xref: /openbmc/linux/drivers/mmc/host/cavium.c (revision 239480ab)
1 /*
2  * Shared part of driver for MMC/SDHC controller on Cavium OCTEON and
3  * ThunderX SOCs.
4  *
5  * This file is subject to the terms and conditions of the GNU General Public
6  * License.  See the file "COPYING" in the main directory of this archive
7  * for more details.
8  *
9  * Copyright (C) 2012-2017 Cavium Inc.
10  * Authors:
11  *   David Daney <david.daney@cavium.com>
12  *   Peter Swain <pswain@cavium.com>
13  *   Steven J. Hill <steven.hill@cavium.com>
14  *   Jan Glauber <jglauber@cavium.com>
15  */
16 #include <linux/bitfield.h>
17 #include <linux/delay.h>
18 #include <linux/dma-direction.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/interrupt.h>
22 #include <linux/mmc/mmc.h>
23 #include <linux/mmc/slot-gpio.h>
24 #include <linux/module.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/scatterlist.h>
27 #include <linux/time.h>
28 
29 #include "cavium.h"
30 
31 const char *cvm_mmc_irq_names[] = {
32 	"MMC Buffer",
33 	"MMC Command",
34 	"MMC DMA",
35 	"MMC Command Error",
36 	"MMC DMA Error",
37 	"MMC Switch",
38 	"MMC Switch Error",
39 	"MMC DMA int Fifo",
40 	"MMC DMA int",
41 };
42 
43 /*
44  * The Cavium MMC host hardware assumes that all commands have fixed
45  * command and response types.  These are correct if MMC devices are
46  * being used.  However, non-MMC devices like SD use command and
47  * response types that are unexpected by the host hardware.
48  *
49  * The command and response types can be overridden by supplying an
50  * XOR value that is applied to the type.  We calculate the XOR value
51  * from the values in this table and the flags passed from the MMC
52  * core.
53  */
54 static struct cvm_mmc_cr_type cvm_mmc_cr_types[] = {
55 	{0, 0},		/* CMD0 */
56 	{0, 3},		/* CMD1 */
57 	{0, 2},		/* CMD2 */
58 	{0, 1},		/* CMD3 */
59 	{0, 0},		/* CMD4 */
60 	{0, 1},		/* CMD5 */
61 	{0, 1},		/* CMD6 */
62 	{0, 1},		/* CMD7 */
63 	{1, 1},		/* CMD8 */
64 	{0, 2},		/* CMD9 */
65 	{0, 2},		/* CMD10 */
66 	{1, 1},		/* CMD11 */
67 	{0, 1},		/* CMD12 */
68 	{0, 1},		/* CMD13 */
69 	{1, 1},		/* CMD14 */
70 	{0, 0},		/* CMD15 */
71 	{0, 1},		/* CMD16 */
72 	{1, 1},		/* CMD17 */
73 	{1, 1},		/* CMD18 */
74 	{3, 1},		/* CMD19 */
75 	{2, 1},		/* CMD20 */
76 	{0, 0},		/* CMD21 */
77 	{0, 0},		/* CMD22 */
78 	{0, 1},		/* CMD23 */
79 	{2, 1},		/* CMD24 */
80 	{2, 1},		/* CMD25 */
81 	{2, 1},		/* CMD26 */
82 	{2, 1},		/* CMD27 */
83 	{0, 1},		/* CMD28 */
84 	{0, 1},		/* CMD29 */
85 	{1, 1},		/* CMD30 */
86 	{1, 1},		/* CMD31 */
87 	{0, 0},		/* CMD32 */
88 	{0, 0},		/* CMD33 */
89 	{0, 0},		/* CMD34 */
90 	{0, 1},		/* CMD35 */
91 	{0, 1},		/* CMD36 */
92 	{0, 0},		/* CMD37 */
93 	{0, 1},		/* CMD38 */
94 	{0, 4},		/* CMD39 */
95 	{0, 5},		/* CMD40 */
96 	{0, 0},		/* CMD41 */
97 	{2, 1},		/* CMD42 */
98 	{0, 0},		/* CMD43 */
99 	{0, 0},		/* CMD44 */
100 	{0, 0},		/* CMD45 */
101 	{0, 0},		/* CMD46 */
102 	{0, 0},		/* CMD47 */
103 	{0, 0},		/* CMD48 */
104 	{0, 0},		/* CMD49 */
105 	{0, 0},		/* CMD50 */
106 	{0, 0},		/* CMD51 */
107 	{0, 0},		/* CMD52 */
108 	{0, 0},		/* CMD53 */
109 	{0, 0},		/* CMD54 */
110 	{0, 1},		/* CMD55 */
111 	{0xff, 0xff},	/* CMD56 */
112 	{0, 0},		/* CMD57 */
113 	{0, 0},		/* CMD58 */
114 	{0, 0},		/* CMD59 */
115 	{0, 0},		/* CMD60 */
116 	{0, 0},		/* CMD61 */
117 	{0, 0},		/* CMD62 */
118 	{0, 0}		/* CMD63 */
119 };
120 
121 static struct cvm_mmc_cr_mods cvm_mmc_get_cr_mods(struct mmc_command *cmd)
122 {
123 	struct cvm_mmc_cr_type *cr;
124 	u8 hardware_ctype, hardware_rtype;
125 	u8 desired_ctype = 0, desired_rtype = 0;
126 	struct cvm_mmc_cr_mods r;
127 
128 	cr = cvm_mmc_cr_types + (cmd->opcode & 0x3f);
129 	hardware_ctype = cr->ctype;
130 	hardware_rtype = cr->rtype;
131 	if (cmd->opcode == MMC_GEN_CMD)
132 		hardware_ctype = (cmd->arg & 1) ? 1 : 2;
133 
134 	switch (mmc_cmd_type(cmd)) {
135 	case MMC_CMD_ADTC:
136 		desired_ctype = (cmd->data->flags & MMC_DATA_WRITE) ? 2 : 1;
137 		break;
138 	case MMC_CMD_AC:
139 	case MMC_CMD_BC:
