blob: 586b9d69fa5e21ffea1644bd1eefa91a877c57ca [file] [log] [blame]
// 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)
{
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,
};
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);