1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2021-2022, Intel Corporation. */
3 
4 #include "ice.h"
5 #include "ice_lib.h"
6 
7 /**
8  * ice_gnss_do_write - Write data to internal GNSS receiver
9  * @pf: board private structure
10  * @buf: command buffer
11  * @size: command buffer size
12  *
13  * Write UBX command data to the GNSS receiver
14  *
15  * Return:
16  * * number of bytes written - success
17  * * negative - error code
18  */
19 static unsigned int
20 ice_gnss_do_write(struct ice_pf *pf, unsigned char *buf, unsigned int size)
21 {
22 	struct ice_aqc_link_topo_addr link_topo;
23 	struct ice_hw *hw = &pf->hw;
24 	unsigned int offset = 0;
25 	int err = 0;
26 
27 	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
28 	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
29 	link_topo.topo_params.node_type_ctx |=
30 		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
31 			   ICE_AQC_LINK_TOPO_NODE_CTX_OVERRIDE);
32 
33 	/* It's not possible to write a single byte to u-blox.
34 	 * Write all bytes in a loop until there are 6 or less bytes left. If
35 	 * there are exactly 6 bytes left, the last write would be only a byte.
36 	 * In this case, do 4+2 bytes writes instead of 5+1. Otherwise, do the
37 	 * last 2 to 5 bytes write.
38 	 */
39 	while (size - offset > ICE_GNSS_UBX_WRITE_BYTES + 1) {
40 		err = ice_aq_write_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
41 				       cpu_to_le16(buf[offset]),
42 				       ICE_MAX_I2C_WRITE_BYTES,
43 				       &buf[offset + 1], NULL);
44 		if (err)
45 			goto err_out;
46 
47 		offset += ICE_GNSS_UBX_WRITE_BYTES;
48 	}
49 
50 	/* Single byte would be written. Write 4 bytes instead of 5. */
51 	if (size - offset == ICE_GNSS_UBX_WRITE_BYTES + 1) {
52 		err = ice_aq_write_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
53 				       cpu_to_le16(buf[offset]),
54 				       ICE_MAX_I2C_WRITE_BYTES - 1,
55 				       &buf[offset + 1], NULL);
56 		if (err)
57 			goto err_out;
58 
59 		offset += ICE_GNSS_UBX_WRITE_BYTES - 1;
60 	}
61 
62 	/* Do the last write, 2 to 5 bytes. */
63 	err = ice_aq_write_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
64 			       cpu_to_le16(buf[offset]), size - offset - 1,
65 			       &buf[offset + 1], NULL);
66 	if (err)
67 		goto err_out;
68 
69 	return size;
70 
71 err_out:
72 	dev_err(ice_pf_to_dev(pf), "GNSS failed to write, offset=%u, size=%u, err=%d\n",
73 		offset, size, err);
74 
75 	return offset;
76 }
77 
78 /**
79  * ice_gnss_write_pending - Write all pending data to internal GNSS
80  * @work: GNSS write work structure
81  */
82 static void ice_gnss_write_pending(struct kthread_work *work)
83 {
84 	struct gnss_serial *gnss = container_of(work, struct gnss_serial,
85 						write_work);
86 	struct ice_pf *pf = gnss->back;
87 
88 	if (!pf)
89 		return;
90 
91 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
92 		return;
93 
94 	if (!list_empty(&gnss->queue)) {
95 		struct gnss_write_buf *write_buf = NULL;
96 		unsigned int bytes;
97 
98 		write_buf = list_first_entry(&gnss->queue,
99 					     struct gnss_write_buf, queue);
100 
101 		bytes = ice_gnss_do_write(pf, write_buf->buf, write_buf->size);
102 		dev_dbg(ice_pf_to_dev(pf), "%u bytes written to GNSS\n", bytes);
103 
104 		list_del(&write_buf->queue);
105 		kfree(write_buf->buf);
106 		kfree(write_buf);
107 	}
108 }
109 
110 /**
111  * ice_gnss_read - Read data from internal GNSS module
112  * @work: GNSS read work structure
113  *
114  * Read the data from internal GNSS receiver, write it to gnss_dev.
