xref: /linux/drivers/net/ethernet/intel/ice/ice_gnss.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
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 int i, bytes_read, data_len, count;
121 	struct ice_aqc_link_topo_addr link_topo;
122 	struct ice_pf *pf;
123 	struct ice_hw *hw;
124 	__be16 data_len_b;
125 	char *buf = NULL;
126 	u8 i2c_params;
127 	int err = 0;
128 
129 	pf = gnss->back;
130 	if (!pf) {
131 		err = -EFAULT;
132 		goto exit;
133 	}
134 
135 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
136 		return;
137 
138 	hw = &pf->hw;
139 	buf = (char *)get_zeroed_page(GFP_KERNEL);
140 	if (!buf) {
141 		err = -ENOMEM;
142 		goto exit;
143 	}
144 
145 	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
146 	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
147 	link_topo.topo_params.node_type_ctx |=
148 		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
149 			   ICE_AQC_LINK_TOPO_NODE_CTX_OVERRIDE);
150 
151 	i2c_params = ICE_GNSS_UBX_DATA_LEN_WIDTH |
152 		     ICE_AQC_I2C_USE_REPEATED_START;
153 
154 	/* Read data length in a loop, when it's not 0 the data is ready */
155 	for (i = 0; i < ICE_MAX_UBX_READ_TRIES; i++) {
156 		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
157 				      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
158 				      i2c_params, (u8 *)&data_len_b, NULL);
159 		if (err)
160 			goto exit_buf;
161 
162 		data_len = be16_to_cpu(data_len_b);
163 		if (data_len != 0 && data_len != U16_MAX)
164 			break;
165 
166 		mdelay(10);
167 	}
168 
169 	data_len = min_t(typeof(data_len), data_len, PAGE_SIZE);
170 	if (!data_len) {
171 		err = -ENOMEM;
172 		goto exit_buf;
173 	}
174 
175 	/* Read received data */
176 	for (i = 0; i < data_len; i += bytes_read) {
177 		unsigned int bytes_left = data_len - i;
178 
179 		bytes_read = min_t(typeof(bytes_left), bytes_left,
180 				   ICE_MAX_I2C_DATA_SIZE);
181 
182 		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
183 				      cpu_to_le16(ICE_GNSS_UBX_EMPTY_DATA),
184 				      bytes_read, &buf[i], NULL);
185 		if (err)
186 			goto exit_buf;
187 	}
188 
189 	count = gnss_insert_raw(pf->gnss_dev, buf, i);
190 	if (count != i)
191 		dev_warn(ice_pf_to_dev(pf),
192 			 "gnss_insert_raw ret=%d size=%d\n",
193 			 count, i);
194 exit_buf:
195 	free_page((unsigned long)buf);
196 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work,
197 				   ICE_GNSS_TIMER_DELAY_TIME);
198 exit:
199 	if (err)
200 		dev_dbg(ice_pf_to_dev(pf), "GNSS failed to read err=%d\n", err);
201 }
202 
203 /**
204  * ice_gnss_struct_init - Initialize GNSS receiver
205  * @pf: Board private structure
206  *
207  * Initialize GNSS structures and workers.
208  *
209  * Return:
210  * * pointer to initialized gnss_serial struct - success
211  * * NULL - error
212  */
213 static struct gnss_serial *ice_gnss_struct_init(struct ice_pf *pf)
214 {
215 	struct device *dev = ice_pf_to_dev(pf);
216 	struct kthread_worker *kworker;
217 	struct gnss_serial *gnss;
218 
219 	gnss = kzalloc(sizeof(*gnss), GFP_KERNEL);
220 	if (!gnss)
221 		return NULL;
222 
223 	gnss->back = pf;
224 	pf->gnss_serial = gnss;
225 
226 	kthread_init_delayed_work(&gnss->read_work, ice_gnss_read);
227 	INIT_LIST_HEAD(&gnss->queue);
228 	kthread_init_work(&gnss->write_work, ice_gnss_write_pending);
229 	kworker = kthread_create_worker(0, "ice-gnss-%s", dev_name(dev));
230 	if (IS_ERR(kworker)) {
231 		kfree(gnss);
232 		return NULL;
233 	}
234 
235 	gnss->kworker = kworker;
236 
237 	return gnss;
238 }
239 
240 /**
241  * ice_gnss_open - Open GNSS device
242  * @gdev: pointer to the gnss device struct
243  *
244  * Open GNSS device and start filling the read buffer for consumer.
