xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision ef22ccbc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Amlogic SD/eMMC driver for the GX/S905 family SoCs
4  *
5  * Copyright (c) 2016 BayLibre, SAS.
6  * Author: Kevin Hilman <khilman@baylibre.com>
7  */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/iopoll.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/ioport.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/mmc/host.h>
19 #include <linux/mmc/mmc.h>
20 #include <linux/mmc/sdio.h>
21 #include <linux/mmc/slot-gpio.h>
22 #include <linux/io.h>
23 #include <linux/clk.h>
24 #include <linux/clk-provider.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/reset.h>
27 #include <linux/interrupt.h>
28 #include <linux/bitfield.h>
29 #include <linux/pinctrl/consumer.h>
30 
31 #define DRIVER_NAME "meson-gx-mmc"
32 
33 #define SD_EMMC_CLOCK 0x0
34 #define   CLK_DIV_MASK GENMASK(5, 0)
35 #define   CLK_SRC_MASK GENMASK(7, 6)
36 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
37 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
38 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
39 #define   CLK_PHASE_0 0
40 #define   CLK_PHASE_180 2
41 #define   CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
42 #define   CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
43 #define   CLK_V2_ALWAYS_ON BIT(24)
44 
45 #define   CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
46 #define   CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
47 #define   CLK_V3_ALWAYS_ON BIT(28)
48 
49 #define   CLK_TX_DELAY_MASK(h)		(h->data->tx_delay_mask)
50 #define   CLK_RX_DELAY_MASK(h)		(h->data->rx_delay_mask)
51 #define   CLK_ALWAYS_ON(h)		(h->data->always_on)
52 
53 #define SD_EMMC_DELAY 0x4
54 #define SD_EMMC_ADJUST 0x8
55 #define   ADJUST_ADJ_DELAY_MASK GENMASK(21, 16)
56 #define   ADJUST_DS_EN BIT(15)
57 #define   ADJUST_ADJ_EN BIT(13)
58 
59 #define SD_EMMC_DELAY1 0x4
60 #define SD_EMMC_DELAY2 0x8
61 #define SD_EMMC_V3_ADJUST 0xc
62 
63 #define SD_EMMC_CALOUT 0x10
64 #define SD_EMMC_START 0x40
65 #define   START_DESC_INIT BIT(0)
66 #define   START_DESC_BUSY BIT(1)
67 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
68 
69 #define SD_EMMC_CFG 0x44
70 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
71 #define   CFG_BUS_WIDTH_1 0x0
72 #define   CFG_BUS_WIDTH_4 0x1
73 #define   CFG_BUS_WIDTH_8 0x2
74 #define   CFG_DDR BIT(2)
75 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
76 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
77 #define   CFG_RC_CC_MASK GENMASK(15, 12)
78 #define   CFG_STOP_CLOCK BIT(22)
79 #define   CFG_CLK_ALWAYS_ON BIT(18)
80 #define   CFG_CHK_DS BIT(20)
81 #define   CFG_AUTO_CLK BIT(23)
82 #define   CFG_ERR_ABORT BIT(27)
83 
84 #define SD_EMMC_STATUS 0x48
85 #define   STATUS_BUSY BIT(31)
86 #define   STATUS_DESC_BUSY BIT(30)
87 #define   STATUS_DATI GENMASK(23, 16)
88 
89 #define SD_EMMC_IRQ_EN 0x4c
90 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
91 #define   IRQ_TXD_ERR BIT(8)
92 #define   IRQ_DESC_ERR BIT(9)
93 #define   IRQ_RESP_ERR BIT(10)
94 #define   IRQ_CRC_ERR \
95 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
96 #define   IRQ_RESP_TIMEOUT BIT(11)
97 #define   IRQ_DESC_TIMEOUT BIT(12)
98 #define   IRQ_TIMEOUTS \
99 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
100 #define   IRQ_END_OF_CHAIN BIT(13)
101 #define   IRQ_RESP_STATUS BIT(14)
102 #define   IRQ_SDIO BIT(15)
103 #define   IRQ_EN_MASK \
104 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
105 	 IRQ_SDIO)
106 
107 #define SD_EMMC_CMD_CFG 0x50
108 #define SD_EMMC_CMD_ARG 0x54
109 #define SD_EMMC_CMD_DAT 0x58
110 #define SD_EMMC_CMD_RSP 0x5c
111 #define SD_EMMC_CMD_RSP1 0x60
112 #define SD_EMMC_CMD_RSP2 0x64
113 #define SD_EMMC_CMD_RSP3 0x68
114 
115 #define SD_EMMC_RXD 0x94
116 #define SD_EMMC_TXD 0x94
117 #define SD_EMMC_LAST_REG SD_EMMC_TXD
118 
119 #define SD_EMMC_SRAM_DATA_BUF_LEN 1536