140 	case MMC_CMD_BCR:
141 		desired_ctype = 0;
142 		break;
143 	}
144 
145 	switch (mmc_resp_type(cmd)) {
146 	case MMC_RSP_NONE:
147 		desired_rtype = 0;
148 		break;
149 	case MMC_RSP_R1:/* MMC_RSP_R5, MMC_RSP_R6, MMC_RSP_R7 */
150 	case MMC_RSP_R1B:
151 		desired_rtype = 1;
152 		break;
153 	case MMC_RSP_R2:
154 		desired_rtype = 2;
155 		break;
156 	case MMC_RSP_R3: /* MMC_RSP_R4 */
157 		desired_rtype = 3;
158 		break;
159 	}
160 	r.ctype_xor = desired_ctype ^ hardware_ctype;
161 	r.rtype_xor = desired_rtype ^ hardware_rtype;
162 	return r;
163 }
164 
165 static void check_switch_errors(struct cvm_mmc_host *host)
166 {
167 	u64 emm_switch;
168 
169 	emm_switch = readq(host->base + MIO_EMM_SWITCH(host));
170 	if (emm_switch & MIO_EMM_SWITCH_ERR0)
171 		dev_err(host->dev, "Switch power class error\n");
172 	if (emm_switch & MIO_EMM_SWITCH_ERR1)
173 		dev_err(host->dev, "Switch hs timing error\n");
174 	if (emm_switch & MIO_EMM_SWITCH_ERR2)
175 		dev_err(host->dev, "Switch bus width error\n");
176 }
177 
178 static void clear_bus_id(u64 *reg)
179 {
180 	u64 bus_id_mask = GENMASK_ULL(61, 60);
181 
182 	*reg &= ~bus_id_mask;
183 }
184 
185 static void set_bus_id(u64 *reg, int bus_id)
186 {
187 	clear_bus_id(reg);
188 	*reg |= FIELD_PREP(GENMASK(61, 60), bus_id);
189 }
190 
191 static int get_bus_id(u64 reg)
192 {
193 	return FIELD_GET(GENMASK_ULL(61, 60), reg);
194 }
195 
196 /*
197  * We never set the switch_exe bit since that would interfere
198  * with the commands send by the MMC core.
199  */
200 static void do_switch(struct cvm_mmc_host *host, u64 emm_switch)
201 {
202 	int retries = 100;
203 	u64 rsp_sts;
204 	int bus_id;
205 
206 	/*
207 	 * Modes setting only taken from slot 0. Work around that hardware
208 	 * issue by first switching to slot 0.
209 	 */
210 	bus_id = get_bus_id(emm_switch);
211 	clear_bus_id(&emm_switch);
212 	writeq(emm_switch, host->base + MIO_EMM_SWITCH(host));
213 
214 	set_bus_id(&emm_switch, bus_id);
215 	writeq(emm_switch, host->base + MIO_EMM_SWITCH(host));
216 
217 	/* wait for the switch to finish */
218 	do {
219 		rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
220 		if (!(rsp_sts & MIO_EMM_RSP_STS_SWITCH_VAL))
221 			break;
222 		udelay(10);
223 	} while (--retries);
224 
225 	check_switch_errors(host);
226 }
227 
228 static bool switch_val_changed(struct cvm_mmc_slot *slot, u64 new_val)
229 {
230 	/* Match BUS_ID, HS_TIMING, BUS_WIDTH, POWER_CLASS, CLK_HI, CLK_LO */
231 	u64 match = 0x3001070fffffffffull;
232 
233 	return (slot->cached_switch & match) != (new_val & match);
234 }
235 
236 static void set_wdog(struct cvm_mmc_slot *slot, unsigned int ns)
237 {
238 	u64 timeout;
239 
240 	if (!slot->clock)
241 		return;
242 
243 	if (ns)
244 		timeout = (slot->clock * ns) / NSEC_PER_SEC;
245 	else
246 		timeout = (slot->clock * 850ull) / 1000ull;
247 	writeq(timeout, slot->host->base + MIO_EMM_WDOG(slot->host));
248 }
249 
250 static void cvm_mmc_reset_bus(struct cvm_mmc_slot *slot)
251 {
252 	struct cvm_mmc_host *host = slot->host;
253 	u64 emm_switch, wdog;
254 
255 	emm_switch = readq(slot->host->base + MIO_EMM_SWITCH(host));
256 	emm_switch &= ~(MIO_EMM_SWITCH_EXE | MIO_EMM_SWITCH_ERR0 |
257 			MIO_EMM_SWITCH_ERR1 | MIO_EMM_SWITCH_ERR2);
258 	set_bus_id(&emm_switch, slot->bus_id);
259 
260 	wdog = readq(slot->host->base + MIO_EMM_WDOG(host));
261 	do_switch(slot->host, emm_switch);
262 
263 	slot->cached_switch = emm_switch;
264 
265 	msleep(20);
266 
267 	writeq(wdog, slot->host->base + MIO_EMM_WDOG(host));
268 }
269 
270 /* Switch to another slot if needed */
271 static void cvm_mmc_switch_to(struct cvm_mmc_slot *slot)
272 {
273 	struct cvm_mmc_host *host = slot->host;
274 	struct cvm_mmc_slot *old_slot;
275 	u64 emm_sample, emm_switch;
276 
277 	if (slot->bus_id == host->last_slot)
278 		return;
279 
280 	if (host->last_slot >= 0 && host->slot[host->last_slot]) {
281 		old_slot = host->slot[host->last_slot];
282 		old_slot->cached_switch = readq(host->base + MIO_EMM_SWITCH(host));
283 		old_slot->cached_rca = readq(host->base + MIO_EMM_RCA(host));
