xref: /freebsd/sys/dev/axgbe/xgbe-i2c.c (revision 1edb7116f450c1a1793f2fd25f6bdc16735ef888)
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 #include "xgbe.h"
116 #include "xgbe-common.h"
117 
118 #define XGBE_ABORT_COUNT	500
119 #define XGBE_DISABLE_COUNT	1000
120 
121 #define XGBE_STD_SPEED		1
122 
123 #define XGBE_INTR_RX_FULL	BIT(IC_RAW_INTR_STAT_RX_FULL_INDEX)
124 #define XGBE_INTR_TX_EMPTY	BIT(IC_RAW_INTR_STAT_TX_EMPTY_INDEX)
125 #define XGBE_INTR_TX_ABRT	BIT(IC_RAW_INTR_STAT_TX_ABRT_INDEX)
126 #define XGBE_INTR_STOP_DET	BIT(IC_RAW_INTR_STAT_STOP_DET_INDEX)
127 #define XGBE_DEFAULT_INT_MASK	(XGBE_INTR_RX_FULL  |	\
128 				 XGBE_INTR_TX_EMPTY |	\
129 				 XGBE_INTR_TX_ABRT  |	\
130 				 XGBE_INTR_STOP_DET)
131 
132 #define XGBE_I2C_READ		BIT(8)
133 #define XGBE_I2C_STOP		BIT(9)
134 
135 static int
136 xgbe_i2c_abort(struct xgbe_prv_data *pdata)
137 {
138 	unsigned int wait = XGBE_ABORT_COUNT;
139 
140 	/* Must be enabled to recognize the abort request */
141 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, 1);
142 
143 	/* Issue the abort */
144 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, ABORT, 1);
145 
146 	while (wait--) {
147 		if (!XI2C_IOREAD_BITS(pdata, IC_ENABLE, ABORT))
148 			return (0);
149 
150 		DELAY(500);
151 	}
152 
153 	return (-EBUSY);
154 }
155 
156 static int
157 xgbe_i2c_set_enable(struct xgbe_prv_data *pdata, bool enable)
158 {
159 	unsigned int wait = XGBE_DISABLE_COUNT;
160 	unsigned int mode = enable ? 1 : 0;
161 
162 	while (wait--) {
163 		XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, mode);
164 		if (XI2C_IOREAD_BITS(pdata, IC_ENABLE_STATUS, EN) == mode)
165 			return (0);
166 
167 		DELAY(100);
168 	}
169 
170 	return (-EBUSY);
171 }
172 
173 static int
174 xgbe_i2c_disable(struct xgbe_prv_data *pdata)
175 {
176 	unsigned int ret;
177 
178 	ret = xgbe_i2c_set_enable(pdata, false);
179 	if (ret) {
180 		/* Disable failed, try an abort */
181 		ret = xgbe_i2c_abort(pdata);
182 		if (ret) {
183 			axgbe_error("%s: i2c_abort %d\n", __func__, ret);
184 			return (ret);
185 		}
186 
187 		/* Abort succeeded, try to disable again */
188 		ret = xgbe_i2c_set_enable(pdata, false);
189 	}
190 
191 	axgbe_printf(3, "%s: final i2c_disable %d\n", __func__, ret);
192 	return (ret);
193 }
194 
195 static int
196 xgbe_i2c_enable(struct xgbe_prv_data *pdata)
197 {
198 	return (xgbe_i2c_set_enable(pdata, true));
199 }
200 
201 static void
202 xgbe_i2c_clear_all_interrupts(struct xgbe_prv_data *pdata)
203 {
204 	XI2C_IOREAD(pdata, IC_CLR_INTR);
205 }
206 
207 static void
208 xgbe_i2c_disable_interrupts(struct xgbe_prv_data *pdata)
209 {
210 	XI2C_IOWRITE(pdata, IC_INTR_MASK, 0);
211 }
212 
213 static void
214 xgbe_i2c_enable_interrupts(struct xgbe_prv_data *pdata)
215 {
216 	XI2C_IOWRITE(pdata, IC_INTR_MASK, XGBE_DEFAULT_INT_MASK);
217 }
218 
219 static void
220 xgbe_i2c_write(struct xgbe_prv_data *pdata)
221 {
