WSL2-Linux-Kernel/drivers/phy/socionext/phy-uniphier-pcie.c

241 строка
6.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* phy-uniphier-pcie.c - PHY driver for UniPhier PCIe controller
* Copyright 2018, Socionext Inc.
* Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
*/
#include <linux/bitops.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/iopoll.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/resource.h>
/* PHY */
#define PCL_PHY_TEST_I 0x2000
#define PCL_PHY_TEST_O 0x2004
#define TESTI_DAT_MASK GENMASK(13, 6)
#define TESTI_ADR_MASK GENMASK(5, 1)
#define TESTI_WR_EN BIT(0)
#define PCL_PHY_RESET 0x200c
#define PCL_PHY_RESET_N_MNMODE BIT(8) /* =1:manual */
#define PCL_PHY_RESET_N BIT(0) /* =1:deasssert */
/* SG */
#define SG_USBPCIESEL 0x590
#define SG_USBPCIESEL_PCIE BIT(0)
#define PCL_PHY_R00 0
#define RX_EQ_ADJ_EN BIT(3) /* enable for EQ adjustment */
#define PCL_PHY_R06 6
#define RX_EQ_ADJ GENMASK(5, 0) /* EQ adjustment value */
#define RX_EQ_ADJ_VAL 0
#define PCL_PHY_R26 26
#define VCO_CTRL GENMASK(7, 4) /* Tx VCO adjustment value */
#define VCO_CTRL_INIT_VAL 5
struct uniphier_pciephy_priv {
void __iomem *base;
struct device *dev;
struct clk *clk;
struct reset_control *rst;
const struct uniphier_pciephy_soc_data *data;
};
struct uniphier_pciephy_soc_data {
bool has_syscon;
};
static void uniphier_pciephy_testio_write(struct uniphier_pciephy_priv *priv,
u32 data)
{
/* need to read TESTO twice after accessing TESTI */
writel(data, priv->base + PCL_PHY_TEST_I);
readl(priv->base + PCL_PHY_TEST_O);
readl(priv->base + PCL_PHY_TEST_O);
}
static void uniphier_pciephy_set_param(struct uniphier_pciephy_priv *priv,
u32 reg, u32 mask, u32 param)
{
u32 val;
/* read previous data */
val = FIELD_PREP(TESTI_DAT_MASK, 1);
val |= FIELD_PREP(TESTI_ADR_MASK, reg);
uniphier_pciephy_testio_write(priv, val);
val = readl(priv->base + PCL_PHY_TEST_O);
/* update value */
val &= ~FIELD_PREP(TESTI_DAT_MASK, mask);
val = FIELD_PREP(TESTI_DAT_MASK, mask & param);
val |= FIELD_PREP(TESTI_ADR_MASK, reg);
uniphier_pciephy_testio_write(priv, val);
uniphier_pciephy_testio_write(priv, val | TESTI_WR_EN);
uniphier_pciephy_testio_write(priv, val);
/* read current data as dummy */
val = FIELD_PREP(TESTI_DAT_MASK, 1);
val |= FIELD_PREP(TESTI_ADR_MASK, reg);
uniphier_pciephy_testio_write(priv, val);
readl(priv->base + PCL_PHY_TEST_O);
}
static void uniphier_pciephy_assert(struct uniphier_pciephy_priv *priv)
{
u32 val;
val = readl(priv->base + PCL_PHY_RESET);
val &= ~PCL_PHY_RESET_N;
val |= PCL_PHY_RESET_N_MNMODE;
writel(val, priv->base + PCL_PHY_RESET);
}
static void uniphier_pciephy_deassert(struct uniphier_pciephy_priv *priv)
{
u32 val;
val = readl(priv->base + PCL_PHY_RESET);
val |= PCL_PHY_RESET_N_MNMODE | PCL_PHY_RESET_N;
writel(val, priv->base + PCL_PHY_RESET);
}
static int uniphier_pciephy_init(struct phy *phy)
{
struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy);
int ret;
ret = clk_prepare_enable(priv->clk);
if (ret)
return ret;
ret = reset_control_deassert(priv->rst);
if (ret)
goto out_clk_disable;
uniphier_pciephy_set_param(priv, PCL_PHY_R00,
RX_EQ_ADJ_EN, RX_EQ_ADJ_EN);
uniphier_pciephy_set_param(priv, PCL_PHY_R06, RX_EQ_ADJ,
FIELD_PREP(RX_EQ_ADJ, RX_EQ_ADJ_VAL));
uniphier_pciephy_set_param(priv, PCL_PHY_R26, VCO_CTRL,
FIELD_PREP(VCO_CTRL, VCO_CTRL_INIT_VAL));
usleep_range(1, 10);
uniphier_pciephy_deassert(priv);
usleep_range(1, 10);
return 0;
out_clk_disable:
clk_disable_unprepare(priv->clk);
return ret;
}
static int uniphier_pciephy_exit(struct phy *phy)
{
struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy);
uniphier_pciephy_assert(priv);
reset_control_assert(priv->rst);
clk_disable_unprepare(priv->clk);
return 0;
}
static const struct phy_ops uniphier_pciephy_ops = {
.init = uniphier_pciephy_init,
.exit = uniphier_pciephy_exit,
.owner = THIS_MODULE,
};
static int uniphier_pciephy_probe(struct platform_device *pdev)
{
struct uniphier_pciephy_priv *priv;
struct phy_provider *phy_provider;
struct device *dev = &pdev->dev;
struct regmap *regmap;
struct resource *res;
struct phy *phy;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->data = of_device_get_match_data(dev);
if (WARN_ON(!priv->data))
return -EINVAL;
priv->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->clk = devm_clk_get(dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
priv->rst = devm_reset_control_get_shared(dev, NULL);
if (IS_ERR(priv->rst))
return PTR_ERR(priv->rst);
phy = devm_phy_create(dev, dev->of_node, &uniphier_pciephy_ops);
if (IS_ERR(phy))
return PTR_ERR(phy);
regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
"socionext,syscon");
if (!IS_ERR(regmap) && priv->data->has_syscon)
regmap_update_bits(regmap, SG_USBPCIESEL,
SG_USBPCIESEL_PCIE, SG_USBPCIESEL_PCIE);
phy_set_drvdata(phy, priv);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
return PTR_ERR_OR_ZERO(phy_provider);
}
static const struct uniphier_pciephy_soc_data uniphier_ld20_data = {
.has_syscon = true,
};
static const struct uniphier_pciephy_soc_data uniphier_pxs3_data = {
.has_syscon = false,
};
static const struct of_device_id uniphier_pciephy_match[] = {
{
.compatible = "socionext,uniphier-ld20-pcie-phy",
.data = &uniphier_ld20_data,
},
{
.compatible = "socionext,uniphier-pxs3-pcie-phy",
.data = &uniphier_pxs3_data,
},
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, uniphier_pciephy_match);
static struct platform_driver uniphier_pciephy_driver = {
.probe = uniphier_pciephy_probe,
.driver = {
.name = "uniphier-pcie-phy",
.of_match_table = uniphier_pciephy_match,
},
};
module_platform_driver(uniphier_pciephy_driver);
MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
MODULE_DESCRIPTION("UniPhier PHY driver for PCIe controller");
MODULE_LICENSE("GPL v2");