xref: /openbmc/linux/drivers/mmc/host/cavium.c (revision aad7ebb5)
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 	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
378 	return 1;
379 }
380 
381 static int finish_dma_sg(struct cvm_mmc_host *host, struct mmc_data *data)
382 {
383 	u64 fifo_cfg;
384 	int count;
385 
386 	/* Check if there are any pending requests left */
387 	fifo_cfg = readq(host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
388 	count = FIELD_GET(MIO_EMM_DMA_FIFO_CFG_COUNT, fifo_cfg);
389 	if (count)
390 		dev_err(host->dev, "%u requests still pending\n", count);
391 
392 	data->bytes_xfered = data->blocks * data->blksz;
393 	data->error = 0;
394 
395 	/* Clear and disable FIFO */
396 	writeq(BIT_ULL(16), host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
397 	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
398 	return 1;
399 }
400 
401 static int finish_dma(struct cvm_mmc_host *host, struct mmc_data *data)
402 {
403 	if (host->use_sg && data->sg_len > 1)
404 		return finish_dma_sg(host, data);
405 	else
406 		return finish_dma_single(host, data);
407 }
408 
409 static int check_status(u64 rsp_sts)
410 {
411 	if (rsp_sts & MIO_EMM_RSP_STS_RSP_BAD_STS ||
412 	    rsp_sts & MIO_EMM_RSP_STS_RSP_CRC_ERR ||
413 	    rsp_sts & MIO_EMM_RSP_STS_BLK_CRC_ERR)
414 		return -EILSEQ;
415 	if (rsp_sts & MIO_EMM_RSP_STS_RSP_TIMEOUT ||
416 	    rsp_sts & MIO_EMM_RSP_STS_BLK_TIMEOUT)
417 		return -ETIMEDOUT;
418 	if (rsp_sts & MIO_EMM_RSP_STS_DBUF_ERR)
419 		return -EIO;
420 	return 0;
421 }
422 
423 /* Try to clean up failed DMA. */
424 static void cleanup_dma(struct cvm_mmc_host *host, u64 rsp_sts)
425 {
426 	u64 emm_dma;
427 
428 	emm_dma = readq(host->base + MIO_EMM_DMA(host));
429 	emm_dma |= FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
430 		   FIELD_PREP(MIO_EMM_DMA_DAT_NULL, 1);
431 	set_bus_id(&emm_dma, get_bus_id(rsp_sts));
432 	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
433 }
434 
435 irqreturn_t cvm_mmc_interrupt(int irq, void *dev_id)
436 {
437 	struct cvm_mmc_host *host = dev_id;
438 	struct mmc_request *req;
439 	unsigned long flags = 0;
440 	u64 emm_int, rsp_sts;
441 	bool host_done;
442 
443 	if (host->need_irq_handler_lock)
444 		spin_lock_irqsave(&host->irq_handler_lock, flags);
445 	else
446 		__acquire(&host->irq_handler_lock);
447 
448 	/* Clear interrupt bits (write 1 clears ). */
449 	emm_int = readq(host->base + MIO_EMM_INT(host));
450 	writeq(emm_int, host->base + MIO_EMM_INT(host));
451 
452 	if (emm_int & MIO_EMM_INT_SWITCH_ERR)
453 		check_switch_errors(host);
454 
455 	req = host->current_req;
456 	if (!req)
457 		goto out;
458 
459 	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
460 	/*
461 	 * dma_val set means DMA is still in progress. Don't touch
462 	 * the request and wait for the interrupt indicating that
463 	 * the DMA is finished.
