1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Amlogic AXG PCIE PHY driver
  4 *
  5 * Copyright (C) 2020 Remi Pommarel <repk@triplefau.lt>
  6 */
  7#include <linux/mod_devicetable.h>
  8#include <linux/module.h>
  9#include <linux/phy/phy.h>
 10#include <linux/regmap.h>
 11#include <linux/reset.h>
 12#include <linux/platform_device.h>
 13#include <linux/bitfield.h>
 14#include <dt-bindings/phy/phy.h>
 15
 16#define MESON_PCIE_REG0 0x00
 17#define		MESON_PCIE_COMMON_CLK	BIT(4)
 18#define		MESON_PCIE_PORT_SEL	GENMASK(3, 2)
 19#define		MESON_PCIE_CLK		BIT(1)
 20#define		MESON_PCIE_POWERDOWN	BIT(0)
 21
 22#define MESON_PCIE_TWO_X1		FIELD_PREP(MESON_PCIE_PORT_SEL, 0x3)
 23#define MESON_PCIE_COMMON_REF_CLK	FIELD_PREP(MESON_PCIE_COMMON_CLK, 0x1)
 24#define MESON_PCIE_PHY_INIT		(MESON_PCIE_TWO_X1 |		\
 25					 MESON_PCIE_COMMON_REF_CLK)
 26#define MESON_PCIE_RESET_DELAY		500
 27
 28struct phy_axg_pcie_priv {
 29	struct phy *phy;
 30	struct phy *analog;
 31	struct regmap *regmap;
 32	struct reset_control *reset;
 33};
 34
 35static const struct regmap_config phy_axg_pcie_regmap_conf = {
 36	.reg_bits = 8,
 37	.val_bits = 32,
 38	.reg_stride = 4,
 39	.max_register = MESON_PCIE_REG0,
 40};
 41
 42static int phy_axg_pcie_power_on(struct phy *phy)
 43{
 44	struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
 45	int ret;
 46
 47	ret = phy_power_on(priv->analog);
 48	if (ret != 0)
 49		return ret;
 50
 51	regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
 52			   MESON_PCIE_POWERDOWN, 0);
 53	return 0;
 54}
 55
 56static int phy_axg_pcie_power_off(struct phy *phy)
 57{
 58	struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
 59	int ret;
 60
 61	ret = phy_power_off(priv->analog);
 62	if (ret != 0)
 63		return ret;
 64
 65	regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
 66			   MESON_PCIE_POWERDOWN, 1);
 67	return 0;
 68}
 69
 70static int phy_axg_pcie_init(struct phy *phy)
 71{
 72	struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
 73	int ret;
 74
 75	ret = phy_init(priv->analog);
 76	if (ret != 0)
 77		return ret;
 78
 79	regmap_write(priv->regmap, MESON_PCIE_REG0, MESON_PCIE_PHY_INIT);
 80	return reset_control_reset(priv->reset);
 81}
 82
 83static int phy_axg_pcie_exit(struct phy *phy)
 84{
 85	struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
 86	int ret;
 87
 88	ret = phy_exit(priv->analog);
 89	if (ret != 0)
 90		return ret;
 91
 92	return reset_control_reset(priv->reset);
 93}
 94
 95static int phy_axg_pcie_reset(struct phy *phy)
 96{
 97	struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
 98	int ret = 0;
 99
100	ret = phy_reset(priv->analog);
101	if (ret != 0)
102		goto out;
103
104	ret = reset_control_assert(priv->reset);
105	if (ret != 0)
106		goto out;
107	udelay(MESON_PCIE_RESET_DELAY);
108
109	ret = reset_control_deassert(priv->reset);
110	if (ret != 0)
111		goto out;
112	udelay(MESON_PCIE_RESET_DELAY);
113
114out:
115	return ret;
116}
117
118static const struct phy_ops phy_axg_pcie_ops = {
119	.init = phy_axg_pcie_init,
120	.exit = phy_axg_pcie_exit,
121	.power_on = phy_axg_pcie_power_on,
122	.power_off = phy_axg_pcie_power_off,
123	.reset = phy_axg_pcie_reset,
124	.owner = THIS_MODULE,
125};
126
127static int phy_axg_pcie_probe(struct platform_device *pdev)
128{
129	struct phy_provider *pphy;
130	struct device *dev = &pdev->dev;
131	struct phy_axg_pcie_priv *priv;
132	struct device_node *np = dev->of_node;
133	void __iomem *base;
134	int ret;
135
136	priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
137	if (!priv)
138		return -ENOMEM;
139
140	priv->phy = devm_phy_create(dev, np, &phy_axg_pcie_ops);
141	if (IS_ERR(priv->phy)) {
142		ret = PTR_ERR(priv->phy);
143		if (ret != -EPROBE_DEFER)
144			dev_err(dev, "failed to create PHY\n");
145		return ret;
146	}
147
148	base = devm_platform_ioremap_resource(pdev, 0);
149	if (IS_ERR(base))
150		return PTR_ERR(base);
151
152	priv->regmap = devm_regmap_init_mmio(dev, base,
153					     &phy_axg_pcie_regmap_conf);
154	if (IS_ERR(priv->regmap))
155		return PTR_ERR(priv->regmap);
156
157	priv->reset = devm_reset_control_array_get_exclusive(dev);
158	if (IS_ERR(priv->reset))
159		return PTR_ERR(priv->reset);
160
161	priv->analog = devm_phy_get(dev, "analog");
162	if (IS_ERR(priv->analog))
163		return PTR_ERR(priv->analog);
164
165	phy_set_drvdata(priv->phy, priv);
166	dev_set_drvdata(dev, priv);
167	pphy = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
168
169	return PTR_ERR_OR_ZERO(pphy);
170}
171
172static const struct of_device_id phy_axg_pcie_of_match[] = {
173	{
174		.compatible = "amlogic,axg-pcie-phy",
175	},
176	{ },
177};
178MODULE_DEVICE_TABLE(of, phy_axg_pcie_of_match);
179
180static struct platform_driver phy_axg_pcie_driver = {
181	.probe = phy_axg_pcie_probe,
182	.driver = {
183		.name = "phy-axg-pcie",
184		.of_match_table = phy_axg_pcie_of_match,
185	},
186};
187module_platform_driver(phy_axg_pcie_driver);
188
189MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
190MODULE_DESCRIPTION("Amlogic AXG PCIE PHY driver");
191MODULE_LICENSE("GPL v2");