xref: /freebsd/sys/dev/axgbe/xgbe-i2c.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * AMD 10Gb Ethernet driver
3  *
4  * Copyright (c) 2020 Advanced Micro Devices, Inc.
5  *
6  * This file is available to you under your choice of the following two
7  * licenses:
8  *
9  * License 1: GPLv2
10  *
11  * This file is free software; you may copy, redistribute and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation, either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This file is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
23  *
24  * This file incorporates work covered by the following copyright and
25  * permission notice:
26  *     The Synopsys DWC ETHER XGMAC Software Driver and documentation
27  *     (hereinafter "Software") is an unsupported proprietary work of Synopsys,
28  *     Inc. unless otherwise expressly agreed to in writing between Synopsys
29  *     and you.
30  *
31  *     The Software IS NOT an item of Licensed Software or Licensed Product
32  *     under any End User Software License Agreement or Agreement for Licensed
33  *     Product with Synopsys or any supplement thereto.  Permission is hereby
34  *     granted, free of charge, to any person obtaining a copy of this software
35  *     annotated with this license and the Software, to deal in the Software
36  *     without restriction, including without limitation the rights to use,
37  *     copy, modify, merge, publish, distribute, sublicense, and/or sell copies
38  *     of the Software, and to permit persons to whom the Software is furnished
39  *     to do so, subject to the following conditions:
40  *
41  *     The above copyright notice and this permission notice shall be included
42  *     in all copies or substantial portions of the Software.
43  *
44  *     THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS"
45  *     BASIS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
46  *     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
47  *     PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS
48  *     BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
49  *     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
50  *     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
51  *     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
52  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
53  *     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
54  *     THE POSSIBILITY OF SUCH DAMAGE.
55  *
56  *
57  * License 2: Modified BSD
58  *
59  * Redistribution and use in source and binary forms, with or without
60  * modification, are permitted provided that the following conditions are met:
61  *     * Redistributions of source code must retain the above copyright
62  *       notice, this list of conditions and the following disclaimer.
63  *     * Redistributions in binary form must reproduce the above copyright
64  *       notice, this list of conditions and the following disclaimer in the
65  *       documentation and/or other materials provided with the distribution.
66  *     * Neither the name of Advanced Micro Devices, Inc. nor the
67  *       names of its contributors may be used to endorse or promote products
68  *       derived from this software without specific prior written permission.
69  *
70  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
71  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
72  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
73  * ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
74  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
75  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
76  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
77  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
78  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
79  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
80  *
81  * This file incorporates work covered by the following copyright and
82  * permission notice:
83  *     The Synopsys DWC ETHER XGMAC Software Driver and documentation
84  *     (hereinafter "Software") is an unsupported proprietary work of Synopsys,
85  *     Inc. unless otherwise expressly agreed to in writing between Synopsys
86  *     and you.
87  *
88  *     The Software IS NOT an item of Licensed Software or Licensed Product
89  *     under any End User Software License Agreement or Agreement for Licensed
90  *     Product with Synopsys or any supplement thereto.  Permission is hereby
91  *     granted, free of charge, to any person obtaining a copy of this software
92  *     annotated with this license and the Software, to deal in the Software
93  *     without restriction, including without limitation the rights to use,
94  *     copy, modify, merge, publish, distribute, sublicense, and/or sell copies
95  *     of the Software, and to permit persons to whom the Software is furnished
96  *     to do so, subject to the following conditions:
97  *
98  *     The above copyright notice and this permission notice shall be included
99  *     in all copies or substantial portions of the Software.
100  *
101  *     THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS"
102  *     BASIS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
103  *     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
104  *     PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS
105  *     BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
106  *     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
107  *     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
108  *     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
109  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
110  *     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
111  *     THE POSSIBILITY OF SUCH DAMAGE.
