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 int
20 ice_gnss_do_write(struct ice_pf *pf, const 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 err;
76 }
77 
78 /**
79  * ice_gnss_read - Read data from internal GNSS module
80  * @work: GNSS read work structure
81  *
82  * Read the data from internal GNSS receiver, write it to gnss_dev.
83  */
84 static void ice_gnss_read(struct kthread_work *work)
85 {
86 	struct gnss_serial *gnss = container_of(work, struct gnss_serial,
87 						read_work.work);
88 	unsigned long delay = ICE_GNSS_POLL_DATA_DELAY_TIME;
89 	unsigned int i, bytes_read, data_len, count;
90 	struct ice_aqc_link_topo_addr link_topo;
91 	struct ice_pf *pf;
92 	struct ice_hw *hw;
93 	__be16 data_len_b;
94 	char *buf = NULL;
95 	u8 i2c_params;
96 	int err = 0;
97 
98 	pf = gnss->back;
99 	if (!pf) {
100 		err = -EFAULT;
101 		goto exit;
102 	}
103 
104 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
105 		return;
106 
107 	hw = &pf->hw;
108 
109 	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
110 	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
111 	link_topo.topo_params.node_type_ctx |=
112 		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
113 			   ICE_AQC_LINK_TOPO_NODE_CTX_OVERRIDE);
114 
115 	i2c_params = ICE_GNSS_UBX_DATA_LEN_WIDTH |
116 		     ICE_AQC_I2C_USE_REPEATED_START;
117 
118 	err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
119 			      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
120 			      i2c_params, (u8 *)&data_len_b, NULL);
121 	if (err)
122 		goto requeue;
123 
124 	data_len = be16_to_cpu(data_len_b);
125 	if (data_len == 0 || data_len == U16_MAX)
126 		goto requeue;
127 
128 	/* The u-blox has data_len bytes for us to read */
129 
130 	data_len = min_t(typeof(data_len), data_len, PAGE_SIZE);
131 
132 	buf = (char *)get_zeroed_page(GFP_KERNEL);
133 	if (!buf) {
134 		err = -ENOMEM;
135 		goto requeue;
136 	}
137 
138 	/* Read received data */
139 	for (i = 0; i < data_len; i += bytes_read) {
140 		unsigned int bytes_left = data_len - i;
141 
142 		bytes_read = min_t(typeof(bytes_left), bytes_left,
143 				   ICE_MAX_I2C_DATA_SIZE);
144 
145 		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
146 				      cpu_to_le16(ICE_GNSS_UBX_EMPTY_DATA),
147 				      bytes_read, &buf[i], NULL);
148 		if (err)
149 			goto free_buf;
150 	}
151 
152 	count = gnss_insert_raw(pf->gnss_dev, buf, i);
153 	if (count != i)
154 		dev_warn(ice_pf_to_dev(pf),
155 			 "gnss_insert_raw ret=%d size=%d\n",
156 			 count, i);
157 	delay = ICE_GNSS_TIMER_DELAY_TIME;
158 free_buf:
159 	free_page((unsigned long)buf);
160 requeue:
161 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, delay);
162 exit:
163 	if (err)
164 		dev_dbg(ice_pf_to_dev(pf), "GNSS failed to read err=%d\n", err);
165 }
166 
167 /**
168  * ice_gnss_struct_init - Initialize GNSS receiver
169  * @pf: Board private structure
170  *
171  * Initialize GNSS structures and workers.
172  *
173  * Return:
174  * * pointer to initialized gnss_serial struct - success
175  * * NULL - error
176  */
177 static struct gnss_serial *ice_gnss_struct_init(struct ice_pf *pf)
178 {
179 	struct device *dev = ice_pf_to_dev(pf);
180 	struct kthread_worker *kworker;
181 	struct gnss_serial *gnss;
182 
183 	gnss = kzalloc(sizeof(*gnss), GFP_KERNEL);
184 	if (!gnss)
185 		return NULL;
186 
187 	gnss->back = pf;
188 	pf->gnss_serial = gnss;
189 
190 	kthread_init_delayed_work(&gnss->read_work, ice_gnss_read);
191 	kworker = kthread_create_worker(0, "ice-gnss-%s", dev_name(dev));
192 	if (IS_ERR(kworker)) {
193 		kfree(gnss);
194 		return NULL;
195 	}
196 
197 	gnss->kworker = kworker;
198 
199 	return gnss;
200 }
201 
202 /**
203  * ice_gnss_open - Open GNSS device
204  * @gdev: pointer to the gnss device struct
205  *
206  * Open GNSS device and start filling the read buffer for consumer.
207  *
208  * Return:
209  * * 0 - success
210  * * negative - error code
211  */
212 static int ice_gnss_open(struct gnss_device *gdev)
213 {
214 	struct ice_pf *pf = gnss_get_drvdata(gdev);
215 	struct gnss_serial *gnss;
216 
217 	if (!pf)
218 		return -EFAULT;
219 
220 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
221 		return -EFAULT;
222 
223 	gnss = pf->gnss_serial;
224 	if (!gnss)
225 		return -ENODEV;
226 
227 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, 0);
228 
229 	return 0;
230 }
231 
232 /**
233  * ice_gnss_close - Close GNSS device
234  * @gdev: pointer to the gnss device struct
235  *
236  * Close GNSS device, cancel worker, stop filling the read buffer.
