xref: /linux/drivers/mmc/host/meson-mx-sdhc-mmc.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Amlogic Meson6/Meson8/Meson8b/Meson8m2 SDHC MMC host controller driver.
4  *
5  * Copyright (C) 2020 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/interrupt.h>
12 #include <linux/iopoll.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/property.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/types.h>
20 
21 #include <linux/mmc/host.h>
22 #include <linux/mmc/mmc.h>
23 #include <linux/mmc/sdio.h>
24 #include <linux/mmc/slot-gpio.h>
25 
26 #include "meson-mx-sdhc.h"
27 
28 #define MESON_SDHC_NUM_BULK_CLKS				4
29 #define MESON_SDHC_MAX_BLK_SIZE					512
30 #define MESON_SDHC_NUM_TUNING_TRIES				10
31 
32 #define MESON_SDHC_WAIT_CMD_READY_SLEEP_US			1
33 #define MESON_SDHC_WAIT_CMD_READY_TIMEOUT_US			100000
34 #define MESON_SDHC_WAIT_BEFORE_SEND_SLEEP_US			1
35 #define MESON_SDHC_WAIT_BEFORE_SEND_TIMEOUT_US			200
36 
37 struct meson_mx_sdhc_data {
38 	void		(*init_hw)(struct mmc_host *mmc);
39 	void		(*set_pdma)(struct mmc_host *mmc);
40 	void		(*wait_before_send)(struct mmc_host *mmc);
41 	bool		hardware_flush_all_cmds;
42 };
43 
44 struct meson_mx_sdhc_host {
45 	struct mmc_host			*mmc;
46 
47 	struct mmc_request		*mrq;
48 	struct mmc_command		*cmd;
49 	int				error;
50 
51 	struct regmap			*regmap;
52 
53 	struct clk			*pclk;
54 	struct clk			*sd_clk;
55 	struct clk_bulk_data		bulk_clks[MESON_SDHC_NUM_BULK_CLKS];
56 	bool				bulk_clks_enabled;
57 
58 	const struct meson_mx_sdhc_data	*platform;
59 };
60 
61 static const struct regmap_config meson_mx_sdhc_regmap_config = {
62 	.reg_bits = 8,
63 	.val_bits = 32,
64 	.reg_stride = 4,
65 	.max_register = MESON_SDHC_CLK2,
66 };
67 
68 static void meson_mx_sdhc_reset(struct meson_mx_sdhc_host *host)
69 {
70 	regmap_write(host->regmap, MESON_SDHC_SRST, MESON_SDHC_SRST_MAIN_CTRL |
71 		     MESON_SDHC_SRST_RXFIFO | MESON_SDHC_SRST_TXFIFO |
72 		     MESON_SDHC_SRST_DPHY_RX | MESON_SDHC_SRST_DPHY_TX |
73 		     MESON_SDHC_SRST_DMA_IF);
74 	usleep_range(10, 100);
75 
76 	regmap_write(host->regmap, MESON_SDHC_SRST, 0);
77 	usleep_range(10, 100);
78 }
79 
80 static void meson_mx_sdhc_clear_fifo(struct mmc_host *mmc)
81 {
82 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
83 	u32 stat;
84 
85 	regmap_read(host->regmap, MESON_SDHC_STAT, &stat);
86 	if (!FIELD_GET(MESON_SDHC_STAT_RXFIFO_CNT, stat) &&
87 	    !FIELD_GET(MESON_SDHC_STAT_TXFIFO_CNT, stat))
88 		return;
89 
90 	regmap_write(host->regmap, MESON_SDHC_SRST, MESON_SDHC_SRST_RXFIFO |
91 		     MESON_SDHC_SRST_TXFIFO | MESON_SDHC_SRST_MAIN_CTRL);
92 	udelay(5);
93 
94 	regmap_read(host->regmap, MESON_SDHC_STAT, &stat);
95 	if (FIELD_GET(MESON_SDHC_STAT_RXFIFO_CNT, stat) ||
96 	    FIELD_GET(MESON_SDHC_STAT_TXFIFO_CNT, stat))
97 		dev_warn(mmc_dev(host->mmc),
98 			 "Failed to clear FIFOs, RX: %lu, TX: %lu\n",
99 			 FIELD_GET(MESON_SDHC_STAT_RXFIFO_CNT, stat),
100 			 FIELD_GET(MESON_SDHC_STAT_TXFIFO_CNT, stat));
101 }
102 
103 static void meson_mx_sdhc_wait_cmd_ready(struct mmc_host *mmc)
104 {
105 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
106 	u32 stat, esta;
107 	int ret;
108 
109 	ret = regmap_read_poll_timeout(host->regmap, MESON_SDHC_STAT, stat,
110 				       !(stat & MESON_SDHC_STAT_CMD_BUSY),
111 				       MESON_SDHC_WAIT_CMD_READY_SLEEP_US,
112 				       MESON_SDHC_WAIT_CMD_READY_TIMEOUT_US);
113 	if (ret) {
114 		dev_warn(mmc_dev(mmc),
115 			 "Failed to poll for CMD_BUSY while processing CMD%d\n",
116 			 host->cmd->opcode);
117 		meson_mx_sdhc_reset(host);
118 	}
119 
120 	ret = regmap_read_poll_timeout(host->regmap, MESON_SDHC_ESTA, esta,
121 				       !(esta & MESON_SDHC_ESTA_11_13),
122 				       MESON_SDHC_WAIT_CMD_READY_SLEEP_US,
