--- /dev/null
+// 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/kernel.h>
+#include <linux/module.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(bus, devfn) \
+ (PCIE_CFG_BUS(bus) | PCIE_CFG_DEVFN(devfn))
+
+#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_LTSSM_STATUS_REG 0x150
+
+#define PCIE_LINK_STATUS_REG 0x154
+#define PCIE_PORT_LINKUP BIT(8)
+
+#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 PCIE_ATR_EN BIT(0)
+#define PCIE_ATR_SIZE(size) \
+ (((((size) - 1) << 1) & GENMASK(6, 1)) | PCIE_ATR_EN)
+#define PCIE_ATR_ID(id) ((id) & GENMASK(3, 0))
+#define PCIE_ATR_TYPE_MEM PCIE_ATR_ID(0)
+#define PCIE_ATR_TYPE_IO PCIE_ATR_ID(1)
+#define PCIE_ATR_TLP_TYPE(type) (((type) << 16) & GENMASK(18, 16))
+#define PCIE_ATR_TLP_TYPE_MEM PCIE_ATR_TLP_TYPE(0)
+#define PCIE_ATR_TLP_TYPE_IO PCIE_ATR_TLP_TYPE(2)
+
+/**
+ * struct mtk_pcie_port - PCIe port information
+ * @dev: pointer to 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
+ */
+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;
+};
+
+/**
+ * mtk_pcie_config_tlp_header() - Configure a configuration TLP header
+ * @bus: PCI bus to query
+ * @devfn: device/function number
+ * @where: offset in config space
+ * @size: data size in TLP header
+ *
+ * Set byte enable field and device information in configuration TLP header.
+ */
+static void mtk_pcie_config_tlp_header(struct pci_bus *bus, unsigned int devfn,
+ int where, int size)
+{
+ struct mtk_pcie_port *port = bus->sysdata;
+ int bytes;
+ u32 val;
+
+ bytes = (GENMASK(size - 1, 0) & 0xf) << (where & 0x3);
+
+ val = PCIE_CFG_FORCE_BYTE_EN | PCIE_CFG_BYTE_EN(bytes) |
+ PCIE_CFG_HEADER(bus->number, devfn);
+
+ writel_relaxed(val, port->base + PCIE_CFGNUM_REG);
+}
+
+static void __iomem *mtk_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+ int where)
+{
+ struct mtk_pcie_port *port = bus->sysdata;
+
+ return port->base + PCIE_CFG_OFFSET_ADDR + where;
+}
+
+static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ mtk_pcie_config_tlp_header(bus, devfn, where, size);
+
+ return pci_generic_config_read32(bus, devfn, where, size, val);
+}
+
+static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ mtk_pcie_config_tlp_header(bus, devfn, where, size);
+
+ if (size <= 2)
+ val <<= (where & 0x3) * 8;
+
+ return pci_generic_config_write32(bus, devfn, where, 4, val);
+}
+
+static struct pci_ops mtk_pcie_ops = {
+ .map_bus = mtk_pcie_map_bus,
+ .read = mtk_pcie_config_read,
+ .write = mtk_pcie_config_write,
+};
+
+static int mtk_pcie_set_trans_table(struct mtk_pcie_port *port,
+ resource_size_t cpu_addr,
+ resource_size_t pci_addr,
+ resource_size_t size,
+ unsigned long type, int num)
+{
+ void __iomem *table;
+ u32 val;
+
+ if (num >= PCIE_MAX_TRANS_TABLES) {
+ dev_err(port->dev, "not enough translate table for addr: %#llx, limited to [%d]\n",
+ (unsigned long long)cpu_addr, PCIE_MAX_TRANS_TABLES);
+ return -ENODEV;
+ }
+
+ table = port->base + PCIE_TRANS_TABLE_BASE_REG +
+ num * PCIE_ATR_TLB_SET_OFFSET;
+
+ writel_relaxed(lower_32_bits(cpu_addr) | PCIE_ATR_SIZE(fls(size) - 1),
+ table);
+ writel_relaxed(upper_32_bits(cpu_addr),
+ table + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
+ writel_relaxed(lower_32_bits(pci_addr),
+ table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
+ writel_relaxed(upper_32_bits(pci_addr),
+ table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);
+
+ if (type == IORESOURCE_IO)
+ val = PCIE_ATR_TYPE_IO | PCIE_ATR_TLP_TYPE_IO;
+ else
+ val = PCIE_ATR_TYPE_MEM | PCIE_ATR_TLP_TYPE_MEM;
+
+ writel_relaxed(val, table + PCIE_ATR_TRSL_PARAM_OFFSET);
+
+ 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_relaxed(port->base + PCIE_SETTING_REG);
+ val |= PCIE_RC_MODE;
+ writel_relaxed(val, port->base + PCIE_SETTING_REG);
+
+ /* Set class code */
+ val = readl_relaxed(port->base + PCIE_PCI_IDS_1);
+ val &= ~GENMASK(31, 8);
+ val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI << 8);
+ writel_relaxed(val, port->base + PCIE_PCI_IDS_1);
+
+ /* Assert all reset signals */
+ val = readl_relaxed(port->base + PCIE_RST_CTRL_REG);
+ val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
+ writel_relaxed(val, port->base + PCIE_RST_CTRL_REG);
+
+ /*
+ * Described in PCIe CEM specification setctions 2.2 (PERST# Signal)
+ * and 2.2.1 (Initial Power-Up (G3 to S0)).