237  */
238 static void ice_gnss_close(struct gnss_device *gdev)
239 {
240 	struct ice_pf *pf = gnss_get_drvdata(gdev);
241 	struct gnss_serial *gnss;
242 
243 	if (!pf)
244 		return;
245 
246 	gnss = pf->gnss_serial;
247 	if (!gnss)
248 		return;
249 
250 	kthread_cancel_delayed_work_sync(&gnss->read_work);
251 }
252 
253 /**
254  * ice_gnss_write - Write to GNSS device
255  * @gdev: pointer to the gnss device struct
256  * @buf: pointer to the user data
257  * @count: size of the buffer to be sent to the GNSS device
258  *
259  * Return:
260  * * number of written bytes - success
261  * * negative - error code
262  */
263 static int
264 ice_gnss_write(struct gnss_device *gdev, const unsigned char *buf,
265 	       size_t count)
266 {
267 	struct ice_pf *pf = gnss_get_drvdata(gdev);
268 	struct gnss_serial *gnss;
269 
270 	/* We cannot write a single byte using our I2C implementation. */
271 	if (count <= 1 || count > ICE_GNSS_TTY_WRITE_BUF)
272 		return -EINVAL;
273 
274 	if (!pf)
275 		return -EFAULT;
276 
277 	if (!test_bit(ICE_FLAG_GNSS, pf->flags))
278 		return -EFAULT;
279 
280 	gnss = pf->gnss_serial;
281 	if (!gnss)
282 		return -ENODEV;
283 
284 	return ice_gnss_do_write(pf, buf, count);
285 }
286 
287 static const struct gnss_operations ice_gnss_ops = {
288 	.open = ice_gnss_open,
289 	.close = ice_gnss_close,
290 	.write_raw = ice_gnss_write,
291 };
292 
293 /**
294  * ice_gnss_register - Register GNSS receiver
295  * @pf: Board private structure
296  *
297  * Allocate and register GNSS receiver in the Linux GNSS subsystem.
298  *
299  * Return:
300  * * 0 - success
301  * * negative - error code
302  */
303 static int ice_gnss_register(struct ice_pf *pf)
304 {
305 	struct gnss_device *gdev;
306 	int ret;
307 
308 	gdev = gnss_allocate_device(ice_pf_to_dev(pf));
309 	if (!gdev) {
310 		dev_err(ice_pf_to_dev(pf),
311 			"gnss_allocate_device returns NULL\n");
312 		return -ENOMEM;
313 	}
314 
315 	gdev->ops = &ice_gnss_ops;
316 	gdev->type = GNSS_TYPE_UBX;
317 	gnss_set_drvdata(gdev, pf);
318 	ret = gnss_register_device(gdev);
319 	if (ret) {
320 		dev_err(ice_pf_to_dev(pf), "gnss_register_device err=%d\n",
321 			ret);
322 		gnss_put_device(gdev);
323 	} else {
324 		pf->gnss_dev = gdev;
325 	}
326 
327 	return ret;
328 }
329 
330 /**
331  * ice_gnss_deregister - Deregister GNSS receiver
332  * @pf: Board private structure
333  *
334  * Deregister GNSS receiver from the Linux GNSS subsystem,
335  * release its resources.
336  */
337 static void ice_gnss_deregister(struct ice_pf *pf)
338 {
339 	if (pf->gnss_dev) {
340 		gnss_deregister_device(pf->gnss_dev);
341 		gnss_put_device(pf->gnss_dev);
342 		pf->gnss_dev = NULL;
343 	}
344 }
345 
346 /**
347  * ice_gnss_init - Initialize GNSS support
348  * @pf: Board private structure
349  */
350 void ice_gnss_init(struct ice_pf *pf)
351 {
352 	int ret;
353 
354 	pf->gnss_serial = ice_gnss_struct_init(pf);
355 	if (!pf->gnss_serial)
356 		return;
357 
358 	ret = ice_gnss_register(pf);
359 	if (!ret) {
360 		set_bit(ICE_FLAG_GNSS, pf->flags);
361 		dev_info(ice_pf_to_dev(pf), "GNSS init successful\n");
362 	} else {
363 		ice_gnss_exit(pf);
364 		dev_err(ice_pf_to_dev(pf), "GNSS init failure\n");
365 	}
366 }
367 
368 /**
369  * ice_gnss_exit - Disable GNSS TTY support
370  * @pf: Board private structure
371  */
372 void ice_gnss_exit(struct ice_pf *pf)
373 {
374 	ice_gnss_deregister(pf);
375 	clear_bit(ICE_FLAG_GNSS, pf->flags);
376 
377 	if (pf->gnss_serial) {
378 		struct gnss_serial *gnss = pf->gnss_serial;
379 
380 		kthread_cancel_delayed_work_sync(&gnss->read_work);
381 		kthread_destroy_worker(gnss->kworker);
382 		gnss->kworker = NULL;
383 
384 		kfree(gnss);
385 		pf->gnss_serial = NULL;
386 	}
387 }
388 
389 /**
390  * ice_gnss_is_gps_present - Check if GPS HW is present
391  * @hw: pointer to HW struct
392  */
393 bool ice_gnss_is_gps_present(struct ice_hw *hw)
394 {
395 	if (!hw->func_caps.ts_func_info.src_tmr_owned)
396 		return false;
397 
398 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
399 	if (ice_is_e810t(hw)) {
400 		int err;
401 		u8 data;
402 
403 		err = ice_read_pca9575_reg_e810t(hw, ICE_PCA9575_P0_IN, &data);
404 		if (err || !!(data & ICE_E810T_P0_GNSS_PRSNT_N))
405 			return false;
406 	} else {
407 		return false;
408 	}
409 #else
410 	if (!ice_is_e810t(hw))
411 		return false;
412 #endif /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
413 
414 	return true;
415 }
416