xref: /linux/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c (revision f5c31bcf604db54470868f3118a60dc4a9ba8813)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2023, Linaro Limited
4  */
5 
6 #include <linux/module.h>
7 #include <linux/platform_device.h>
8 #include <linux/regulator/consumer.h>
9 #include <linux/regmap.h>
10 #include <linux/of.h>
11 #include <linux/phy/phy.h>
12 
13 /* eUSB2 status registers */
14 #define EUSB2_RPTR_STATUS		0x08
15 #define	RPTR_OK				BIT(7)
16 
17 /* eUSB2 control registers */
18 #define EUSB2_EN_CTL1			0x46
19 #define EUSB2_RPTR_EN			BIT(7)
20 
21 #define EUSB2_FORCE_EN_5		0xe8
22 #define F_CLK_19P2M_EN			BIT(6)
23 
24 #define EUSB2_FORCE_VAL_5		0xeD
25 #define V_CLK_19P2M_EN			BIT(6)
26 
27 #define EUSB2_TUNE_USB2_CROSSOVER	0x50
28 #define EUSB2_TUNE_IUSB2		0x51
29 #define EUSB2_TUNE_RES_FSDIF		0x52
30 #define EUSB2_TUNE_HSDISC		0x53
31 #define EUSB2_TUNE_SQUELCH_U		0x54
32 #define EUSB2_TUNE_USB2_SLEW		0x55
33 #define EUSB2_TUNE_USB2_EQU		0x56
34 #define EUSB2_TUNE_USB2_PREEM		0x57
35 #define EUSB2_TUNE_USB2_HS_COMP_CUR	0x58
36 #define EUSB2_TUNE_EUSB_SLEW		0x59
37 #define EUSB2_TUNE_EUSB_EQU		0x5A
38 #define EUSB2_TUNE_EUSB_HS_COMP_CUR	0x5B
39 
40 enum eusb2_reg_layout {
41 	TUNE_EUSB_HS_COMP_CUR,
42 	TUNE_EUSB_EQU,
43 	TUNE_EUSB_SLEW,
44 	TUNE_USB2_HS_COMP_CUR,
45 	TUNE_USB2_PREEM,
46 	TUNE_USB2_EQU,
47 	TUNE_USB2_SLEW,
48 	TUNE_SQUELCH_U,
49 	TUNE_HSDISC,
50 	TUNE_RES_FSDIF,
51 	TUNE_IUSB2,
52 	TUNE_USB2_CROSSOVER,
53 	NUM_TUNE_FIELDS,
54 
55 	FORCE_VAL_5 = NUM_TUNE_FIELDS,
56 	FORCE_EN_5,
57 
58 	EN_CTL1,
59 
60 	RPTR_STATUS,
61 	LAYOUT_SIZE,
62 };
63 
64 struct eusb2_repeater_cfg {
65 	const u32 *init_tbl;
66 	int init_tbl_num;
67 	const char * const *vreg_list;
68 	int num_vregs;
69 };
70 
71 struct eusb2_repeater {
72 	struct device *dev;
73 	struct regmap *regmap;
74 	struct phy *phy;
75 	struct regulator_bulk_data *vregs;
76 	const struct eusb2_repeater_cfg *cfg;
77 	u32 base;
78 	enum phy_mode mode;
79 };
80 
81 static const char * const pm8550b_vreg_l[] = {
82 	"vdd18", "vdd3",
83 };
84 
85 static const u32 pm8550b_init_tbl[NUM_TUNE_FIELDS] = {
86 	[TUNE_IUSB2] = 0x8,
87 	[TUNE_SQUELCH_U] = 0x3,
88 	[TUNE_USB2_PREEM] = 0x5,
89 };
90 
91 static const struct eusb2_repeater_cfg pm8550b_eusb2_cfg = {
92 	.init_tbl	= pm8550b_init_tbl,
93 	.init_tbl_num	= ARRAY_SIZE(pm8550b_init_tbl),
94 	.vreg_list	= pm8550b_vreg_l,
95 	.num_vregs	= ARRAY_SIZE(pm8550b_vreg_l),
96 };
97 
98 static int eusb2_repeater_init_vregs(struct eusb2_repeater *rptr)
99 {
100 	int num = rptr->cfg->num_vregs;
101 	struct device *dev = rptr->dev;
102 	int i;
103 
104 	rptr->vregs = devm_kcalloc(dev, num, sizeof(*rptr->vregs), GFP_KERNEL);
105 	if (!rptr->vregs)