112  */
113 
114 #include <sys/cdefs.h>
115 __FBSDID("$FreeBSD$");
116 
117 #include "xgbe.h"
118 #include "xgbe-common.h"
119 
120 #define XGBE_ABORT_COUNT	500
121 #define XGBE_DISABLE_COUNT	1000
122 
123 #define XGBE_STD_SPEED		1
124 
125 #define XGBE_INTR_RX_FULL	BIT(IC_RAW_INTR_STAT_RX_FULL_INDEX)
126 #define XGBE_INTR_TX_EMPTY	BIT(IC_RAW_INTR_STAT_TX_EMPTY_INDEX)
127 #define XGBE_INTR_TX_ABRT	BIT(IC_RAW_INTR_STAT_TX_ABRT_INDEX)
128 #define XGBE_INTR_STOP_DET	BIT(IC_RAW_INTR_STAT_STOP_DET_INDEX)
129 #define XGBE_DEFAULT_INT_MASK	(XGBE_INTR_RX_FULL  |	\
130 				 XGBE_INTR_TX_EMPTY |	\
131 				 XGBE_INTR_TX_ABRT  |	\
132 				 XGBE_INTR_STOP_DET)
133 
134 #define XGBE_I2C_READ		BIT(8)
135 #define XGBE_I2C_STOP		BIT(9)
136 
137 static int
138 xgbe_i2c_abort(struct xgbe_prv_data *pdata)
139 {
140 	unsigned int wait = XGBE_ABORT_COUNT;
141 
142 	/* Must be enabled to recognize the abort request */
143 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, 1);
144 
145 	/* Issue the abort */
146 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, ABORT, 1);
147 
148 	while (wait--) {
149 		if (!XI2C_IOREAD_BITS(pdata, IC_ENABLE, ABORT))
150 			return (0);
151 
152 		DELAY(500);
153 	}
154 
155 	return (-EBUSY);
156 }
157 
158 static int
159 xgbe_i2c_set_enable(struct xgbe_prv_data *pdata, bool enable)
160 {
161 	unsigned int wait = XGBE_DISABLE_COUNT;
162 	unsigned int mode = enable ? 1 : 0;
163 
164 	while (wait--) {
165 		XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, mode);
166 		if (XI2C_IOREAD_BITS(pdata, IC_ENABLE_STATUS, EN) == mode)
167 			return (0);
168 
169 		DELAY(100);
170 	}
171 
172 	return (-EBUSY);
173 }
174 
175 static int
176 xgbe_i2c_disable(struct xgbe_prv_data *pdata)
177 {
178 	unsigned int ret;
179 
180 	ret = xgbe_i2c_set_enable(pdata, false);
181 	if (ret) {
182 		/* Disable failed, try an abort */
183 		ret = xgbe_i2c_abort(pdata);
184 		if (ret) {
185 			axgbe_error("%s: i2c_abort %d\n", __func__, ret);
186 			return (ret);
187 		}
188 
189 		/* Abort succeeded, try to disable again */
190 		ret = xgbe_i2c_set_enable(pdata, false);
191 	}
192 
193 	axgbe_printf(3, "%s: final i2c_disable %d\n", __func__, ret);
194 	return (ret);
195 }
196 
197 static int
198 xgbe_i2c_enable(struct xgbe_prv_data *pdata)
199 {
200 	return (xgbe_i2c_set_enable(pdata, true));
201 }
202 
203 static void
204 xgbe_i2c_clear_all_interrupts(struct xgbe_prv_data *pdata)
205 {
206 	XI2C_IOREAD(pdata, IC_CLR_INTR);
207 }
208 
209 static void
210 xgbe_i2c_disable_interrupts(struct xgbe_prv_data *pdata)
211 {
212 	XI2C_IOWRITE(pdata, IC_INTR_MASK, 0);
213 }
214 
215 static void
216 xgbe_i2c_enable_interrupts(struct xgbe_prv_data *pdata)
217 {
218 	XI2C_IOWRITE(pdata, IC_INTR_MASK, XGBE_DEFAULT_INT_MASK);
219 }
220 
221 static void
222 xgbe_i2c_write(struct xgbe_prv_data *pdata)
223 {
224 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