245  *
246  * Return:
247  * * 0 - success
248  * * negative - error code
249  */
250 static int ice_gnss_open(struct gnss_device *gdev)
251 {
252 	struct ice_pf *pf = gnss_get_drvdata(gdev);
253 	struct gnss_serial *gnss;
254 
255 	if (!pf)
256 		return -EFAULT;
257 
258 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
259 		return -EFAULT;
260 
261 	gnss = pf->gnss_serial;
262 	if (!gnss)
263 		return -ENODEV;
264 
265 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, 0);
266 
267 	return 0;
268 }
269 
270 /**
271  * ice_gnss_close - Close GNSS device
272  * @gdev: pointer to the gnss device struct
273  *
274  * Close GNSS device, cancel worker, stop filling the read buffer.
275  */
276 static void ice_gnss_close(struct gnss_device *gdev)
277 {
278 	struct ice_pf *pf = gnss_get_drvdata(gdev);
279 	struct gnss_serial *gnss;
280 
281 	if (!pf)
282 		return;
283 
284 	gnss = pf->gnss_serial;
285 	if (!gnss)
286 		return;
287 
288 	kthread_cancel_work_sync(&gnss->write_work);
289 	kthread_cancel_delayed_work_sync(&gnss->read_work);
290 }
291 
292 /**
293  * ice_gnss_write - Write to GNSS device
294  * @gdev: pointer to the gnss device struct
295  * @buf: pointer to the user data
296  * @count: size of the buffer to be sent to the GNSS device
297  *
298  * Return:
299  * * number of written bytes - success
300  * * negative - error code
301  */
302 static int
303 ice_gnss_write(struct gnss_device *gdev, const unsigned char *buf,
304 	       size_t count)
305 {
306 	struct ice_pf *pf = gnss_get_drvdata(gdev);
307 	struct gnss_write_buf *write_buf;
308 	struct gnss_serial *gnss;
309 	unsigned char *cmd_buf;
310 	int err = count;
311 
312 	/* We cannot write a single byte using our I2C implementation. */
313 	if (count <= 1 || count > ICE_GNSS_TTY_WRITE_BUF)
314 		return -EINVAL;
315 
316 	if (!pf)
317 		return -EFAULT;
318 
319 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
320 		return -EFAULT;
321 
322 	gnss = pf->gnss_serial;
323 	if (!gnss)
324 		return -ENODEV;
325 
326 	cmd_buf = kcalloc(count, sizeof(*buf), GFP_KERNEL);
327 	if (!cmd_buf)
328 		return -ENOMEM;
329 
330 	memcpy(cmd_buf, buf, count);
331 	write_buf = kzalloc(sizeof(*write_buf), GFP_KERNEL);
332 	if (!write_buf) {
333 		kfree(cmd_buf);
334 		return -ENOMEM;
335 	}
336 
337 	write_buf->buf = cmd_buf;
338 	write_buf->size = count;
339 	INIT_LIST_HEAD(&write_buf->queue);
340 	list_add_tail(&write_buf->queue, &gnss->queue);
341 	kthread_queue_work(gnss->kworker, &gnss->write_work);
342 
343 	return err;
344 }
345 
346 static const struct gnss_operations ice_gnss_ops = {
347 	.open = ice_gnss_open,
348 	.close = ice_gnss_close,
349 	.write_raw = ice_gnss_write,
350 };
351 
352 /**
353  * ice_gnss_register - Register GNSS receiver
354  * @pf: Board private structure
355  *
356  * Allocate and register GNSS receiver in the Linux GNSS subsystem.
