1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Lantiq XWAY SoC RCU module based USB 1.1/2.0 PHY driver
4 *
5 * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
6 * Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
7 */
8
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_device.h>
16 #include <linux/phy/phy.h>
17 #include <linux/platform_device.h>
18 #include <linux/property.h>
19 #include <linux/regmap.h>
20 #include <linux/reset.h>
21
22 /* Transmitter HS Pre-Emphasis Enable */
23 #define RCU_CFG1_TX_PEE BIT(0)
24 /* Disconnect Threshold */
25 #define RCU_CFG1_DIS_THR_MASK 0x00038000
26 #define RCU_CFG1_DIS_THR_SHIFT 15
27
28 struct ltq_rcu_usb2_bits {
29 u8 hostmode;
30 u8 slave_endianness;
31 u8 host_endianness;
32 bool have_ana_cfg;
33 };
34
35 struct ltq_rcu_usb2_priv {
36 struct regmap *regmap;
37 unsigned int phy_reg_offset;
38 unsigned int ana_cfg1_reg_offset;
39 const struct ltq_rcu_usb2_bits *reg_bits;
40 struct device *dev;
41 struct phy *phy;
42 struct clk *phy_gate_clk;
43 struct reset_control *ctrl_reset;
44 struct reset_control *phy_reset;
45 };
46
47 static const struct ltq_rcu_usb2_bits xway_rcu_usb2_reg_bits = {
48 .hostmode = 11,
49 .slave_endianness = 9,
50 .host_endianness = 10,
51 .have_ana_cfg = false,
52 };
53
54 static const struct ltq_rcu_usb2_bits xrx100_rcu_usb2_reg_bits = {
55 .hostmode = 11,
56 .slave_endianness = 17,
57 .host_endianness = 10,
58 .have_ana_cfg = false,
59 };
60
61 static const struct ltq_rcu_usb2_bits xrx200_rcu_usb2_reg_bits = {
62 .hostmode = 11,
63 .slave_endianness = 9,
64 .host_endianness = 10,
65 .have_ana_cfg = true,
66 };
67
68 static const struct of_device_id ltq_rcu_usb2_phy_of_match[] = {
69 {
70 .compatible = "lantiq,ase-usb2-phy",
71 .data = &xway_rcu_usb2_reg_bits,
72 },
73 {
74 .compatible = "lantiq,danube-usb2-phy",
75 .data = &xway_rcu_usb2_reg_bits,
76 },
77 {
78 .compatible = "lantiq,xrx100-usb2-phy",
79 .data = &xrx100_rcu_usb2_reg_bits,
80 },
81 {
82 .compatible = "lantiq,xrx200-usb2-phy",
83 .data = &xrx200_rcu_usb2_reg_bits,
84 },
85 {
86 .compatible = "lantiq,xrx300-usb2-phy",
87 .data = &xrx200_rcu_usb2_reg_bits,
88 },
89 { },
90 };
91 MODULE_DEVICE_TABLE(of, ltq_rcu_usb2_phy_of_match);
92
ltq_rcu_usb2_phy_init(struct phy * phy)93 static int ltq_rcu_usb2_phy_init(struct phy *phy)
94 {
95 struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
96
97 if (priv->reg_bits->have_ana_cfg) {
98 regmap_update_bits(priv->regmap, priv->ana_cfg1_reg_offset,
99 RCU_CFG1_TX_PEE, RCU_CFG1_TX_PEE);
100 regmap_update_bits(priv->regmap, priv->ana_cfg1_reg_offset,
101 RCU_CFG1_DIS_THR_MASK, 7 << RCU_CFG1_DIS_THR_SHIFT);
102 }
103
104 /* Configure core to host mode */
105 regmap_update_bits(priv->regmap, priv->phy_reg_offset,
106 BIT(priv->reg_bits->hostmode), 0);
107
108 /* Select DMA endianness (Host-endian: big-endian) */
109 regmap_update_bits(priv->regmap, priv->phy_reg_offset,
110 BIT(priv->reg_bits->slave_endianness), 0);
111 regmap_update_bits(priv->regmap, priv->phy_reg_offset,
112 BIT(priv->reg_bits->host_endianness),
113 BIT(priv->reg_bits->host_endianness));
114
115 return 0;
116 }
117
ltq_rcu_usb2_phy_power_on(struct phy * phy)118 static int ltq_rcu_usb2_phy_power_on(struct phy *phy)
119 {
120 struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
121 struct device *dev = priv->dev;
122 int ret;
123
124 reset_control_deassert(priv->phy_reset);
125
126 ret = clk_prepare_enable(priv->phy_gate_clk);
127 if (ret) {
128 dev_err(dev, "failed to enable PHY gate\n");
129 return ret;
130 }
131
132 /*
133 * at least the xrx200 usb2 phy requires some extra time to be