115  */
116 static void ice_gnss_read(struct kthread_work *work)
117 {
118 	struct gnss_serial *gnss = container_of(work, struct gnss_serial,
119 						read_work.work);
120 	unsigned long delay = ICE_GNSS_POLL_DATA_DELAY_TIME;
121 	unsigned int i, bytes_read, data_len, count;
122 	struct ice_aqc_link_topo_addr link_topo;
123 	struct ice_pf *pf;
124 	struct ice_hw *hw;
125 	__be16 data_len_b;
126 	char *buf = NULL;
127 	u8 i2c_params;
128 	int err = 0;
129 
130 	pf = gnss->back;
131 	if (!pf) {
132 		err = -EFAULT;
133 		goto exit;
134 	}
135 
136 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
137 		return;
138 
139 	hw = &pf->hw;
140 
141 	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
142 	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
143 	link_topo.topo_params.node_type_ctx |=
144 		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
145 			   ICE_AQC_LINK_TOPO_NODE_CTX_OVERRIDE);
146 
147 	i2c_params = ICE_GNSS_UBX_DATA_LEN_WIDTH |
148 		     ICE_AQC_I2C_USE_REPEATED_START;
149 
150 	err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
151 			      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
152 			      i2c_params, (u8 *)&data_len_b, NULL);
153 	if (err)
154 		goto requeue;
155 
156 	data_len = be16_to_cpu(data_len_b);
157 	if (data_len == 0 || data_len == U16_MAX)
158 		goto requeue;
159 
160 	/* The u-blox has data_len bytes for us to read */
161 
162 	data_len = min_t(typeof(data_len), data_len, PAGE_SIZE);
163 
164 	buf = (char *)get_zeroed_page(GFP_KERNEL);
165 	if (!buf) {
166 		err = -ENOMEM;
167 		goto requeue;
168 	}
169 
170 	/* Read received data */
171 	for (i = 0; i < data_len; i += bytes_read) {
172 		unsigned int bytes_left = data_len - i;
173 
174 		bytes_read = min_t(typeof(bytes_left), bytes_left,
175 				   ICE_MAX_I2C_DATA_SIZE);
176 
177 		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
178 				      cpu_to_le16(ICE_GNSS_UBX_EMPTY_DATA),
179 				      bytes_read, &buf[i], NULL);
180 		if (err)
181 			goto free_buf;
182 	}
183 
184 	count = gnss_insert_raw(pf->gnss_dev, buf, i);
185 	if (count != i)
186 		dev_warn(ice_pf_to_dev(pf),
187 			 "gnss_insert_raw ret=%d size=%d\n",
188 			 count, i);
189 	delay = ICE_GNSS_TIMER_DELAY_TIME;
190 free_buf:
191 	free_page((unsigned long)buf);
192 requeue:
193 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, delay);
194 exit:
195 	if (err)
196 		dev_dbg(ice_pf_to_dev(pf), "GNSS failed to read err=%d\n", err);
197 }
198 
199 /**
200  * ice_gnss_struct_init - Initialize GNSS receiver
201  * @pf: Board private structure
202  *
203  * Initialize GNSS structures and workers.
204  *
205  * Return:
206  * * pointer to initialized gnss_serial struct - success
207  * * NULL - error
208  */
209 static struct gnss_serial *ice_gnss_struct_init(struct ice_pf *pf)
210 {
211 	struct device *dev = ice_pf_to_dev(pf);
212 	struct kthread_worker *kworker;
213 	struct gnss_serial *gnss;
214 
215 	gnss = kzalloc(sizeof(*gnss), GFP_KERNEL);
216 	if (!gnss)
217 		return NULL;
218 
219 	gnss->back = pf;
220 	pf->gnss_serial = gnss;
221 
222 	kthread_init_delayed_work(&gnss->read_work, ice_gnss_read);
223 	INIT_LIST_HEAD(&gnss->queue);
224 	kthread_init_work(&gnss->write_work, ice_gnss_write_pending);
225 	kworker = kthread_create_worker(0, "ice-gnss-%s", dev_name(dev));
226 	if (IS_ERR(kworker)) {
227 		kfree(gnss);
228 		return NULL;
229 	}
230 
231 	gnss->kworker = kworker;
232 
233 	return gnss;
234 }
235 
236 /**
237  * ice_gnss_open - Open GNSS device
238  * @gdev: pointer to the gnss device struct
239  *
240  * Open GNSS device and start filling the read buffer for consumer.
