1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
4  * Copyright (c) 2023, Linaro Ltd
5  */
6 #include <linux/auxiliary_bus.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/property.h>
10 #include <linux/soc/qcom/pdr.h>
11 #include <linux/soc/qcom/pmic_glink.h>
12 #include "ucsi.h"
13 
14 #define UCSI_BUF_SIZE                   48
15 
16 #define MSG_TYPE_REQ_RESP               1
17 #define UCSI_BUF_SIZE                   48
18 
19 #define UC_NOTIFY_RECEIVER_UCSI         0x0
20 #define UC_UCSI_READ_BUF_REQ            0x11
21 #define UC_UCSI_WRITE_BUF_REQ           0x12
22 #define UC_UCSI_USBC_NOTIFY_IND         0x13
23 
24 struct ucsi_read_buf_req_msg {
25 	struct pmic_glink_hdr   hdr;
26 };
27 
28 struct ucsi_read_buf_resp_msg {
29 	struct pmic_glink_hdr   hdr;
30 	u8                      buf[UCSI_BUF_SIZE];
31 	u32                     ret_code;
32 };
33 
34 struct ucsi_write_buf_req_msg {
35 	struct pmic_glink_hdr   hdr;
36 	u8                      buf[UCSI_BUF_SIZE];
37 	u32                     reserved;
38 };
39 
40 struct ucsi_write_buf_resp_msg {
41 	struct pmic_glink_hdr   hdr;
42 	u32                     ret_code;
43 };
44 
45 struct ucsi_notify_ind_msg {
46 	struct pmic_glink_hdr   hdr;
47 	u32                     notification;
48 	u32                     receiver;
49 	u32                     reserved;
50 };
51 
52 struct pmic_glink_ucsi {
53 	struct device *dev;
54 
55 	struct pmic_glink_client *client;
56 
57 	struct ucsi *ucsi;
58 	struct completion read_ack;
59 	struct completion write_ack;
60 	struct completion sync_ack;
61 	bool sync_pending;
62 	struct mutex lock;	/* protects concurrent access to PMIC Glink interface */
63 
64 	int sync_val;
65 
66 	struct work_struct notify_work;
67 	struct work_struct register_work;
68 
69 	u8 read_buf[UCSI_BUF_SIZE];
70 };
71 
72 static int pmic_glink_ucsi_read(struct ucsi *__ucsi, unsigned int offset,
73 				void *val, size_t val_len)
74 {
75 	struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(__ucsi);
76 	struct ucsi_read_buf_req_msg req = {};
77 	unsigned long left;
78 	int ret;
79 
80 	req.hdr.owner = PMIC_GLINK_OWNER_USBC;
81 	req.hdr.type = MSG_TYPE_REQ_RESP;
82 	req.hdr.opcode = UC_UCSI_READ_BUF_REQ;
83 
84 	mutex_lock(&ucsi->lock);
85 	memset(ucsi->read_buf, 0, sizeof(ucsi->read_buf));
86 	reinit_completion(&ucsi->read_ack);
87 
88 	ret = pmic_glink_send(ucsi->client, &req, sizeof(req));
89 	if (ret < 0) {
90 		dev_err(ucsi->dev, "failed to send UCSI read request: %d\n", ret);
91 		goto out_unlock;
92 	}
93 
94 	left = wait_for_completion_timeout(&ucsi->read_ack, 5 * HZ);
95 	if (!left) {
96 		dev_err(ucsi->dev, "timeout waiting for UCSI read response\n");
97 		ret = -ETIMEDOUT;
98 		goto out_unlock;
99 	}
100 
101 	memcpy(val, &ucsi->read_buf[offset], val_len);
102 	ret = 0;
103 
104 out_unlock:
105 	mutex_unlock(&ucsi->lock);
106 
107 	return ret;
108 }
109 
110 static int pmic_glink_ucsi_locked_write(struct pmic_glink_ucsi *ucsi, unsigned int offset,
111 					const void *val, size_t val_len)
112 {
113 	struct ucsi_write_buf_req_msg req = {};
114 	unsigned long left;
115 	int ret;
116 
117 	req.hdr.owner = PMIC_GLINK_OWNER_USBC;
118 	req.hdr.type = MSG_TYPE_REQ_RESP;
119 	req.hdr.opcode = UC_UCSI_WRITE_BUF_REQ;
120 	memcpy(&req.buf[offset], val, val_len);
121 
122 	reinit_completion(&ucsi->write_ack);
123 
