xref: /linux/drivers/net/ethernet/amd/xgbe/xgbe-i2c.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * AMD 10Gb Ethernet driver
3  *
4  * This file is available to you under your choice of the following two
5  * licenses:
6  *
7  * License 1: GPLv2
8  *
9  * Copyright (c) 2016 Advanced Micro Devices, Inc.
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  * Copyright (c) 2016 Advanced Micro Devices, Inc.
60  * All rights reserved.
61  *
62  * Redistribution and use in source and binary forms, with or without
63  * modification, are permitted provided that the following conditions are met:
64  *     * Redistributions of source code must retain the above copyright
65  *       notice, this list of conditions and the following disclaimer.
66  *     * Redistributions in binary form must reproduce the above copyright
67  *       notice, this list of conditions and the following disclaimer in the
68  *       documentation and/or other materials provided with the distribution.
69  *     * Neither the name of Advanced Micro Devices, Inc. nor the
70  *       names of its contributors may be used to endorse or promote products
71  *       derived from this software without specific prior written permission.
72  *
73  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
74  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
75  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
76  * ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
77  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
78  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
79  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
80  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
81  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
82  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
83  *
84  * This file incorporates work covered by the following copyright and
85  * permission notice:
86  *     The Synopsys DWC ETHER XGMAC Software Driver and documentation
87  *     (hereinafter "Software") is an unsupported proprietary work of Synopsys,
88  *     Inc. unless otherwise expressly agreed to in writing between Synopsys
89  *     and you.
90  *
91  *     The Software IS NOT an item of Licensed Software or Licensed Product
92  *     under any End User Software License Agreement or Agreement for Licensed
93  *     Product with Synopsys or any supplement thereto.  Permission is hereby
94  *     granted, free of charge, to any person obtaining a copy of this software
95  *     annotated with this license and the Software, to deal in the Software
96  *     without restriction, including without limitation the rights to use,
97  *     copy, modify, merge, publish, distribute, sublicense, and/or sell copies
98  *     of the Software, and to permit persons to whom the Software is furnished
99  *     to do so, subject to the following conditions:
100  *
101  *     The above copyright notice and this permission notice shall be included
102  *     in all copies or substantial portions of the Software.
103  *
104  *     THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS"
105  *     BASIS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
106  *     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
107  *     PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS
108  *     BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
109  *     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
110  *     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
111  *     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
112  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
113  *     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
114  *     THE POSSIBILITY OF SUCH DAMAGE.
115  */
116 
117 #include <linux/module.h>
118 #include <linux/kmod.h>
119 #include <linux/delay.h>
120 #include <linux/completion.h>
121 #include <linux/mutex.h>
122 
123 #include "xgbe.h"
124 #include "xgbe-common.h"
125 
126 #define XGBE_ABORT_COUNT	500
127 #define XGBE_DISABLE_COUNT	1000
128 
129 #define XGBE_STD_SPEED		1
130 
131 #define XGBE_INTR_RX_FULL	BIT(IC_RAW_INTR_STAT_RX_FULL_INDEX)
132 #define XGBE_INTR_TX_EMPTY	BIT(IC_RAW_INTR_STAT_TX_EMPTY_INDEX)
133 #define XGBE_INTR_TX_ABRT	BIT(IC_RAW_INTR_STAT_TX_ABRT_INDEX)
134 #define XGBE_INTR_STOP_DET	BIT(IC_RAW_INTR_STAT_STOP_DET_INDEX)
135 #define XGBE_DEFAULT_INT_MASK	(XGBE_INTR_RX_FULL  |	\
136 				 XGBE_INTR_TX_EMPTY |	\
137 				 XGBE_INTR_TX_ABRT  |	\
138 				 XGBE_INTR_STOP_DET)
139 
140 #define XGBE_I2C_READ		BIT(8)
141 #define XGBE_I2C_STOP		BIT(9)
142 
143 static int xgbe_i2c_abort(struct xgbe_prv_data *pdata)
144 {
145 	unsigned int wait = XGBE_ABORT_COUNT;
146 
147 	/* Must be enabled to recognize the abort request */
148 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, 1);
149 
150 	/* Issue the abort */
151 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, ABORT, 1);
152 
153 	while (wait--) {
154 		if (!XI2C_IOREAD_BITS(pdata, IC_ENABLE, ABORT))
155 			return 0;
156 
157 		usleep_range(500, 600);
158 	}
159 
160 	return -EBUSY;
161 }
162 
163 static int xgbe_i2c_set_enable(struct xgbe_prv_data *pdata, bool enable)
164 {
165 	unsigned int wait = XGBE_DISABLE_COUNT;
166 	unsigned int mode = enable ? 1 : 0;
167 
168 	while (wait--) {
169 		XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, mode);
170 		if (XI2C_IOREAD_BITS(pdata, IC_ENABLE_STATUS, EN) == mode)
171 			return 0;
172 
173 		usleep_range(100, 110);
174 	}
175 
176 	return -EBUSY;
177 }
178 
179 static int xgbe_i2c_disable(struct xgbe_prv_data *pdata)
180 {
181 	unsigned int ret;
182 
183 	ret = xgbe_i2c_set_enable(pdata, false);
184 	if (ret) {
185 		/* Disable failed, try an abort */
186 		ret = xgbe_i2c_abort(pdata);
187 		if (ret)
188 			return ret;
189 
190 		/* Abort succeeded, try to disable again */
191 		ret = xgbe_i2c_set_enable(pdata, false);
192 	}
193 
194 	return ret;
195 }
196 
197 static int xgbe_i2c_enable(struct xgbe_prv_data *pdata)
198 {
199 	return xgbe_i2c_set_enable(pdata, true);
200 }
201 
202 static void xgbe_i2c_clear_all_interrupts(struct xgbe_prv_data *pdata)
203 {
204 	XI2C_IOREAD(pdata, IC_CLR_INTR);
205 }
206 
207 static void xgbe_i2c_disable_interrupts(struct xgbe_prv_data *pdata)
208 {
209 	XI2C_IOWRITE(pdata, IC_INTR_MASK, 0);
210 }
211 
212 static void xgbe_i2c_enable_interrupts(struct xgbe_prv_data *pdata)
213 {
214 	XI2C_IOWRITE(pdata, IC_INTR_MASK, XGBE_DEFAULT_INT_MASK);
215 }
216 
217 static void xgbe_i2c_write(struct xgbe_prv_data *pdata)
218 {
219 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
220 	unsigned int tx_slots;
221 	unsigned int cmd;
222 
223 	/* Configured to never receive Rx overflows, so fill up Tx fifo */
224 	tx_slots = pdata->i2c.tx_fifo_size - XI2C_IOREAD(pdata, IC_TXFLR);
225 	while (tx_slots && state->tx_len) {
226 		if (state->op->cmd == XGBE_I2C_CMD_READ)
227 			cmd = XGBE_I2C_READ;
228 		else
229 			cmd = *state->tx_buf++;
230 
231 		if (state->tx_len == 1)
232 			XI2C_SET_BITS(cmd, IC_DATA_CMD, STOP, 1);
233 
234 		XI2C_IOWRITE(pdata, IC_DATA_CMD, cmd);
235 
236 		tx_slots--;
237 		state->tx_len--;
238 	}
239 
240 	/* No more Tx operations, so ignore TX_EMPTY and return */
241 	if (!state->tx_len)
242 		XI2C_IOWRITE_BITS(pdata, IC_INTR_MASK, TX_EMPTY, 0);
243 }
244 
245 static void xgbe_i2c_read(struct xgbe_prv_data *pdata)
246 {
247 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
248 	unsigned int rx_slots;
249 
250 	/* Anything to be read? */
251 	if (state->op->cmd != XGBE_I2C_CMD_READ)
252 		return;
253 
254 	rx_slots = XI2C_IOREAD(pdata, IC_RXFLR);
255 	while (rx_slots && state->rx_len) {
256 		*state->rx_buf++ = XI2C_IOREAD(pdata, IC_DATA_CMD);
257 		state->rx_len--;
258 		rx_slots--;
259 	}
260 }
261 
262 static void xgbe_i2c_clear_isr_interrupts(struct xgbe_prv_data *pdata,
263 					  unsigned int isr)
264 {
265 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
266 
267 	if (isr & XGBE_INTR_TX_ABRT) {
268 		state->tx_abort_source = XI2C_IOREAD(pdata, IC_TX_ABRT_SOURCE);
269 		XI2C_IOREAD(pdata, IC_CLR_TX_ABRT);
270 	}
271 
272 	if (isr & XGBE_INTR_STOP_DET)
273 		XI2C_IOREAD(pdata, IC_CLR_STOP_DET);
274 }
275 
276 static irqreturn_t xgbe_i2c_isr(int irq, void *data)
277 {
278 	struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
279 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
280 	unsigned int isr;
281 
282 	isr = XI2C_IOREAD(pdata, IC_RAW_INTR_STAT);
283 	netif_dbg(pdata, intr, pdata->netdev,
284 		  "I2C interrupt received: status=%#010x\n", isr);
285 
286 	xgbe_i2c_clear_isr_interrupts(pdata, isr);
287 
288 	if (isr & XGBE_INTR_TX_ABRT) {
289 		netif_dbg(pdata, link, pdata->netdev,
290 			  "I2C TX_ABRT received (%#010x) for target %#04x\n",
291 			  state->tx_abort_source, state->op->target);
292 
293 		xgbe_i2c_disable_interrupts(pdata);
294 
295 		state->ret = -EIO;
296 		goto out;
297 	}
298 
299 	/* Check for data in the Rx fifo */
300 	xgbe_i2c_read(pdata);
301 
302 	/* Fill up the Tx fifo next */
303 	xgbe_i2c_write(pdata);
304 
305 out:
306 	/* Complete on an error or STOP condition */
307 	if (state->ret || XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET))
308 		complete(&pdata->i2c_complete);
309 
310 	return IRQ_HANDLED;
311 }
312 
313 static void xgbe_i2c_set_mode(struct xgbe_prv_data *pdata)
314 {
315 	unsigned int reg;
316 
317 	reg = XI2C_IOREAD(pdata, IC_CON);
318 	XI2C_SET_BITS(reg, IC_CON, MASTER_MODE, 1);
319 	XI2C_SET_BITS(reg, IC_CON, SLAVE_DISABLE, 1);
320 	XI2C_SET_BITS(reg, IC_CON, RESTART_EN, 1);
321 	XI2C_SET_BITS(reg, IC_CON, SPEED, XGBE_STD_SPEED);
322 	XI2C_SET_BITS(reg, IC_CON, RX_FIFO_FULL_HOLD, 1);
323 	XI2C_IOWRITE(pdata, IC_CON, reg);
324 }
325 
326 static void xgbe_i2c_get_features(struct xgbe_prv_data *pdata)
327 {
328 	struct xgbe_i2c *i2c = &pdata->i2c;
329 	unsigned int reg;
330 
331 	reg = XI2C_IOREAD(pdata, IC_COMP_PARAM_1);
332 	i2c->max_speed_mode = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
333 					    MAX_SPEED_MODE);
334 	i2c->rx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
335 					  RX_BUFFER_DEPTH);
336 	i2c->tx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
337 					  TX_BUFFER_DEPTH);
338 
339 	if (netif_msg_probe(pdata))
340 		dev_dbg(pdata->dev, "I2C features: %s=%u, %s=%u, %s=%u\n",
341 			"MAX_SPEED_MODE", i2c->max_speed_mode,
342 			"RX_BUFFER_DEPTH", i2c->rx_fifo_size,
343 			"TX_BUFFER_DEPTH", i2c->tx_fifo_size);
344 }
345 
346 static void xgbe_i2c_set_target(struct xgbe_prv_data *pdata, unsigned int addr)
347 {
348 	XI2C_IOWRITE(pdata, IC_TAR, addr);
349 }
350 
351 static irqreturn_t xgbe_i2c_combined_isr(int irq, struct xgbe_prv_data *pdata)
352 {
353 	if (!XI2C_IOREAD(pdata, IC_RAW_INTR_STAT))
354 		return IRQ_HANDLED;
355 
356 	return xgbe_i2c_isr(irq, pdata);
357 }
358 
359 static int xgbe_i2c_xfer(struct xgbe_prv_data *pdata, struct xgbe_i2c_op *op)
360 {
361 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
362 	int ret;
363 
364 	mutex_lock(&pdata->i2c_mutex);
365 
366 	reinit_completion(&pdata->i2c_complete);
367 
368 	ret = xgbe_i2c_disable(pdata);
369 	if (ret) {
370 		netdev_err(pdata->netdev, "failed to disable i2c master\n");
371 		goto unlock;
372 	}
373 
374 	xgbe_i2c_set_target(pdata, op->target);
375 
376 	memset(state, 0, sizeof(*state));
377 	state->op = op;
378 	state->tx_len = op->len;
379 	state->tx_buf = op->buf;
380 	state->rx_len = op->len;
381 	state->rx_buf = op->buf;
382 
383 	xgbe_i2c_clear_all_interrupts(pdata);
384 	ret = xgbe_i2c_enable(pdata);
385 	if (ret) {
386 		netdev_err(pdata->netdev, "failed to enable i2c master\n");
387 		goto unlock;
388 	}
389 
390 	/* Enabling the interrupts will cause the TX FIFO empty interrupt to
391 	 * fire and begin to process the command via the ISR.
392 	 */
393 	xgbe_i2c_enable_interrupts(pdata);
394 
395 	if (!wait_for_completion_timeout(&pdata->i2c_complete, HZ)) {
396 		netdev_err(pdata->netdev, "i2c operation timed out\n");
397 		ret = -ETIMEDOUT;
398 		goto disable;
399 	}
400 
401 	ret = state->ret;
402 	if (ret) {
403 		if (state->tx_abort_source & IC_TX_ABRT_7B_ADDR_NOACK)
404 			ret = -ENOTCONN;
405 		else if (state->tx_abort_source & IC_TX_ABRT_ARB_LOST)
406 			ret = -EAGAIN;
407 	}
408 
409 disable:
410 	xgbe_i2c_disable_interrupts(pdata);
411 	xgbe_i2c_disable(pdata);
412 
413 unlock:
414 	mutex_unlock(&pdata->i2c_mutex);
415 
416 	return ret;
417 }
418 
419 static void xgbe_i2c_stop(struct xgbe_prv_data *pdata)
420 {
421 	if (!pdata->i2c.started)
422 		return;
423 
424 	netif_dbg(pdata, link, pdata->netdev, "stopping I2C\n");
425 
426 	pdata->i2c.started = 0;
427 
428 	xgbe_i2c_disable_interrupts(pdata);
429 	xgbe_i2c_disable(pdata);
430 	xgbe_i2c_clear_all_interrupts(pdata);
431 
432 	if (pdata->dev_irq != pdata->i2c_irq)
433 		devm_free_irq(pdata->dev, pdata->i2c_irq, pdata);
434 }
435 
436 static int xgbe_i2c_start(struct xgbe_prv_data *pdata)
437 {
438 	int ret;
439 
440 	if (pdata->i2c.started)
441 		return 0;
442 
443 	netif_dbg(pdata, link, pdata->netdev, "starting I2C\n");
444 
445 	/* If we have a separate I2C irq, enable it */
446 	if (pdata->dev_irq != pdata->i2c_irq) {
447 		ret = devm_request_irq(pdata->dev, pdata->i2c_irq,
448 				       xgbe_i2c_isr, 0, pdata->i2c_name,
449 				       pdata);
450 		if (ret) {
451 			netdev_err(pdata->netdev, "i2c irq request failed\n");
452 			return ret;
453 		}
454 	}
455 
456 	pdata->i2c.started = 1;
457 
458 	return 0;
459 }
460 
461 static int xgbe_i2c_init(struct xgbe_prv_data *pdata)
462 {
463 	int ret;
464 
465 	xgbe_i2c_disable_interrupts(pdata);
466 
467 	ret = xgbe_i2c_disable(pdata);
468 	if (ret) {
469 		dev_err(pdata->dev, "failed to disable i2c master\n");
470 		return ret;
471 	}
472 
473 	xgbe_i2c_get_features(pdata);
474 
475 	xgbe_i2c_set_mode(pdata);
476 
477 	xgbe_i2c_clear_all_interrupts(pdata);
478 
479 	return 0;
480 }
481 
482 void xgbe_init_function_ptrs_i2c(struct xgbe_i2c_if *i2c_if)
483 {
484 	i2c_if->i2c_init		= xgbe_i2c_init;
485 
486 	i2c_if->i2c_start		= xgbe_i2c_start;
487 	i2c_if->i2c_stop		= xgbe_i2c_stop;
488 
489 	i2c_if->i2c_xfer		= xgbe_i2c_xfer;
490 
491 	i2c_if->i2c_isr			= xgbe_i2c_combined_isr;
492 }
493