464 	 */
465 	if ((rsp_sts & MIO_EMM_RSP_STS_DMA_VAL) && host->dma_active)
466 		goto out;
467 
468 	if (!host->dma_active && req->data &&
469 	    (emm_int & MIO_EMM_INT_BUF_DONE)) {
470 		unsigned int type = (rsp_sts >> 7) & 3;
471 
472 		if (type == 1)
473 			do_read(host, req, rsp_sts & MIO_EMM_RSP_STS_DBUF);
474 		else if (type == 2)
475 			do_write(req);
476 	}
477 
478 	host_done = emm_int & MIO_EMM_INT_CMD_DONE ||
479 		    emm_int & MIO_EMM_INT_DMA_DONE ||
480 		    emm_int & MIO_EMM_INT_CMD_ERR  ||
481 		    emm_int & MIO_EMM_INT_DMA_ERR;
482 
483 	if (!(host_done && req->done))
484 		goto no_req_done;
485 
486 	req->cmd->error = check_status(rsp_sts);
487 
488 	if (host->dma_active && req->data)
489 		if (!finish_dma(host, req->data))
490 			goto no_req_done;
491 
492 	set_cmd_response(host, req, rsp_sts);
493 	if ((emm_int & MIO_EMM_INT_DMA_ERR) &&
494 	    (rsp_sts & MIO_EMM_RSP_STS_DMA_PEND))
495 		cleanup_dma(host, rsp_sts);
496 
497 	host->current_req = NULL;
498 	req->done(req);
499 
500 no_req_done:
501 	if (host->dmar_fixup_done)
502 		host->dmar_fixup_done(host);
503 	if (host_done)
504 		host->release_bus(host);
505 out:
506 	if (host->need_irq_handler_lock)
507 		spin_unlock_irqrestore(&host->irq_handler_lock, flags);
508 	else
509 		__release(&host->irq_handler_lock);
510 	return IRQ_RETVAL(emm_int != 0);
511 }
512 
513 /*
514  * Program DMA_CFG and if needed DMA_ADR.
515  * Returns 0 on error, DMA address otherwise.
516  */
517 static u64 prepare_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
518 {
519 	u64 dma_cfg, addr;
520 	int count, rw;
521 
522 	count = dma_map_sg(host->dev, data->sg, data->sg_len,
523 			   get_dma_dir(data));
524 	if (!count)
525 		return 0;
526 
527 	rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
528 	dma_cfg = FIELD_PREP(MIO_EMM_DMA_CFG_EN, 1) |
529 		  FIELD_PREP(MIO_EMM_DMA_CFG_RW, rw);
530 #ifdef __LITTLE_ENDIAN
531 	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ENDIAN, 1);
532 #endif
533 	dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_SIZE,
534 			      (sg_dma_len(&data->sg[0]) / 8) - 1);
535 
536 	addr = sg_dma_address(&data->sg[0]);
537 	if (!host->big_dma_addr)
538 		dma_cfg |= FIELD_PREP(MIO_EMM_DMA_CFG_ADR, addr);
539 	writeq(dma_cfg, host->dma_base + MIO_EMM_DMA_CFG(host));
540 
541 	pr_debug("[%s] sg_dma_len: %u  total sg_elem: %d\n",
542 		 (rw) ? "W" : "R", sg_dma_len(&data->sg[0]), count);
543 
544 	if (host->big_dma_addr)
545 		writeq(addr, host->dma_base + MIO_EMM_DMA_ADR(host));
546 	return addr;
547 }
548 
549 /*
550  * Queue complete sg list into the FIFO.
551  * Returns 0 on error, 1 otherwise.
552  */
553 static u64 prepare_dma_sg(struct cvm_mmc_host *host, struct mmc_data *data)
554 {
555 	struct scatterlist *sg;
556 	u64 fifo_cmd, addr;
557 	int count, i, rw;
558 
559 	count = dma_map_sg(host->dev, data->sg, data->sg_len,
560 			   get_dma_dir(data));
561 	if (!count)
562 		return 0;
563 	if (count > 16)
564 		goto error;
565 
566 	/* Enable FIFO by removing CLR bit */
567 	writeq(0, host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
568 
569 	for_each_sg(data->sg, sg, count, i) {
570 		/* Program DMA address */
571 		addr = sg_dma_address(sg);
572 		if (addr & 7)
573 			goto error;
574 		writeq(addr, host->dma_base + MIO_EMM_DMA_FIFO_ADR(host));
575 
576 		/*
577 		 * If we have scatter-gather support we also have an extra
578 		 * register for the DMA addr, so no need to check
579 		 * host->big_dma_addr here.
