linux/drivers/pci/host/pcie-qcom.c
Stanimir Varbanov 82a823833f PCI: qcom: Add Qualcomm PCIe controller driver
The PCIe driver reuses the Designware common code for host and MSI
initialization, and also programs the Qualcomm application specific
registers.

[bhelgaas: remove COMPILE_TEST Kconfig dependency]
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-01-05 15:31:27 -06:00

617 lines
14 KiB
C

/*
* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
* Copyright 2015 Linaro Limited.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "pcie-designware.h"
#define PCIE20_PARF_PHY_CTRL 0x40
#define PCIE20_PARF_PHY_REFCLK 0x4C
#define PCIE20_PARF_DBI_BASE_ADDR 0x168
#define PCIE20_PARF_SLV_ADDR_SPACE_SIZE 0x16c
#define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT 0x178
#define PCIE20_ELBI_SYS_CTRL 0x04
#define PCIE20_ELBI_SYS_CTRL_LT_ENABLE BIT(0)
#define PCIE20_CAP 0x70
#define PERST_DELAY_US 1000
struct qcom_pcie_resources_v0 {
struct clk *iface_clk;
struct clk *core_clk;
struct clk *phy_clk;
struct reset_control *pci_reset;
struct reset_control *axi_reset;
struct reset_control *ahb_reset;
struct reset_control *por_reset;
struct reset_control *phy_reset;
struct regulator *vdda;
struct regulator *vdda_phy;
struct regulator *vdda_refclk;
};
struct qcom_pcie_resources_v1 {
struct clk *iface;
struct clk *aux;
struct clk *master_bus;
struct clk *slave_bus;
struct reset_control *core;
struct regulator *vdda;
};
union qcom_pcie_resources {
struct qcom_pcie_resources_v0 v0;
struct qcom_pcie_resources_v1 v1;
};
struct qcom_pcie;
struct qcom_pcie_ops {
int (*get_resources)(struct qcom_pcie *pcie);
int (*init)(struct qcom_pcie *pcie);
void (*deinit)(struct qcom_pcie *pcie);
};
struct qcom_pcie {
struct pcie_port pp;
struct device *dev;
union qcom_pcie_resources res;
void __iomem *parf;
void __iomem *dbi;
void __iomem *elbi;
struct phy *phy;
struct gpio_desc *reset;
struct qcom_pcie_ops *ops;
};
#define to_qcom_pcie(x) container_of(x, struct qcom_pcie, pp)
static void qcom_ep_reset_assert(struct qcom_pcie *pcie)
{
gpiod_set_value(pcie->reset, 1);
usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
}
static void qcom_ep_reset_deassert(struct qcom_pcie *pcie)
{
gpiod_set_value(pcie->reset, 0);
usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
}
static irqreturn_t qcom_pcie_msi_irq_handler(int irq, void *arg)
{
struct pcie_port *pp = arg;
return dw_handle_msi_irq(pp);
}
static int qcom_pcie_establish_link(struct qcom_pcie *pcie)
{
struct device *dev = pcie->dev;
unsigned int retries = 0;
u32 val;
if (dw_pcie_link_up(&pcie->pp))
return 0;
/* enable link training */
val = readl(pcie->elbi + PCIE20_ELBI_SYS_CTRL);
val |= PCIE20_ELBI_SYS_CTRL_LT_ENABLE;
writel(val, pcie->elbi + PCIE20_ELBI_SYS_CTRL);
do {
if (dw_pcie_link_up(&pcie->pp))
return 0;
usleep_range(250, 1000);
} while (retries < 200);
dev_warn(dev, "phy link never came up\n");
return -ETIMEDOUT;
}
static int qcom_pcie_get_resources_v0(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v0 *res = &pcie->res.v0;
struct device *dev = pcie->dev;
res->vdda = devm_regulator_get(dev, "vdda");
if (IS_ERR(res->vdda))
return PTR_ERR(res->vdda);
res->vdda_phy = devm_regulator_get(dev, "vdda_phy");
if (IS_ERR(res->vdda_phy))
return PTR_ERR(res->vdda_phy);
res->vdda_refclk = devm_regulator_get(dev, "vdda_refclk");
if (IS_ERR(res->vdda_refclk))
return PTR_ERR(res->vdda_refclk);
res->iface_clk = devm_clk_get(dev, "iface");
if (IS_ERR(res->iface_clk))
return PTR_ERR(res->iface_clk);
res->core_clk = devm_clk_get(dev, "core");
if (IS_ERR(res->core_clk))
return PTR_ERR(res->core_clk);
res->phy_clk = devm_clk_get(dev, "phy");
if (IS_ERR(res->phy_clk))
return PTR_ERR(res->phy_clk);
res->pci_reset = devm_reset_control_get(dev, "pci");
if (IS_ERR(res->pci_reset))
return PTR_ERR(res->pci_reset);
res->axi_reset = devm_reset_control_get(dev, "axi");
if (IS_ERR(res->axi_reset))
return PTR_ERR(res->axi_reset);
res->ahb_reset = devm_reset_control_get(dev, "ahb");
if (IS_ERR(res->ahb_reset))
return PTR_ERR(res->ahb_reset);
res->por_reset = devm_reset_control_get(dev, "por");
if (IS_ERR(res->por_reset))
return PTR_ERR(res->por_reset);
res->phy_reset = devm_reset_control_get(dev, "phy");
if (IS_ERR(res->phy_reset))
return PTR_ERR(res->phy_reset);
return 0;
}
static int qcom_pcie_get_resources_v1(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v1 *res = &pcie->res.v1;
struct device *dev = pcie->dev;
res->vdda = devm_regulator_get(dev, "vdda");
if (IS_ERR(res->vdda))
return PTR_ERR(res->vdda);
res->iface = devm_clk_get(dev, "iface");
if (IS_ERR(res->iface))
return PTR_ERR(res->iface);
res->aux = devm_clk_get(dev, "aux");
if (IS_ERR(res->aux))
return PTR_ERR(res->aux);
res->master_bus = devm_clk_get(dev, "master_bus");
if (IS_ERR(res->master_bus))
return PTR_ERR(res->master_bus);
res->slave_bus = devm_clk_get(dev, "slave_bus");
if (IS_ERR(res->slave_bus))
return PTR_ERR(res->slave_bus);
res->core = devm_reset_control_get(dev, "core");
if (IS_ERR(res->core))
return PTR_ERR(res->core);
return 0;
}
static void qcom_pcie_deinit_v0(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v0 *res = &pcie->res.v0;
reset_control_assert(res->pci_reset);
reset_control_assert(res->axi_reset);
reset_control_assert(res->ahb_reset);
reset_control_assert(res->por_reset);
reset_control_assert(res->pci_reset);
clk_disable_unprepare(res->iface_clk);
clk_disable_unprepare(res->core_clk);
clk_disable_unprepare(res->phy_clk);
regulator_disable(res->vdda);
regulator_disable(res->vdda_phy);
regulator_disable(res->vdda_refclk);
}
static int qcom_pcie_init_v0(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v0 *res = &pcie->res.v0;
struct device *dev = pcie->dev;
u32 val;
int ret;
ret = regulator_enable(res->vdda);
if (ret) {
dev_err(dev, "cannot enable vdda regulator\n");
return ret;
}
ret = regulator_enable(res->vdda_refclk);
if (ret) {
dev_err(dev, "cannot enable vdda_refclk regulator\n");
goto err_refclk;
}
ret = regulator_enable(res->vdda_phy);
if (ret) {
dev_err(dev, "cannot enable vdda_phy regulator\n");
goto err_vdda_phy;
}
ret = reset_control_assert(res->ahb_reset);
if (ret) {
dev_err(dev, "cannot assert ahb reset\n");
goto err_assert_ahb;
}
ret = clk_prepare_enable(res->iface_clk);
if (ret) {
dev_err(dev, "cannot prepare/enable iface clock\n");
goto err_assert_ahb;
}
ret = clk_prepare_enable(res->phy_clk);
if (ret) {
dev_err(dev, "cannot prepare/enable phy clock\n");
goto err_clk_phy;
}
ret = clk_prepare_enable(res->core_clk);
if (ret) {
dev_err(dev, "cannot prepare/enable core clock\n");
goto err_clk_core;
}
ret = reset_control_deassert(res->ahb_reset);
if (ret) {
dev_err(dev, "cannot deassert ahb reset\n");
goto err_deassert_ahb;
}
/* enable PCIe clocks and resets */
val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
val &= ~BIT(0);
writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
/* enable external reference clock */
val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK);
val |= BIT(16);
writel(val, pcie->parf + PCIE20_PARF_PHY_REFCLK);
ret = reset_control_deassert(res->phy_reset);
if (ret) {
dev_err(dev, "cannot deassert phy reset\n");
return ret;
}
ret = reset_control_deassert(res->pci_reset);
if (ret) {
dev_err(dev, "cannot deassert pci reset\n");
return ret;
}
ret = reset_control_deassert(res->por_reset);
if (ret) {
dev_err(dev, "cannot deassert por reset\n");
return ret;
}
ret = reset_control_deassert(res->axi_reset);
if (ret) {
dev_err(dev, "cannot deassert axi reset\n");
return ret;
}
/* wait for clock acquisition */
usleep_range(1000, 1500);
return 0;
err_deassert_ahb:
clk_disable_unprepare(res->core_clk);
err_clk_core:
clk_disable_unprepare(res->phy_clk);
err_clk_phy:
clk_disable_unprepare(res->iface_clk);
err_assert_ahb:
regulator_disable(res->vdda_phy);
err_vdda_phy:
regulator_disable(res->vdda_refclk);
err_refclk:
regulator_disable(res->vdda);
return ret;
}
static void qcom_pcie_deinit_v1(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v1 *res = &pcie->res.v1;
reset_control_assert(res->core);
clk_disable_unprepare(res->slave_bus);
clk_disable_unprepare(res->master_bus);
clk_disable_unprepare(res->iface);
clk_disable_unprepare(res->aux);
regulator_disable(res->vdda);
}
static int qcom_pcie_init_v1(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_v1 *res = &pcie->res.v1;
struct device *dev = pcie->dev;
int ret;
ret = reset_control_deassert(res->core);
if (ret) {
dev_err(dev, "cannot deassert core reset\n");
return ret;
}
ret = clk_prepare_enable(res->aux);
if (ret) {
dev_err(dev, "cannot prepare/enable aux clock\n");
goto err_res;
}
ret = clk_prepare_enable(res->iface);
if (ret) {
dev_err(dev, "cannot prepare/enable iface clock\n");
goto err_aux;
}
ret = clk_prepare_enable(res->master_bus);
if (ret) {
dev_err(dev, "cannot prepare/enable master_bus clock\n");
goto err_iface;
}
ret = clk_prepare_enable(res->slave_bus);
if (ret) {
dev_err(dev, "cannot prepare/enable slave_bus clock\n");
goto err_master;
}
ret = regulator_enable(res->vdda);
if (ret) {
dev_err(dev, "cannot enable vdda regulator\n");
goto err_slave;
}
/* change DBI base address */
writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
if (IS_ENABLED(CONFIG_PCI_MSI)) {
u32 val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
val |= BIT(31);
writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
}
return 0;
err_slave:
clk_disable_unprepare(res->slave_bus);
err_master:
clk_disable_unprepare(res->master_bus);
err_iface:
clk_disable_unprepare(res->iface);
err_aux:
clk_disable_unprepare(res->aux);
err_res:
reset_control_assert(res->core);
return ret;
}
static int qcom_pcie_link_up(struct pcie_port *pp)
{
struct qcom_pcie *pcie = to_qcom_pcie(pp);
u16 val = readw(pcie->dbi + PCIE20_CAP + PCI_EXP_LNKSTA);
return !!(val & PCI_EXP_LNKSTA_DLLLA);
}
static void qcom_pcie_host_init(struct pcie_port *pp)
{
struct qcom_pcie *pcie = to_qcom_pcie(pp);
int ret;
qcom_ep_reset_assert(pcie);
ret = pcie->ops->init(pcie);
if (ret)
goto err_deinit;
ret = phy_power_on(pcie->phy);
if (ret)
goto err_deinit;
dw_pcie_setup_rc(pp);
if (IS_ENABLED(CONFIG_PCI_MSI))
dw_pcie_msi_init(pp);
qcom_ep_reset_deassert(pcie);
ret = qcom_pcie_establish_link(pcie);
if (ret)
goto err;
return;
err:
qcom_ep_reset_assert(pcie);
phy_power_off(pcie->phy);
err_deinit:
pcie->ops->deinit(pcie);
}
static int qcom_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
u32 *val)
{
/* the device class is not reported correctly from the register */
if (where == PCI_CLASS_REVISION && size == 4) {
*val = readl(pp->dbi_base + PCI_CLASS_REVISION);
*val &= 0xff; /* keep revision id */
*val |= PCI_CLASS_BRIDGE_PCI << 16;
return PCIBIOS_SUCCESSFUL;
}
return dw_pcie_cfg_read(pp->dbi_base + where, size, val);
}
static struct pcie_host_ops qcom_pcie_dw_ops = {
.link_up = qcom_pcie_link_up,
.host_init = qcom_pcie_host_init,
.rd_own_conf = qcom_pcie_rd_own_conf,
};
static const struct qcom_pcie_ops ops_v0 = {
.get_resources = qcom_pcie_get_resources_v0,
.init = qcom_pcie_init_v0,
.deinit = qcom_pcie_deinit_v0,
};
static const struct qcom_pcie_ops ops_v1 = {
.get_resources = qcom_pcie_get_resources_v1,
.init = qcom_pcie_init_v1,
.deinit = qcom_pcie_deinit_v1,
};
static int qcom_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct qcom_pcie *pcie;
struct pcie_port *pp;
int ret;
pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
if (!pcie)
return -ENOMEM;
pcie->ops = (struct qcom_pcie_ops *)of_device_get_match_data(dev);
pcie->dev = dev;
pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_LOW);
if (IS_ERR(pcie->reset))
return PTR_ERR(pcie->reset);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf");
pcie->parf = devm_ioremap_resource(dev, res);
if (IS_ERR(pcie->parf))
return PTR_ERR(pcie->parf);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
pcie->dbi = devm_ioremap_resource(dev, res);
if (IS_ERR(pcie->dbi))
return PTR_ERR(pcie->dbi);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
pcie->elbi = devm_ioremap_resource(dev, res);
if (IS_ERR(pcie->elbi))
return PTR_ERR(pcie->elbi);
pcie->phy = devm_phy_optional_get(dev, "pciephy");
if (IS_ERR(pcie->phy))
return PTR_ERR(pcie->phy);
ret = pcie->ops->get_resources(pcie);
if (ret)
return ret;
pp = &pcie->pp;
pp->dev = dev;
pp->dbi_base = pcie->dbi;
pp->root_bus_nr = -1;
pp->ops = &qcom_pcie_dw_ops;
if (IS_ENABLED(CONFIG_PCI_MSI)) {
pp->msi_irq = platform_get_irq_byname(pdev, "msi");
if (pp->msi_irq < 0)
return pp->msi_irq;
ret = devm_request_irq(dev, pp->msi_irq,
qcom_pcie_msi_irq_handler,
IRQF_SHARED, "qcom-pcie-msi", pp);
if (ret) {
dev_err(dev, "cannot request msi irq\n");
return ret;
}
}
ret = phy_init(pcie->phy);
if (ret)
return ret;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "cannot initialize host\n");
return ret;
}
platform_set_drvdata(pdev, pcie);
return 0;
}
static int qcom_pcie_remove(struct platform_device *pdev)
{
struct qcom_pcie *pcie = platform_get_drvdata(pdev);
qcom_ep_reset_assert(pcie);
phy_power_off(pcie->phy);
phy_exit(pcie->phy);
pcie->ops->deinit(pcie);
return 0;
}
static const struct of_device_id qcom_pcie_match[] = {
{ .compatible = "qcom,pcie-ipq8064", .data = &ops_v0 },
{ .compatible = "qcom,pcie-apq8064", .data = &ops_v0 },
{ .compatible = "qcom,pcie-apq8084", .data = &ops_v1 },
{ }
};
MODULE_DEVICE_TABLE(of, qcom_pcie_match);
static struct platform_driver qcom_pcie_driver = {
.probe = qcom_pcie_probe,
.remove = qcom_pcie_remove,
.driver = {
.name = "qcom-pcie",
.of_match_table = qcom_pcie_match,
},
};
module_platform_driver(qcom_pcie_driver);
MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
MODULE_DESCRIPTION("Qualcomm PCIe root complex driver");
MODULE_LICENSE("GPL v2");