106 		return -ENOMEM;
107 
108 	for (i = 0; i < num; i++)
109 		rptr->vregs[i].supply = rptr->cfg->vreg_list[i];
110 
111 	return devm_regulator_bulk_get(dev, num, rptr->vregs);
112 }
113 
114 static int eusb2_repeater_init(struct phy *phy)
115 {
116 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
117 	struct device_node *np = rptr->dev->of_node;
118 	struct regmap *regmap = rptr->regmap;
119 	const u32 *init_tbl = rptr->cfg->init_tbl;
120 	u8 tune_usb2_preem = init_tbl[TUNE_USB2_PREEM];
121 	u8 tune_hsdisc = init_tbl[TUNE_HSDISC];
122 	u8 tune_iusb2 = init_tbl[TUNE_IUSB2];
123 	u32 base = rptr->base;
124 	u32 val;
125 	int ret;
126 
127 	of_property_read_u8(np, "qcom,tune-usb2-amplitude", &tune_iusb2);
128 	of_property_read_u8(np, "qcom,tune-usb2-disc-thres", &tune_hsdisc);
129 	of_property_read_u8(np, "qcom,tune-usb2-preem", &tune_usb2_preem);
130 
131 	ret = regulator_bulk_enable(rptr->cfg->num_vregs, rptr->vregs);
132 	if (ret)
133 		return ret;
134 
135 	regmap_write(regmap, base + EUSB2_EN_CTL1, EUSB2_RPTR_EN);
136 
137 	regmap_write(regmap, base + EUSB2_TUNE_EUSB_HS_COMP_CUR, init_tbl[TUNE_EUSB_HS_COMP_CUR]);
138 	regmap_write(regmap, base + EUSB2_TUNE_EUSB_EQU, init_tbl[TUNE_EUSB_EQU]);
139 	regmap_write(regmap, base + EUSB2_TUNE_EUSB_SLEW, init_tbl[TUNE_EUSB_SLEW]);
140 	regmap_write(regmap, base + EUSB2_TUNE_USB2_HS_COMP_CUR, init_tbl[TUNE_USB2_HS_COMP_CUR]);
141 	regmap_write(regmap, base + EUSB2_TUNE_USB2_EQU, init_tbl[TUNE_USB2_EQU]);
142 	regmap_write(regmap, base + EUSB2_TUNE_USB2_SLEW, init_tbl[TUNE_USB2_SLEW]);
143 	regmap_write(regmap, base + EUSB2_TUNE_SQUELCH_U, init_tbl[TUNE_SQUELCH_U]);
144 	regmap_write(regmap, base + EUSB2_TUNE_RES_FSDIF, init_tbl[TUNE_RES_FSDIF]);
145 	regmap_write(regmap, base + EUSB2_TUNE_USB2_CROSSOVER, init_tbl[TUNE_USB2_CROSSOVER]);
146 
147 	regmap_write(regmap, base + EUSB2_TUNE_USB2_PREEM, tune_usb2_preem);
148 	regmap_write(regmap, base + EUSB2_TUNE_HSDISC, tune_hsdisc);
149 	regmap_write(regmap, base + EUSB2_TUNE_IUSB2, tune_iusb2);
150 
151 	ret = regmap_read_poll_timeout(regmap, base + EUSB2_RPTR_STATUS, val, val & RPTR_OK, 10, 5);
152 	if (ret)
153 		dev_err(rptr->dev, "initialization timed-out\n");
154 
155 	return ret;
156 }
157 
158 static int eusb2_repeater_set_mode(struct phy *phy,
159 				   enum phy_mode mode, int submode)
160 {
161 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
162 	struct regmap *regmap = rptr->regmap;
163 	u32 base = rptr->base;
164 
165 	switch (mode) {
166 	case PHY_MODE_USB_HOST:
167 		/*
168 		 * CM.Lx is prohibited when repeater is already into Lx state as
169 		 * per eUSB 1.2 Spec. Below implement software workaround until
170 		 * PHY and controller is fixing seen observation.
