unsigned int table_index = 0;
> + int err;
> + u32 val;
> +
> + /* Set as RC mode */
> + val = readl(port->base + PCIE_SETTING_REG);
> + val |= PCIE_RC_MODE;
> + writel(val, port->base + PCIE_SETTING_REG);
> +
> + /* Set class code */
> + val = readl(port->base + PCIE_PCI_IDS_1);
> + val &= ~GENMASK(31, 8);
> + val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI << 8);
> + writel(val, port->base + PCIE_PCI_IDS_1);
> +
> + /* Assert all reset signals */
> + val = readl(port->base + PCIE_RST_CTRL_REG);
> + val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
> + writel(val, port->base + PCIE_RST_CTRL_REG);
> +
> + /* De-assert reset signals*/

Missing space at end of comment.

> + val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
> + writel(val, port->base + PCIE_RST_CTRL_REG);
> +
> + /* Delay 100ms to wait the reference clocks become stable */
> + usleep_range(100 * 1000, 120 * 1000);
> +
> + /* De-assert pe reset*/

Missing space at end of comment. "pe" looks like something that
should be capitalized, since I assume it's some sort of initialism.

> + val &= ~PCIE_PE_RSTB;
> + writel(val, port->base + PCIE_RST_CTRL_REG);
> +
> + /* Check if the link is up or not */
> + err = readl_poll_timeout(port->base + PCIE_LINK_STATUS_REG, val,
> + !!(val & PCIE_PORT_LINKUP), 20,
> + 50 * USEC_PER_MSEC);
> + if (err) {
> + val = readl(port->base + PCIE_LTSSM_STATUS_REG);
> + dev_dbg(port->dev, "ltssm reg val: %#x\n", val);
> + return err;
> + }
> +
> + /* Set PCIe translation windows */
> + resource_list_for_each_entry(entry, &host->windows) {
> + unsigned long type = resource_type(entry->res);
> + struct resource *res = NULL;
> + resource_size_t cpu_addr;
> + resource_size_t pci_addr;
> +
> + if (!(type & (IORESOURCE_MEM | IORESOURCE_IO)))
> + continue;
> +
> + res = entry->res;
> + cpu_addr = res->start;
> + pci_addr = res->start - entry->offset;
> + mtk_pcie_set_trans_table(port->base + PCIE_TRANS_TABLE_BASE_REG,
> + cpu_addr, pci_addr, resource_size(res),
> + table_index);
> +
> + dev_dbg(port->dev, "Set %s trans window[%d]: cpu_addr = %#llx, pci_addr = %#llx, size = %#llx\n",
> + (!!(type & IORESOURCE_MEM) ? "MEM" : "IO"), table_index,
> + cpu_addr, pci_addr, resource_size(res));
> +
> + table_index++;
> + }
> +
> + return 0;
> +}
> +
> +static inline struct mtk_pcie_msi *mtk_get_msi_info(struct mtk_pcie_port *port,
> + unsigned long hwirq)
> +{
> + return port->msi_info[hwirq / PCIE_MSI_IRQS_PER_SET];
> +}
> +
> +static int mtk_pcie_set_affinity(struct irq_data *data,
> + const struct cpumask *mask, bool force)
> +{
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + int ret;
> +
> + ret = irq_set_affinity_hint(port->irq, mask);
> + if (ret)
> + return ret;
> +
> + irq_data_update_effective_affinity(data, mask);
> +
> + return 0;
> +}
> +
> +static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct mtk_pcie_msi *msi_info;
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> +
> + msi_info = mtk_get_msi_info(port, data->hwirq);
> +
> + msg->address_hi = 0;
> + msg->address_lo = lower_32_bits(msi_info->msg_addr);
> +
> + msg->data = data->hwirq;
> + dev_dbg(port->dev, "msi#%#lx address_hi %#x address_lo %#x data %d\n",
> + data->hwirq, msg->address_hi, msg->address_lo, msg->data);
> +}
> +
> +static void mtk_msi_irq_ack(struct irq_data *data)
> +{
> + struct mtk_pcie_msi *msi_info;
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + unsigned long hwirq;
> +
> + msi_info = mtk_get_msi_info(port, data->hwirq);
> +
> + hwirq = data->hwirq % PCIE_MSI_IRQS_PER_SET;
> +
> + writel(1 << hwirq, msi_info->base + PCIE_MSI_STATUS_OFFSET);
> +}
> +
> +static void mtk_msi_irq_mask(struct irq_data *data)
> +{
> + struct mtk_pcie_msi *msi_info;
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + u32 val;
> +
> + msi_info = mtk_get_msi_info(port, data->hwirq);
> + val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
> + val &= ~(1 << data->hwirq);
> + writel(val, msi_info->base + PCIE_MSI_ENABLE_OFFSET);
> +
> + pci_msi_mask_irq(data);
> +}
> +
> +static void mtk_msi_irq_unmask(struct irq_data *data)
> +{
> + struct mtk_pcie_msi *msi_info;
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + u32 val;
> +
> + msi_info = mtk_get_msi_info(port, data->hwirq);
> + val = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