222 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
223 	unsigned int tx_slots, cmd;
224 
225 	/* Configured to never receive Rx overflows, so fill up Tx fifo */
226 	tx_slots = pdata->i2c.tx_fifo_size - XI2C_IOREAD(pdata, IC_TXFLR);
227 	axgbe_printf(3, "%s: tx_slots %d tx_len %d\n", __func__, tx_slots,
228 	    state->tx_len);
229 
230 	while (tx_slots && state->tx_len) {
231 		if (state->op->cmd == XGBE_I2C_CMD_READ)
232 			cmd = XGBE_I2C_READ;
233 		else
234 			cmd = *state->tx_buf++;
235 
236 		axgbe_printf(3, "%s: cmd %d tx_len %d\n", __func__, cmd,
237 		    state->tx_len);
238 
239 		if (state->tx_len == 1)
240 			XI2C_SET_BITS(cmd, IC_DATA_CMD, STOP, 1);
241 
242 		XI2C_IOWRITE(pdata, IC_DATA_CMD, cmd);
243 
244 		tx_slots--;
245 		state->tx_len--;
246 	}
247 
248 	/* No more Tx operations, so ignore TX_EMPTY and return */
249 	if (!state->tx_len)
250 		XI2C_IOWRITE_BITS(pdata, IC_INTR_MASK, TX_EMPTY, 0);
251 }
252 
253 static void
254 xgbe_i2c_read(struct xgbe_prv_data *pdata)
255 {
256 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
257 	unsigned int rx_slots;
258 
259 	/* Anything to be read? */
260 	axgbe_printf(3, "%s: op cmd %d\n", __func__, state->op->cmd);
261 	if (state->op->cmd != XGBE_I2C_CMD_READ)
262 		return;
263 
264 	rx_slots = XI2C_IOREAD(pdata, IC_RXFLR);
265 	axgbe_printf(3, "%s: rx_slots %d rx_len %d\n", __func__, rx_slots,
266 	    state->rx_len);
267 
268 	while (rx_slots && state->rx_len) {
269 		*state->rx_buf++ = XI2C_IOREAD(pdata, IC_DATA_CMD);
270 		state->rx_len--;
271 		rx_slots--;
272 	}
273 }
274 
275 static void
276 xgbe_i2c_clear_isr_interrupts(struct xgbe_prv_data *pdata, unsigned int isr)
277 {
278 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
279 
280 	if (isr & XGBE_INTR_TX_ABRT) {
281 		state->tx_abort_source = XI2C_IOREAD(pdata, IC_TX_ABRT_SOURCE);
282 		XI2C_IOREAD(pdata, IC_CLR_TX_ABRT);
283 	}
284 
285 	if (isr & XGBE_INTR_STOP_DET)
286 		XI2C_IOREAD(pdata, IC_CLR_STOP_DET);
287 }
288 
289 static void
290 xgbe_i2c_isr(void *data)
291 {
292 	struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
293 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
294 	unsigned int isr;
295 
296 	isr = XI2C_IOREAD(pdata, IC_RAW_INTR_STAT);
297 	axgbe_printf(3, "%s: isr 0x%x\n", __func__, isr);
298 	if (!isr)
299 		goto reissue_check;
300 
301 	axgbe_printf(3, "%s: I2C interrupt status=%#010x\n", __func__, isr);
302 
303 	xgbe_i2c_clear_isr_interrupts(pdata, isr);
304 
305 	if (isr & XGBE_INTR_TX_ABRT) {
306 		axgbe_printf(1, "%s: I2C TX_ABRT received (%#010x) for target "
307 		    "%#04x\n", __func__, state->tx_abort_source,
308 		    state->op->target);
309 
310 		xgbe_i2c_disable_interrupts(pdata);
311 
312 		state->ret = -EIO;
313 		goto out;
314 	}
315 
316 	/* Check for data in the Rx fifo */
317 	xgbe_i2c_read(pdata);
318 
319 	/* Fill up the Tx fifo next */
320 	xgbe_i2c_write(pdata);
321 
322 out:
323 	/* Complete on an error or STOP condition */
324 	axgbe_printf(3, "%s: ret %d stop %d\n", __func__, state->ret,
325 	    XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET));
326 
327 	if (state->ret || XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET))
328 		pdata->i2c_complete = true;
329 
330 	return;
331 
332 reissue_check:
333 	/* Reissue interrupt if status is not clear */
334 	if (pdata->vdata->irq_reissue_support)
335 		XP_IOWRITE(pdata, XP_INT_REISSUE_EN, 1 << 2);
336 }
337 
338 static void
339 xgbe_i2c_set_mode(struct xgbe_prv_data *pdata)
340 {
341 	unsigned int reg;
342 
343 	reg = XI2C_IOREAD(pdata, IC_CON);
344 	XI2C_SET_BITS(reg, IC_CON, MASTER_MODE, 1);
345 	XI2C_SET_BITS(reg, IC_CON, SLAVE_DISABLE, 1);
346 	XI2C_SET_BITS(reg, IC_CON, RESTART_EN, 1);
347 	XI2C_SET_BITS(reg, IC_CON, SPEED, XGBE_STD_SPEED);
348 	XI2C_SET_BITS(reg, IC_CON, RX_FIFO_FULL_HOLD, 1);
349 	XI2C_IOWRITE(pdata, IC_CON, reg);
350 }
351 
352 static void
353 xgbe_i2c_get_features(struct xgbe_prv_data *pdata)
354 {
355 	struct xgbe_i2c *i2c = &pdata->i2c;
356 	unsigned int reg;
357 
358 	reg = XI2C_IOREAD(pdata, IC_COMP_PARAM_1);
359 	i2c->max_speed_mode = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
360 					    MAX_SPEED_MODE);
361 	i2c->rx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
362 					  RX_BUFFER_DEPTH);
363 	i2c->tx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
364 					  TX_BUFFER_DEPTH);
365 
366 	axgbe_printf(3, "%s: I2C features: %s=%u, %s=%u, %s=%u\n", __func__,
367 	    "MAX_SPEED_MODE", i2c->max_speed_mode,
368 	    "RX_BUFFER_DEPTH", i2c->rx_fifo_size,
369 	    "TX_BUFFER_DEPTH", i2c->tx_fifo_size);
370 }
371 
372 static void
373 xgbe_i2c_set_target(struct xgbe_prv_data *pdata, unsigned int addr)
374 {
375 	XI2C_IOWRITE(pdata, IC_TAR, addr);
376 }
377 
378 static void
379 xgbe_i2c_combined_isr(struct xgbe_prv_data *pdata)
380 {
381 	xgbe_i2c_isr(pdata);
382 }
383 
384 static int
385 xgbe_i2c_xfer(struct xgbe_prv_data *pdata, struct xgbe_i2c_op *op)
386 {
387 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
388 	unsigned long timeout;
389 	int ret;
390 
391 	mtx_lock(&pdata->i2c_mutex);
392 
393 	axgbe_printf(3, "i2c xfer started ---->>>\n");
394 
395 	ret = xgbe_i2c_disable(pdata);
396 	if (ret) {
397 		axgbe_error("failed to disable i2c master\n");
398 		goto out;
399 	}
400 
401 	xgbe_i2c_set_target(pdata, op->target);
402 
403 	memset(state, 0, sizeof(*state));
404 	state->op = op;
405 	state->tx_len = op->len;
406 	state->tx_buf = op->buf;
407 	state->rx_len = op->len;
408 	state->rx_buf = op->buf;
409 
410 	xgbe_i2c_clear_all_interrupts(pdata);
411 	ret = xgbe_i2c_enable(pdata);
412 	if (ret) {
413 		axgbe_error("failed to enable i2c master\n");
414 		goto out;
415 	}
416 
417 	/* Enabling the interrupts will cause the TX FIFO empty interrupt to
418 	 * fire and begin to process the command via the ISR.