284 	}
285 
286 	writeq(slot->cached_rca, host->base + MIO_EMM_RCA(host));
287 	emm_switch = slot->cached_switch;
288 	set_bus_id(&emm_switch, slot->bus_id);
289 	do_switch(host, emm_switch);
290 
291 	emm_sample = FIELD_PREP(MIO_EMM_SAMPLE_CMD_CNT, slot->cmd_cnt) |
292 		     FIELD_PREP(MIO_EMM_SAMPLE_DAT_CNT, slot->dat_cnt);
293 	writeq(emm_sample, host->base + MIO_EMM_SAMPLE(host));
294 
295 	host->last_slot = slot->bus_id;
296 }
297 
298 static void do_read(struct cvm_mmc_host *host, struct mmc_request *req,
299 		    u64 dbuf)
300 {
301 	struct sg_mapping_iter *smi = &host->smi;
302 	int data_len = req->data->blocks * req->data->blksz;
303 	int bytes_xfered, shift = -1;
304 	u64 dat = 0;
305 
306 	/* Auto inc from offset zero */
307 	writeq((0x10000 | (dbuf << 6)), host->base + MIO_EMM_BUF_IDX(host));
308 
309 	for (bytes_xfered = 0; bytes_xfered < data_len;) {
310 		if (smi->consumed >= smi->length) {
311 			if (!sg_miter_next(smi))
312 				break;
313 			smi->consumed = 0;
314 		}
315 
316 		if (shift < 0) {
317 			dat = readq(host->base + MIO_EMM_BUF_DAT(host));
318 			shift = 56;
319 		}
320 
321 		while (smi->consumed < smi->length && shift >= 0) {
322 			((u8 *)smi->addr)[smi->consumed] = (dat >> shift) & 0xff;
323 			bytes_xfered++;
324 			smi->consumed++;
325 			shift -= 8;
326 		}
327 	}
328 
329 	sg_miter_stop(smi);
330 	req->data->bytes_xfered = bytes_xfered;
331 	req->data->error = 0;
332 }
333 
334 static void do_write(struct mmc_request *req)
335 {
336 	req->data->bytes_xfered = req->data->blocks * req->data->blksz;
337 	req->data->error = 0;
338 }
339 
340 static void set_cmd_response(struct cvm_mmc_host *host, struct mmc_request *req,
341 			     u64 rsp_sts)
342 {
343 	u64 rsp_hi, rsp_lo;
344 
345 	if (!(rsp_sts & MIO_EMM_RSP_STS_RSP_VAL))
346 		return;
347 
348 	rsp_lo = readq(host->base + MIO_EMM_RSP_LO(host));
349 
350 	switch (FIELD_GET(MIO_EMM_RSP_STS_RSP_TYPE, rsp_sts)) {
351 	case 1:
352 	case 3:
353 		req->cmd->resp[0] = (rsp_lo >> 8) & 0xffffffff;
354 		req->cmd->resp[1] = 0;
355 		req->cmd->resp[2] = 0;
356 		req->cmd->resp[3] = 0;
357 		break;
358 	case 2:
359 		req->cmd->resp[3] = rsp_lo & 0xffffffff;
360 		req->cmd->resp[2] = (rsp_lo >> 32) & 0xffffffff;
361 		rsp_hi = readq(host->base + MIO_EMM_RSP_HI(host));
362 		req->cmd->resp[1] = rsp_hi & 0xffffffff;
363 		req->cmd->resp[0] = (rsp_hi >> 32) & 0xffffffff;
364 		break;
365 	}
366 }
367 
368 static int get_dma_dir(struct mmc_data *data)
369 {
370 	return (data->flags & MMC_DATA_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
371 }
372 
373 static int finish_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
374 {
375 	data->bytes_xfered = data->blocks * data->blksz;
376 	data->error = 0;
377 	return 1;
378 }
379 
380 static int finish_dma_sg(struct cvm_mmc_host *host, struct mmc_data *data)
381 {
382 	u64 fifo_cfg;
383 	int count;
384 
385 	/* Check if there are any pending requests left */
386 	fifo_cfg = readq(host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
387 	count = FIELD_GET(MIO_EMM_DMA_FIFO_CFG_COUNT, fifo_cfg);
388 	if (count)
389 		dev_err(host->dev, "%u requests still pending\n", count);
390 
391 	data->bytes_xfered = data->blocks * data->blksz;
392 	data->error = 0;
393 
394 	/* Clear and disable FIFO */
395 	writeq(BIT_ULL(16), host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
396 	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
397 	return 1;
398 }
399 
400 static int finish_dma(struct cvm_mmc_host *host, struct mmc_data *data)
401 {
402 	if (host->use_sg && data->sg_len > 1)
403 		return finish_dma_sg(host, data);
404 	else
405 		return finish_dma_single(host, data);
406 }
407 
408 static int check_status(u64 rsp_sts)
409 {
410 	if (rsp_sts & MIO_EMM_RSP_STS_RSP_BAD_STS ||
411 	    rsp_sts & MIO_EMM_RSP_STS_RSP_CRC_ERR ||
412 	    rsp_sts & MIO_EMM_RSP_STS_BLK_CRC_ERR)
413 		return -EILSEQ;
414 	if (rsp_sts & MIO_EMM_RSP_STS_RSP_TIMEOUT ||
415 	    rsp_sts & MIO_EMM_RSP_STS_BLK_TIMEOUT)
416 		return -ETIMEDOUT;