225 	unsigned int tx_slots, cmd;
226 
227 	/* Configured to never receive Rx overflows, so fill up Tx fifo */
228 	tx_slots = pdata->i2c.tx_fifo_size - XI2C_IOREAD(pdata, IC_TXFLR);
229 	axgbe_printf(3, "%s: tx_slots %d tx_len %d\n", __func__, tx_slots,
230 	    state->tx_len);
231 
232 	while (tx_slots && state->tx_len) {
233 		if (state->op->cmd == XGBE_I2C_CMD_READ)
234 			cmd = XGBE_I2C_READ;
235 		else
236 			cmd = *state->tx_buf++;
237 
238 		axgbe_printf(3, "%s: cmd %d tx_len %d\n", __func__, cmd,
239 		    state->tx_len);
240 
241 		if (state->tx_len == 1)
242 			XI2C_SET_BITS(cmd, IC_DATA_CMD, STOP, 1);
243 
244 		XI2C_IOWRITE(pdata, IC_DATA_CMD, cmd);
245 
246 		tx_slots--;
247 		state->tx_len--;
248 	}
249 
250 	/* No more Tx operations, so ignore TX_EMPTY and return */
251 	if (!state->tx_len)
252 		XI2C_IOWRITE_BITS(pdata, IC_INTR_MASK, TX_EMPTY, 0);
253 }
254 
255 static void
256 xgbe_i2c_read(struct xgbe_prv_data *pdata)
257 {
258 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
259 	unsigned int rx_slots;
260 
261 	/* Anything to be read? */
262 	axgbe_printf(3, "%s: op cmd %d\n", __func__, state->op->cmd);
263 	if (state->op->cmd != XGBE_I2C_CMD_READ)
264 		return;
265 
266 	rx_slots = XI2C_IOREAD(pdata, IC_RXFLR);
267 	axgbe_printf(3, "%s: rx_slots %d rx_len %d\n", __func__, rx_slots,
268 	    state->rx_len);
269 
270 	while (rx_slots && state->rx_len) {
271 		*state->rx_buf++ = XI2C_IOREAD(pdata, IC_DATA_CMD);
272 		state->rx_len--;
273 		rx_slots--;
274 	}
275 }
276 
277 static void
278 xgbe_i2c_clear_isr_interrupts(struct xgbe_prv_data *pdata, unsigned int isr)
279 {
280 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
281 
282 	if (isr & XGBE_INTR_TX_ABRT) {
283 		state->tx_abort_source = XI2C_IOREAD(pdata, IC_TX_ABRT_SOURCE);
284 		XI2C_IOREAD(pdata, IC_CLR_TX_ABRT);
285 	}
286 
287 	if (isr & XGBE_INTR_STOP_DET)
288 		XI2C_IOREAD(pdata, IC_CLR_STOP_DET);
289 }
290 
291 static void
292 xgbe_i2c_isr(void *data)
293 {
294 	struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
295 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
296 	unsigned int isr;
297 
298 	isr = XI2C_IOREAD(pdata, IC_RAW_INTR_STAT);
299 	axgbe_printf(3, "%s: isr 0x%x\n", __func__, isr);
300 	if (!isr)
301 		goto reissue_check;
302 
303 	axgbe_printf(3, "%s: I2C interrupt status=%#010x\n", __func__, isr);
304 
305 	xgbe_i2c_clear_isr_interrupts(pdata, isr);
306 
307 	if (isr & XGBE_INTR_TX_ABRT) {
308 		axgbe_printf(1, "%s: I2C TX_ABRT received (%#010x) for target "
309 		    "%#04x\n", __func__, state->tx_abort_source,
310 		    state->op->target);
311 
312 		xgbe_i2c_disable_interrupts(pdata);
313 
314 		state->ret = -EIO;
315 		goto out;
316 	}
317 
318 	/* Check for data in the Rx fifo */
319 	xgbe_i2c_read(pdata);
320 
321 	/* Fill up the Tx fifo next */
322 	xgbe_i2c_write(pdata);
323 
324 out:
325 	/* Complete on an error or STOP condition */
326 	axgbe_printf(3, "%s: ret %d stop %d\n", __func__, state->ret,
327 	    XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET));
328 
329 	if (state->ret || XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET))
330 		pdata->i2c_complete = true;
331 
332 	return;
333 
334 reissue_check:
335 	/* Reissue interrupt if status is not clear */
336 	if (pdata->vdata->irq_reissue_support)
337 		XP_IOWRITE(pdata, XP_INT_REISSUE_EN, 1 << 2);
338 }
339 
340 static void
341 xgbe_i2c_set_mode(struct xgbe_prv_data *pdata)
342 {
343 	unsigned int reg;
344 
345 	reg = XI2C_IOREAD(pdata, IC_CON);
346 	XI2C_SET_BITS(reg, IC_CON, MASTER_MODE, 1);
347 	XI2C_SET_BITS(reg, IC_CON, SLAVE_DISABLE, 1);
348 	XI2C_SET_BITS(reg, IC_CON, RESTART_EN, 1);
349 	XI2C_SET_BITS(reg, IC_CON, SPEED, XGBE_STD_SPEED);
350 	XI2C_SET_BITS(reg, IC_CON, RX_FIFO_FULL_HOLD, 1);
351 	XI2C_IOWRITE(pdata, IC_CON, reg);
352 }
353 
354 static void
355 xgbe_i2c_get_features(struct xgbe_prv_data *pdata)
356 {
357 	struct xgbe_i2c *i2c = &pdata->i2c;
358 	unsigned int reg;
359 
360 	reg = XI2C_IOREAD(pdata, IC_COMP_PARAM_1);
361 	i2c->max_speed_mode = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
362 					    MAX_SPEED_MODE);
363 	i2c->rx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
364 					  RX_BUFFER_DEPTH);
365 	i2c->tx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
366 					  TX_BUFFER_DEPTH);
367 
368 	axgbe_printf(3, "%s: I2C features: %s=%u, %s=%u, %s=%u\n", __func__,
369 	    "MAX_SPEED_MODE", i2c->max_speed_mode,
370 	    "RX_BUFFER_DEPTH", i2c->rx_fifo_size,
371 	    "TX_BUFFER_DEPTH", i2c->tx_fifo_size);
372 }
373 
374 static void
375 xgbe_i2c_set_target(struct xgbe_prv_data *pdata, unsigned int addr)
376 {
377 	XI2C_IOWRITE(pdata, IC_TAR, addr);
378 }
379 
380 static void
381 xgbe_i2c_combined_isr(struct xgbe_prv_data *pdata)
382 {
383 	xgbe_i2c_isr(pdata);
384 }
385 
386 static int
387 xgbe_i2c_xfer(struct xgbe_prv_data *pdata, struct xgbe_i2c_op *op)
388 {
389 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
390 	unsigned long timeout;
391 	int ret;
392 
393 	mtx_lock(&pdata->i2c_mutex);
394 
395 	axgbe_printf(3, "i2c xfer started ---->>>\n");
396 
397 	ret = xgbe_i2c_disable(pdata);
398 	if (ret) {
399 		axgbe_error("failed to disable i2c master\n");
400 		goto out;
401 	}
402 
403 	xgbe_i2c_set_target(pdata, op->target);
404 
405 	memset(state, 0, sizeof(*state));
406 	state->op = op;
407 	state->tx_len = op->len;
408 	state->tx_buf = op->buf;
409 	state->rx_len = op->len;
410 	state->rx_buf = op->buf;
411 
412 	xgbe_i2c_clear_all_interrupts(pdata);
413 	ret = xgbe_i2c_enable(pdata);
414 	if (ret) {
415 		axgbe_error("failed to enable i2c master\n");
416 		goto out;
417 	}
418 
419 	/* Enabling the interrupts will cause the TX FIFO empty interrupt to
420 	 * fire and begin to process the command via the ISR.