124 	ret = pmic_glink_send(ucsi->client, &req, sizeof(req));
125 	if (ret < 0) {
126 		dev_err(ucsi->dev, "failed to send UCSI write request: %d\n", ret);
127 		return ret;
128 	}
129 
130 	left = wait_for_completion_timeout(&ucsi->write_ack, 5 * HZ);
131 	if (!left) {
132 		dev_err(ucsi->dev, "timeout waiting for UCSI write response\n");
133 		return -ETIMEDOUT;
134 	}
135 
136 	return 0;
137 }
138 
139 static int pmic_glink_ucsi_async_write(struct ucsi *__ucsi, unsigned int offset,
140 				       const void *val, size_t val_len)
141 {
142 	struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(__ucsi);
143 	int ret;
144 
145 	mutex_lock(&ucsi->lock);
146 	ret = pmic_glink_ucsi_locked_write(ucsi, offset, val, val_len);
147 	mutex_unlock(&ucsi->lock);
148 
149 	return ret;
150 }
151 
152 static int pmic_glink_ucsi_sync_write(struct ucsi *__ucsi, unsigned int offset,
153 				      const void *val, size_t val_len)
154 {
155 	struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(__ucsi);
156 	unsigned long left;
157 	int ret;
158 
159 	/* TOFIX: Downstream forces recipient to CON when UCSI_GET_ALTERNATE_MODES command */
160 
161 	mutex_lock(&ucsi->lock);
162 	ucsi->sync_val = 0;
163 	reinit_completion(&ucsi->sync_ack);
164 	ucsi->sync_pending = true;
165 	ret = pmic_glink_ucsi_locked_write(ucsi, offset, val, val_len);
166 	mutex_unlock(&ucsi->lock);
167 
168 	left = wait_for_completion_timeout(&ucsi->sync_ack, 5 * HZ);
169 	if (!left) {
170 		dev_err(ucsi->dev, "timeout waiting for UCSI sync write response\n");
171 		ret = -ETIMEDOUT;
172 	} else if (ucsi->sync_val) {
173 		dev_err(ucsi->dev, "sync write returned: %d\n", ucsi->sync_val);
174 	}
175 
176 	ucsi->sync_pending = false;
177 
178 	return ret;
179 }
180 
181 static const struct ucsi_operations pmic_glink_ucsi_ops = {
182 	.read = pmic_glink_ucsi_read,
183 	.sync_write = pmic_glink_ucsi_sync_write,
184 	.async_write = pmic_glink_ucsi_async_write
185 };
186 
187 static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
188 {
189 	const struct ucsi_read_buf_resp_msg *resp = data;
190 
191 	if (resp->ret_code)
192 		return;
193 
194 	memcpy(ucsi->read_buf, resp->buf, UCSI_BUF_SIZE);
195 	complete(&ucsi->read_ack);
196 }
197 
198 static void pmic_glink_ucsi_write_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
199 {
200 	const struct ucsi_write_buf_resp_msg *resp = data;
201 
202 	if (resp->ret_code)
203 		return;
204 
205 	ucsi->sync_val = resp->ret_code;
206 	complete(&ucsi->write_ack);
207 }
208 
209 static void pmic_glink_ucsi_notify(struct work_struct *work)
210 {
211 	struct pmic_glink_ucsi *ucsi = container_of(work, struct pmic_glink_ucsi, notify_work);
212 	unsigned int con_num;
213 	u32 cci;
214 	int ret;
215 
216 	ret = pmic_glink_ucsi_read(ucsi->ucsi, UCSI_CCI, &cci, sizeof(cci));
217 	if (ret) {
218 		dev_err(ucsi->dev, "failed to read CCI on notification\n");
219 		return;
220 	}
221 
222 	con_num = UCSI_CCI_CONNECTOR(cci);
223 	if (con_num)
224 		ucsi_connector_change(ucsi->ucsi, con_num);
225 
226 	if (ucsi->sync_pending && cci & UCSI_CCI_BUSY) {
227 		ucsi->sync_val = -EBUSY;
228 		complete(&ucsi->sync_ack);
229 	} else if (ucsi->sync_pending &&
230 		   (cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))) {
231 		complete(&ucsi->sync_ack);
232 	}
233 }
234 
235 static void pmic_glink_ucsi_register(struct work_struct *work)