580 		 */
581 		rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
582 		fifo_cmd = FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_RW, rw);
583 
584 		/* enable interrupts on the last element */
585 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_INTDIS,
586 				       (i + 1 == count) ? 0 : 1);
587 
588 #ifdef __LITTLE_ENDIAN
589 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_ENDIAN, 1);
590 #endif
591 		fifo_cmd |= FIELD_PREP(MIO_EMM_DMA_FIFO_CMD_SIZE,
592 				       sg_dma_len(sg) / 8 - 1);
593 		/*
594 		 * The write copies the address and the command to the FIFO
595 		 * and increments the FIFO's COUNT field.
596 		 */
597 		writeq(fifo_cmd, host->dma_base + MIO_EMM_DMA_FIFO_CMD(host));
598 		pr_debug("[%s] sg_dma_len: %u  sg_elem: %d/%d\n",
599 			 (rw) ? "W" : "R", sg_dma_len(sg), i, count);
600 	}
601 
602 	/*
603 	 * In difference to prepare_dma_single we don't return the
604 	 * address here, as it would not make sense for scatter-gather.
605 	 * The dma fixup is only required on models that don't support
606 	 * scatter-gather, so that is not a problem.
607 	 */
608 	return 1;
609 
610 error:
611 	WARN_ON_ONCE(1);
612 	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
613 	/* Disable FIFO */
614 	writeq(BIT_ULL(16), host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
615 	return 0;
616 }
617 
618 static u64 prepare_dma(struct cvm_mmc_host *host, struct mmc_data *data)
619 {
620 	if (host->use_sg && data->sg_len > 1)
621 		return prepare_dma_sg(host, data);
622 	else
623 		return prepare_dma_single(host, data);
624 }
625 
626 static u64 prepare_ext_dma(struct mmc_host *mmc, struct mmc_request *mrq)
627 {
628 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
629 	u64 emm_dma;
630 
631 	emm_dma = FIELD_PREP(MIO_EMM_DMA_VAL, 1) |
632 		  FIELD_PREP(MIO_EMM_DMA_SECTOR,
633 			     mmc_card_is_blockaddr(mmc->card) ? 1 : 0) |
634 		  FIELD_PREP(MIO_EMM_DMA_RW,
635 			     (mrq->data->flags & MMC_DATA_WRITE) ? 1 : 0) |
636 		  FIELD_PREP(MIO_EMM_DMA_BLOCK_CNT, mrq->data->blocks) |
637 		  FIELD_PREP(MIO_EMM_DMA_CARD_ADDR, mrq->cmd->arg);
638 	set_bus_id(&emm_dma, slot->bus_id);
639 
640 	if (mmc_card_mmc(mmc->card) || (mmc_card_sd(mmc->card) &&
641 	    (mmc->card->scr.cmds & SD_SCR_CMD23_SUPPORT)))
642 		emm_dma |= FIELD_PREP(MIO_EMM_DMA_MULTI, 1);
643 
644 	pr_debug("[%s] blocks: %u  multi: %d\n",
645 		(emm_dma & MIO_EMM_DMA_RW) ? "W" : "R",
646 		 mrq->data->blocks, (emm_dma & MIO_EMM_DMA_MULTI) ? 1 : 0);
647 	return emm_dma;
648 }
649 
650 static void cvm_mmc_dma_request(struct mmc_host *mmc,
651 				struct mmc_request *mrq)
652 {
653 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
654 	struct cvm_mmc_host *host = slot->host;
655 	struct mmc_data *data;
656 	u64 emm_dma, addr;
657 
658 	if (!mrq->data || !mrq->data->sg || !mrq->data->sg_len ||
659 	    !mrq->stop || mrq->stop->opcode != MMC_STOP_TRANSMISSION) {
660 		dev_err(&mmc->card->dev,
661 			"Error: cmv_mmc_dma_request no data\n");
662 		goto error;
663 	}
664 
665 	cvm_mmc_switch_to(slot);
666 
667 	data = mrq->data;
668 	pr_debug("DMA request  blocks: %d  block_size: %d  total_size: %d\n",
669 		 data->blocks, data->blksz, data->blocks * data->blksz);
670 	if (data->timeout_ns)
671 		set_wdog(slot, data->timeout_ns);
672 
673 	WARN_ON(host->current_req);
674 	host->current_req = mrq;
675 
676 	emm_dma = prepare_ext_dma(mmc, mrq);
677 	addr = prepare_dma(host, data);
678 	if (!addr) {
679 		dev_err(host->dev, "prepare_dma failed\n");
680 		goto error;
681 	}
682 
683 	host->dma_active = true;
684 	host->int_enable(host, MIO_EMM_INT_CMD_ERR | MIO_EMM_INT_DMA_DONE |
685 			 MIO_EMM_INT_DMA_ERR);
686 
687 	if (host->dmar_fixup)
688 		host->dmar_fixup(host, mrq->cmd, data, addr);
689 
690 	/*
691 	 * If we have a valid SD card in the slot, we set the response
692 	 * bit mask to check for CRC errors and timeouts only.