> + val |= (1 << data->hwirq);
> + writel(val, msi_info->base + PCIE_MSI_ENABLE_OFFSET);
> +
> + pci_msi_unmask_irq(data);
> +}
> +
> +static struct irq_chip mtk_msi_irq_chip = {
> + .irq_ack = mtk_msi_irq_ack,
> + .irq_compose_msi_msg = mtk_compose_msi_msg,
> + .irq_mask = mtk_msi_irq_mask,
> + .irq_unmask = mtk_msi_irq_unmask,
> + .irq_set_affinity = mtk_pcie_set_affinity,
> + .name = "PCIe",
> +};
> +
> +static irq_hw_number_t mtk_pcie_msi_get_hwirq(struct msi_domain_info *info,
> + msi_alloc_info_t *arg)
> +{
> + struct msi_desc *entry = arg->desc;
> + struct mtk_pcie_port *port = info->chip_data;
> + int hwirq;
> +
> + mutex_lock(&port->lock);
> +
> + hwirq = bitmap_find_free_region(port->msi_irq_in_use, PCIE_MSI_IRQS_NUM,
> + order_base_2(entry->nvec_used));
> + if (hwirq < 0) {
> + mutex_unlock(&port->lock);
> + return -ENOSPC;
> + }
> +
> + mutex_unlock(&port->lock);
> +
> + return hwirq;
> +}
> +
> +static void mtk_pcie_msi_free(struct irq_domain *domain,
> + struct msi_domain_info *info, unsigned int virq)
> +{
> + struct irq_data *data = irq_domain_get_irq_data(domain, virq);
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> +
> + mutex_lock(&port->lock);
> +
> + bitmap_clear(port->msi_irq_in_use, data->hwirq, 1);
> +
> + mutex_unlock(&port->lock);
> +}
> +
> +static struct msi_domain_ops mtk_msi_domain_ops = {
> + .get_hwirq = mtk_pcie_msi_get_hwirq,
> + .msi_free = mtk_pcie_msi_free,
> +};
> +
> +static struct msi_domain_info mtk_msi_domain_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_PCI_MSIX |
> + MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI),
> + .chip = &mtk_msi_irq_chip,
> + .ops = &mtk_msi_domain_ops,
> + .handler = handle_edge_irq,
> + .handler_name = "MSI",
> +};
> +
> +static void mtk_msi_top_irq_eoi(struct irq_data *data)
> +{
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + unsigned long msi_irq = data->hwirq + PCIE_MSI_SHIFT;
> +
> + writel(1 << msi_irq, port->base + PCIE_INT_STATUS_REG);
> +}
> +
> +static struct irq_chip mtk_msi_top_irq_chip = {
> + .irq_eoi = mtk_msi_top_irq_eoi,
> + .name = "PCIe",
> +};
> +
> +static void mtk_pcie_msi_handler(struct irq_desc *desc)
> +{
> + struct mtk_pcie_msi *msi_info = irq_desc_get_handler_data(desc);
> + struct irq_chip *irqchip = irq_desc_get_chip(desc);
> + unsigned long msi_enable, msi_status;
> + unsigned int virq;
> + irq_hw_number_t bit, hwirq;
> +
> + chained_irq_enter(irqchip, desc);
> +
> + msi_enable = readl(msi_info->base + PCIE_MSI_ENABLE_OFFSET);
> + while ((msi_status = readl(msi_info->base + PCIE_MSI_STATUS_OFFSET))) {
> + msi_status &= msi_enable;
> + for_each_set_bit(bit, &msi_status, PCIE_MSI_IRQS_PER_SET) {
> + hwirq = bit + msi_info->index * PCIE_MSI_IRQS_PER_SET;
> + virq = irq_find_mapping(msi_info->domain, hwirq);
> + generic_handle_irq(virq);
> + }
> + }
> +
> + chained_irq_exit(irqchip, desc);
> +}
> +
> +static int mtk_msi_top_domain_map(struct irq_domain *domain,
> + unsigned int virq, irq_hw_number_t hwirq)
> +{
> + struct mtk_pcie_port *port = domain->host_data;
> + struct mtk_pcie_msi *msi_info = port->msi_info[hwirq];
> +
> + irq_domain_set_info(domain, virq, hwirq,
> + &mtk_msi_top_irq_chip, domain->host_data,
> + mtk_pcie_msi_handler, msi_info, NULL);
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops mtk_msi_top_domain_ops = {
> + .map = mtk_msi_top_domain_map,
> +};
> +
> +static void mtk_intx_mask(struct irq_data *data)
> +{
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + u32 val;
> +
> + val = readl(port->base + PCIE_INT_ENABLE_REG);
> + val &= ~(1 << (data->hwirq + PCIE_INTX_SHIFT));
> + writel(val, port->base + PCIE_INT_ENABLE_REG);
> +}
> +
> +static void mtk_intx_unmask(struct irq_data *data)
> +{
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + u32 val;
> +
> + val = readl(port->base + PCIE_INT_ENABLE_REG);
> + val |= 1 << (data->hwirq + PCIE_INTX_SHIFT);
> + writel(val, port->base + PCIE_INT_ENABLE_REG);
> +}
> +
> +static void mtk_intx_eoi(struct irq_data *data)
> +{
> + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
> + unsigned long hwirq;
> +
> + /**
> + * As an emulated level irq, its interrupt status will be remained
> + * until receive the corresponding message of de-assert, hence that
> + * the status can only be cleared when the interrupt has been serviced.