171 		 */
172 		regmap_write(regmap, base + EUSB2_FORCE_EN_5, F_CLK_19P2M_EN);
173 		regmap_write(regmap, base + EUSB2_FORCE_VAL_5, V_CLK_19P2M_EN);
174 		break;
175 	case PHY_MODE_USB_DEVICE:
176 		/*
177 		 * In device mode clear host mode related workaround as there
178 		 * is no repeater reset available, and enable/disable of
179 		 * repeater doesn't clear previous value due to shared
180 		 * regulators (say host <-> device mode switch).
181 		 */
182 		regmap_write(regmap, base + EUSB2_FORCE_EN_5, 0);
183 		regmap_write(regmap, base + EUSB2_FORCE_VAL_5, 0);
184 		break;
185 	default:
186 		return -EINVAL;
187 	}
188 
189 	return 0;
190 }
191 
192 static int eusb2_repeater_exit(struct phy *phy)
193 {
194 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
195 
196 	return regulator_bulk_disable(rptr->cfg->num_vregs, rptr->vregs);
197 }
198 
199 static const struct phy_ops eusb2_repeater_ops = {
200 	.init		= eusb2_repeater_init,
201 	.exit		= eusb2_repeater_exit,
202 	.set_mode	= eusb2_repeater_set_mode,
203 	.owner		= THIS_MODULE,
204 };
205 
206 static int eusb2_repeater_probe(struct platform_device *pdev)
207 {
208 	struct eusb2_repeater *rptr;
209 	struct device *dev = &pdev->dev;
210 	struct phy_provider *phy_provider;
211 	struct device_node *np = dev->of_node;
212 	u32 res;
213 	int ret;
214 
215 	rptr = devm_kzalloc(dev, sizeof(*rptr), GFP_KERNEL);
216 	if (!rptr)
217 		return -ENOMEM;
218 
219 	rptr->dev = dev;
220 	dev_set_drvdata(dev, rptr);
221 
222 	rptr->cfg = of_device_get_match_data(dev);
223 	if (!rptr->cfg)
224 		return -EINVAL;
225 
226 	rptr->regmap = dev_get_regmap(dev->parent, NULL);
227 	if (!rptr->regmap)
228 		return -ENODEV;
229 
230 	ret = of_property_read_u32(np, "reg", &res);
231 	if (ret < 0)
232 		return ret;
233 
234 	rptr->base = res;
235 
236 	ret = eusb2_repeater_init_vregs(rptr);
237 	if (ret < 0) {
238 		dev_err(dev, "unable to get supplies\n");
239 		return ret;
240 	}
241 
242 	rptr->phy = devm_phy_create(dev, np, &eusb2_repeater_ops);
243 	if (IS_ERR(rptr->phy)) {
244 		dev_err(dev, "failed to create PHY: %d\n", ret);
245 		return PTR_ERR(rptr->phy);
246 	}
247 
248 	phy_set_drvdata(rptr->phy, rptr);
249 
250 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
251 	if (IS_ERR(phy_provider))
252 		return PTR_ERR(phy_provider);
253 
254 	dev_info(dev, "Registered Qcom-eUSB2 repeater\n");
255 
256 	return 0;
257 }
258 
259 static void eusb2_repeater_remove(struct platform_device *pdev)
260 {
261 	struct eusb2_repeater *rptr = platform_get_drvdata(pdev);
262 
263 	if (!rptr)
264 		return;
265 
266 	eusb2_repeater_exit(rptr->phy);
267 }
268 
269 static const struct of_device_id eusb2_repeater_of_match_table[] = {
270 	{
271 		.compatible = "qcom,pm8550b-eusb2-repeater",
272 		.data = &pm8550b_eusb2_cfg,
273 	},
274 	{ },
275 };
276 MODULE_DEVICE_TABLE(of, eusb2_repeater_of_match_table);
277 
278 static struct platform_driver eusb2_repeater_driver = {
279 	.probe		= eusb2_repeater_probe,
280 	.remove_new	= eusb2_repeater_remove,
281 	.driver = {
282 		.name	= "qcom-eusb2-repeater",
283 		.of_match_table = eusb2_repeater_of_match_table,
284 	},
285 };
286 
287 module_platform_driver(eusb2_repeater_driver);
288 
289 MODULE_DESCRIPTION("Qualcomm PMIC eUSB2 Repeater driver");
290 MODULE_LICENSE("GPL");
291