123 				       MESON_SDHC_WAIT_CMD_READY_TIMEOUT_US);
124 	if (ret) {
125 		dev_warn(mmc_dev(mmc),
126 			 "Failed to poll for ESTA[13:11] while processing CMD%d\n",
127 			 host->cmd->opcode);
128 		meson_mx_sdhc_reset(host);
129 	}
130 }
131 
132 static void meson_mx_sdhc_start_cmd(struct mmc_host *mmc,
133 				    struct mmc_command *cmd)
134 {
135 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
136 	bool manual_stop = false;
137 	u32 ictl, send;
138 	int pack_len;
139 
140 	host->cmd = cmd;
141 
142 	ictl = MESON_SDHC_ICTL_DATA_TIMEOUT | MESON_SDHC_ICTL_DATA_ERR_CRC |
143 	       MESON_SDHC_ICTL_RXFIFO_FULL | MESON_SDHC_ICTL_TXFIFO_EMPTY |
144 	       MESON_SDHC_ICTL_RESP_TIMEOUT | MESON_SDHC_ICTL_RESP_ERR_CRC;
145 
146 	send = FIELD_PREP(MESON_SDHC_SEND_CMD_INDEX, cmd->opcode);
147 
148 	if (cmd->data) {
149 		send |= MESON_SDHC_SEND_CMD_HAS_DATA;
150 		send |= FIELD_PREP(MESON_SDHC_SEND_TOTAL_PACK,
151 				   cmd->data->blocks - 1);
152 
153 		if (cmd->data->blksz < MESON_SDHC_MAX_BLK_SIZE)
154 			pack_len = cmd->data->blksz;
155 		else
156 			pack_len = 0;
157 
158 		if (cmd->data->flags & MMC_DATA_WRITE)
159 			send |= MESON_SDHC_SEND_DATA_DIR;
160 
161 		/*
162 		 * If command with no data, just wait response done
163 		 * interrupt(int[0]), and if command with data transfer, just
164 		 * wait dma done interrupt(int[11]), don't need care about
165 		 * dat0 busy or not.
166 		 */
167 		if (host->platform->hardware_flush_all_cmds ||
168 		    cmd->data->flags & MMC_DATA_WRITE)
169 			/* hardware flush: */
170 			ictl |= MESON_SDHC_ICTL_DMA_DONE;
171 		else
172 			/* software flush: */
173 			ictl |= MESON_SDHC_ICTL_DATA_XFER_OK;
174 
175 		/*
176 		 * Mimic the logic from the vendor driver where (only)
177 		 * SD_IO_RW_EXTENDED commands with more than one block set the
178 		 * MESON_SDHC_MISC_MANUAL_STOP bit. This fixes the firmware
179 		 * download in the brcmfmac driver for a BCM43362/1 card.
180 		 * Without this sdio_memcpy_toio() (with a size of 219557
181 		 * bytes) times out if MESON_SDHC_MISC_MANUAL_STOP is not set.
182 		 */
183 		manual_stop = cmd->data->blocks > 1 &&
184 			      cmd->opcode == SD_IO_RW_EXTENDED;
185 	} else {
186 		pack_len = 0;
187 
188 		ictl |= MESON_SDHC_ICTL_RESP_OK;
189 	}
190 
191 	regmap_update_bits(host->regmap, MESON_SDHC_MISC,
192 			   MESON_SDHC_MISC_MANUAL_STOP,
193 			   manual_stop ? MESON_SDHC_MISC_MANUAL_STOP : 0);
194 
195 	if (cmd->opcode == MMC_STOP_TRANSMISSION)
196 		send |= MESON_SDHC_SEND_DATA_STOP;
197 
198 	if (cmd->flags & MMC_RSP_PRESENT)
199 		send |= MESON_SDHC_SEND_CMD_HAS_RESP;
200 
201 	if (cmd->flags & MMC_RSP_136) {
202 		send |= MESON_SDHC_SEND_RESP_LEN;
203 		send |= MESON_SDHC_SEND_RESP_NO_CRC;
204 	}
205 
206 	if (!(cmd->flags & MMC_RSP_CRC))
207 		send |= MESON_SDHC_SEND_RESP_NO_CRC;
208 
209 	if (cmd->flags & MMC_RSP_BUSY)
210 		send |= MESON_SDHC_SEND_R1B;
211 
212 	/* enable the new IRQs and mask all pending ones */
213 	regmap_write(host->regmap, MESON_SDHC_ICTL, ictl);
214 	regmap_write(host->regmap, MESON_SDHC_ISTA, MESON_SDHC_ISTA_ALL_IRQS);
215 
216 	regmap_write(host->regmap, MESON_SDHC_ARGU, cmd->arg);
217 
218 	regmap_update_bits(host->regmap, MESON_SDHC_CTRL,
219 			   MESON_SDHC_CTRL_PACK_LEN,
220 			   FIELD_PREP(MESON_SDHC_CTRL_PACK_LEN, pack_len));
221 
222 	if (cmd->data)
223 		regmap_write(host->regmap, MESON_SDHC_ADDR,
224 			     sg_dma_address(cmd->data->sg));
225 
226 	meson_mx_sdhc_wait_cmd_ready(mmc);
227 
228 	if (cmd->data)
229 		host->platform->set_pdma(mmc);
230 
231 	if (host->platform->wait_before_send)
232 		host->platform->wait_before_send(mmc);
233 
234 	regmap_write(host->regmap, MESON_SDHC_SEND, send);
235 }
236 