421 	 */
422 	xgbe_i2c_enable_interrupts(pdata);
423 
424 	timeout = ticks + (20 * hz);
425 	while (ticks < timeout) {
426 
427 		if (!pdata->i2c_complete) {
428 			DELAY(200);
429 			continue;
430 		}
431 
432 		axgbe_printf(1, "%s: I2C OP complete\n", __func__);
433 		break;
434 	}
435 
436 	if ((ticks >= timeout) && !pdata->i2c_complete) {
437 		axgbe_error("%s: operation timed out\n", __func__);
438 		ret = -ETIMEDOUT;
439 		goto disable;
440 	}
441 
442 	ret = state->ret;
443 	axgbe_printf(3, "%s: i2c xfer ret %d abrt_source 0x%x \n", __func__,
444 	    ret, state->tx_abort_source);
445 	if (ret) {
446 
447 		axgbe_error("%s: i2c xfer ret %d abrt_source 0x%x \n", __func__,
448 		    ret, state->tx_abort_source);
449 		if (state->tx_abort_source & IC_TX_ABRT_7B_ADDR_NOACK)
450 			ret = -ENOTCONN;
451 		else if (state->tx_abort_source & IC_TX_ABRT_ARB_LOST)
452 			ret = -EAGAIN;
453 	}
454 
455 	axgbe_printf(3, "i2c xfer finished ---->>>\n");
456 
457 disable:
458 	pdata->i2c_complete = false;
459 	xgbe_i2c_disable_interrupts(pdata);
460 	xgbe_i2c_disable(pdata);
461 
462 out:
463 	mtx_unlock(&pdata->i2c_mutex);
464 	return (ret);
465 }
466 
467 static void
468 xgbe_i2c_stop(struct xgbe_prv_data *pdata)
469 {
470 	if (!pdata->i2c.started)
471 		return;
472 
473 	axgbe_printf(3, "stopping I2C\n");
474 
475 	pdata->i2c.started = 0;
476 
477 	xgbe_i2c_disable_interrupts(pdata);
478 	xgbe_i2c_disable(pdata);
479 	xgbe_i2c_clear_all_interrupts(pdata);
480 }
481 
482 static int
483 xgbe_i2c_start(struct xgbe_prv_data *pdata)
484 {
485 	if (pdata->i2c.started)
486 		return (0);
487 
488 	pdata->i2c.started = 1;
489 
490 	return (0);
491 }
492 
493 static int
494 xgbe_i2c_init(struct xgbe_prv_data *pdata)
495 {
496 	int ret;
497 
498 	/* initialize lock for i2c */
499 	mtx_init(&pdata->i2c_mutex, "xgbe i2c mutex lock", NULL, MTX_DEF);
500 	pdata->i2c_complete = false;
501 
502 	xgbe_i2c_disable_interrupts(pdata);
503 
504 	ret = xgbe_i2c_disable(pdata);
505 	if (ret) {
506 		axgbe_error("failed to disable i2c master\n");
507 		return (ret);
508 	}
509 
510 	xgbe_i2c_get_features(pdata);
511 
512 	xgbe_i2c_set_mode(pdata);
513 
514 	xgbe_i2c_clear_all_interrupts(pdata);
515 
516 	xgbe_dump_i2c_registers(pdata);
517 
518 	return (0);
519 }
520 
521 void
522 xgbe_init_function_ptrs_i2c(struct xgbe_i2c_if *i2c_if)
523 {
524 	i2c_if->i2c_init		= xgbe_i2c_init;
525 
526 	i2c_if->i2c_start		= xgbe_i2c_start;
527 	i2c_if->i2c_stop		= xgbe_i2c_stop;
528 
529 	i2c_if->i2c_xfer		= xgbe_i2c_xfer;
530 
531 	i2c_if->i2c_isr			= xgbe_i2c_combined_isr;
532 }
533