693 	 * Otherwise, use the default power reset value.
694 	 */
695 	if (mmc_card_sd(mmc->card))
696 		writeq(0x00b00000ull, host->base + MIO_EMM_STS_MASK(host));
697 	else
698 		writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
699 	writeq(emm_dma, host->base + MIO_EMM_DMA(host));
700 	return;
701 
702 error:
703 	mrq->cmd->error = -EINVAL;
704 	if (mrq->done)
705 		mrq->done(mrq);
706 	host->release_bus(host);
707 }
708 
709 static void do_read_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
710 {
711 	sg_miter_start(&host->smi, mrq->data->sg, mrq->data->sg_len,
712 		       SG_MITER_ATOMIC | SG_MITER_TO_SG);
713 }
714 
715 static void do_write_request(struct cvm_mmc_host *host, struct mmc_request *mrq)
716 {
717 	unsigned int data_len = mrq->data->blocks * mrq->data->blksz;
718 	struct sg_mapping_iter *smi = &host->smi;
719 	unsigned int bytes_xfered;
720 	int shift = 56;
721 	u64 dat = 0;
722 
723 	/* Copy data to the xmit buffer before issuing the command. */
724 	sg_miter_start(smi, mrq->data->sg, mrq->data->sg_len, SG_MITER_FROM_SG);
725 
726 	/* Auto inc from offset zero, dbuf zero */
727 	writeq(0x10000ull, host->base + MIO_EMM_BUF_IDX(host));
728 
729 	for (bytes_xfered = 0; bytes_xfered < data_len;) {
730 		if (smi->consumed >= smi->length) {
731 			if (!sg_miter_next(smi))
732 				break;
733 			smi->consumed = 0;
734 		}
735 
736 		while (smi->consumed < smi->length && shift >= 0) {
737 			dat |= (u64)((u8 *)smi->addr)[smi->consumed] << shift;
738 			bytes_xfered++;
739 			smi->consumed++;
740 			shift -= 8;
741 		}
742 
743 		if (shift < 0) {
744 			writeq(dat, host->base + MIO_EMM_BUF_DAT(host));
745 			shift = 56;
746 			dat = 0;
747 		}
748 	}
749 	sg_miter_stop(smi);
750 }
751 
752 static void cvm_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
753 {
754 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
755 	struct cvm_mmc_host *host = slot->host;
756 	struct mmc_command *cmd = mrq->cmd;
757 	struct cvm_mmc_cr_mods mods;
758 	u64 emm_cmd, rsp_sts;
759 	int retries = 100;
760 
761 	/*
762 	 * Note about locking:
763 	 * All MMC devices share the same bus and controller. Allow only a
764 	 * single user of the bootbus/MMC bus at a time. The lock is acquired
765 	 * on all entry points from the MMC layer.
766 	 *
767 	 * For requests the lock is only released after the completion
768 	 * interrupt!
