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.

Add support for new Gen3 controller which can be found on MT8192.

Signed-off-by: Jianjun Wang <jianjun.w...@mediatek.com>
Acked-by: Ryder Lee <ryder....@mediatek.com>
---
 drivers/pci/controller/Kconfig              |   14 +
 drivers/pci/controller/Makefile             |    1 +
 drivers/pci/controller/pcie-mediatek-gen3.c | 1076 +++++++++++++++++++
 3 files changed, 1091 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"
+       depends on ARCH_MEDIATEK || COMPILE_TEST
+       depends on OF
+       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
+         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..f8c8bdf88d33
--- /dev/null
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -0,0 +1,1076 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek PCIe host controller driver.
+ *
+ * Copyright (c) 2020 MediaTek Inc.
+ * Author: Jianjun Wang <jianjun.w...@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))
+
+#define PCIE_CFG_HEADER_FORCE_BE(devfn, bus, bytes) \
+       (PCIE_CFG_HEADER(devfn, bus) | PCIE_CFG_BYTE_EN(bytes) \
+        | PCIE_CFG_FORCE_BYTE_EN)
+
+#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)
+
+#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
+#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)
+
+#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)
+
+#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
+ * @hwirq: Hardware interrupt number
+ * @irq: MSI set Interrupt number
+ * @index: MSI set number
+ * @msg_addr: MSI message address
+ * @domain: IRQ domain
+ */
+struct mtk_pcie_msi {
+       void __iomem *base;
+       int hwirq;
+       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 **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);
+       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));
+
+       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);
+       u32 val;
+       int err = 0, table_index = 0;
+
+       /* 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*/
+       val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
+       writel(val, port->base + PCIE_RST_CTRL_REG);
+
+       usleep_range(100 * 1000, 120 * 1000);
+
+       /* De-assert pe reset*/
+       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)
+               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 int 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);
+       int 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);
+       int 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);
+       int 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_ack(struct irq_data *data)
+{
+       struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+       int 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_ack        = mtk_msi_top_irq_ack,
+       .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;
+       u32 virq, bit, hwirq;
+
+       raw_spin_lock(&desc->lock);
+
+       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);
+               }
+       }
+
+       irqchip->irq_ack(&desc->irq_data);
+
+       raw_spin_unlock(&desc->lock);
+}
+
+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_ack(struct irq_data *data)
+{
+       struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+       int hwirq;
+
+       hwirq = data->hwirq + PCIE_INTX_SHIFT;
+       writel(1 << hwirq, port->base + PCIE_INT_STATUS_REG);
+}
+
+static void mtk_intx_mask(struct irq_data *data)
+{
+       struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
+       int 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);
+       int val, hwirq;
+
+       /**
+        * As an emulated level irq, this interrupt status will be remained
+        * until receive the corresponding message of de-assert, hence that
+        * the status can only be cleared at this point.
+        */
+       hwirq = data->hwirq + PCIE_INTX_SHIFT;
+       writel(1 << hwirq, port->base + PCIE_INT_STATUS_REG);
+
+       val = readl(port->base + PCIE_INT_ENABLE_REG);
+       val |= 1 << (data->hwirq + PCIE_INTX_SHIFT);
+       writel(val, port->base + PCIE_INT_ENABLE_REG);
+}
+
+static struct irq_chip mtk_intx_irq_chip = {
+       .irq_ack                = mtk_intx_ack,
+       .irq_mask               = mtk_intx_mask,
+       .irq_unmask             = mtk_intx_unmask,
+       .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_level_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, val, ret;
+
+       /* Setup INTx */
+       intc_node = of_get_child_by_name(node, "interrupt-controller");
+       if (!intc_node) {
+               dev_notice(dev, "Missing PCIe Intc node\n");
+               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");
+               ret = -ENODEV;
+               goto err_msi_domain;
+       }
+
+       /* Enable MSI and setup pcie domains */
+       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");
+               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;
+
+               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->hwirq = i;