s/irq/IRQ/

As an emulated level IRQ, its interrupt status will remain until the
corresponding de-assert message is received; hence that ...

> + */
> + hwirq = data->hwirq + PCIE_INTX_SHIFT;
> + writel(1 << hwirq, port->base + PCIE_INT_STATUS_REG);
> +}
> +
> +static struct irq_chip mtk_intx_irq_chip = {
> + .irq_mask = mtk_intx_mask,
> + .irq_unmask = mtk_intx_unmask,
> + .irq_eoi = mtk_intx_eoi,
> + .irq_set_affinity = mtk_pcie_set_affinity,
> + .name = "PCIe",
> +};
> +
> +static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> + irq_hw_number_t hwirq)
> +{
> + irq_set_chip_and_handler_name(irq, &mtk_intx_irq_chip,
> + handle_fasteoi_irq, "INTx");
> + irq_set_chip_data(irq, domain->host_data);
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops intx_domain_ops = {
> + .map = mtk_pcie_intx_map,
> +};
> +
> +static int mtk_pcie_init_irq_domains(struct mtk_pcie_port *port,
> + struct device_node *node)
> +{
> + struct device *dev = port->dev;
> + struct device_node *intc_node;
> + struct fwnode_handle *fwnode = of_node_to_fwnode(node);
> + struct mtk_pcie_msi *msi_info;
> + struct msi_domain_info *info;
> + int i, ret;
> +
> + /* Setup INTx */
> + intc_node = of_get_child_by_name(node, "interrupt-controller");
> + if (!intc_node) {
> + dev_notice(dev, "Missing PCIe Intc node\n");

s/Missing/missing/ to match other messages.

