1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ITE IT5205 Type-C USB alternate mode passive mux
4 *
5 * Copyright (c) 2020 MediaTek Inc.
6 * Copyright (c) 2024 Collabora Ltd.
7 *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
8 *
9 */
10
11#include <linux/delay.h>
12#include <linux/i2c.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/of_platform.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18#include <linux/regulator/consumer.h>
19#include <linux/usb/tcpm.h>
20#include <linux/usb/typec.h>
21#include <linux/usb/typec_dp.h>
22#include <linux/usb/typec_mux.h>
23
24#define IT5205_REG_CHIP_ID(x)	(0x4 + (x))
25#define IT5205FN_CHIP_ID	0x35303235 /* "5025" -> "5205" */
26
27/* MUX power down register */
28#define IT5205_REG_MUXPDR        0x10
29#define IT5205_MUX_POWER_DOWN    BIT(0)
30
31/* MUX control register */
32#define IT5205_REG_MUXCR         0x11
33#define IT5205_POLARITY_INVERTED BIT(4)
34#define IT5205_DP_USB_CTRL_MASK  GENMASK(3, 0)
35#define IT5205_DP                0x0f
36#define IT5205_DP_USB            0x03
37#define IT5205_USB               0x07
38
39/* Vref Select Register */
40#define IT5205_REG_VSR            0x10
41#define IT5205_VREF_SELECT_MASK   GENMASK(5, 4)
42#define IT5205_VREF_SELECT_3_3V   0x00
43#define IT5205_VREF_SELECT_OFF    0x20
44
45/* CSBU Over Voltage Protection Register */
46#define IT5205_REG_CSBUOVPSR      0x1e
47#define IT5205_OVP_SELECT_MASK    GENMASK(5, 4)
48#define IT5205_OVP_3_90V          0x00
49#define IT5205_OVP_3_68V          0x10
50#define IT5205_OVP_3_62V          0x20
51#define IT5205_OVP_3_57V          0x30
52
53/* CSBU Switch Register */
54#define IT5205_REG_CSBUSR         0x22
55#define IT5205_CSBUSR_SWITCH      BIT(0)
56
57/* Interrupt Switch Register */
58#define IT5205_REG_ISR            0x25
59#define IT5205_ISR_CSBU_MASK      BIT(4)
60#define IT5205_ISR_CSBU_OVP       BIT(0)
61
62struct it5205 {
63	struct i2c_client *client;
64	struct regmap *regmap;
65	struct typec_switch_dev *sw;
66	struct typec_mux_dev *mux;
67};
68
69static int it5205_switch_set(struct typec_switch_dev *sw, enum typec_orientation orientation)
70{
71	struct it5205 *it = typec_switch_get_drvdata(sw);
72
73	switch (orientation) {
74	case TYPEC_ORIENTATION_NORMAL:
75		regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
76				   IT5205_POLARITY_INVERTED, 0);
77		break;
78	case TYPEC_ORIENTATION_REVERSE:
79		regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
80				   IT5205_POLARITY_INVERTED, IT5205_POLARITY_INVERTED);
81		break;
82	case TYPEC_ORIENTATION_NONE:
83		fallthrough;
84	default:
85		regmap_write(it->regmap, IT5205_REG_MUXCR, 0);
86		break;
87	}
88
89	return 0;
90}
91
92static int it5205_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
93{
94	struct it5205 *it = typec_mux_get_drvdata(mux);
95	u8 val;
96
97	if (state->mode >= TYPEC_STATE_MODAL &&
98	    state->alt->svid != USB_TYPEC_DP_SID)
99		return -EINVAL;
100
101	switch (state->mode) {
102	case TYPEC_STATE_USB:
103		val = IT5205_USB;
104		break;
105	case TYPEC_DP_STATE_C:
106		fallthrough;
107	case TYPEC_DP_STATE_E:
108		val = IT5205_DP;
109		break;
110	case TYPEC_DP_STATE_D:
111		val = IT5205_DP_USB;
112		break;
113	case TYPEC_STATE_SAFE:
114		fallthrough;
115	default:
116		val = 0;
117		break;
118	}
119
120	return regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
121				  IT5205_DP_USB_CTRL_MASK, val);
122}
123
124static irqreturn_t it5205_irq_handler(int irq, void *data)
125{
126	struct it5205 *it = data;
127	int ret;
128	u32 val;
129
130	ret = regmap_read(it->regmap, IT5205_REG_ISR, &val);
131	if (ret)
132		return IRQ_NONE;
133
134	if (val & IT5205_ISR_CSBU_OVP) {
135		dev_warn(&it->client->dev, "Overvoltage detected!\n");
136
137		/* Reset CSBU */
138		regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
139				   IT5205_CSBUSR_SWITCH, 0);
140		regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
141				   IT5205_CSBUSR_SWITCH, IT5205_CSBUSR_SWITCH);
142	}
143
144	return IRQ_HANDLED;
145}
146
147static void it5205_enable_ovp(struct it5205 *it)
148{
149	/* Select Vref 3.3v */
150	regmap_update_bits(it->regmap, IT5205_REG_VSR,
151			   IT5205_VREF_SELECT_MASK, IT5205_VREF_SELECT_3_3V);