134 * operational after enabling the clock
135 */
136 usleep_range(100, 200);
137
138 return ret;
139 }
140
ltq_rcu_usb2_phy_power_off(struct phy * phy)141 static int ltq_rcu_usb2_phy_power_off(struct phy *phy)
142 {
143 struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
144
145 reset_control_assert(priv->phy_reset);
146
147 clk_disable_unprepare(priv->phy_gate_clk);
148
149 return 0;
150 }
151
152 static const struct phy_ops ltq_rcu_usb2_phy_ops = {
153 .init = ltq_rcu_usb2_phy_init,
154 .power_on = ltq_rcu_usb2_phy_power_on,
155 .power_off = ltq_rcu_usb2_phy_power_off,
156 .owner = THIS_MODULE,
157 };
158
ltq_rcu_usb2_of_parse(struct ltq_rcu_usb2_priv * priv,struct platform_device * pdev)159 static int ltq_rcu_usb2_of_parse(struct ltq_rcu_usb2_priv *priv,
160 struct platform_device *pdev)
161 {
162 struct device *dev = priv->dev;
163 const __be32 *offset;
164
165 priv->reg_bits = of_device_get_match_data(dev);
166
167 priv->regmap = syscon_node_to_regmap(dev->of_node->parent);
168 if (IS_ERR(priv->regmap)) {
169 dev_err(dev, "Failed to lookup RCU regmap\n");
170 return PTR_ERR(priv->regmap);
171 }
172
173 offset = of_get_address(dev->of_node, 0, NULL, NULL);
174 if (!offset) {
175 dev_err(dev, "Failed to get RCU PHY reg offset\n");
176 return -ENOENT;
177 }
178 priv->phy_reg_offset = __be32_to_cpu(*offset);
179
180 if (priv->reg_bits->have_ana_cfg) {
181 offset = of_get_address(dev->of_node, 1, NULL, NULL);
182 if (!offset) {
183 dev_err(dev, "Failed to get RCU ANA CFG1 reg offset\n");
184 return -ENOENT;
185 }
186 priv->ana_cfg1_reg_offset = __be32_to_cpu(*offset);
187 }
188
189 priv->phy_gate_clk = devm_clk_get(dev, "phy");
190 if (IS_ERR(priv->phy_gate_clk)) {
191 dev_err(dev, "Unable to get USB phy gate clk\n");
192 return PTR_ERR(priv->phy_gate_clk);
193 }
194
195 priv->ctrl_reset = devm_reset_control_get_shared(dev, "ctrl");
196 if (IS_ERR(priv->ctrl_reset)) {
197 if (PTR_ERR(priv->ctrl_reset) != -EPROBE_DEFER)
198 dev_err(dev, "failed to get 'ctrl' reset\n");
199 return PTR_ERR(priv->ctrl_reset);
200 }
201
202 priv->phy_reset = devm_reset_control_get_optional(dev, "phy");
203
204 return PTR_ERR_OR_ZERO(priv->phy_reset);
205 }
206
ltq_rcu_usb2_phy_probe(struct platform_device * pdev)207 static int ltq_rcu_usb2_phy_probe(struct platform_device *pdev)
208 {
209 struct device *dev = &pdev->dev;
210 struct ltq_rcu_usb2_priv *priv;
211 struct phy_provider *provider;
212 int ret;
213
214 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
215 if (!priv)
216 return -ENOMEM;
217
218 priv->dev = dev;
219
220 ret = ltq_rcu_usb2_of_parse(priv, pdev);
221 if (ret)
222 return ret;
223
224 /* Reset USB core through reset controller */
225 reset_control_deassert(priv->ctrl_reset);
226
227 reset_control_assert(priv->phy_reset);
228
229 priv->phy = devm_phy_create(dev, dev->of_node, <q_rcu_usb2_phy_ops);
230 if (IS_ERR(priv->phy)) {
231 dev_err(dev, "failed to create PHY\n");
232 return PTR_ERR(priv->phy);
233 }
234
235 phy_set_drvdata(priv->phy, priv);
236
237 provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
238 if (IS_ERR(provider))
239 return PTR_ERR(provider);
240
241 dev_set_drvdata(priv->dev, priv);
242 return 0;
243 }
244
245 static struct platform_driver ltq_rcu_usb2_phy_driver = {
246 .probe = ltq_rcu_usb2_phy_probe,
247 .driver = {
248 .name = "lantiq-rcu-usb2-phy",
249 .of_match_table = ltq_rcu_usb2_phy_of_match,
250 }
251 };
252 module_platform_driver(ltq_rcu_usb2_phy_driver);
253
254 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
255 MODULE_DESCRIPTION("Lantiq XWAY USB2 PHY driver");
256 MODULE_LICENSE("GPL v2");
257