769 	 */
770 	host->acquire_bus(host);
771 
772 	if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
773 	    cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)
774 		return cvm_mmc_dma_request(mmc, mrq);
775 
776 	cvm_mmc_switch_to(slot);
777 
778 	mods = cvm_mmc_get_cr_mods(cmd);
779 
780 	WARN_ON(host->current_req);
781 	host->current_req = mrq;
782 
783 	if (cmd->data) {
784 		if (cmd->data->flags & MMC_DATA_READ)
785 			do_read_request(host, mrq);
786 		else
787 			do_write_request(host, mrq);
788 
789 		if (cmd->data->timeout_ns)
790 			set_wdog(slot, cmd->data->timeout_ns);
791 	} else
792 		set_wdog(slot, 0);
793 
794 	host->dma_active = false;
795 	host->int_enable(host, MIO_EMM_INT_CMD_DONE | MIO_EMM_INT_CMD_ERR);
796 
797 	emm_cmd = FIELD_PREP(MIO_EMM_CMD_VAL, 1) |
798 		  FIELD_PREP(MIO_EMM_CMD_CTYPE_XOR, mods.ctype_xor) |
799 		  FIELD_PREP(MIO_EMM_CMD_RTYPE_XOR, mods.rtype_xor) |
800 		  FIELD_PREP(MIO_EMM_CMD_IDX, cmd->opcode) |
801 		  FIELD_PREP(MIO_EMM_CMD_ARG, cmd->arg);
802 	set_bus_id(&emm_cmd, slot->bus_id);
803 	if (cmd->data && mmc_cmd_type(cmd) == MMC_CMD_ADTC)
804 		emm_cmd |= FIELD_PREP(MIO_EMM_CMD_OFFSET,
805 				64 - ((cmd->data->blocks * cmd->data->blksz) / 8));
806 
807 	writeq(0, host->base + MIO_EMM_STS_MASK(host));
808 
809 retry:
810 	rsp_sts = readq(host->base + MIO_EMM_RSP_STS(host));
811 	if (rsp_sts & MIO_EMM_RSP_STS_DMA_VAL ||
812 	    rsp_sts & MIO_EMM_RSP_STS_CMD_VAL ||
813 	    rsp_sts & MIO_EMM_RSP_STS_SWITCH_VAL ||
814 	    rsp_sts & MIO_EMM_RSP_STS_DMA_PEND) {
815 		udelay(10);
816 		if (--retries)
817 			goto retry;
818 	}
819 	if (!retries)
820 		dev_err(host->dev, "Bad status: %llx before command write\n", rsp_sts);
821 	writeq(emm_cmd, host->base + MIO_EMM_CMD(host));
822 }
823 
824 static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
825 {
826 	struct cvm_mmc_slot *slot = mmc_priv(mmc);
827 	struct cvm_mmc_host *host = slot->host;
828 	int clk_period = 0, power_class = 10, bus_width = 0;
829 	u64 clock, emm_switch;
830 
831 	host->acquire_bus(host);
832 	cvm_mmc_switch_to(slot);
833 
834 	/* Set the power state */
835 	switch (ios->power_mode) {
836 	case MMC_POWER_ON:
837 		break;
838 
839 	case MMC_POWER_OFF:
840 		cvm_mmc_reset_bus(slot);
841 		if (host->global_pwr_gpiod)
842 			host->set_shared_power(host, 0);
843 		else if (!IS_ERR(mmc->supply.vmmc))
844 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
845 		break;
846 
847 	case MMC_POWER_UP:
848 		if (host->global_pwr_gpiod)
849 			host->set_shared_power(host, 1);
850 		else if (!IS_ERR(mmc->supply.vmmc))
851 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
852 		break;
853 	}
854 
855 	/* Convert bus width to HW definition */
856 	switch (ios->bus_width) {
857 	case MMC_BUS_WIDTH_8:
858 		bus_width = 2;
859 		break;
860 	case MMC_BUS_WIDTH_4:
861 		bus_width = 1;
862 		break;
863 	case MMC_BUS_WIDTH_1:
864 		bus_width = 0;
865 		break;
866 	}
867 
868 	/* DDR is available for 4/8 bit bus width */
869 	if (ios->bus_width && ios->timing == MMC_TIMING_MMC_DDR52)
870 		bus_width |= 4;
871 
872 	/* Change the clock frequency. */
873 	clock = ios->clock;
874 	if (clock > 52000000)
875 		clock = 52000000;
876 	slot->clock = clock;
877 