241  *
242  * Return:
243  * * 0 - success
244  * * negative - error code
245  */
246 static int ice_gnss_open(struct gnss_device *gdev)
247 {
248 	struct ice_pf *pf = gnss_get_drvdata(gdev);
249 	struct gnss_serial *gnss;
250 
251 	if (!pf)
252 		return -EFAULT;
253 
254 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
255 		return -EFAULT;
256 
257 	gnss = pf->gnss_serial;
258 	if (!gnss)
259 		return -ENODEV;
260 
261 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, 0);
262 
263 	return 0;
264 }
265 
266 /**
267  * ice_gnss_close - Close GNSS device
268  * @gdev: pointer to the gnss device struct
269  *
270  * Close GNSS device, cancel worker, stop filling the read buffer.
271  */
272 static void ice_gnss_close(struct gnss_device *gdev)
273 {
274 	struct ice_pf *pf = gnss_get_drvdata(gdev);
275 	struct gnss_serial *gnss;
276 
277 	if (!pf)
278 		return;
279 
280 	gnss = pf->gnss_serial;
281 	if (!gnss)
282 		return;
283 
284 	kthread_cancel_work_sync(&gnss->write_work);
285 	kthread_cancel_delayed_work_sync(&gnss->read_work);
286 }
287 
288 /**
289  * ice_gnss_write - Write to GNSS device
290  * @gdev: pointer to the gnss device struct
291  * @buf: pointer to the user data
292  * @count: size of the buffer to be sent to the GNSS device
293  *
294  * Return:
295  * * number of written bytes - success
296  * * negative - error code
297  */
298 static int
299 ice_gnss_write(struct gnss_device *gdev, const unsigned char *buf,
300 	       size_t count)
301 {
302 	struct ice_pf *pf = gnss_get_drvdata(gdev);
303 	struct gnss_write_buf *write_buf;
304 	struct gnss_serial *gnss;
305 	unsigned char *cmd_buf;
306 	int err = count;
307 
308 	/* We cannot write a single byte using our I2C implementation. */
309 	if (count <= 1 || count > ICE_GNSS_TTY_WRITE_BUF)
310 		return -EINVAL;
311 
312 	if (!pf)
313 		return -EFAULT;
314 
315 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
316 		return -EFAULT;
317 
318 	gnss = pf->gnss_serial;
319 	if (!gnss)
320 		return -ENODEV;
321 
322 	cmd_buf = kcalloc(count, sizeof(*buf), GFP_KERNEL);
323 	if (!cmd_buf)
324 		return -ENOMEM;
325 
326 	memcpy(cmd_buf, buf, count);
327 	write_buf = kzalloc(sizeof(*write_buf), GFP_KERNEL);
328 	if (!write_buf) {
329 		kfree(cmd_buf);
330 		return -ENOMEM;
331 	}
332 
333 	write_buf->buf = cmd_buf;
334 	write_buf->size = count;
335 	INIT_LIST_HEAD(&write_buf->queue);
336 	list_add_tail(&write_buf->queue, &gnss->queue);
337 	kthread_queue_work(gnss->kworker, &gnss->write_work);
338 
339 	return err;
340 }
341 
342 static const struct gnss_operations ice_gnss_ops = {
343 	.open = ice_gnss_open,
344 	.close = ice_gnss_close,
345 	.write_raw = ice_gnss_write,
346 };
347 
348 /**
349  * ice_gnss_register - Register GNSS receiver
350  * @pf: Board private structure
351  *
352  * Allocate and register GNSS receiver in the Linux GNSS subsystem.
353  *
354  * Return:
355  * * 0 - success
356  * * negative - error code
357  */
358 static int ice_gnss_register(struct ice_pf *pf)
359 {
360 	struct gnss_device *gdev;
361 	int ret;
362 
363 	gdev = gnss_allocate_device(ice_pf_to_dev(pf));
364 	if (!gdev) {
365 		dev_err(ice_pf_to_dev(pf),
366 			"gnss_allocate_device returns NULL\n");
367 		return -ENOMEM;
368 	}
369 
370 	gdev->ops = &ice_gnss_ops;
371 	gdev->type = GNSS_TYPE_UBX;
372 	gnss_set_drvdata(gdev, pf);
373 	ret = gnss_register_device(gdev);
374 	if (ret) {
375 		dev_err(ice_pf_to_dev(pf), "gnss_register_device err=%d\n",
376 			ret);
377 		gnss_put_device(gdev);
378 	} else {
379 		pf->gnss_dev = gdev;
380 	}
381 
382 	return ret;
383 }
384 
385 /**
386  * ice_gnss_deregister - Deregister GNSS receiver
387  * @pf: Board private structure
388  *
389  * Deregister GNSS receiver from the Linux GNSS subsystem,
390  * release its resources.
391  */
392 static void ice_gnss_deregister(struct ice_pf *pf)
393 {
394 	if (pf->gnss_dev) {
395 		gnss_deregister_device(pf->gnss_dev);
396 		gnss_put_device(pf->gnss_dev);
397 		pf->gnss_dev = NULL;
398 	}
399 }
400 
401 /**
402  * ice_gnss_init - Initialize GNSS support
403  * @pf: Board private structure
404  */
405 void ice_gnss_init(struct ice_pf *pf)
406 {
407 	int ret;
408 
409 	pf->gnss_serial = ice_gnss_struct_init(pf);
410 	if (!pf->gnss_serial)
411 		return;
412 
413 	ret = ice_gnss_register(pf);
414 	if (!ret) {
415 		set_bit(ICE_FLAG_GNSS, pf->flags);
416 		dev_info(ice_pf_to_dev(pf), "GNSS init successful\n");
417 	} else {
418 		ice_gnss_exit(pf);
419 		dev_err(ice_pf_to_dev(pf), "GNSS init failure\n");
420 	}
421 }
422 
423 /**
424  * ice_gnss_exit - Disable GNSS TTY support
425  * @pf: Board private structure
426  */
427 void ice_gnss_exit(struct ice_pf *pf)
428 {
429 	ice_gnss_deregister(pf);
430 	clear_bit(ICE_FLAG_GNSS, pf->flags);
431 
432 	if (pf->gnss_serial) {
433 		struct gnss_serial *gnss = pf->gnss_serial;
434 
435 		kthread_cancel_work_sync(&gnss->write_work);
436 		kthread_cancel_delayed_work_sync(&gnss->read_work);
437 		kthread_destroy_worker(gnss->kworker);
438 		gnss->kworker = NULL;
439 
440 		kfree(gnss);
441 		pf->gnss_serial = NULL;
442 	}
443 }
444 
445 /**
446  * ice_gnss_is_gps_present - Check if GPS HW is present
447  * @hw: pointer to HW struct
448  */
449 bool ice_gnss_is_gps_present(struct ice_hw *hw)
450 {
451 	if (!hw->func_caps.ts_func_info.src_tmr_owned)
452 		return false;
453 
454 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
455 	if (ice_is_e810t(hw)) {
456 		int err;
457 		u8 data;
458 
459 		err = ice_read_pca9575_reg_e810t(hw, ICE_PCA9575_P0_IN, &data);
460 		if (err || !!(data & ICE_E810T_P0_GNSS_PRSNT_N))
461 			return false;
462 	} else {
463 		return false;
464 	}
465 #else
466 	if (!ice_is_e810t(hw))
467 		return false;
468 #endif /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
469 
470 	return true;
471 }
472