357  *
358  * Return:
359  * * 0 - success
360  * * negative - error code
361  */
362 static int ice_gnss_register(struct ice_pf *pf)
363 {
364 	struct gnss_device *gdev;
365 	int ret;
366 
367 	gdev = gnss_allocate_device(ice_pf_to_dev(pf));
368 	if (!gdev) {
369 		dev_err(ice_pf_to_dev(pf),
370 			"gnss_allocate_device returns NULL\n");
371 		return -ENOMEM;
372 	}
373 
374 	gdev->ops = &ice_gnss_ops;
375 	gdev->type = GNSS_TYPE_UBX;
376 	gnss_set_drvdata(gdev, pf);
377 	ret = gnss_register_device(gdev);
378 	if (ret) {
379 		dev_err(ice_pf_to_dev(pf), "gnss_register_device err=%d\n",
380 			ret);
381 		gnss_put_device(gdev);
382 	} else {
383 		pf->gnss_dev = gdev;
384 	}
385 
386 	return ret;
387 }
388 
389 /**
390  * ice_gnss_deregister - Deregister GNSS receiver
391  * @pf: Board private structure
392  *
393  * Deregister GNSS receiver from the Linux GNSS subsystem,
394  * release its resources.
395  */
396 static void ice_gnss_deregister(struct ice_pf *pf)
397 {
398 	if (pf->gnss_dev) {
399 		gnss_deregister_device(pf->gnss_dev);
400 		gnss_put_device(pf->gnss_dev);
401 		pf->gnss_dev = NULL;
402 	}
403 }
404 
405 /**
406  * ice_gnss_init - Initialize GNSS support
407  * @pf: Board private structure
408  */
409 void ice_gnss_init(struct ice_pf *pf)
410 {
411 	int ret;
412 
413 	pf->gnss_serial = ice_gnss_struct_init(pf);
414 	if (!pf->gnss_serial)
415 		return;
416 
417 	ret = ice_gnss_register(pf);
418 	if (!ret) {
419 		set_bit(ICE_FLAG_GNSS, pf->flags);
420 		dev_info(ice_pf_to_dev(pf), "GNSS init successful\n");
421 	} else {
422 		ice_gnss_exit(pf);
423 		dev_err(ice_pf_to_dev(pf), "GNSS init failure\n");
424 	}
425 }
426 
427 /**
428  * ice_gnss_exit - Disable GNSS TTY support
429  * @pf: Board private structure
430  */
431 void ice_gnss_exit(struct ice_pf *pf)
432 {
433 	ice_gnss_deregister(pf);
434 	clear_bit(ICE_FLAG_GNSS, pf->flags);
435 
436 	if (pf->gnss_serial) {
437 		struct gnss_serial *gnss = pf->gnss_serial;
438 
439 		kthread_cancel_work_sync(&gnss->write_work);
440 		kthread_cancel_delayed_work_sync(&gnss->read_work);
441 		kthread_destroy_worker(gnss->kworker);
442 		gnss->kworker = NULL;
443 
444 		kfree(gnss);
445 		pf->gnss_serial = NULL;
446 	}
447 }
448 
449 /**
450  * ice_gnss_is_gps_present - Check if GPS HW is present
451  * @hw: pointer to HW struct
452  */
453 bool ice_gnss_is_gps_present(struct ice_hw *hw)
454 {
455 	if (!hw->func_caps.ts_func_info.src_tmr_owned)
456 		return false;
457 
458 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
459 	if (ice_is_e810t(hw)) {
460 		int err;
461 		u8 data;
462 
463 		err = ice_read_pca9575_reg_e810t(hw, ICE_PCA9575_P0_IN, &data);
464 		if (err || !!(data & ICE_E810T_P0_GNSS_PRSNT_N))
465 			return false;
466 	} else {
467 		return false;
468 	}
469 #else
470 	if (!ice_is_e810t(hw))
471 		return false;
472 #endif /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
473 
474 	return true;
475 }
476