> + return -ENODEV;
> + }
> +
> + port->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX,
> + &intx_domain_ops, port);
> + if (!port->intx_domain) {
> + dev_notice(dev, "failed to get INTx IRQ domain\n");
> + return -ENODEV;
> + }
> +
> + /* Setup MSI */
> + mutex_init(&port->lock);
> +
> + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + memcpy(info, &mtk_msi_domain_info, sizeof(*info));
> + info->chip_data = port;
> +
> + port->msi_domain = pci_msi_create_irq_domain(fwnode, info, NULL);
> + if (!port->msi_domain) {
> + dev_info(dev, "failed to create msi domain\n");

s/msi/MSI/

> + ret = -ENODEV;
> + goto err_msi_domain;
> + }
> +
> + /* Enable MSI and setup pcie domains */

s/pcie/PCIe/

> + port->msi_top_domain = irq_domain_add_hierarchy(NULL, 0, 0, node,
> + &mtk_msi_top_domain_ops,
> + port);
> + if (!port->msi_top_domain) {
> + dev_info(dev, "failed to create msi top domain\n");

s/msi/MSI/

> + ret = -ENODEV;
> + goto err_msi_top_domain;
> + }
> +
> + port->msi_info = devm_kzalloc(dev, PCIE_MSI_SET_NUM, GFP_KERNEL);
> + if (!port->msi_info) {
> + ret = -ENOMEM;
> + goto err_msi_info;
> + }
> +
> + for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
> + int offset = i * PCIE_MSI_SET_OFFSET;
> + u32 val;
> +
> + msi_info = devm_kzalloc(dev, sizeof(*msi_info), GFP_KERNEL);
> + if (!msi_info) {
> + ret = -ENOMEM;
> + goto err_msi_set;
> + }
> +
> + msi_info->base = port->base + PCIE_MSI_ADDR_BASE_REG + offset;
> + msi_info->msg_addr = port->reg_base + PCIE_MSI_ADDR_BASE_REG +
> + offset;
> +
> + writel(lower_32_bits(msi_info->msg_addr), msi_info->base);
> +
> + msi_info->index = i;
> + msi_info->domain = port->msi_domain;
> +
> + port->msi_info[i] = msi_info;
> +
> + /* Alloc irq for each msi set */

s/irq/IRQ/
s/msi/MSI/

> + msi_info->irq = irq_create_mapping(port->msi_top_domain, i);
> + if (!msi_info->irq) {
> + dev_info(dev, "allocate msi top irq failed\n");

s/irq/IRQ/
s/msi/MSI/

> + ret = -ENOSPC;
> + goto err_msi_set;
> + }
> +
> + val = readl(port->base + PCIE_INT_ENABLE_REG);
> + val |= (1 << (i + PCIE_MSI_SHIFT));
> + writel(val, port->base + PCIE_INT_ENABLE_REG);
> +
> + val = readl(port->base + PCIE_MSI_SET_ENABLE_REG);
> + val |= (1 << i);
> + writel(val, port->base + PCIE_MSI_SET_ENABLE_REG);
> + }
> +
> + return 0;
> +
> +err_msi_set:
> + while (--i >= 0) {

(i-- > 0) would be more idiomatic.