+ * The deassertion of PERST# should be delayed 100ms (TPVPERL)
+ * for the power and clock to become stable.
+ */
+ msleep(100);
+
+ /* De-assert reset signals */
+ val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB);
+ writel_relaxed(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,
+ PCI_PM_D3COLD_WAIT * USEC_PER_MSEC);
+ if (err) {
+ val = readl_relaxed(port->base + PCIE_LTSSM_STATUS_REG);
+ dev_err(port->dev, "PCIe link down, ltssm reg val: %#x\n", val);
+ return err;
+ }
+
+ /* Set PCIe translation windows */
+ resource_list_for_each_entry(entry, &host->windows) {
+ struct resource *res = entry->res;
+ unsigned long type = resource_type(res);
+ resource_size_t cpu_addr;
+ resource_size_t pci_addr;
+ resource_size_t size;
+ const char *range_type;
+
+ if (type == IORESOURCE_IO) {
+ cpu_addr = pci_pio_to_address(res->start);
+ range_type = "IO";
+ } else if (type == IORESOURCE_MEM) {
+ cpu_addr = res->start;
+ range_type = "MEM";
+ } else {
+ continue;
+ }
+
+ pci_addr = res->start - entry->offset;
+ size = resource_size(res);
+ err = mtk_pcie_set_trans_table(port, cpu_addr, pci_addr, size,
+ type, table_index);
+ if (err)
+ return err;
+
+ dev_dbg(port->dev, "set %s trans window[%d]: cpu_addr = %#llx, pci_addr = %#llx, size = %#llx\n",
+ range_type, table_index, (unsigned long long)cpu_addr,
+ (unsigned long long)pci_addr, (unsigned long long)size);
+
+ table_index++;
+ }
+
+ return 0;
+}
+
+static int mtk_pcie_parse_port(struct mtk_pcie_port *port)
+{
+ struct device *dev = port->dev;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct resource *regs;
+ int ret;
+
+ regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
+ if (!regs)
+ return -EINVAL;
+ port->base = devm_ioremap_resource(dev, regs);
+ if (IS_ERR(port->base)) {
+ dev_err(dev, "failed to map register base\n");
+ return PTR_ERR(port->base);
+ }
+
+ port->reg_base = regs->start;
+
+ port->phy_reset = devm_reset_control_get_optional_exclusive(dev, "phy");
+ if (IS_ERR(port->phy_reset)) {
+ ret = PTR_ERR(port->phy_reset);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get PHY reset\n");
+
+ return ret;
+ }
+
+ port->mac_reset = devm_reset_control_get_optional_exclusive(dev, "mac");
+ if (IS_ERR(port->mac_reset)) {
+ ret = PTR_ERR(port->mac_reset);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get MAC reset\n");
+
+ return ret;
+ }
+
+ port->phy = devm_phy_optional_get(dev, "pcie-phy");
+ if (IS_ERR(port->phy)) {
+ ret = PTR_ERR(port->phy);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to get PHY\n");
+
+ return ret;
+ }
+
+ port->num_clks = devm_clk_bulk_get_all(dev, &port->clks);
+ if (port->num_clks < 0) {
+ dev_err(dev, "failed to get clocks\n");
+ return port->num_clks;
+ }
+
+ return 0;
+}
+
+static int mtk_pcie_power_up(struct mtk_pcie_port *port)
+{
+ struct device *dev = port->dev;
+ int err;
+
+ /* PHY power on and enable pipe clock */
+ reset_control_deassert(port->phy_reset);
+
+ err = phy_init(port->phy);
+ if (err) {
+ dev_err(dev, "failed to initialize PHY\n");
+ goto err_phy_init;
+ }
+
+ err = phy_power_on(port->phy);
+ if (err) {
+ dev_err(dev, "failed to power on PHY\n");
+ goto err_phy_on;
+ }
+
+ /* MAC power on and enable transaction layer clocks */
+ reset_control_deassert(port->mac_reset);
+
+ pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);
+
+ err = clk_bulk_prepare_enable(port->num_clks, port->clks);
+ if (err) {
+ dev_err(dev, "failed to enable clocks\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);
+err_phy_init:
+ 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)
+{
+ int err;
+
+ err = mtk_pcie_parse_port(port);
+ if (err)
+ return err;
+
+ /* 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)
+ goto err_setup;
+
+ 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_power_down(port);
+
+ return 0;
+}
+
+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,
+ },
+};
+
+module_platform_driver(mtk_pcie_driver);
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff