linux/drivers/phy/tegra/phy-tegra194-p2u.c
Vidya Sagar 5dae15b21d phy: tegra: Add PCIe PIPE2UPHY support
Synopsys DesignWare core based PCIe controllers in Tegra 194 SoC
interface with Universal PHY (UPHY) module through a PIPE2UPHY (P2U)
module. For each PCIe lane of a controller, there is a P2U unit
instantiated at hardware level. This driver provides support for the
programming required for each P2U that is going to be used for a PCIe
controller.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Thierry Reding <treding@nvidia.com>
2019-08-13 16:01:15 +01:00

121 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* P2U (PIPE to UPHY) driver for Tegra T194 SoC
*
* Copyright (C) 2019 NVIDIA Corporation.
*
* Author: Vidya Sagar <vidyas@nvidia.com>
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>
#define P2U_PERIODIC_EQ_CTRL_GEN3 0xc0
#define P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN BIT(0)
#define P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN BIT(1)
#define P2U_PERIODIC_EQ_CTRL_GEN4 0xc4
#define P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN BIT(1)
#define P2U_RX_DEBOUNCE_TIME 0xa4
#define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK 0xffff
#define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL 160
struct tegra_p2u {
void __iomem *base;
};
static inline void p2u_writel(struct tegra_p2u *phy, const u32 value,
const u32 reg)
{
writel_relaxed(value, phy->base + reg);
}
static inline u32 p2u_readl(struct tegra_p2u *phy, const u32 reg)
{
return readl_relaxed(phy->base + reg);
}
static int tegra_p2u_power_on(struct phy *x)
{
struct tegra_p2u *phy = phy_get_drvdata(x);
u32 val;
val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN3);
val &= ~P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN;
val |= P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN;
p2u_writel(phy, val, P2U_PERIODIC_EQ_CTRL_GEN3);
val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN4);
val |= P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN;
p2u_writel(phy, val, P2U_PERIODIC_EQ_CTRL_GEN4);
val = p2u_readl(phy, P2U_RX_DEBOUNCE_TIME);
val &= ~P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK;
val |= P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL;
p2u_writel(phy, val, P2U_RX_DEBOUNCE_TIME);
return 0;
}
static const struct phy_ops ops = {
.power_on = tegra_p2u_power_on,
.owner = THIS_MODULE,
};
static int tegra_p2u_probe(struct platform_device *pdev)
{
struct phy_provider *phy_provider;
struct device *dev = &pdev->dev;
struct phy *generic_phy;
struct tegra_p2u *phy;
struct resource *res;
phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
if (!phy)
return -ENOMEM;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctl");
phy->base = devm_ioremap_resource(dev, res);
if (IS_ERR(phy->base))
return PTR_ERR(phy->base);
platform_set_drvdata(pdev, phy);
generic_phy = devm_phy_create(dev, NULL, &ops);
if (IS_ERR(generic_phy))
return PTR_ERR(generic_phy);
phy_set_drvdata(generic_phy, phy);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(phy_provider))
return PTR_ERR(phy_provider);
return 0;
}
static const struct of_device_id tegra_p2u_id_table[] = {
{
.compatible = "nvidia,tegra194-p2u",
},
{}
};
MODULE_DEVICE_TABLE(of, tegra_p2u_id_table);
static struct platform_driver tegra_p2u_driver = {
.probe = tegra_p2u_probe,
.driver = {
.name = "tegra194-p2u",
.of_match_table = tegra_p2u_id_table,
},
};
module_platform_driver(tegra_p2u_driver);
MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
MODULE_DESCRIPTION("NVIDIA Tegra194 PIPE2UPHY PHY driver");
MODULE_LICENSE("GPL v2");