+               msi_info->index = i;
+               msi_info->domain = port->msi_domain;
+
+               port->msi_info[i] = msi_info;
+
+               /* Alloc irq for each msi set */
+               msi_info->irq = irq_create_mapping(port->msi_top_domain, i);
+               if (msi_info->irq < 0) {
+                       dev_info(dev, "allocate msi top irq failed\n");
+                       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) {
+               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;
+       u32 virq;
+       u32 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)
+{
+       struct device *dev = port->dev;
+       struct device_node *np = dev->of_node;
+       int i;
+
+       port->num_clks = of_clk_get_parent_count(np);
+       if (port->num_clks == 0) {
+               dev_notice(dev, "pcie clock is not found\n");
+               return -EINVAL;
+       }
+
+       port->clks = devm_kzalloc(dev, port->num_clks, GFP_KERNEL);
+       if (!port->clks)
+               return -ENOMEM;
+
+       for (i = 0; i < port->num_clks; i++) {
+               struct clk      *clk;
+               int             ret;
+
+               clk = of_clk_get(np, i);
+               if (IS_ERR(clk)) {
+                       while (--i >= 0)
+                               clk_put(port->clks[i]);
+                       return PTR_ERR(clk);
+               }
+
+               ret = clk_prepare_enable(clk);
+               if (ret < 0) {
+                       while (--i >= 0) {
+                               clk_disable_unprepare(port->clks[i]);
+                               clk_put(port->clks[i]);
+                       }
+                       clk_put(clk);
+
+                       return ret;
+               }
+
+               port->clks[i] = clk;
+       }
+
+       return 0;
+}
+
+static int mtk_pcie_disable_clk(struct mtk_pcie_port *port)
+{
+       int i;
+
+       if (port->num_clks == 0)
+               return 0;
+
+       for (i = 0; i < port->num_clks; i++) {
+               clk_disable_unprepare(port->clks[i]);
+               clk_put(port->clks[i]);
+       }
+
+       port->num_clks = 0;
+
+       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(dev, "phy-rst");
+       if (PTR_ERR(port->phy_reset) == -EPROBE_DEFER)
+               return PTR_ERR(port->phy_reset);
+
+       reset_control_deassert(port->phy_reset);
+
+       /* phy power on and enable pipe clock */
+       port->phy = devm_phy_optional_get(dev, "pcie-phy");
+       if (IS_ERR(port->phy))
+               port->phy = NULL;
+
+       err = phy_init(port->phy);
+       if (err) {
+               dev_notice(dev, "failed to initialize pcie phy\n");
+               return -ENODEV;
+       }
+
+       err = phy_power_on(port->phy);
+       if (err) {
+               dev_notice(dev, "failed to power on pcie phy\n");
+               goto err_phy_on;
+       }
+
+       port->mac_reset = devm_reset_control_get_optional(dev, "mac-rst");
+       if (PTR_ERR(port->mac_reset) == -EPROBE_DEFER)
+               return PTR_ERR(port->mac_reset);
+
+       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);
+       phy_power_off(port->phy);
+err_phy_on:
+       phy_exit(port->phy);
+       reset_control_assert(port->phy_reset);
+
+       return -EBUSY;
+}
+
+static void mtk_pcie_power_down(struct mtk_pcie_port *port)
+{
+       phy_power_off(port->phy);
+       phy_exit(port->phy);
+
+       mtk_pcie_disable_clk(port);
+
+       pm_runtime_put_sync(port->dev);
+       pm_runtime_disable(port->dev);
+}
+
+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;
+       }
+
+       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->dev.parent = port->dev;
+       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_stop_root_bus(host->bus);
+       pci_remove_root_bus(host->bus);
+
+       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)
+{
+       int 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 i, err, 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:
+       phy_power_off(port->phy);
+
+       for (i = 0; i < port->num_clks; i++)
+               clk_disable_unprepare(port->clks[i]);
+
+       pm_runtime_put_sync(port->dev);
+
+       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 i, err;
+
+       if (!port->is_suspended)
+               return 0;
+
+       phy_power_on(port->phy);
+
+       pm_runtime_get_sync(port->dev);
+
+       for (i = 0; i < port->num_clks; i++) {
+               err = clk_prepare_enable(port->clks[i]);
+               if (err < 0) {
+                       while (--i >= 0)
+                               clk_disable_unprepare(port->clks[i]);
+                       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,gen3-pcie" },
+       { .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,
+               .suppress_bind_attrs = true,
+               .pm = &mtk_pcie_pm_ops,
+       },
+};
+
+module_platform_driver(mtk_pcie_driver);
+MODULE_LICENSE("GPL v2");
-- 
2.25.1

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