417 	if (rsp_sts & MIO_EMM_RSP_STS_DBUF_ERR)
418 		return -EIO;
419 	return 0;
420 }
421 
422 /* Try to clean up failed DMA. */
423 static void cleanup_dma(struct cvm_mmc_host *host, u64 rsp_sts)
424 {
425 	u64 emm_dma;
426 
427 	emm_dma = readq(host->base + MIO_EMM_DMA(host));
428 	emm_dma |= FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
429 		   FIELD_PREP(MIO_EMM_DMA_DAT_NULL, 1);
430 	set_bus_id(&emm_dma, get_bus_id(rsp_sts));
431 	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
432 }
433 
434 irqreturn_t cvm_mmc_interrupt(int irq, void *dev_id)
435 {
436 	struct cvm_mmc_host *host = dev_id;
437 	struct mmc_request *req;
438 	unsigned long flags = 0;
439 	u64 emm_int, rsp_sts;
440 	bool host_done;
441 
442 	if (host->need_irq_handler_lock)
443 		spin_lock_irqsave(&host->irq_handler_lock, flags);
444 	else
445 		__acquire(&host->irq_handler_lock);
446 
447 	/* Clear interrupt bits (write 1 clears ). */
448 	emm_int = readq(host->base + MIO_EMM_INT(host));
449 	writeq(emm_int, host->base + MIO_EMM_INT(host));
450 
451 	if (emm_int & MIO_EMM_INT_SWITCH_ERR)
452 		check_switch_errors(host);
453 
454 	req = host->current_req;
455 	if (!req)
456 		goto out;
457 
458 	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
459 	/*
460 	 * dma_val set means DMA is still in progress. Don't touch
461 	 * the request and wait for the interrupt indicating that
462 	 * the DMA is finished.
463 	 */
464 	if ((rsp_sts & MIO_EMM_RSP_STS_DMA_VAL) && host->dma_active)
465 		goto out;
466 
467 	if (!host->dma_active && req->data &&
468 	    (emm_int & MIO_EMM_INT_BUF_DONE)) {
469 		unsigned int type = (rsp_sts >> 7) & 3;
470 
471 		if (type == 1)
472 			do_read(host, req, rsp_sts & MIO_EMM_RSP_STS_DBUF);
473 		else if (type == 2)
474 			do_write(req);
475 	}
476 
477 	host_done = emm_int & MIO_EMM_INT_CMD_DONE ||
478 		    emm_int & MIO_EMM_INT_DMA_DONE ||
479 		    emm_int & MIO_EMM_INT_CMD_ERR  ||
480 		    emm_int & MIO_EMM_INT_DMA_ERR;
481 
482 	if (!(host_done && req->done))
483 		goto no_req_done;
484 
485 	req->cmd->error = check_status(rsp_sts);
486 
487 	if (host->dma_active && req->data)
488 		if (!finish_dma(host, req->data))
489 			goto no_req_done;
490 
491 	set_cmd_response(host, req, rsp_sts);
492 	if ((emm_int & MIO_EMM_INT_DMA_ERR) &&
493 	    (rsp_sts & MIO_EMM_RSP_STS_DMA_PEND))
494 		cleanup_dma(host, rsp_sts);
495 
496 	host->current_req = NULL;
497 	req->done(req);
498 
499 no_req_done:
500 	if (host->dmar_fixup_done)
501 		host->dmar_fixup_done(host);
502 	if (host_done)
503 		host->release_bus(host);
504 out:
505 	if (host->need_irq_handler_lock)
506 		spin_unlock_irqrestore(&host->irq_handler_lock, flags);
507 	else
508 		__release(&host->irq_handler_lock);
509 	return IRQ_RETVAL(emm_int != 0);
510 }
511 
512 /*
513  * Program DMA_CFG and if needed DMA_ADR.
514  * Returns 0 on error, DMA address otherwise.
515  */
516 static u64 prepare_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
517 {
518 	u64 dma_cfg, addr;
519 	int count, rw;
520 
521 	count = dma_map_sg(host->dev, data->sg, data->sg_len,
522 			   get_dma_dir(data));
523 	if (!count)
524 		return 0;
525 
526 	rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
527 	dma_cfg = FIELD_PREP(MIO_EMM_DMA_CFG_EN, 1) |
528 		  FIELD_PREP(MIO_EMM_DMA_CFG_RW, rw);
529 #ifdef __LITTLE_ENDIAN
530 	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ENDIAN, 1);
531 #endif
532 	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_SIZE,
533 			      (sg_dma_len(&data->sg[0]) / 8) - 1);
534 
535 	addr = sg_dma_address(&data->sg[0]);
536 	if (!host->big_dma_addr)
537 		dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ADR, addr);
538 	writeq(dma_cfg, host->dma_base + MIO_EMM_DMA_CFG(host));
539 
540 	pr_debug("[%s] sg_dma_len: %u  total sg_elem: %d\n",
541 		 (rw) ? "W" : "R", sg_dma_len(&data->sg[0]), count);
542 
543 	if (host->big_dma_addr)
544 		writeq(addr, host->dma_base + MIO_EMM_DMA_ADR(host));
545 	return addr;
546 }
547 
548 /*
549  * Queue complete sg list into the FIFO.