> + msi_info = port->msi_info[i];
> + irq_dispose_mapping(msi_info->irq);
> + }
> +err_msi_info:
> + irq_domain_remove(port->msi_top_domain);
> +err_msi_top_domain:
> + irq_domain_remove(port->msi_domain);
> +err_msi_domain:
> + irq_domain_remove(port->intx_domain);
> +
> + return ret;
> +}
> +
> +static void mtk_pcie_irq_teardown(struct mtk_pcie_port *port)
> +{
> + struct mtk_pcie_msi *msi_info;
> + int i;
> +
> + irq_set_chained_handler_and_data(port->irq, NULL, NULL);
> +
> + if (port->intx_domain)
> + irq_domain_remove(port->intx_domain);
> +
> + if (port->msi_domain)
> + irq_domain_remove(port->msi_domain);
> +
> + if (port->msi_top_domain) {
> + for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
> + msi_info = port->msi_info[i];
> + irq_dispose_mapping(msi_info->irq);
> + }
> +
> + irq_domain_remove(port->msi_top_domain);
> + }
> +
> + irq_dispose_mapping(port->irq);
> +}
> +
> +static void mtk_pcie_irq_handler(struct irq_desc *desc)
> +{
> + struct mtk_pcie_port *port = irq_desc_get_handler_data(desc);
> + struct irq_chip *irqchip = irq_desc_get_chip(desc);
> + unsigned long status;
> + unsigned int virq;
> + irq_hw_number_t irq_bit = PCIE_INTX_SHIFT;
> +
> + chained_irq_enter(irqchip, desc);
> +
> + status = readl(port->base + PCIE_INT_STATUS_REG);
> + if (status & PCIE_INTX_MASK) {
> + for_each_set_bit_from(irq_bit, &status, PCI_NUM_INTX +
> + PCIE_INTX_SHIFT) {
> + virq = irq_find_mapping(port->intx_domain,
> + irq_bit - PCIE_INTX_SHIFT);
> + generic_handle_irq(virq);
> + }
> + }
> +
> + if (status & PCIE_MSI_MASK) {
> + irq_bit = PCIE_MSI_SHIFT;
> + for_each_set_bit_from(irq_bit, &status, PCIE_MSI_SET_NUM +
> + PCIE_MSI_SHIFT) {
> + virq = irq_find_mapping(port->msi_top_domain,
> + irq_bit - PCIE_MSI_SHIFT);
> + generic_handle_irq(virq);
> + }
> + }
> +
> + chained_irq_exit(irqchip, desc);
> +}
> +
> +static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
> + struct device_node *node)
> +{
> + struct device *dev = port->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + int err;
> +
> + err = mtk_pcie_init_irq_domains(port, node);
> + if (err) {
> + dev_notice(dev, "failed to init PCIe IRQ domain\n");
> + return err;
> + }
> +
> + port->irq = platform_get_irq(pdev, 0);
> + if (port->irq < 0)
> + return port->irq;
> +
> + irq_set_chained_handler_and_data(port->irq, mtk_pcie_irq_handler, port);
> +
> + return 0;
> +}
> +
> +static int mtk_pcie_clk_init(struct mtk_pcie_port *port)
> +{
> + int ret;
> +
> + port->num_clks = devm_clk_bulk_get_all(port->dev, &port->clks);
> + if (port->num_clks < 0) {
> + dev_notice(port->dev, "failed to get pcie clock\n");

s/pcie/PCIe/

> + return port->num_clks;
> + }
> +
> + ret = clk_bulk_prepare_enable(port->num_clks, port->clks);
> + if (ret) {
> + dev_notice(port->dev, "failed to enable pcie clocks\n");

s/pcie/PCIe/

> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int mtk_pcie_power_up(struct mtk_pcie_port *port)
> +{
> + struct device *dev = port->dev;
> + int err;
> +
> + port->phy_reset = devm_reset_control_get_optional_exclusive(dev, "phy");
> + if (IS_ERR(port->phy_reset))
> + return PTR_ERR(port->phy_reset);
> +
> + /* PHY power on and enable pipe clock */
> + port->phy = devm_phy_optional_get(dev, "pcie-phy");
> + if (IS_ERR(port->phy))
> + return PTR_ERR(port->phy);
> +
> + reset_control_deassert(port->phy_reset);
> +
> + err = phy_power_on(port->phy);
> + if (err) {
> + dev_notice(dev, "failed to power on pcie phy\n");