236 {
237 	struct pmic_glink_ucsi *ucsi = container_of(work, struct pmic_glink_ucsi, register_work);
238 
239 	ucsi_register(ucsi->ucsi);
240 }
241 
242 static void pmic_glink_ucsi_callback(const void *data, size_t len, void *priv)
243 {
244 	struct pmic_glink_ucsi *ucsi = priv;
245 	const struct pmic_glink_hdr *hdr = data;
246 
247 	switch (le32_to_cpu(hdr->opcode)) {
248 	case UC_UCSI_READ_BUF_REQ:
249 		pmic_glink_ucsi_read_ack(ucsi, data, len);
250 		break;
251 	case UC_UCSI_WRITE_BUF_REQ:
252 		pmic_glink_ucsi_write_ack(ucsi, data, len);
253 		break;
254 	case UC_UCSI_USBC_NOTIFY_IND:
255 		schedule_work(&ucsi->notify_work);
256 		break;
257 	};
258 }
259 
260 static void pmic_glink_ucsi_pdr_notify(void *priv, int state)
261 {
262 	struct pmic_glink_ucsi *ucsi = priv;
263 
264 	if (state == SERVREG_SERVICE_STATE_UP)
265 		schedule_work(&ucsi->register_work);
266 	else if (state == SERVREG_SERVICE_STATE_DOWN)
267 		ucsi_unregister(ucsi->ucsi);
268 }
269 
270 static void pmic_glink_ucsi_destroy(void *data)
271 {
272 	struct pmic_glink_ucsi *ucsi = data;
273 
274 	/* Protect to make sure we're not in a middle of a transaction from a glink callback */
275 	mutex_lock(&ucsi->lock);
276 	ucsi_destroy(ucsi->ucsi);
277 	mutex_unlock(&ucsi->lock);
278 }
279 
280 static int pmic_glink_ucsi_probe(struct auxiliary_device *adev,
281 				 const struct auxiliary_device_id *id)
282 {
283 	struct pmic_glink_ucsi *ucsi;
284 	struct device *dev = &adev->dev;
285 	int ret;
286 
287 	ucsi = devm_kzalloc(dev, sizeof(*ucsi), GFP_KERNEL);
288 	if (!ucsi)
289 		return -ENOMEM;
290 
291 	ucsi->dev = dev;
292 	dev_set_drvdata(dev, ucsi);
293 
294 	INIT_WORK(&ucsi->notify_work, pmic_glink_ucsi_notify);
295 	INIT_WORK(&ucsi->register_work, pmic_glink_ucsi_register);
296 	init_completion(&ucsi->read_ack);
297 	init_completion(&ucsi->write_ack);
298 	init_completion(&ucsi->sync_ack);
299 	mutex_init(&ucsi->lock);
300 
301 	ucsi->ucsi = ucsi_create(dev, &pmic_glink_ucsi_ops);
302 	if (IS_ERR(ucsi->ucsi))
303 		return PTR_ERR(ucsi->ucsi);
304 
305 	/* Make sure we destroy *after* pmic_glink unregister */
306 	ret = devm_add_action_or_reset(dev, pmic_glink_ucsi_destroy, ucsi);
307 	if (ret)
308 		return ret;
309 
310 	ucsi_set_drvdata(ucsi->ucsi, ucsi);
311 
312 	ucsi->client = devm_pmic_glink_register_client(dev,
313 						       PMIC_GLINK_OWNER_USBC,
314 						       pmic_glink_ucsi_callback,
315 						       pmic_glink_ucsi_pdr_notify,
316 						       ucsi);
317 	return PTR_ERR_OR_ZERO(ucsi->client);
318 }
319 
320 static void pmic_glink_ucsi_remove(struct auxiliary_device *adev)
321 {
322 	struct pmic_glink_ucsi *ucsi = dev_get_drvdata(&adev->dev);
323 
324 	/* Unregister first to stop having read & writes */
325 	ucsi_unregister(ucsi->ucsi);
326 }
327 
328 static const struct auxiliary_device_id pmic_glink_ucsi_id_table[] = {
329 	{ .name = "pmic_glink.ucsi", },
330 	{},
331 };
332 MODULE_DEVICE_TABLE(auxiliary, pmic_glink_ucsi_id_table);
333 
334 static struct auxiliary_driver pmic_glink_ucsi_driver = {
335 	.name = "pmic_glink_ucsi",
336 	.probe = pmic_glink_ucsi_probe,
337 	.remove = pmic_glink_ucsi_remove,
338 	.id_table = pmic_glink_ucsi_id_table,
339 };
340 
341 module_auxiliary_driver(pmic_glink_ucsi_driver);
342 
343 MODULE_DESCRIPTION("Qualcomm PMIC GLINK UCSI driver");
344 MODULE_LICENSE("GPL");
345