550  * Returns 0 on error, 1 otherwise.
551  */
552 static u64 prepare_dma_sg(struct cvm_mmc_host *host, struct mmc_data *data)
553 {
554 	struct scatterlist *sg;
555 	u64 fifo_cmd, addr;
556 	int count, i, rw;
557 
558 	count = dma_map_sg(host->dev, data->sg, data->sg_len,
559 			   get_dma_dir(data));
560 	if (!count)
561 		return 0;
562 	if (count > 16)
563 		goto error;
564 
565 	/* Enable FIFO by removing CLR bit */
566 	writeq(0, host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
567 
568 	for_each_sg(data->sg, sg, count, i) {
569 		/* Program DMA address */
570 		addr = sg_dma_address(sg);
571 		if (addr & 7)
572 			goto error;
573 		writeq(addr, host->dma_base + MIO_EMM_DMA_FIFO_ADR(host));
574 
575 		/*
576 		 * If we have scatter-gather support we also have an extra
577 		 * register for the DMA addr, so no need to check
578 		 * host->big_dma_addr here.
579 		 */
580 		rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
581 		fifo_cmd = FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_RW, rw);
582 
583 		/* enable interrupts on the last element */
584 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_INTDIS,
585 				       (i + 1 == count) ? 0 : 1);
586 
587 #ifdef __LITTLE_ENDIAN
588 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_ENDIAN, 1);
589 #endif
590 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_SIZE,
591 				       sg_dma_len(sg) / 8 - 1);
592 		/*
593 		 * The write copies the address and the command to the FIFO
594 		 * and increments the FIFO's COUNT field.
595 		 */
596 		writeq(fifo_cmd, host->dma_base + MIO_EMM_DMA_FIFO_CMD(host));
597 		pr_debug("[%s] sg_dma_len: %u  sg_elem: %d/%d\n",
598 			 (rw) ? "W" : "R", sg_dma_len(sg), i, count);
599 	}
600 
601 	/*
602 	 * In difference to prepare_dma_single we don't return the
603 	 * address here, as it would not make sense for scatter-gather.
604 	 * The dma fixup is only required on models that don't support
605 	 * scatter-gather, so that is not a problem.
606 	 */
607 	return 1;
608 
609 error:
610 	WARN_ON_ONCE(1);
611 	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
612 	/* Disable FIFO */
613 	writeq(BIT_ULL(16), host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
614 	return 0;
615 }
616 
617 static u64 prepare_dma(struct cvm_mmc_host *host, struct mmc_data *data)
618 {
619 	if (host->use_sg && data->sg_len > 1)
620 		return prepare_dma_sg(host, data);
621 	else
622 		return prepare_dma_single(host, data);
623 }
624 
625 static u64 prepare_ext_dma(struct mmc_host *mmc, struct mmc_request *mrq)
626 {
627 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
628 	u64 emm_dma;
629 
630 	emm_dma = FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
631 		  FIELD_PREP(MIO_EMM_DMA_SECTOR,
632 			     mmc_card_is_blockaddr(mmc->card) ? 1 : 0) |
633 		  FIELD_PREP(MIO_EMM_DMA_RW,
634 			     (mrq->data->flags & MMC_DATA_WRITE) ? 1 : 0) |
635 		  FIELD_PREP(MIO_EMM_DMA_BLOCK_CNT, mrq->data->blocks) |
636 		  FIELD_PREP(MIO_EMM_DMA_CARD_ADDR, mrq->cmd->arg);
637 	set_bus_id(&emm_dma, slot->bus_id);
638 
639 	if (mmc_card_mmc(mmc->card) || (mmc_card_sd(mmc->card) &&
640 	    (mmc->card->scr.cmds & SD_SCR_CMD23_SUPPORT)))
641 		emm_dma |= FIELD_PREP(MIO_EMM_DMA_MULTI, 1);
642 
643 	pr_debug("[%s] blocks: %u  multi: %d\n",
644 		(emm_dma & MIO_EMM_DMA_RW) ? "W" : "R",
645 		 mrq->data->blocks, (emm_dma & MIO_EMM_DMA_MULTI) ? 1 : 0);
646 	return emm_dma;
647 }
648 
649 static void cvm_mmc_dma_request(struct mmc_host *mmc,
650 				struct mmc_request *mrq)
651 {
652 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
653 	struct cvm_mmc_host *host = slot->host;
654 	struct mmc_data *data;
655 	u64 emm_dma, addr;
656 
657 	if (!mrq->data || !mrq->data->sg || !mrq->data->sg_len ||
658 	    !mrq->stop || mrq->stop->opcode != MMC_STOP_TRANSMISSION) {
659 		dev_err(&mmc->card->dev,
660 			"Error: cmv_mmc_dma_request no data\n");
661 		goto error;
662 	}
663 
664 	cvm_mmc_switch_to(slot);
665 
666 	data = mrq->data;
667 	pr_debug("DMA request  blocks: %d  block_size: %d  total_size: %d\n",
668 		 data->blocks, data->blksz, data->blocks * data->blksz);
669 	if (data->timeout_ns)
670 		set_wdog(slot, data->timeout_ns);
671 
672 	WARN_ON(host->current_req);
673 	host->current_req = mrq;
674 
675 	emm_dma = prepare_ext_dma(mmc, mrq);
676 	addr = prepare_dma(host, data);
677 	if (!addr) {
678 		dev_err(host->dev, "prepare_dma failed\n");
679 		goto error;
680 	}
681 
682 	host->dma_active = true;
683 	host->int_enable(host, MIO_EMM_INT_CMD_ERR | MIO_EMM_INT_DMA_DONE |
684 			 MIO_EMM_INT_DMA_ERR);
685 
686 	if (host->dmar_fixup)
687 		host->dmar_fixup(host, mrq->cmd, data, addr);
688 
689 	/*
690 	 * If we have a valid SD card in the slot, we set the response
691 	 * bit mask to check for CRC errors and timeouts only.