878 	if (clock)
879 		clk_period = (host->sys_freq + clock - 1) / (2 * clock);
880 
881 	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_HS_TIMING,
882 				(ios->timing == MMC_TIMING_MMC_HS)) |
883 		     FIELD_PREP(MIO_EMM_SWITCH_BUS_WIDTH, bus_width) |
884 		     FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, power_class) |
885 		     FIELD_PREP(MIO_EMM_SWITCH_CLK_HI, clk_period) |
886 		     FIELD_PREP(MIO_EMM_SWITCH_CLK_LO, clk_period);
887 	set_bus_id(&emm_switch, slot->bus_id);
888 
889 	if (!switch_val_changed(slot, emm_switch))
890 		goto out;
891 
892 	set_wdog(slot, 0);
893 	do_switch(host, emm_switch);
894 	slot->cached_switch = emm_switch;
895 out:
896 	host->release_bus(host);
897 }
898 
899 static const struct mmc_host_ops cvm_mmc_ops = {
900 	.request        = cvm_mmc_request,
901 	.set_ios        = cvm_mmc_set_ios,
902 	.get_ro		= mmc_gpio_get_ro,
903 	.get_cd		= mmc_gpio_get_cd,
904 };
905 
906 static void cvm_mmc_set_clock(struct cvm_mmc_slot *slot, unsigned int clock)
907 {
908 	struct mmc_host *mmc = slot->mmc;
909 
910 	clock = min(clock, mmc->f_max);
911 	clock = max(clock, mmc->f_min);
912 	slot->clock = clock;
913 }
914 
915 static int cvm_mmc_init_lowlevel(struct cvm_mmc_slot *slot)
916 {
917 	struct cvm_mmc_host *host = slot->host;
918 	u64 emm_switch;
919 
920 	/* Enable this bus slot. */
921 	host->emm_cfg |= (1ull << slot->bus_id);
922 	writeq(host->emm_cfg, slot->host->base + MIO_EMM_CFG(host));
923 	udelay(10);
924 
925 	/* Program initial clock speed and power. */
926 	cvm_mmc_set_clock(slot, slot->mmc->f_min);
927 	emm_switch = FIELD_PREP(MIO_EMM_SWITCH_POWER_CLASS, 10);
928 	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_HI,
929 				 (host->sys_freq / slot->clock) / 2);
930 	emm_switch |= FIELD_PREP(MIO_EMM_SWITCH_CLK_LO,
931 				 (host->sys_freq / slot->clock) / 2);
932 
933 	/* Make the changes take effect on this bus slot. */
934 	set_bus_id(&emm_switch, slot->bus_id);
935 	do_switch(host, emm_switch);
936 
937 	slot->cached_switch = emm_switch;
938 
939 	/*
940 	 * Set watchdog timeout value and default reset value
941 	 * for the mask register. Finally, set the CARD_RCA
942 	 * bit so that we can get the card address relative
943 	 * to the CMD register for CMD7 transactions.
944 	 */
945 	set_wdog(slot, 0);
946 	writeq(0xe4390080ull, host->base + MIO_EMM_STS_MASK(host));
947 	writeq(1, host->base + MIO_EMM_RCA(host));
948 	return 0;
949 }
950 
951 static int cvm_mmc_of_parse(struct device *dev, struct cvm_mmc_slot *slot)
952 {
953 	u32 id, cmd_skew = 0, dat_skew = 0, bus_width = 0;
954 	struct device_node *node = dev->of_node;
955 	struct mmc_host *mmc = slot->mmc;
956 	u64 clock_period;
957 	int ret;
958 
959 	ret = of_property_read_u32(node, "reg", &id);
960 	if (ret) {
961 		dev_err(dev, "Missing or invalid reg property on %pOF\n", node);
962 		return ret;
963 	}
964 
965 	if (id >= CAVIUM_MAX_MMC || slot->host->slot[id]) {
966 		dev_err(dev, "Invalid reg property on %pOF\n", node);
967 		return -EINVAL;
968 	}
969 
970 	ret = mmc_regulator_get_supply(mmc);
971 	if (ret)
972 		return ret;
973 	/*
974 	 * Legacy Octeon firmware has no regulator entry, fall-back to
975 	 * a hard-coded voltage to get a sane OCR.
