--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * pci-j721e - PCIe controller driver for TI's J721E SoCs
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/io.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include "../../pci.h"
+#include "pcie-cadence.h"
+
+#define ENABLE_REG_SYS_2 0x108
+#define STATUS_REG_SYS_2 0x508
+#define STATUS_CLR_REG_SYS_2 0x708
+#define LINK_DOWN BIT(1)
+
+#define J721E_PCIE_USER_CMD_STATUS 0x4
+#define LINK_TRAINING_ENABLE BIT(0)
+
+#define J721E_PCIE_USER_LINKSTATUS 0x14
+#define LINK_STATUS GENMASK(1, 0)
+
+enum link_status {
+ NO_RECEIVERS_DETECTED,
+ LINK_TRAINING_IN_PROGRESS,
+ LINK_UP_DL_IN_PROGRESS,
+ LINK_UP_DL_COMPLETED,
+};
+
+#define J721E_MODE_RC BIT(7)
+#define LANE_COUNT_MASK BIT(8)
+#define LANE_COUNT(n) ((n) << 8)
+
+#define GENERATION_SEL_MASK GENMASK(1, 0)
+
+#define MAX_LANES 2
+
+struct j721e_pcie {
+ struct device *dev;
+ u32 mode;
+ u32 num_lanes;
+ struct cdns_pcie *cdns_pcie;
+ void __iomem *user_cfg_base;
+ void __iomem *intd_cfg_base;
+};
+
+enum j721e_pcie_mode {
+ PCI_MODE_RC,
+ PCI_MODE_EP,
+};
+
+struct j721e_pcie_data {
+ enum j721e_pcie_mode mode;
+};
+
+static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
+{
+ return readl(pcie->user_cfg_base + offset);
+}
+
+static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
+ u32 value)
+{
+ writel(value, pcie->user_cfg_base + offset);
+}
+
+static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
+{
+ return readl(pcie->intd_cfg_base + offset);
+}
+
+static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
+ u32 value)
+{
+ writel(value, pcie->intd_cfg_base + offset);
+}
+
+static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
+{
+ struct j721e_pcie *pcie = priv;
+ struct device *dev = pcie->dev;
+ u32 reg;
+
+ reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
+ if (!(reg & LINK_DOWN))
+ return IRQ_NONE;
+
+ dev_err(dev, "LINK DOWN!\n");
+
+ j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, LINK_DOWN);
+ return IRQ_HANDLED;
+}
+
+static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
+{
+ u32 reg;
+
+ reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
+ reg |= LINK_DOWN;
+ j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
+}
+
+static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
+{
+ struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
+ u32 reg;
+
+ reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
+ reg |= LINK_TRAINING_ENABLE;
+ j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
+
+ return 0;
+}
+
+static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
+{
+ struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
+ u32 reg;
+
+ reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
+ reg &= ~LINK_TRAINING_ENABLE;
+ j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
+}
+
+static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
+{
+ struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
+ u32 reg;
+
+ reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
+ reg &= LINK_STATUS;
+ if (reg == LINK_UP_DL_COMPLETED)
+ return true;
+
+ return false;
+}
+
+static const struct cdns_pcie_ops j721e_pcie_ops = {
+ .start_link = j721e_pcie_start_link,
+ .stop_link = j721e_pcie_stop_link,
+ .link_up = j721e_pcie_link_up,
+};
+
+static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon)
+{
+ struct device *dev = pcie->dev;
+ u32 mask = J721E_MODE_RC;
+ u32 mode = pcie->mode;
+ u32 val = 0;
+ int ret = 0;
+
+ if (mode == PCI_MODE_RC)
+ val = J721E_MODE_RC;
+
+ ret = regmap_update_bits(syscon, 0, mask, val);
+ if (ret)
+ dev_err(dev, "failed to set pcie mode\n");
+