692 	 * Otherwise, use the default power reset value.
693 	 */
694 	if (mmc_card_sd(mmc->card))
695 		writeq(0x00b00000ull, host->base + MIO_EMM_STS_MASK(host));
696 	else
697 		writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
698 	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
699 	return;
700 
701 error:
702 	mrq->cmd->error = -EINVAL;
703 	if (mrq->done)
704 		mrq->done(mrq);
705 	host->release_bus(host);
706 }
707 
708 static void do_read_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
709 {
710 	sg_miter_start(&host->smi, mrq->data->sg, mrq->data->sg_len,
711 		       SG_MITER_ATOMIC | SG_MITER_TO_SG);
712 }
713 
714 static void do_write_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
715 {
716 	unsigned int data_len = mrq->data->blocks * mrq->data->blksz;
717 	struct sg_mapping_iter *smi = &host->smi;
718 	unsigned int bytes_xfered;
719 	int shift = 56;
720 	u64 dat = 0;
721 
722 	/* Copy data to the xmit buffer before issuing the command. */
723 	sg_miter_start(smi, mrq->data->sg, mrq->data->sg_len, SG_MITER_FROM_SG);
724 
725 	/* Auto inc from offset zero, dbuf zero */
726 	writeq(0x10000ull, host->base + MIO_EMM_BUF_IDX(host));
727 
728 	for (bytes_xfered = 0; bytes_xfered < data_len;) {
729 		if (smi->consumed >= smi->length) {
730 			if (!sg_miter_next(smi))
731 				break;
732 			smi->consumed = 0;
733 		}
734 
735 		while (smi->consumed < smi->length && shift >= 0) {
736 			dat |= (u64)((u8 *)smi->addr)[smi->consumed] << shift;
737 			bytes_xfered++;
738 			smi->consumed++;
739 			shift -= 8;
740 		}
741 
742 		if (shift < 0) {
743 			writeq(dat, host->base + MIO_EMM_BUF_DAT(host));
744 			shift = 56;
745 			dat = 0;
746 		}
747 	}
748 	sg_miter_stop(smi);
749 }
750 
751 static void cvm_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
752 {
753 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
754 	struct cvm_mmc_host *host = slot->host;
755 	struct mmc_command *cmd = mrq->cmd;
756 	struct cvm_mmc_cr_mods mods;
757 	u64 emm_cmd, rsp_sts;
758 	int retries = 100;
759 
760 	/*
761 	 * Note about locking:
762 	 * All MMC devices share the same bus and controller. Allow only a
763 	 * single user of the bootbus/MMC bus at a time. The lock is acquired
764 	 * on all entry points from the MMC layer.
765 	 *
766 	 * For requests the lock is only released after the completion
767 	 * interrupt!
768 	 */
769 	host->acquire_bus(host);
770 
771 	if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
772 	    cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)
773 		return cvm_mmc_dma_request(mmc, mrq);
774 
775 	cvm_mmc_switch_to(slot);
776 
777 	mods = cvm_mmc_get_cr_mods(cmd);
778 
779 	WARN_ON(host->current_req);
780 	host->current_req = mrq;
781 
782 	if (cmd->data) {
783 		if (cmd->data->flags & MMC_DATA_READ)
784 			do_read_request(host, mrq);
785 		else
786 			do_write_request(host, mrq);
787 
788 		if (cmd->data->timeout_ns)
789 			set_wdog(slot, cmd->data->timeout_ns);
790 	} else
791 		set_wdog(slot, 0);
792 
793 	host->dma_active = false;
794 	host->int_enable(host, MIO_EMM_INT_CMD_DONE | MIO_EMM_INT_CMD_ERR);
795 
796 	emm_cmd = FIELD_PREP(MIO_EMM_CMD_VAL, 1) |
797 		  FIELD_PREP(MIO_EMM_CMD_CTYPE_XOR, mods.ctype_xor) |
798 		  FIELD_PREP(MIO_EMM_CMD_RTYPE_XOR, mods.rtype_xor) |
799 		  FIELD_PREP(MIO_EMM_CMD_IDX, cmd->opcode) |
800 		  FIELD_PREP(MIO_EMM_CMD_ARG, cmd->arg);
801 	set_bus_id(&emm_cmd, slot->bus_id);
802 	if (cmd->data && mmc_cmd_type(cmd) == MMC_CMD_ADTC)
803 		emm_cmd |= FIELD_PREP(MIO_EMM_CMD_OFFSET,
804 				64 - ((cmd->data->blocks * cmd->data->blksz) / 8));
805 
806 	writeq(0, host->base + MIO_EMM_STS_MASK(host));
807 
808 retry:
809 	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
810 	if (rsp_sts & MIO_EMM_RSP_STS_DMA_VAL ||
811 	    rsp_sts & MIO_EMM_RSP_STS_CMD_VAL ||
812 	    rsp_sts & MIO_EMM_RSP_STS_SWITCH_VAL ||
813 	    rsp_sts & MIO_EMM_RSP_STS_DMA_PEND) {