s/pcie/PCIe/

> + goto err_phy_on;
> + }
> +
> + err = phy_init(port->phy);
> + if (err) {
> + dev_notice(dev, "failed to initialize pcie phy\n");

s/pcie/PCIe/

> + goto err_phy_init;
> + }
> +
> + port->mac_reset = devm_reset_control_get_optional_exclusive(dev, "mac");
> + if (IS_ERR(port->mac_reset)) {
> + err = PTR_ERR(port->mac_reset);
> + goto err_mac_rst;
> + }
> +
> + reset_control_deassert(port->mac_reset);
> +
> + /* MAC power on and enable transaction layer clocks */
> + pm_runtime_enable(dev);
> + pm_runtime_get_sync(dev);
> +
> + err = mtk_pcie_clk_init(port);
> + if (err) {
> + dev_notice(dev, "clock init failed\n");
> + goto err_clk_init;
> + }
> +
> + return 0;
> +
> +err_clk_init:
> + pm_runtime_put_sync(dev);
> + pm_runtime_disable(dev);
> + reset_control_assert(port->mac_reset);
> +err_mac_rst:
> + phy_exit(port->phy);
> +err_phy_init:
> + phy_power_off(port->phy);
> +err_phy_on:
> + reset_control_assert(port->phy_reset);
> +
> + return err;
> +}
> +
> +static void mtk_pcie_power_down(struct mtk_pcie_port *port)
> +{
> + clk_bulk_disable_unprepare(port->num_clks, port->clks);
> +
> + pm_runtime_put_sync(port->dev);
> + pm_runtime_disable(port->dev);
> + reset_control_assert(port->mac_reset);
> +
> + phy_power_off(port->phy);
> + phy_exit(port->phy);
> + reset_control_assert(port->phy_reset);
> +}
> +
> +static int mtk_pcie_setup(struct mtk_pcie_port *port)
> +{
> + struct device *dev = port->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + struct resource *regs;
> + int err;
> +
> + regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
> + port->base = devm_ioremap_resource(dev, regs);
> + if (IS_ERR(port->base)) {
> + dev_notice(dev, "failed to map register base\n");
> + return PTR_ERR(port->base);
> + }
> +
> + port->reg_base = regs->start;
> +
> + /* Don't touch the hardware registers before power up */
> + err = mtk_pcie_power_up(port);
> + if (err)
> + return err;
> +
> + /* Try link up */
> + err = mtk_pcie_startup_port(port);
> + if (err) {
> + dev_notice(dev, "PCIe link down\n");
> + goto err_setup;

Generally it should not be a fatal error if the link is not up at
probe-time. You may be able to hot-add a device, or the device may
have some external power control that will power it up later.