976 	 */
977 	if (IS_ERR(mmc->supply.vmmc))
978 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
979 
980 	/* Common MMC bindings */
981 	ret = mmc_of_parse(mmc);
982 	if (ret)
983 		return ret;
984 
985 	/* Set bus width */
986 	if (!(mmc->caps & (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA))) {
987 		of_property_read_u32(node, "cavium,bus-max-width", &bus_width);
988 		if (bus_width == 8)
989 			mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;
990 		else if (bus_width == 4)
991 			mmc->caps |= MMC_CAP_4_BIT_DATA;
992 	}
993 
994 	/* Set maximum and minimum frequency */
995 	if (!mmc->f_max)
996 		of_property_read_u32(node, "spi-max-frequency", &mmc->f_max);
997 	if (!mmc->f_max || mmc->f_max > 52000000)
998 		mmc->f_max = 52000000;
999 	mmc->f_min = 400000;
1000 
1001 	/* Sampling register settings, period in picoseconds */
1002 	clock_period = 1000000000000ull / slot->host->sys_freq;
1003 	of_property_read_u32(node, "cavium,cmd-clk-skew", &cmd_skew);
1004 	of_property_read_u32(node, "cavium,dat-clk-skew", &dat_skew);
1005 	slot->cmd_cnt = (cmd_skew + clock_period / 2) / clock_period;
1006 	slot->dat_cnt = (dat_skew + clock_period / 2) / clock_period;
1007 
1008 	return id;
1009 }
1010 
1011 int cvm_mmc_of_slot_probe(struct device *dev, struct cvm_mmc_host *host)
1012 {
1013 	struct cvm_mmc_slot *slot;
1014 	struct mmc_host *mmc;
1015 	int ret, id;
1016 
1017 	mmc = mmc_alloc_host(sizeof(struct cvm_mmc_slot), dev);
1018 	if (!mmc)
1019 		return -ENOMEM;
1020 
1021 	slot = mmc_priv(mmc);
1022 	slot->mmc = mmc;
1023 	slot->host = host;
1024 
1025 	ret = cvm_mmc_of_parse(dev, slot);
1026 	if (ret < 0)
1027 		goto error;
1028 	id = ret;
1029 
1030 	/* Set up host parameters */
1031 	mmc->ops = &cvm_mmc_ops;
1032 
1033 	/*
1034 	 * We only have a 3.3v supply, we cannot support any
1035 	 * of the UHS modes. We do support the high speed DDR
1036 	 * modes up to 52MHz.
1037 	 *
1038 	 * Disable bounce buffers for max_segs = 1
1039 	 */
1040 	mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
1041 		     MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_POWER_OFF_CARD |
1042 		     MMC_CAP_3_3V_DDR;
1043 
1044 	if (host->use_sg)
1045 		mmc->max_segs = 16;
1046 	else
1047 		mmc->max_segs = 1;
1048 
1049 	/* DMA size field can address up to 8 MB */
1050 	mmc->max_seg_size = min_t(unsigned int, 8 * 1024 * 1024,
1051 				  dma_get_max_seg_size(host->dev));
1052 	mmc->max_req_size = mmc->max_seg_size;
1053 	/* External DMA is in 512 byte blocks */
1054 	mmc->max_blk_size = 512;
1055 	/* DMA block count field is 15 bits */
1056 	mmc->max_blk_count = 32767;
1057 
1058 	slot->clock = mmc->f_min;
1059 	slot->bus_id = id;
1060 	slot->cached_rca = 1;
1061 
1062 	host->acquire_bus(host);
1063 	host->slot[id] = slot;
1064 	cvm_mmc_switch_to(slot);
1065 	cvm_mmc_init_lowlevel(slot);
1066 	host->release_bus(host);
1067 
1068 	ret = mmc_add_host(mmc);
1069 	if (ret) {
1070 		dev_err(dev, "mmc_add_host() returned %d\n", ret);
1071 		slot->host->slot[id] = NULL;
1072 		goto error;
1073 	}
1074 	return 0;
1075 
1076 error:
1077 	mmc_free_host(slot->mmc);
1078 	return ret;
1079 }
1080 
1081 int cvm_mmc_of_slot_remove(struct cvm_mmc_slot *slot)
1082 {
1083 	mmc_remove_host(slot->mmc);
1084 	slot->host->slot[slot->bus_id] = NULL;
1085 	mmc_free_host(slot->mmc);
1086 	return 0;
1087 }
1088