814 		udelay(10);
815 		if (--retries)
816 			goto retry;
817 	}
818 	if (!retries)
819 		dev_err(host->dev, "Bad status: %llx before command write\n", rsp_sts);
820 	writeq(emm_cmd, host->base + MIO_EMM_CMD(host));
821 }
822 
823 static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
824 {
825 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
826 	struct cvm_mmc_host *host = slot->host;
827 	int clk_period = 0, power_class = 10, bus_width = 0;
828 	u64 clock, emm_switch;
829 
830 	host->acquire_bus(host);
831 	cvm_mmc_switch_to(slot);
832 
833 	/* Set the power state */
834 	switch (ios->power_mode) {
835 	case MMC_POWER_ON:
836 		break;
837 
838 	case MMC_POWER_OFF:
839 		cvm_mmc_reset_bus(slot);
840 		if (host->global_pwr_gpiod)
841 			host->set_shared_power(host, 0);
842 		else
843 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
844 		break;
845 
846 	case MMC_POWER_UP:
847 		if (host->global_pwr_gpiod)
848 			host->set_shared_power(host, 1);
849 		else
850 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
851 		break;
852 	}
853 
854 	/* Convert bus width to HW definition */
855 	switch (ios->bus_width) {
856 	case MMC_BUS_WIDTH_8:
857 		bus_width = 2;
858 		break;
859 	case MMC_BUS_WIDTH_4:
860 		bus_width = 1;
861 		break;
862 	case MMC_BUS_WIDTH_1:
863 		bus_width = 0;
864 		break;
865 	}
866 
867 	/* DDR is available for 4/8 bit bus width */
868 	if (ios->bus_width && ios->timing == MMC_TIMING_MMC_DDR52)
869 		bus_width |= 4;
870 
871 	/* Change the clock frequency. */
872 	clock = ios->clock;
873 	if (clock > 52000000)
874 		clock = 52000000;
875 	slot->clock = clock;
876 
877 	if (clock)
878 		clk_period = (host->sys_freq + clock - 1) / (2 * clock);
879 
880 	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_HS_TIMING,
881 				(ios->timing == MMC_TIMING_MMC_HS)) |
882 		     FIELD_PREP(MIO_EMM_SWITCH_BUS_WIDTH, bus_width) |
883 		     FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, power_class) |
884 		     FIELD_PREP(MIO_EMM_SWITCH_CLK_HI, clk_period) |
885 		     FIELD_PREP(MIO_EMM_SWITCH_CLK_LO, clk_period);
886 	set_bus_id(&emm_switch, slot->bus_id);
887 
888 	if (!switch_val_changed(slot, emm_switch))
889 		goto out;
890 
891 	set_wdog(slot, 0);
892 	do_switch(host, emm_switch);
893 	slot->cached_switch = emm_switch;
894 out:
895 	host->release_bus(host);
896 }
897 
898 static const struct mmc_host_ops cvm_mmc_ops = {
899 	.request        = cvm_mmc_request,
900 	.set_ios        = cvm_mmc_set_ios,
901 	.get_ro		= mmc_gpio_get_ro,
902 	.get_cd		= mmc_gpio_get_cd,
903 };
904 
905 static void cvm_mmc_set_clock(struct cvm_mmc_slot *slot, unsigned int clock)
906 {
907 	struct mmc_host *mmc = slot->mmc;
908 
909 	clock = min(clock, mmc->f_max);
910 	clock = max(clock, mmc->f_min);
911 	slot->clock = clock;
912 }
913 
914 static int cvm_mmc_init_lowlevel(struct cvm_mmc_slot *slot)
915 {
916 	struct cvm_mmc_host *host = slot->host;
917 	u64 emm_switch;
918 
919 	/* Enable this bus slot. */
920 	host->emm_cfg |= (1ull << slot->bus_id);
921 	writeq(host->emm_cfg, slot->host->base + MIO_EMM_CFG(host));
922 	udelay(10);
923 
924 	/* Program initial clock speed and power. */
925 	cvm_mmc_set_clock(slot, slot->mmc->f_min);
926 	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, 10);
927 	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_HI,
928 				 (host->sys_freq / slot->clock) / 2);
929 	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_LO,
930 				 (host->sys_freq / slot->clock) / 2);
931 
932 	/* Make the changes take effect on this bus slot. */
933 	set_bus_id(&emm_switch, slot->bus_id);
934 	do_switch(host, emm_switch);
935 
936 	slot->cached_switch = emm_switch;
937 
938 	/*
939 	 * Set watchdog timeout value and default reset value
940 	 * for the mask register. Finally, set the CARD_RCA
941 	 * bit so that we can get the card address relative
942 	 * to the CMD register for CMD7 transactions.