> + }
> +
> + err = mtk_pcie_setup_irq(port, dev->of_node);
> + if (err)
> + goto err_setup;
> +
> + dev_info(dev, "PCIe link up success!\n");
> +
> + return 0;
> +
> +err_setup:
> + mtk_pcie_power_down(port);
> +
> + return err;
> +}
> +
> +static int mtk_pcie_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct mtk_pcie_port *port;
> + struct pci_host_bridge *host;
> + int err;
> +
> + host = devm_pci_alloc_host_bridge(dev, sizeof(*port));
> + if (!host)
> + return -ENOMEM;
> +
> + port = pci_host_bridge_priv(host);
> +
> + port->dev = dev;
> + platform_set_drvdata(pdev, port);
> +
> + err = mtk_pcie_setup(port);
> + if (err)
> + return err;
> +
> + host->ops = &mtk_pcie_ops;
> + host->sysdata = port;
> +
> + err = pci_host_probe(host);
> + if (err) {
> + mtk_pcie_power_down(port);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int mtk_pcie_remove(struct platform_device *pdev)
> +{
> + struct mtk_pcie_port *port = platform_get_drvdata(pdev);
> + struct pci_host_bridge *host = pci_host_bridge_from_priv(port);
> +
> + pci_lock_rescan_remove();
> + pci_stop_root_bus(host->bus);
> + pci_remove_root_bus(host->bus);
> + pci_unlock_rescan_remove();
> +
> + mtk_pcie_irq_teardown(port);
> + mtk_pcie_power_down(port);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused mtk_pcie_turn_off_link(struct mtk_pcie_port *port)
> +{
> + u32 val;
> +
> + val = readl(port->base + PCIE_ICMD_PM_REG);
> + val |= PCIE_TURN_OFF_LINK;
> + writel(val, port->base + PCIE_ICMD_PM_REG);
> +
> + /* Check the link is L2 */
> + return readl_poll_timeout(port->base + PCIE_LTSSM_STATUS_REG, val,
> + (PCIE_LTSSM_STATE(val) ==
> + PCIE_LTSSM_STATE_L2_IDLE), 20,
> + 50 * USEC_PER_MSEC);
> +}
> +
> +static int __maybe_unused mtk_pcie_suspend_noirq(struct device *dev)
> +{
> + struct mtk_pcie_port *port = dev_get_drvdata(dev);
> + int err;
> + u32 val;
> +
> + if (port->is_suspended)
> + return 0;
> +
> + /* Trigger link to L2 state */
> + err = mtk_pcie_turn_off_link(port);
> + if (err) {
> + dev_notice(port->dev, "can not enter L2 state\n");
> + goto power_off;
> + }
> +
> + /* Pull down the PERST# pin */
> + val = readl(port->base + PCIE_RST_CTRL_REG);
> + val |= PCIE_PE_RSTB;
> + writel(val, port->base + PCIE_RST_CTRL_REG);
> +
> + dev_info(port->dev, "enter L2 state success");
> +
> +power_off:
> + clk_bulk_disable_unprepare(port->num_clks, port->clks);
> +
> + phy_power_off(port->phy);
> +
> + port->is_suspended = true;
> +
> + return 0;
> +}
> +
> +static int __maybe_unused mtk_pcie_resume_noirq(struct device *dev)
> +{
> + struct mtk_pcie_port *port = dev_get_drvdata(dev);
> + int err;
> +
> + if (!port->is_suspended)
> + return 0;
> +
> + phy_power_on(port->phy);
> +
> + err = clk_bulk_prepare_enable(port->num_clks, port->clks);
> + if (err) {
> + dev_dbg(dev, "failed to enable pcie clocks\n");

s/pcie/PCIe/

> + return err;
> + }
> +
> + err = mtk_pcie_startup_port(port);
> + if (err) {
> + dev_notice(port->dev, "resume failed\n");
> + return err;
> + }
> +
> + port->is_suspended = false;
> +
> + dev_info(port->dev, "resume done\n");
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops mtk_pcie_pm_ops = {
> + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_pcie_suspend_noirq,
> + mtk_pcie_resume_noirq)
> +};
> +
> +static const struct of_device_id mtk_pcie_of_match[] = {
> + { .compatible = "mediatek,mt8192-pcie" },
> + {},
> +};
> +
> +static struct platform_driver mtk_pcie_driver = {
> + .probe = mtk_pcie_probe,
> + .remove = mtk_pcie_remove,
> + .driver = {
> + .name = "mtk-pcie",
> + .of_match_table = mtk_pcie_of_match,
> + .pm = &mtk_pcie_pm_ops,
> + },
> +};
> +
> +module_platform_driver(mtk_pcie_driver);
> +MODULE_LICENSE("GPL v2");
> --
> 2.25.1
>