120 #define SD_EMMC_SRAM_DATA_BUF_OFF 0x200
121 
122 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
123 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
124 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
125 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
126 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
127 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
128 
129 #define SD_EMMC_PRE_REQ_DONE BIT(0)
130 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
131 
132 #define MUX_CLK_NUM_PARENTS 2
133 
134 struct meson_mmc_data {
135 	unsigned int tx_delay_mask;
136 	unsigned int rx_delay_mask;
137 	unsigned int always_on;
138 	unsigned int adjust;
139 };
140 
141 struct sd_emmc_desc {
142 	u32 cmd_cfg;
143 	u32 cmd_arg;
144 	u32 cmd_data;
145 	u32 cmd_resp;
146 };
147 
148 struct meson_host {
149 	struct	device		*dev;
150 	struct	meson_mmc_data *data;
151 	struct	mmc_host	*mmc;
152 	struct	mmc_command	*cmd;
153 
154 	void __iomem *regs;
155 	struct clk *core_clk;
156 	struct clk *mux_clk;
157 	struct clk *mmc_clk;
158 	unsigned long req_rate;
159 	bool ddr;
160 
161 	bool dram_access_quirk;
162 
163 	struct pinctrl *pinctrl;
164 	struct pinctrl_state *pins_clk_gate;
165 
166 	unsigned int bounce_buf_size;
167 	void *bounce_buf;
168 	dma_addr_t bounce_dma_addr;
169 	struct sd_emmc_desc *descs;
170 	dma_addr_t descs_dma_addr;
171 
172 	int irq;
173 
174 	bool vqmmc_enabled;
175 };
176 
177 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
178 #define CMD_CFG_BLOCK_MODE BIT(9)
179 #define CMD_CFG_R1B BIT(10)
180 #define CMD_CFG_END_OF_CHAIN BIT(11)
181 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
182 #define CMD_CFG_NO_RESP BIT(16)
183 #define CMD_CFG_NO_CMD BIT(17)
184 #define CMD_CFG_DATA_IO BIT(18)
185 #define CMD_CFG_DATA_WR BIT(19)
186 #define CMD_CFG_RESP_NOCRC BIT(20)
187 #define CMD_CFG_RESP_128 BIT(21)
188 #define CMD_CFG_RESP_NUM BIT(22)
189 #define CMD_CFG_DATA_NUM BIT(23)
190 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
191 #define CMD_CFG_ERROR BIT(30)
192 #define CMD_CFG_OWNER BIT(31)
193 
194 #define CMD_DATA_MASK GENMASK(31, 2)
195 #define CMD_DATA_BIG_ENDIAN BIT(1)
196 #define CMD_DATA_SRAM BIT(0)
197 #define CMD_RESP_MASK GENMASK(31, 1)
198 #define CMD_RESP_SRAM BIT(0)
199 
200 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
201 {
202 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
203 
204 	if (!timeout)
205 		return SD_EMMC_CMD_TIMEOUT_DATA;
206 
207 	timeout = roundup_pow_of_two(timeout);
208 
209 	return min(timeout, 32768U); /* max. 2^15 ms */
210 }
211 
212 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
213 {
214 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
215 		return cmd->mrq->cmd;
216 	else if (mmc_op_multi(cmd->opcode) &&
217 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
218 		return cmd->mrq->stop;
219 	else
220 		return NULL;
221 }
222 
223 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
224 					struct mmc_request *mrq)
225 {
226 	struct meson_host *host = mmc_priv(mmc);
227 	struct mmc_data *data = mrq->data;
228 	struct scatterlist *sg;
229 	int i;
230 
231 	/*
232 	 * When Controller DMA cannot directly access DDR memory, disable
233 	 * support for Chain Mode to directly use the internal SRAM using
234 	 * the bounce buffer mode.
235 	 */
236 	if (host->dram_access_quirk)
237 		return;
238 
239 	/* SD_IO_RW_EXTENDED (CMD53) can also use block mode under the hood */
240 	if (data->blocks > 1 || mrq->cmd->opcode == SD_IO_RW_EXTENDED) {
241 		/*
242 		 * In block mode DMA descriptor format, "length" field indicates
243 		 * number of blocks and there is no way to pass DMA size that
244 		 * is not multiple of SDIO block size, making it impossible to
245 		 * tie more than one memory buffer with single SDIO block.
246 		 * Block mode sg buffer size should be aligned with SDIO block
247 		 * size, otherwise chain mode could not be used.
