xref: /linux/drivers/net/ethernet/amd/xgbe/xgbe-i2c.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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/interrupt.h>
119 #include <linux/kmod.h>
120 #include <linux/delay.h>
121 #include <linux/completion.h>
122 #include <linux/mutex.h>
123 
124 #include "xgbe.h"
125 #include "xgbe-common.h"
126 
127 #define XGBE_ABORT_COUNT	500
128 #define XGBE_DISABLE_COUNT	1000
129 
130 #define XGBE_STD_SPEED		1
131 
132 #define XGBE_INTR_RX_FULL	BIT(IC_RAW_INTR_STAT_RX_FULL_INDEX)
133 #define XGBE_INTR_TX_EMPTY	BIT(IC_RAW_INTR_STAT_TX_EMPTY_INDEX)
134 #define XGBE_INTR_TX_ABRT	BIT(IC_RAW_INTR_STAT_TX_ABRT_INDEX)
135 #define XGBE_INTR_STOP_DET	BIT(IC_RAW_INTR_STAT_STOP_DET_INDEX)
136 #define XGBE_DEFAULT_INT_MASK	(XGBE_INTR_RX_FULL  |	\
137 				 XGBE_INTR_TX_EMPTY |	\
138 				 XGBE_INTR_TX_ABRT  |	\
139 				 XGBE_INTR_STOP_DET)
140 
141 #define XGBE_I2C_READ		BIT(8)
142 #define XGBE_I2C_STOP		BIT(9)
143 
144 static int xgbe_i2c_abort(struct xgbe_prv_data *pdata)
145 {
146 	unsigned int wait = XGBE_ABORT_COUNT;
147 
148 	/* Must be enabled to recognize the abort request */
149 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, 1);
150 
151 	/* Issue the abort */
152 	XI2C_IOWRITE_BITS(pdata, IC_ENABLE, ABORT, 1);
153 
154 	while (wait--) {
155 		if (!XI2C_IOREAD_BITS(pdata, IC_ENABLE, ABORT))
156 			return 0;
157 
158 		usleep_range(500, 600);
159 	}
160 
161 	return -EBUSY;
162 }
163 
164 static int xgbe_i2c_set_enable(struct xgbe_prv_data *pdata, bool enable)
165 {
166 	unsigned int wait = XGBE_DISABLE_COUNT;
167 	unsigned int mode = enable ? 1 : 0;
168 
169 	while (wait--) {
170 		XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, mode);
171 		if (XI2C_IOREAD_BITS(pdata, IC_ENABLE_STATUS, EN) == mode)
172 			return 0;
173 
174 		usleep_range(100, 110);
175 	}
176 
177 	return -EBUSY;
178 }
179 
180 static int xgbe_i2c_disable(struct xgbe_prv_data *pdata)
181 {
182 	unsigned int ret;
183 
184 	ret = xgbe_i2c_set_enable(pdata, false);
185 	if (ret) {
186 		/* Disable failed, try an abort */
187 		ret = xgbe_i2c_abort(pdata);
188 		if (ret)
189 			return ret;
190 
191 		/* Abort succeeded, try to disable again */
192 		ret = xgbe_i2c_set_enable(pdata, false);
193 	}
194 
195 	return ret;
196 }
197 
198 static int xgbe_i2c_enable(struct xgbe_prv_data *pdata)
199 {
200 	return xgbe_i2c_set_enable(pdata, true);
201 }
202 
203 static void xgbe_i2c_clear_all_interrupts(struct xgbe_prv_data *pdata)
204 {
205 	XI2C_IOREAD(pdata, IC_CLR_INTR);
206 }
207 
208 static void xgbe_i2c_disable_interrupts(struct xgbe_prv_data *pdata)
209 {
210 	XI2C_IOWRITE(pdata, IC_INTR_MASK, 0);
211 }
212 
213 static void xgbe_i2c_enable_interrupts(struct xgbe_prv_data *pdata)
214 {
215 	XI2C_IOWRITE(pdata, IC_INTR_MASK, XGBE_DEFAULT_INT_MASK);
216 }
217 
218 static void xgbe_i2c_write(struct xgbe_prv_data *pdata)
219 {
220 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
221 	unsigned int tx_slots;
222 	unsigned int cmd;
223 
224 	/* Configured to never receive Rx overflows, so fill up Tx fifo */
225 	tx_slots = pdata->i2c.tx_fifo_size - XI2C_IOREAD(pdata, IC_TXFLR);
226 	while (tx_slots && state->tx_len) {
227 		if (state->op->cmd == XGBE_I2C_CMD_READ)
228 			cmd = XGBE_I2C_READ;
229 		else
230 			cmd = *state->tx_buf++;
231 
232 		if (state->tx_len == 1)
233 			XI2C_SET_BITS(cmd, IC_DATA_CMD, STOP, 1);
234 
235 		XI2C_IOWRITE(pdata, IC_DATA_CMD, cmd);
236 
237 		tx_slots--;
238 		state->tx_len--;
239 	}
240 
241 	/* No more Tx operations, so ignore TX_EMPTY and return */
242 	if (!state->tx_len)
243 		XI2C_IOWRITE_BITS(pdata, IC_INTR_MASK, TX_EMPTY, 0);
244 }
245 
246 static void xgbe_i2c_read(struct xgbe_prv_data *pdata)
247 {
248 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
249 	unsigned int rx_slots;
250 
251 	/* Anything to be read? */
252 	if (state->op->cmd != XGBE_I2C_CMD_READ)
253 		return;
254 
255 	rx_slots = XI2C_IOREAD(pdata, IC_RXFLR);
256 	while (rx_slots && state->rx_len) {
257 		*state->rx_buf++ = XI2C_IOREAD(pdata, IC_DATA_CMD);
258 		state->rx_len--;
259 		rx_slots--;
260 	}
261 }
262 
263 static void xgbe_i2c_clear_isr_interrupts(struct xgbe_prv_data *pdata,
264 					  unsigned int isr)
265 {
266 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
267 
268 	if (isr & XGBE_INTR_TX_ABRT) {
269 		state->tx_abort_source = XI2C_IOREAD(pdata, IC_TX_ABRT_SOURCE);
270 		XI2C_IOREAD(pdata, IC_CLR_TX_ABRT);
271 	}
272 
273 	if (isr & XGBE_INTR_STOP_DET)
274 		XI2C_IOREAD(pdata, IC_CLR_STOP_DET);
275 }
276 
277 static irqreturn_t xgbe_i2c_isr(int irq, void *data)
278 {
279 	struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
280 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
281 	unsigned int isr;
282 
283 	isr = XI2C_IOREAD(pdata, IC_RAW_INTR_STAT);
284 	netif_dbg(pdata, intr, pdata->netdev,
285 		  "I2C interrupt received: status=%#010x\n", isr);
286 
287 	xgbe_i2c_clear_isr_interrupts(pdata, isr);
288 
289 	if (isr & XGBE_INTR_TX_ABRT) {
290 		netif_dbg(pdata, link, pdata->netdev,
291 			  "I2C TX_ABRT received (%#010x) for target %#04x\n",
292 			  state->tx_abort_source, state->op->target);
293 
294 		xgbe_i2c_disable_interrupts(pdata);
295 
296 		state->ret = -EIO;
297 		goto out;
298 	}
299 
300 	/* Check for data in the Rx fifo */
301 	xgbe_i2c_read(pdata);
302 
303 	/* Fill up the Tx fifo next */
304 	xgbe_i2c_write(pdata);
305 
306 out:
307 	/* Complete on an error or STOP condition */
308 	if (state->ret || XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET))
309 		complete(&pdata->i2c_complete);
310 
311 	return IRQ_HANDLED;
312 }
313 
314 static void xgbe_i2c_set_mode(struct xgbe_prv_data *pdata)
315 {
316 	unsigned int reg;
317 
318 	reg = XI2C_IOREAD(pdata, IC_CON);
319 	XI2C_SET_BITS(reg, IC_CON, MASTER_MODE, 1);
320 	XI2C_SET_BITS(reg, IC_CON, SLAVE_DISABLE, 1);
321 	XI2C_SET_BITS(reg, IC_CON, RESTART_EN, 1);
322 	XI2C_SET_BITS(reg, IC_CON, SPEED, XGBE_STD_SPEED);
323 	XI2C_SET_BITS(reg, IC_CON, RX_FIFO_FULL_HOLD, 1);
324 	XI2C_IOWRITE(pdata, IC_CON, reg);
325 }
326 
327 static void xgbe_i2c_get_features(struct xgbe_prv_data *pdata)
328 {
329 	struct xgbe_i2c *i2c = &pdata->i2c;
330 	unsigned int reg;
331 
332 	reg = XI2C_IOREAD(pdata, IC_COMP_PARAM_1);
333 	i2c->max_speed_mode = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
334 					    MAX_SPEED_MODE);
335 	i2c->rx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
336 					  RX_BUFFER_DEPTH);
337 	i2c->tx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
338 					  TX_BUFFER_DEPTH);
339 
340 	if (netif_msg_probe(pdata))
341 		dev_dbg(pdata->dev, "I2C features: %s=%u, %s=%u, %s=%u\n",
342 			"MAX_SPEED_MODE", i2c->max_speed_mode,
343 			"RX_BUFFER_DEPTH", i2c->rx_fifo_size,
344 			"TX_BUFFER_DEPTH", i2c->tx_fifo_size);
345 }
346 
347 static void xgbe_i2c_set_target(struct xgbe_prv_data *pdata, unsigned int addr)
348 {
349 	XI2C_IOWRITE(pdata, IC_TAR, addr);
350 }
351 
352 static irqreturn_t xgbe_i2c_combined_isr(int irq, struct xgbe_prv_data *pdata)
353 {
354 	if (!XI2C_IOREAD(pdata, IC_RAW_INTR_STAT))
355 		return IRQ_HANDLED;
356 
357 	return xgbe_i2c_isr(irq, pdata);
358 }
359 
360 static int xgbe_i2c_xfer(struct xgbe_prv_data *pdata, struct xgbe_i2c_op *op)
361 {
362 	struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
363 	int ret;
364 
365 	mutex_lock(&pdata->i2c_mutex);
366 
367 	reinit_completion(&pdata->i2c_complete);
368 
369 	ret = xgbe_i2c_disable(pdata);
370 	if (ret) {
371 		netdev_err(pdata->netdev, "failed to disable i2c master\n");
372 		goto unlock;
373 	}
374 
375 	xgbe_i2c_set_target(pdata, op->target);
376 
377 	memset(state, 0, sizeof(*state));
378 	state->op = op;
379 	state->tx_len = op->len;
380 	state->tx_buf = op->buf;
381 	state->rx_len = op->len;
382 	state->rx_buf = op->buf;
383 
384 	xgbe_i2c_clear_all_interrupts(pdata);
385 	ret = xgbe_i2c_enable(pdata);
386 	if (ret) {
387 		netdev_err(pdata->netdev, "failed to enable i2c master\n");
388 		goto unlock;
389 	}
390 
391 	/* Enabling the interrupts will cause the TX FIFO empty interrupt to
392 	 * fire and begin to process the command via the ISR.
393 	 */
394 	xgbe_i2c_enable_interrupts(pdata);
395 
396 	if (!wait_for_completion_timeout(&pdata->i2c_complete, HZ)) {
397 		netdev_err(pdata->netdev, "i2c operation timed out\n");
398 		ret = -ETIMEDOUT;
399 		goto disable;
400 	}
401 
402 	ret = state->ret;
403 	if (ret) {
404 		if (state->tx_abort_source & IC_TX_ABRT_7B_ADDR_NOACK)
405 			ret = -ENOTCONN;
406 		else if (state->tx_abort_source & IC_TX_ABRT_ARB_LOST)
407 			ret = -EAGAIN;
408 	}
409 
410 disable:
411 	xgbe_i2c_disable_interrupts(pdata);
412 	xgbe_i2c_disable(pdata);
413 
414 unlock:
415 	mutex_unlock(&pdata->i2c_mutex);
416 
417 	return ret;
418 }
419 
420 static void xgbe_i2c_stop(struct xgbe_prv_data *pdata)
421 {
422 	if (!pdata->i2c.started)
423 		return;
424 
425 	netif_dbg(pdata, link, pdata->netdev, "stopping I2C\n");
426 
427 	pdata->i2c.started = 0;
428 
429 	xgbe_i2c_disable_interrupts(pdata);
430 	xgbe_i2c_disable(pdata);
431 	xgbe_i2c_clear_all_interrupts(pdata);
432 
433 	if (pdata->dev_irq != pdata->i2c_irq)
434 		devm_free_irq(pdata->dev, pdata->i2c_irq, pdata);
435 }
436 
437 static int xgbe_i2c_start(struct xgbe_prv_data *pdata)
438 {
439 	int ret;
440 
441 	if (pdata->i2c.started)
442 		return 0;
443 
444 	netif_dbg(pdata, link, pdata->netdev, "starting I2C\n");
445 
446 	/* If we have a separate I2C irq, enable it */
447 	if (pdata->dev_irq != pdata->i2c_irq) {
448 		ret = devm_request_irq(pdata->dev, pdata->i2c_irq,
449 				       xgbe_i2c_isr, 0, pdata->i2c_name,
450 				       pdata);
451 		if (ret) {
452 			netdev_err(pdata->netdev, "i2c irq request failed\n");
453 			return ret;
454 		}
455 	}
456 
457 	pdata->i2c.started = 1;
458 
459 	return 0;
460 }
461 
462 static int xgbe_i2c_init(struct xgbe_prv_data *pdata)
463 {
464 	int ret;
465 
466 	xgbe_i2c_disable_interrupts(pdata);
467 
468 	ret = xgbe_i2c_disable(pdata);
469 	if (ret) {
470 		dev_err(pdata->dev, "failed to disable i2c master\n");
471 		return ret;
472 	}
473 
474 	xgbe_i2c_get_features(pdata);
475 
476 	xgbe_i2c_set_mode(pdata);
477 
478 	xgbe_i2c_clear_all_interrupts(pdata);
479 
480 	return 0;
481 }
482 
483 void xgbe_init_function_ptrs_i2c(struct xgbe_i2c_if *i2c_if)
484 {
485 	i2c_if->i2c_init		= xgbe_i2c_init;
486 
487 	i2c_if->i2c_start		= xgbe_i2c_start;
488 	i2c_if->i2c_stop		= xgbe_i2c_stop;
489 
490 	i2c_if->i2c_xfer		= xgbe_i2c_xfer;
491 
492 	i2c_if->i2c_isr			= xgbe_i2c_combined_isr;
493 }
494