diff options
Diffstat (limited to 'drivers/pci/controller/cadence/pci-j721e.c')
| -rw-r--r-- | drivers/pci/controller/cadence/pci-j721e.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c new file mode 100644 index 000000000..8a6d68e13 --- /dev/null +++ b/drivers/pci/controller/cadence/pci-j721e.c @@ -0,0 +1,539 @@ +// 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 J7200_LINK_DOWN BIT(10) + +#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; + u32 linkdown_irq_regfield; +}; + +enum j721e_pcie_mode { + PCI_MODE_RC, + PCI_MODE_EP, +}; + +struct j721e_pcie_data { + enum j721e_pcie_mode mode; + unsigned int quirk_retrain_flag:1; + unsigned int quirk_detect_quiet_flag:1; + u32 linkdown_irq_regfield; + unsigned int byte_access_allowed:1; +}; + +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 & pcie->linkdown_irq_regfield)) + return IRQ_NONE; + + dev_err(dev, "LINK DOWN!\n"); + + j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield); + 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 |= pcie->linkdown_irq_regfield; + 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) +{ + if (pci_is_root_bus(bus)) + 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) +{ + if (pci_is_root_bus(bus)) + 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, + .quirk_retrain_flag = true, + .byte_access_allowed = false, + .linkdown_irq_regfield = LINK_DOWN, +}; + +static const struct j721e_pcie_data j721e_pcie_ep_data = { + .mode = PCI_MODE_EP, + .linkdown_irq_regfield = LINK_DOWN, +}; + +static const struct j721e_pcie_data j7200_pcie_rc_data = { + .mode = PCI_MODE_RC, + .quirk_detect_quiet_flag = true, + .linkdown_irq_regfield = J7200_LINK_DOWN, + .byte_access_allowed = true, +}; + +static const struct j721e_pcie_data j7200_pcie_ep_data = { + .mode = PCI_MODE_EP, + .quirk_detect_quiet_flag = true, +}; + +static const struct j721e_pcie_data am64_pcie_rc_data = { + .mode = PCI_MODE_RC, + .linkdown_irq_regfield = J7200_LINK_DOWN, + .byte_access_allowed = true, +}; + +static const struct j721e_pcie_data am64_pcie_ep_data = { + .mode = PCI_MODE_EP, + .linkdown_irq_regfield = J7200_LINK_DOWN, +}; + +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, + }, + { + .compatible = "ti,j7200-pcie-host", + .data = &j7200_pcie_rc_data, + }, + { + .compatible = "ti,j7200-pcie-ep", + .data = &j7200_pcie_ep_data, + }, + { + .compatible = "ti,am64-pcie-host", + .data = &am64_pcie_rc_data, + }, + { + .compatible = "ti,am64-pcie-ep", + .data = &am64_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; + pcie->linkdown_irq_regfield = data->linkdown_irq_regfield; + + 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; + } + + if (!data->byte_access_allowed) + bridge->ops = &cdns_ti_pcie_host_ops; + rc = pci_host_bridge_priv(bridge); + rc->quirk_retrain_flag = data->quirk_retrain_flag; + rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; + + 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; + } + ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; + + 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); |