+ return ret;
+}
+
+static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
+ struct regmap *syscon)
+{
+ struct device *dev = pcie->dev;
+ struct device_node *np = dev->of_node;
+ int link_speed;
+ u32 val = 0;
+ int ret;
+
+ link_speed = of_pci_get_max_link_speed(np);
+ if (link_speed < 2)
+ link_speed = 2;
+
+ val = link_speed - 1;
+ ret = regmap_update_bits(syscon, 0, GENERATION_SEL_MASK, val);
+ if (ret)
+ dev_err(dev, "failed to set link speed\n");
+
+ return ret;
+}
+
+static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
+ struct regmap *syscon)
+{
+ struct device *dev = pcie->dev;
+ u32 lanes = pcie->num_lanes;
+ u32 val = 0;
+ int ret;
+
+ val = LANE_COUNT(lanes - 1);
+ ret = regmap_update_bits(syscon, 0, LANE_COUNT_MASK, val);
+ if (ret)
+ dev_err(dev, "failed to set link count\n");
+
+ return ret;
+}
+
+static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
+{
+ struct device *dev = pcie->dev;
+ struct device_node *node = dev->of_node;
+ struct regmap *syscon;
+ int ret;
+
+ syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
+ if (IS_ERR(syscon)) {
+ dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
+ return PTR_ERR(syscon);
+ }
+
+ ret = j721e_pcie_set_mode(pcie, syscon);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set pci mode\n");
+ return ret;
+ }
+
+ ret = j721e_pcie_set_link_speed(pcie, syscon);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set link speed\n");
+ return ret;
+ }
+
+ ret = j721e_pcie_set_lane_count(pcie, syscon);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set num-lanes\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *value)
+{
+ struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
+ struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
+ unsigned int busn = bus->number;
+
+ if (busn == rc->bus_range->start)
+ return pci_generic_config_read32(bus, devfn, where, size,
+ value);
+
+ return pci_generic_config_read(bus, devfn, where, size, value);
+}
+
+static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 value)
+{
+ struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
+ struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
+ unsigned int busn = bus->number;
+
+ if (busn == rc->bus_range->start)
+ return pci_generic_config_write32(bus, devfn, where, size,
+ value);
+
+ return pci_generic_config_write(bus, devfn, where, size, value);
+}
+
+static struct pci_ops cdns_ti_pcie_host_ops = {
+ .map_bus = cdns_pci_map_bus,
+ .read = cdns_ti_pcie_config_read,
+ .write = cdns_ti_pcie_config_write,
+};
+
+static const struct j721e_pcie_data j721e_pcie_rc_data = {
+ .mode = PCI_MODE_RC,
+};
+
+static const struct j721e_pcie_data j721e_pcie_ep_data = {
+ .mode = PCI_MODE_EP,
+};
+
+static const struct of_device_id of_j721e_pcie_match[] = {
+ {
+ .compatible = "ti,j721e-pcie-host",
+ .data = &j721e_pcie_rc_data,
+ },
+ {
+ .compatible = "ti,j721e-pcie-ep",
+ .data = &j721e_pcie_ep_data,
+ },
+ {},
+};
+
+static int j721e_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct pci_host_bridge *bridge;
+ struct j721e_pcie_data *data;
+ struct cdns_pcie *cdns_pcie;
+ struct j721e_pcie *pcie;
+ struct cdns_pcie_rc *rc;
+ struct cdns_pcie_ep *ep;
+ struct gpio_desc *gpiod;
+ void __iomem *base;
+ u32 num_lanes;
+ u32 mode;
+ int ret;
+ int irq;
+
+ data = (struct j721e_pcie_data *)of_device_get_match_data(dev);
+ if (!data)
+ return -EINVAL;
+
+ mode = (u32)data->mode;
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ pcie->dev = dev;
+ pcie->mode = mode;
+
+ base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+ pcie->intd_cfg_base = base;
+