943 	 */
944 	set_wdog(slot, 0);
945 	writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
946 	writeq(1, host->base + MIO_EMM_RCA(host));
947 	return 0;
948 }
949 
950 static int cvm_mmc_of_parse(struct device *dev, struct cvm_mmc_slot *slot)
951 {
952 	u32 id, cmd_skew = 0, dat_skew = 0, bus_width = 0;
953 	struct device_node *node = dev->of_node;
954 	struct mmc_host *mmc = slot->mmc;
955 	u64 clock_period;
956 	int ret;
957 
958 	ret = of_property_read_u32(node, "reg", &id);
959 	if (ret) {
960 		dev_err(dev, "Missing or invalid reg property on %s\n",
961 			of_node_full_name(node));
962 		return ret;
963 	}
964 
965 	if (id >= CAVIUM_MAX_MMC || slot->host->slot[id]) {
966 		dev_err(dev, "Invalid reg property on %s\n",
967 			of_node_full_name(node));
968 		return -EINVAL;
969 	}
970 
971 	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
972 	if (IS_ERR(mmc->supply.vmmc)) {
973 		if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
974 			return -EPROBE_DEFER;
975 		/*
976 		 * Legacy Octeon firmware has no regulator entry, fall-back to
977 		 * a hard-coded voltage to get a sane OCR.
978 		 */
979 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
980 	} else {
981 		ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
982 		if (ret > 0)
983 			mmc->ocr_avail = ret;
984 	}
985 
986 	/* Common MMC bindings */
987 	ret = mmc_of_parse(mmc);
988 	if (ret)
989 		return ret;
990 
991 	/* Set bus width */
992 	if (!(mmc->caps & (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA))) {
993 		of_property_read_u32(node, "cavium,bus-max-width", &bus_width);
994 		if (bus_width == 8)
995 			mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;
996 		else if (bus_width == 4)
997 			mmc->caps |= MMC_CAP_4_BIT_DATA;
998 	}
999 
1000 	/* Set maximum and minimum frequency */
1001 	if (!mmc->f_max)
1002 		of_property_read_u32(node, "spi-max-frequency", &mmc->f_max);
1003 	if (!mmc->f_max || mmc->f_max > 52000000)
1004 		mmc->f_max = 52000000;
1005 	mmc->f_min = 400000;
1006 
1007 	/* Sampling register settings, period in picoseconds */
1008 	clock_period = 1000000000000ull / slot->host->sys_freq;
1009 	of_property_read_u32(node, "cavium,cmd-clk-skew", &cmd_skew);
1010 	of_property_read_u32(node, "cavium,dat-clk-skew", &dat_skew);
1011 	slot->cmd_cnt = (cmd_skew + clock_period / 2) / clock_period;
1012 	slot->dat_cnt = (dat_skew + clock_period / 2) / clock_period;
1013 
1014 	return id;
1015 }
1016 
1017 int cvm_mmc_of_slot_probe(struct device *dev, struct cvm_mmc_host *host)
1018 {
1019 	struct cvm_mmc_slot *slot;
1020 	struct mmc_host *mmc;
1021 	int ret, id;
1022 
1023 	mmc = mmc_alloc_host(sizeof(struct cvm_mmc_slot), dev);
1024 	if (!mmc)
1025 		return -ENOMEM;
1026 
1027 	slot = mmc_priv(mmc);
1028 	slot->mmc = mmc;
1029 	slot->host = host;
1030 
1031 	ret = cvm_mmc_of_parse(dev, slot);
1032 	if (ret < 0)
1033 		goto error;
1034 	id = ret;
1035 
1036 	/* Set up host parameters */
1037 	mmc->ops = &cvm_mmc_ops;
1038 
1039 	/*
1040 	 * We only have a 3.3v supply, we cannot support any
1041 	 * of the UHS modes. We do support the high speed DDR
1042 	 * modes up to 52MHz.
1043 	 */
1044 	mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
1045 		     MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_POWER_OFF_CARD |
1046 		     MMC_CAP_3_3V_DDR;
1047 
1048 	if (host->use_sg)
1049 		mmc->max_segs = 16;
1050 	else
1051 		mmc->max_segs = 1;
1052 
1053 	/* DMA size field can address up to 8 MB */
1054 	mmc->max_seg_size = 8 * 1024 * 1024;
1055 	mmc->max_req_size = mmc->max_seg_size;
1056 	/* External DMA is in 512 byte blocks */
1057 	mmc->max_blk_size = 512;
1058 	/* DMA block count field is 15 bits */
1059 	mmc->max_blk_count = 32767;
1060 
1061 	slot->clock = mmc->f_min;
1062 	slot->bus_id = id;
1063 	slot->cached_rca = 1;
1064 
1065 	host->acquire_bus(host);
1066 	host->slot[id] = slot;
1067 	cvm_mmc_switch_to(slot);
1068 	cvm_mmc_init_lowlevel(slot);
1069 	host->release_bus(host);
1070 
1071 	ret = mmc_add_host(mmc);
1072 	if (ret) {
1073 		dev_err(dev, "mmc_add_host() returned %d\n", ret);
1074 		slot->host->slot[id] = NULL;
1075 		goto error;
1076 	}
1077 	return 0;
1078 
1079 error:
1080 	mmc_free_host(slot->mmc);
1081 	return ret;
1082 }
1083 
1084 int cvm_mmc_of_slot_remove(struct cvm_mmc_slot *slot)
1085 {
1086 	mmc_remove_host(slot->mmc);
1087 	slot->host->slot[slot->bus_id] = NULL;
1088 	mmc_free_host(slot->mmc);
1089 	return 0;
1090 }
1091