152
153	/* Trigger OVP at 3.68V */
154	regmap_update_bits(it->regmap, IT5205_REG_CSBUOVPSR,
155			   IT5205_OVP_SELECT_MASK, IT5205_OVP_3_68V);
156
157	/* Unmask OVP interrupt */
158	regmap_update_bits(it->regmap, IT5205_REG_ISR,
159			   IT5205_ISR_CSBU_MASK, 0);
160
161	/* Enable CSBU Interrupt */
162	regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
163			   IT5205_CSBUSR_SWITCH, IT5205_CSBUSR_SWITCH);
164}
165
166static const struct regmap_config it5205_regmap = {
167	.max_register = 0x2f,
168	.reg_bits = 8,
169	.val_bits = 8,
170};
171
172static int it5205_probe(struct i2c_client *client)
173{
174	struct typec_switch_desc sw_desc = { };
175	struct typec_mux_desc mux_desc = { };
176	struct device *dev = &client->dev;
177	struct it5205 *it;
178	u32 val, chipid = 0;
179	int i, ret;
180
181	it = devm_kzalloc(dev, sizeof(*it), GFP_KERNEL);
182	if (!it)
183		return -ENOMEM;
184
185	ret = devm_regulator_get_enable(dev, "vcc");
186	if (ret)
187		return dev_err_probe(dev, ret, "Failed to get regulator\n");
188
189	it->client = client;
190
191	it->regmap = devm_regmap_init_i2c(client, &it5205_regmap);
192	if (IS_ERR(it->regmap))
193		return dev_err_probe(dev, PTR_ERR(it->regmap),
194				     "Failed to init regmap\n");
195
196	/* IT5205 needs a long time to power up after enabling regulator */
197	msleep(50);
198
199	/* Unset poweroff bit */
200	ret = regmap_write(it->regmap, IT5205_REG_MUXPDR, 0);
201	if (ret)
202		return dev_err_probe(dev, ret, "Failed to set power on\n");
203
204	/* Read the 32 bits ChipID */
205	for (i = 3; i >= 0; i--) {
206		ret = regmap_read(it->regmap, IT5205_REG_CHIP_ID(i), &val);
207		if (ret)
208			return ret;
209
210		chipid |= val << (i * 8);
211	}
212
213	if (chipid != IT5205FN_CHIP_ID)
214		return dev_err_probe(dev, -EINVAL,
215				     "Unknown ChipID 0x%x\n", chipid);
216
217	/* Initialize as USB mode with default (non-inverted) polarity */
218	ret = regmap_write(it->regmap, IT5205_REG_MUXCR, IT5205_USB);
219	if (ret)
220		return dev_err_probe(dev, ret, "Cannot set mode to USB\n");
221
222	sw_desc.drvdata = it;
223	sw_desc.fwnode = dev_fwnode(dev);
224	sw_desc.set = it5205_switch_set;
225
226	it->sw = typec_switch_register(dev, &sw_desc);
227	if (IS_ERR(it->sw))
228		return dev_err_probe(dev, PTR_ERR(it->sw),
229				     "failed to register typec switch\n");
230
231	mux_desc.drvdata = it;
232	mux_desc.fwnode = dev_fwnode(dev);
233	mux_desc.set = it5205_mux_set;
234
235	it->mux = typec_mux_register(dev, &mux_desc);
236	if (IS_ERR(it->mux)) {
237		typec_switch_unregister(it->sw);
238		return dev_err_probe(dev, PTR_ERR(it->mux),
239				     "failed to register typec mux\n");
240	}
241
242	i2c_set_clientdata(client, it);
243
244	if (of_property_read_bool(dev->of_node, "ite,ovp-enable") && client->irq) {
245		it5205_enable_ovp(it);
246
247		ret = devm_request_threaded_irq(dev, client->irq, NULL,
248						it5205_irq_handler,
249						IRQF_ONESHOT, dev_name(dev), it);
250		if (ret) {
251			typec_mux_unregister(it->mux);
252			typec_switch_unregister(it->sw);
253			return dev_err_probe(dev, ret, "Failed to request irq\n");
254		}
255	}
256
257	return 0;
258}
259
260static void it5205_remove(struct i2c_client *client)
261{
262	struct it5205 *it = i2c_get_clientdata(client);
263
264	typec_mux_unregister(it->mux);
265	typec_switch_unregister(it->sw);
266}
267
268static const struct i2c_device_id it5205_table[] = {
269	{ "it5205" },
270	{ /* sentinel */ }
271};
272MODULE_DEVICE_TABLE(i2c, it5205_table);
273
274static const struct of_device_id it5205_of_table[] = {
275	{ .compatible = "ite,it5205" },
276	{ /* sentinel */ }
277};
278MODULE_DEVICE_TABLE(of, it5205_of_table);
279
280static struct i2c_driver it5205_driver = {
281	.driver = {
282		.name = "it5205",
283		.of_match_table = it5205_of_table,
284	},
285	.probe = it5205_probe,
286	.remove = it5205_remove,
287	.id_table = it5205_table,
288};
289module_i2c_driver(it5205_driver);
290
291MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
292MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
293MODULE_DESCRIPTION("ITE IT5205 alternate mode passive MUX driver");
294MODULE_LICENSE("GPL");
295