+ base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+ pcie->user_cfg_base = base;
+
+ ret = of_property_read_u32(node, "num-lanes", &num_lanes);
+ if (ret || num_lanes > MAX_LANES)
+ num_lanes = 1;
+ pcie->num_lanes = num_lanes;
+
+ if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
+ return -EINVAL;
+
+ irq = platform_get_irq_byname(pdev, "link_state");
+ if (irq < 0)
+ return irq;
+
+ dev_set_drvdata(dev, pcie);
+ pm_runtime_enable(dev);
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ dev_err(dev, "pm_runtime_get_sync failed\n");
+ goto err_get_sync;
+ }
+
+ ret = j721e_pcie_ctrl_init(pcie);
+ if (ret < 0) {
+ dev_err(dev, "pm_runtime_get_sync failed\n");
+ goto err_get_sync;
+ }
+
+ ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
+ "j721e-pcie-link-down-irq", pcie);
+ if (ret < 0) {
+ dev_err(dev, "failed to request link state IRQ %d\n", irq);
+ goto err_get_sync;
+ }
+
+ j721e_pcie_config_link_irq(pcie);
+
+ switch (mode) {
+ case PCI_MODE_RC:
+ if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) {
+ ret = -ENODEV;
+ goto err_get_sync;
+ }
+
+ bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
+ if (!bridge) {
+ ret = -ENOMEM;
+ goto err_get_sync;
+ }
+
+ bridge->ops = &cdns_ti_pcie_host_ops;
+ rc = pci_host_bridge_priv(bridge);
+
+ cdns_pcie = &rc->pcie;
+ cdns_pcie->dev = dev;
+ cdns_pcie->ops = &j721e_pcie_ops;
+ pcie->cdns_pcie = cdns_pcie;
+
+ gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(gpiod)) {
+ ret = PTR_ERR(gpiod);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get reset GPIO\n");
+ goto err_get_sync;
+ }
+
+ ret = cdns_pcie_init_phy(dev, cdns_pcie);
+ if (ret) {
+ dev_err(dev, "Failed to init phy\n");
+ goto err_get_sync;
+ }
+
+ /*
+ * "Power Sequencing and Reset Signal Timings" table in
+ * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
+ * indicates PERST# should be deasserted after minimum of 100us
+ * once REFCLK is stable. The REFCLK to the connector in RC
+ * mode is selected while enabling the PHY. So deassert PERST#
+ * after 100 us.
+ */
+ if (gpiod) {
+ usleep_range(100, 200);
+ gpiod_set_value_cansleep(gpiod, 1);
+ }
+
+ ret = cdns_pcie_host_setup(rc);
+ if (ret < 0)
+ goto err_pcie_setup;
+
+ break;
+ case PCI_MODE_EP:
+ if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) {
+ ret = -ENODEV;
+ goto err_get_sync;
+ }
+
+ ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
+ if (!ep) {
+ ret = -ENOMEM;
+ goto err_get_sync;
+ }
+
+ cdns_pcie = &ep->pcie;
+ cdns_pcie->dev = dev;
+ cdns_pcie->ops = &j721e_pcie_ops;
+ pcie->cdns_pcie = cdns_pcie;
+
+ ret = cdns_pcie_init_phy(dev, cdns_pcie);
+ if (ret) {
+ dev_err(dev, "Failed to init phy\n");
+ goto err_get_sync;
+ }
+
+ ret = cdns_pcie_ep_setup(ep);
+ if (ret < 0)
+ goto err_pcie_setup;
+
+ break;
+ default:
+ dev_err(dev, "INVALID device type %d\n", mode);
+ }
+
+ return 0;
+
+err_pcie_setup:
+ cdns_pcie_disable_phy(cdns_pcie);
+
+err_get_sync:
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
+ return ret;
+}
+
+static int j721e_pcie_remove(struct platform_device *pdev)
+{
+ struct j721e_pcie *pcie = platform_get_drvdata(pdev);
+ struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
+ struct device *dev = &pdev->dev;
+
+ cdns_pcie_disable_phy(cdns_pcie);
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
+ return 0;
+}
+
+static struct platform_driver j721e_pcie_driver = {
+ .probe = j721e_pcie_probe,
+ .remove = j721e_pcie_remove,
+ .driver = {
+ .name = "j721e-pcie",
+ .of_match_table = of_j721e_pcie_match,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(j721e_pcie_driver);
projects / platform / kernel / linux-starfive.git / commitdiff