237 static void meson_mx_sdhc_disable_clks(struct mmc_host *mmc)
238 {
239 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
240 
241 	if (!host->bulk_clks_enabled)
242 		return;
243 
244 	clk_bulk_disable_unprepare(MESON_SDHC_NUM_BULK_CLKS, host->bulk_clks);
245 
246 	host->bulk_clks_enabled = false;
247 }
248 
249 static int meson_mx_sdhc_enable_clks(struct mmc_host *mmc)
250 {
251 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
252 	int ret;
253 
254 	if (host->bulk_clks_enabled)
255 		return 0;
256 
257 	ret = clk_bulk_prepare_enable(MESON_SDHC_NUM_BULK_CLKS,
258 				      host->bulk_clks);
259 	if (ret)
260 		return ret;
261 
262 	host->bulk_clks_enabled = true;
263 
264 	return 0;
265 }
266 
267 static int meson_mx_sdhc_set_clk(struct mmc_host *mmc, struct mmc_ios *ios)
268 {
269 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
270 	u32 val, rx_clk_phase;
271 	int ret;
272 
273 	meson_mx_sdhc_disable_clks(mmc);
274 
275 	if (ios->clock) {
276 		ret = clk_set_rate(host->sd_clk, ios->clock);
277 		if (ret) {
278 			dev_warn(mmc_dev(mmc),
279 				 "Failed to set MMC clock to %uHz: %d\n",
280 				 ios->clock, host->error);
281 			return ret;
282 		}
283 
284 		ret = meson_mx_sdhc_enable_clks(mmc);
285 		if (ret)
286 			return ret;
287 
288 		mmc->actual_clock = clk_get_rate(host->sd_clk);
289 
290 		/*
291 		 * Phase 90 should work in most cases. For data transmission,
292 		 * meson_mx_sdhc_execute_tuning() will find a accurate value
293 		 */
294 		regmap_read(host->regmap, MESON_SDHC_CLKC, &val);
295 		rx_clk_phase = FIELD_GET(MESON_SDHC_CLKC_CLK_DIV, val) / 4;
296 		regmap_update_bits(host->regmap, MESON_SDHC_CLK2,
297 				   MESON_SDHC_CLK2_RX_CLK_PHASE,
298 				   FIELD_PREP(MESON_SDHC_CLK2_RX_CLK_PHASE,
299 					      rx_clk_phase));
300 	} else {
301 		mmc->actual_clock = 0;
302 	}
303 
304 	return 0;
305 }
306 
307 static void meson_mx_sdhc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
308 {
309 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
310 	unsigned short vdd = ios->vdd;
311 
312 	switch (ios->power_mode) {
313 	case MMC_POWER_OFF:
314 		vdd = 0;
315 		fallthrough;
316 
317 	case MMC_POWER_UP:
318 		if (!IS_ERR(mmc->supply.vmmc)) {
319 			host->error = mmc_regulator_set_ocr(mmc,
320 							    mmc->supply.vmmc,
321 							    vdd);
322 			if (host->error)
323 				return;
324 		}
325 
326 		break;
327 
328 	case MMC_POWER_ON:
329 		break;
330 	}
331 
332 	host->error = meson_mx_sdhc_set_clk(mmc, ios);
333 	if (host->error)
334 		return;
335 
336 	switch (ios->bus_width) {
337 	case MMC_BUS_WIDTH_1:
338 		regmap_update_bits(host->regmap, MESON_SDHC_CTRL,
339 				   MESON_SDHC_CTRL_DAT_TYPE,
340 				   FIELD_PREP(MESON_SDHC_CTRL_DAT_TYPE, 0));
341 		break;
342 
343 	case MMC_BUS_WIDTH_4:
344 		regmap_update_bits(host->regmap, MESON_SDHC_CTRL,
345 				   MESON_SDHC_CTRL_DAT_TYPE,
346 				   FIELD_PREP(MESON_SDHC_CTRL_DAT_TYPE, 1));
347 		break;
348 
349 	case MMC_BUS_WIDTH_8:
350 		regmap_update_bits(host->regmap, MESON_SDHC_CTRL,
351 				   MESON_SDHC_CTRL_DAT_TYPE,
352 				   FIELD_PREP(MESON_SDHC_CTRL_DAT_TYPE, 2));
353 		break;
354 
355 	default:
356 		dev_err(mmc_dev(mmc), "unsupported bus width: %d\n",
357 			ios->bus_width);
358 		host->error = -EINVAL;
359 		return;
360 	}
361 }
362 
363 static int meson_mx_sdhc_map_dma(struct mmc_host *mmc, struct mmc_request *mrq)
364 {
365 	struct mmc_data *data = mrq->data;
366 	unsigned int dma_len;
367 
368 	if (!data)
369 		return 0;
370 
371 	dma_len = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
372 			     mmc_get_dma_dir(data));
373 	if (!dma_len) {
374 		dev_err(mmc_dev(mmc), "dma_map_sg failed\n");
375 		return -ENOMEM;
376 	}
377 
378 	return 0;
379 }
380 
381 static void meson_mx_sdhc_request(struct mmc_host *mmc, struct mmc_request *mrq)
382 {
383 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
384 	struct mmc_command *cmd = mrq->cmd;
385 
386 	if (!host->error)
387 		host->error = meson_mx_sdhc_map_dma(mmc, mrq);
388 
389 	if (host->error) {
390 		cmd->error = host->error;
391 		mmc_request_done(mmc, mrq);
392 		return;
393 	}
394 
395 	host->mrq = mrq;
396 
397 	meson_mx_sdhc_start_cmd(mmc, mrq->cmd);
398 }
399 
400 static int meson_mx_sdhc_card_busy(struct mmc_host *mmc)
401 {
402 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
403 	u32 stat;
404 
405 	regmap_read(host->regmap, MESON_SDHC_STAT, &stat);
406 	return FIELD_GET(MESON_SDHC_STAT_DAT3_0, stat) == 0;
407 }
408 
409 static bool meson_mx_sdhc_tuning_point_matches(struct mmc_host *mmc,
410 					       u32 opcode)
411 {
412 	unsigned int i, num_matches = 0;
413 	int ret;
414 
415 	for (i = 0; i < MESON_SDHC_NUM_TUNING_TRIES; i++) {
416 		ret = mmc_send_tuning(mmc, opcode, NULL);
417 		if (!ret)
418 			num_matches++;
419 	}
420 
421 	return num_matches == MESON_SDHC_NUM_TUNING_TRIES;
422 }
423 
424 static int meson_mx_sdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
425 {
426 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
427 	int div, start, len, best_start, best_len;
428 	int curr_phase, old_phase, new_phase;
429 	u32 val;
430 
431 	len = 0;
432 	start = 0;
433 	best_len = 0;
434 
435 	regmap_read(host->regmap, MESON_SDHC_CLK2, &val);
436 	old_phase = FIELD_GET(MESON_SDHC_CLK2_RX_CLK_PHASE, val);
437 
438 	regmap_read(host->regmap, MESON_SDHC_CLKC, &val);
439 	div = FIELD_GET(MESON_SDHC_CLKC_CLK_DIV, val);
440 
441 	for (curr_phase = 0; curr_phase <= div; curr_phase++) {
442 		regmap_update_bits(host->regmap, MESON_SDHC_CLK2,
443 				   MESON_SDHC_CLK2_RX_CLK_PHASE,
444 				   FIELD_PREP(MESON_SDHC_CLK2_RX_CLK_PHASE,
445 					      curr_phase));
446 
447 		if (meson_mx_sdhc_tuning_point_matches(mmc, opcode)) {
448 			if (!len) {
449 				start = curr_phase;
450 
451 				dev_dbg(mmc_dev(mmc),
452 					"New RX phase window starts at %u\n",
453 					start);
454 			}
455 
456 			len++;
457 		} else {
458 			if (len > best_len) {
459 				best_start = start;
460 				best_len = len;
461 
462 				dev_dbg(mmc_dev(mmc),
463 					"New best RX phase window: %u - %u\n",
464 					best_start, best_start + best_len);
465 			}
466 
467 			/* reset the current window */
468 			len = 0;
469 		}
470 	}
471 
472 	if (len > best_len)
473 		/* the last window is the best (or possibly only) window */
474 		new_phase = start + (len / 2);
475 	else if (best_len)
476 		/* there was a better window than the last */
477 		new_phase = best_start + (best_len / 2);
478 	else
479 		/* no window was found at all, reset to the original phase */
480 		new_phase = old_phase;
481 
482 	regmap_update_bits(host->regmap, MESON_SDHC_CLK2,
483 			   MESON_SDHC_CLK2_RX_CLK_PHASE,
484 			   FIELD_PREP(MESON_SDHC_CLK2_RX_CLK_PHASE,
485 				      new_phase));
486 
487 	if (!len && !best_len)
488 		return -EIO;
489 
490 	dev_dbg(mmc_dev(mmc), "Tuned RX clock phase to %u\n", new_phase);
491 
492 	return 0;
493 }
494 
495 static const struct mmc_host_ops meson_mx_sdhc_ops = {
496 	.request			= meson_mx_sdhc_request,
497 	.set_ios			= meson_mx_sdhc_set_ios,
498 	.card_busy			= meson_mx_sdhc_card_busy,
499 	.execute_tuning			= meson_mx_sdhc_execute_tuning,
500 	.get_cd				= mmc_gpio_get_cd,
501 	.get_ro				= mmc_gpio_get_ro,
502 };
503 
504 static void meson_mx_sdhc_request_done(struct meson_mx_sdhc_host *host)
505 {
506 	struct mmc_request *mrq = host->mrq;
507 	struct mmc_host *mmc = host->mmc;
508 
509 	/* disable interrupts and mask all pending ones */
510 	regmap_update_bits(host->regmap, MESON_SDHC_ICTL,
511 			   MESON_SDHC_ICTL_ALL_IRQS, 0);
512 	regmap_update_bits(host->regmap, MESON_SDHC_ISTA,
513 			   MESON_SDHC_ISTA_ALL_IRQS, MESON_SDHC_ISTA_ALL_IRQS);
514 
515 	host->mrq = NULL;
516 	host->cmd = NULL;
517 
518 	mmc_request_done(mmc, mrq);
519 }
520 
521 static u32 meson_mx_sdhc_read_response(struct meson_mx_sdhc_host *host, u8 idx)
522 {
523 	u32 val;
524 
525 	regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
526 			   MESON_SDHC_PDMA_DMA_MODE, 0);
527 
528 	regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
529 			   MESON_SDHC_PDMA_PIO_RDRESP,
530 			   FIELD_PREP(MESON_SDHC_PDMA_PIO_RDRESP, idx));
531 
532 	regmap_read(host->regmap, MESON_SDHC_ARGU, &val);
533 
534 	return val;
535 }
536 
537 static irqreturn_t meson_mx_sdhc_irq(int irq, void *data)
538 {
539 	struct meson_mx_sdhc_host *host = data;
540 	struct mmc_command *cmd = host->cmd;
541 	u32 ictl, ista;
542 
543 	regmap_read(host->regmap, MESON_SDHC_ICTL, &ictl);
544 	regmap_read(host->regmap, MESON_SDHC_ISTA, &ista);
545 
546 	if (!(ictl & ista))
547 		return IRQ_NONE;
548 
549 	if (ista & MESON_SDHC_ISTA_RXFIFO_FULL ||
550 	    ista & MESON_SDHC_ISTA_TXFIFO_EMPTY)
551 		cmd->error = -EIO;
552 	else if (ista & MESON_SDHC_ISTA_RESP_ERR_CRC)
553 		cmd->error = -EILSEQ;
554 	else if (ista & MESON_SDHC_ISTA_RESP_TIMEOUT)
555 		cmd->error = -ETIMEDOUT;
556 
557 	if (cmd->data) {
558 		if (ista & MESON_SDHC_ISTA_DATA_ERR_CRC)
559 			cmd->data->error = -EILSEQ;
560 		else if (ista & MESON_SDHC_ISTA_DATA_TIMEOUT)
561 			cmd->data->error = -ETIMEDOUT;
562 	}
563 
564 	if (cmd->error || (cmd->data && cmd->data->error))
565 		dev_dbg(mmc_dev(host->mmc), "CMD%d error, ISTA: 0x%08x\n",
566 			cmd->opcode, ista);
567 
568 	return IRQ_WAKE_THREAD;
569 }
570 
571 static irqreturn_t meson_mx_sdhc_irq_thread(int irq, void *irq_data)
572 {
573 	struct meson_mx_sdhc_host *host = irq_data;
574 	struct mmc_command *cmd;
575 	u32 val;
576 
577 	cmd = host->cmd;
578 	if (WARN_ON(!cmd))
579 		return IRQ_HANDLED;
580 
581 	if (cmd->data && !cmd->data->error) {
582 		if (!host->platform->hardware_flush_all_cmds &&
583 		    cmd->data->flags & MMC_DATA_READ) {
584 			meson_mx_sdhc_wait_cmd_ready(host->mmc);
585 
586 			/*
587 			 * If MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH was
588 			 * previously 0x1 then it has to be set to 0x3. If it
589 			 * was 0x0 before then it has to be set to 0x2. Without
590 			 * this reading SD cards sometimes transfers garbage,
591 			 * which results in cards not being detected due to:
592 			 *   unrecognised SCR structure version <random number>
593 			 */
594 			val = FIELD_PREP(MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH,
595 					 2);
596 			regmap_update_bits(host->regmap, MESON_SDHC_PDMA, val,
597 					   val);
598 		}
599 
600 		dma_unmap_sg(mmc_dev(host->mmc), cmd->data->sg,
601 			     cmd->data->sg_len, mmc_get_dma_dir(cmd->data));
602 
603 		cmd->data->bytes_xfered = cmd->data->blksz * cmd->data->blocks;
604 	}
605 
606 	meson_mx_sdhc_wait_cmd_ready(host->mmc);
607 
608 	if (cmd->flags & MMC_RSP_136) {
609 		cmd->resp[0] = meson_mx_sdhc_read_response(host, 4);
610 		cmd->resp[1] = meson_mx_sdhc_read_response(host, 3);
611 		cmd->resp[2] = meson_mx_sdhc_read_response(host, 2);
612 		cmd->resp[3] = meson_mx_sdhc_read_response(host, 1);
613 	} else {
614 		cmd->resp[0] = meson_mx_sdhc_read_response(host, 0);
615 	}
616 
617 	if (cmd->error == -EIO || cmd->error == -ETIMEDOUT)
618 		meson_mx_sdhc_reset(host);
619 	else if (cmd->data)
620 		/*
621 		 * Clear the FIFOs after completing data transfers to prevent
622 		 * corrupting data on write access. It's not clear why this is
623 		 * needed (for reads and writes), but it mimics what the BSP
624 		 * kernel did.
625 		 */
626 		meson_mx_sdhc_clear_fifo(host->mmc);
627 
628 	meson_mx_sdhc_request_done(host);
629 
630 	return IRQ_HANDLED;
631 }
632 
633 static void meson_mx_sdhc_init_hw_meson8(struct mmc_host *mmc)
634 {
635 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
636 
637 	regmap_write(host->regmap, MESON_SDHC_MISC,
638 		     FIELD_PREP(MESON_SDHC_MISC_TXSTART_THRES, 7) |
639 		     FIELD_PREP(MESON_SDHC_MISC_WCRC_ERR_PATT, 5) |
640 		     FIELD_PREP(MESON_SDHC_MISC_WCRC_OK_PATT, 2));
641 
642 	regmap_write(host->regmap, MESON_SDHC_ENHC,
643 		     FIELD_PREP(MESON_SDHC_ENHC_RXFIFO_TH, 63) |
644 		     MESON_SDHC_ENHC_MESON6_DMA_WR_RESP |
645 		     FIELD_PREP(MESON_SDHC_ENHC_MESON6_RX_TIMEOUT, 255) |
646 		     FIELD_PREP(MESON_SDHC_ENHC_SDIO_IRQ_PERIOD, 12));
647 };
648 
649 static void meson_mx_sdhc_set_pdma_meson8(struct mmc_host *mmc)
650 {
651 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
652 
653 	if (host->cmd->data->flags & MMC_DATA_WRITE)
654 		regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
655 				   MESON_SDHC_PDMA_DMA_MODE |
656 				   MESON_SDHC_PDMA_RD_BURST |
657 				   MESON_SDHC_PDMA_TXFIFO_FILL,
658 				   MESON_SDHC_PDMA_DMA_MODE |
659 				   FIELD_PREP(MESON_SDHC_PDMA_RD_BURST, 31) |
660 				   MESON_SDHC_PDMA_TXFIFO_FILL);
661 	else
662 		regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
663 				   MESON_SDHC_PDMA_DMA_MODE |
664 				   MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH,
665 				   MESON_SDHC_PDMA_DMA_MODE |
666 				   FIELD_PREP(MESON_SDHC_PDMA_RXFIFO_MANUAL_FLUSH,
667 					      1));
668 
669 	if (host->cmd->data->flags & MMC_DATA_WRITE)
670 		regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
671 				   MESON_SDHC_PDMA_RD_BURST,
672 				   FIELD_PREP(MESON_SDHC_PDMA_RD_BURST, 15));
673 }
674 
675 static void meson_mx_sdhc_wait_before_send_meson8(struct mmc_host *mmc)
676 {
677 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
678 	u32 val;
679 	int ret;
680 
681 	ret = regmap_read_poll_timeout(host->regmap, MESON_SDHC_ESTA, val,
682 				       val == 0,
683 				       MESON_SDHC_WAIT_BEFORE_SEND_SLEEP_US,
684 				       MESON_SDHC_WAIT_BEFORE_SEND_TIMEOUT_US);
685 	if (ret)
686 		dev_warn(mmc_dev(mmc),
687 			 "Failed to wait for ESTA to clear: 0x%08x\n", val);
688 
689 	if (host->cmd->data && host->cmd->data->flags & MMC_DATA_WRITE) {
690 		ret = regmap_read_poll_timeout(host->regmap, MESON_SDHC_STAT,
691 					val, val & MESON_SDHC_STAT_TXFIFO_CNT,
692 					MESON_SDHC_WAIT_BEFORE_SEND_SLEEP_US,
693 					MESON_SDHC_WAIT_BEFORE_SEND_TIMEOUT_US);
694 		if (ret)
695 			dev_warn(mmc_dev(mmc),
696 				 "Failed to wait for TX FIFO to fill\n");
697 	}
698 }
699 
700 static void meson_mx_sdhc_init_hw_meson8m2(struct mmc_host *mmc)
701 {
702 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
703 
704 	regmap_write(host->regmap, MESON_SDHC_MISC,
705 		     FIELD_PREP(MESON_SDHC_MISC_TXSTART_THRES, 6) |
706 		     FIELD_PREP(MESON_SDHC_MISC_WCRC_ERR_PATT, 5) |
707 		     FIELD_PREP(MESON_SDHC_MISC_WCRC_OK_PATT, 2));
708 
709 	regmap_write(host->regmap, MESON_SDHC_ENHC,
710 		     FIELD_PREP(MESON_SDHC_ENHC_RXFIFO_TH, 64) |
711 		     FIELD_PREP(MESON_SDHC_ENHC_MESON8M2_DEBUG, 1) |
712 		     MESON_SDHC_ENHC_MESON8M2_WRRSP_MODE |
713 		     FIELD_PREP(MESON_SDHC_ENHC_SDIO_IRQ_PERIOD, 12));
714 }
715 
716 static void meson_mx_sdhc_set_pdma_meson8m2(struct mmc_host *mmc)
717 {
718 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
719 
720 	regmap_update_bits(host->regmap, MESON_SDHC_PDMA,
721 			   MESON_SDHC_PDMA_DMA_MODE, MESON_SDHC_PDMA_DMA_MODE);
722 }
723 
724 static void meson_mx_sdhc_init_hw(struct mmc_host *mmc)
725 {
726 	struct meson_mx_sdhc_host *host = mmc_priv(mmc);
727 
728 	meson_mx_sdhc_reset(host);
729 
730 	regmap_write(host->regmap, MESON_SDHC_CTRL,
731 		     FIELD_PREP(MESON_SDHC_CTRL_RX_PERIOD, 0xf) |
732 		     FIELD_PREP(MESON_SDHC_CTRL_RX_TIMEOUT, 0x7f) |
733 		     FIELD_PREP(MESON_SDHC_CTRL_RX_ENDIAN, 0x7) |
734 		     FIELD_PREP(MESON_SDHC_CTRL_TX_ENDIAN, 0x7));
735 
736 	/*
737 	 * start with a valid divider and enable the memory (un-setting
738 	 * MESON_SDHC_CLKC_MEM_PWR_OFF).
739 	 */
740 	regmap_write(host->regmap, MESON_SDHC_CLKC, MESON_SDHC_CLKC_CLK_DIV);
741 
742 	regmap_write(host->regmap, MESON_SDHC_CLK2,
743 		     FIELD_PREP(MESON_SDHC_CLK2_SD_CLK_PHASE, 1));
744 
745 	regmap_write(host->regmap, MESON_SDHC_PDMA,
746 		     MESON_SDHC_PDMA_DMA_URGENT |
747 		     FIELD_PREP(MESON_SDHC_PDMA_WR_BURST, 7) |
748 		     FIELD_PREP(MESON_SDHC_PDMA_TXFIFO_TH, 49) |
749 		     FIELD_PREP(MESON_SDHC_PDMA_RD_BURST, 15) |
750 		     FIELD_PREP(MESON_SDHC_PDMA_RXFIFO_TH, 7));
751 
752 	/* some initialization bits depend on the SoC: */
753 	host->platform->init_hw(mmc);
754 
755 	/* disable and mask all interrupts: */
756 	regmap_write(host->regmap, MESON_SDHC_ICTL, 0);
757 	regmap_write(host->regmap, MESON_SDHC_ISTA, MESON_SDHC_ISTA_ALL_IRQS);
758 }
759 
760 static void meason_mx_mmc_free_host(void *data)
761 {
762        mmc_free_host(data);
763 }
764 
765 static int meson_mx_sdhc_probe(struct platform_device *pdev)
766 {
767 	struct device *dev = &pdev->dev;
768 	struct meson_mx_sdhc_host *host;
769 	struct mmc_host *mmc;
770 	void __iomem *base;
771 	int ret, irq;
772 
773 	mmc = mmc_alloc_host(sizeof(*host), dev);
774 	if (!mmc)
775 		return -ENOMEM;
776 
777 	ret = devm_add_action_or_reset(dev, meason_mx_mmc_free_host, mmc);
778 	if (ret) {
779 		dev_err(dev, "Failed to register mmc_free_host action\n");
780 		return ret;
781 	}
782 
783 	host = mmc_priv(mmc);
784 	host->mmc = mmc;
785 
786 	platform_set_drvdata(pdev, host);
787 
788 	host->platform = device_get_match_data(dev);
789 	if (!host->platform)
790 		return -EINVAL;
791 
792 	base = devm_platform_ioremap_resource(pdev, 0);
793 	if (IS_ERR(base))
794 		return PTR_ERR(base);
795 
796 	host->regmap = devm_regmap_init_mmio(dev, base,
797 					     &meson_mx_sdhc_regmap_config);
798 	if (IS_ERR(host->regmap))
799 		return PTR_ERR(host->regmap);
800 
801 	host->pclk = devm_clk_get(dev, "pclk");
802 	if (IS_ERR(host->pclk))
803 		return PTR_ERR(host->pclk);
804 
805 	/* accessing any register requires the module clock to be enabled: */
806 	ret = clk_prepare_enable(host->pclk);
807 	if (ret) {
808 		dev_err(dev, "Failed to enable 'pclk' clock\n");
809 		return ret;
810 	}
811 
812 	meson_mx_sdhc_init_hw(mmc);
813 
814 	ret = meson_mx_sdhc_register_clkc(dev, base, host->bulk_clks);
815 	if (ret)
816 		goto err_disable_pclk;
817 
818 	host->sd_clk = host->bulk_clks[1].clk;
819 
820 	/* Get regulators and the supported OCR mask */
821 	ret = mmc_regulator_get_supply(mmc);
822 	if (ret)
823 		goto err_disable_pclk;
824 
825 	mmc->max_req_size = SZ_128K;
826 	mmc->max_seg_size = mmc->max_req_size;
827 	mmc->max_blk_count = FIELD_GET(MESON_SDHC_SEND_TOTAL_PACK, ~0);
828 	mmc->max_blk_size = MESON_SDHC_MAX_BLK_SIZE;
829 	mmc->max_busy_timeout = 30 * MSEC_PER_SEC;
830 	mmc->f_min = clk_round_rate(host->sd_clk, 1);
831 	mmc->f_max = clk_round_rate(host->sd_clk, ULONG_MAX);
832 	mmc->max_current_180 = 300;
833 	mmc->max_current_330 = 300;
834 	mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | MMC_CAP_HW_RESET;
835 	mmc->ops = &meson_mx_sdhc_ops;
836 
837 	ret = mmc_of_parse(mmc);
838 	if (ret)
839 		goto err_disable_pclk;
840 
841 	irq = platform_get_irq(pdev, 0);
842 	if (irq < 0) {
843 		ret = irq;
844 		goto err_disable_pclk;
845 	}
846 
847 	ret = devm_request_threaded_irq(dev, irq, meson_mx_sdhc_irq,
848 					meson_mx_sdhc_irq_thread, IRQF_ONESHOT,
849 					NULL, host);
850 	if (ret)
851 		goto err_disable_pclk;
852 
853 	ret = mmc_add_host(mmc);
854 	if (ret)
855 		goto err_disable_pclk;
856 
857 	return 0;
858 
859 err_disable_pclk:
860 	clk_disable_unprepare(host->pclk);
861 	return ret;
862 }
863 
864 static void meson_mx_sdhc_remove(struct platform_device *pdev)
865 {
866 	struct meson_mx_sdhc_host *host = platform_get_drvdata(pdev);
867 
868 	mmc_remove_host(host->mmc);
869 
870 	meson_mx_sdhc_disable_clks(host->mmc);
871 
872 	clk_disable_unprepare(host->pclk);
873 }
874 
875 static const struct meson_mx_sdhc_data meson_mx_sdhc_data_meson8 = {
876 	.init_hw			= meson_mx_sdhc_init_hw_meson8,
877 	.set_pdma			= meson_mx_sdhc_set_pdma_meson8,
878 	.wait_before_send		= meson_mx_sdhc_wait_before_send_meson8,
879 	.hardware_flush_all_cmds	= false,
880 };
881 
882 static const struct meson_mx_sdhc_data meson_mx_sdhc_data_meson8m2 = {
883 	.init_hw			= meson_mx_sdhc_init_hw_meson8m2,
884 	.set_pdma			= meson_mx_sdhc_set_pdma_meson8m2,
885 	.hardware_flush_all_cmds	= true,
886 };
887 
888 static const struct of_device_id meson_mx_sdhc_of_match[] = {
889 	{
890 		.compatible = "amlogic,meson8-sdhc",
891 		.data = &meson_mx_sdhc_data_meson8
892 	},
893 	{
894 		.compatible = "amlogic,meson8b-sdhc",
895 		.data = &meson_mx_sdhc_data_meson8
896 	},
897 	{
898 		.compatible = "amlogic,meson8m2-sdhc",
899 		.data = &meson_mx_sdhc_data_meson8m2
900 	},
901 	{ /* sentinel */ }
902 };
903 MODULE_DEVICE_TABLE(of, meson_mx_sdhc_of_match);
904 
905 static struct platform_driver meson_mx_sdhc_driver = {
906 	.probe   = meson_mx_sdhc_probe,
907 	.remove = meson_mx_sdhc_remove,
908 	.driver  = {
909 		.name = "meson-mx-sdhc",
910 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
911 		.of_match_table = of_match_ptr(meson_mx_sdhc_of_match),
912 	},
913 };
914 
915 module_platform_driver(meson_mx_sdhc_driver);
916 
917 MODULE_DESCRIPTION("Meson6, Meson8, Meson8b and Meson8m2 SDHC Host Driver");
918 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
919 MODULE_LICENSE("GPL v2");
920