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
40enum 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
64struct 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
71struct 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
81static const char * const pm8550b_vreg_l[] = {
82	"vdd18", "vdd3",
83};
84
85static const u32 pm8550b_init_tbl[NUM_TUNE_FIELDS] = {
86	[TUNE_IUSB2] = 0x8,
87	[TUNE_SQUELCH_U] = 0x3,
88	[TUNE_USB2_PREEM] = 0x5,
89};
90
91static 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
98static 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
114static 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
158static 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
192static 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
199static 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
206static 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
259static 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
269static 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};
276MODULE_DEVICE_TABLE(of, eusb2_repeater_of_match_table);
277
278static 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
287module_platform_driver(eusb2_repeater_driver);
288
289MODULE_DESCRIPTION("Qualcomm PMIC eUSB2 Repeater driver");
290MODULE_LICENSE("GPL");
291