419 	 */
420 	xgbe_i2c_enable_interrupts(pdata);
421 
422 	timeout = ticks + (20 * hz);
423 	while (ticks < timeout) {
424 
425 		if (!pdata->i2c_complete) {
426 			DELAY(200);
427 			continue;
428 		}
429 
430 		axgbe_printf(1, "%s: I2C OP complete\n", __func__);
431 		break;
432 	}
433 
434 	if ((ticks >= timeout) && !pdata->i2c_complete) {
435 		axgbe_error("%s: operation timed out\n", __func__);
436 		ret = -ETIMEDOUT;
437 		goto disable;
438 	}
439 
440 	ret = state->ret;
441 	axgbe_printf(3, "%s: i2c xfer ret %d abrt_source 0x%x\n", __func__,
442 	    ret, state->tx_abort_source);
443 	if (ret) {
444 		axgbe_printf(1, "%s: i2c xfer ret %d abrt_source 0x%x\n", __func__,
445 		    ret, state->tx_abort_source);
446 		if (state->tx_abort_source & IC_TX_ABRT_7B_ADDR_NOACK)
447 			ret = -ENOTCONN;
448 		else if (state->tx_abort_source & IC_TX_ABRT_ARB_LOST)
449 			ret = -EAGAIN;
450 	}
451 
452 	axgbe_printf(3, "i2c xfer finished ---->>>\n");
453 
454 disable:
455 	pdata->i2c_complete = false;
456 	xgbe_i2c_disable_interrupts(pdata);
457 	xgbe_i2c_disable(pdata);
458 
459 out:
460 	mtx_unlock(&pdata->i2c_mutex);
461 	return (ret);
462 }
463 
464 static void
465 xgbe_i2c_stop(struct xgbe_prv_data *pdata)
466 {
467 	if (!pdata->i2c.started)
468 		return;
469 
470 	axgbe_printf(3, "stopping I2C\n");
471 
472 	pdata->i2c.started = 0;
473 
474 	xgbe_i2c_disable_interrupts(pdata);
475 	xgbe_i2c_disable(pdata);
476 	xgbe_i2c_clear_all_interrupts(pdata);
477 }
478 
479 static int
480 xgbe_i2c_start(struct xgbe_prv_data *pdata)
481 {
482 	if (pdata->i2c.started)
483 		return (0);
484 
485 	pdata->i2c.started = 1;
486 
487 	return (0);
488 }
489 
490 static int
491 xgbe_i2c_init(struct xgbe_prv_data *pdata)
492 {
493 	int ret;
494 
495 	/* initialize lock for i2c */
496 	mtx_init(&pdata->i2c_mutex, "xgbe i2c mutex lock", NULL, MTX_DEF);
497 	pdata->i2c_complete = false;
498 
499 	xgbe_i2c_disable_interrupts(pdata);
500 
501 	ret = xgbe_i2c_disable(pdata);
502 	if (ret) {
503 		axgbe_error("failed to disable i2c master\n");
504 		return (ret);
505 	}
506 
507 	xgbe_i2c_get_features(pdata);
508 
509 	xgbe_i2c_set_mode(pdata);
510 
511 	xgbe_i2c_clear_all_interrupts(pdata);
512 
513 	xgbe_dump_i2c_registers(pdata);
514 
515 	return (0);
516 }
517 
518 void
519 xgbe_init_function_ptrs_i2c(struct xgbe_i2c_if *i2c_if)
520 {
521 	i2c_if->i2c_init		= xgbe_i2c_init;
522 
523 	i2c_if->i2c_start		= xgbe_i2c_start;
524 	i2c_if->i2c_stop		= xgbe_i2c_stop;
525 
526 	i2c_if->i2c_xfer		= xgbe_i2c_xfer;
527 
528 	i2c_if->i2c_isr			= xgbe_i2c_combined_isr;
529 }
530