248 		 */
249 		for_each_sg(data->sg, sg, data->sg_len, i) {
250 			if (sg->length % data->blksz) {
251 				dev_warn_once(mmc_dev(mmc),
252 					      "unaligned sg len %u blksize %u, disabling descriptor DMA for transfer\n",
253 					      sg->length, data->blksz);
254 				return;
255 			}
256 		}
257 	}
258 
259 	for_each_sg(data->sg, sg, data->sg_len, i) {
260 		/* check for 8 byte alignment */
261 		if (sg->offset % 8) {
262 			dev_warn_once(mmc_dev(mmc),
263 				      "unaligned sg offset %u, disabling descriptor DMA for transfer\n",
264 				      sg->offset);
265 			return;
266 		}
267 	}
268 
269 	data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
270 }
271 
272 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
273 {
274 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
275 }
276 
277 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
278 {
279 	return data && data->flags & MMC_DATA_READ &&
280 	       !meson_mmc_desc_chain_mode(data);
281 }
282 
283 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
284 {
285 	struct mmc_data *data = mrq->data;
286 
287 	if (!data)
288 		return;
289 
290 	meson_mmc_get_transfer_mode(mmc, mrq);
291 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
292 
293 	if (!meson_mmc_desc_chain_mode(data))
294 		return;
295 
296 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
297                                    mmc_get_dma_dir(data));
298 	if (!data->sg_count)
299 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
300 }
301 
302 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
303 			       int err)
304 {
305 	struct mmc_data *data = mrq->data;
306 
307 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
308 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
309 			     mmc_get_dma_dir(data));
310 }
311 
312 /*
313  * Gating the clock on this controller is tricky.  It seems the mmc clock
314  * is also used by the controller.  It may crash during some operation if the
315  * clock is stopped.  The safest thing to do, whenever possible, is to keep
316  * clock running at stop it at the pad using the pinmux.
317  */
318 static void meson_mmc_clk_gate(struct meson_host *host)
319 {
320 	u32 cfg;
321 
322 	if (host->pins_clk_gate) {
323 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
324 	} else {
325 		/*
326 		 * If the pinmux is not provided - default to the classic and
327 		 * unsafe method
328 		 */
329 		cfg = readl(host->regs + SD_EMMC_CFG);
330 		cfg |= CFG_STOP_CLOCK;
331 		writel(cfg, host->regs + SD_EMMC_CFG);
332 	}
333 }
334 
335 static void meson_mmc_clk_ungate(struct meson_host *host)
336 {
337 	u32 cfg;
338 
339 	if (host->pins_clk_gate)
340 		pinctrl_select_default_state(host->dev);
341 
342 	/* Make sure the clock is not stopped in the controller */
343 	cfg = readl(host->regs + SD_EMMC_CFG);
344 	cfg &= ~CFG_STOP_CLOCK;
345 	writel(cfg, host->regs + SD_EMMC_CFG);
346 }
347 
348 static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
349 			     bool ddr)
350 {
351 	struct mmc_host *mmc = host->mmc;
352 	int ret;
353 	u32 cfg;
354 
355 	/* Same request - bail-out */
356 	if (host->ddr == ddr && host->req_rate == rate)
357 		return 0;
358 
359 	/* stop clock */
360 	meson_mmc_clk_gate(host);
361 	host->req_rate = 0;
362 	mmc->actual_clock = 0;
363 
364 	/* return with clock being stopped */
365 	if (!rate)
366 		return 0;
367 
368 	/* Stop the clock during rate change to avoid glitches */
369 	cfg = readl(host->regs + SD_EMMC_CFG);
370 	cfg |= CFG_STOP_CLOCK;
371 	writel(cfg, host->regs + SD_EMMC_CFG);
372 
373 	if (ddr) {
374 		/* DDR modes require higher module clock */
375 		rate <<= 1;
376 		cfg |= CFG_DDR;
377 	} else {
378 		cfg &= ~CFG_DDR;
379 	}
380 	writel(cfg, host->regs + SD_EMMC_CFG);
381 	host->ddr = ddr;
382 
383 	ret = clk_set_rate(host->mmc_clk, rate);
384 	if (ret) {
385 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
386 			rate, ret);
387 		return ret;
388 	}
389 
390 	host->req_rate = rate;
391 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
392 
393 	/* We should report the real output frequency of the controller */
394 	if (ddr) {
395 		host->req_rate >>= 1;
396 		mmc->actual_clock >>= 1;
397 	}
398 
399 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
400 	if (rate != mmc->actual_clock)
401 		dev_dbg(host->dev, "requested rate was %lu\n", rate);
402 
403 	/* (re)start clock */
404 	meson_mmc_clk_ungate(host);
405 
406 	return 0;
407 }
408 
409 /*
410  * The SD/eMMC IP block has an internal mux and divider used for
411  * generating the MMC clock.  Use the clock framework to create and
412  * manage these clocks.
413  */
414 static int meson_mmc_clk_init(struct meson_host *host)
415 {
416 	struct clk_init_data init;
417 	struct clk_mux *mux;
418 	struct clk_divider *div;
419 	char clk_name[32];
420 	int i, ret = 0;
421 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
422 	const char *clk_parent[1];
423 	u32 clk_reg;
424 
425 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
426 	clk_reg = CLK_ALWAYS_ON(host);
427 	clk_reg |= CLK_DIV_MASK;
428 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
429 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
430 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
431 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
432 
433 	/* get the mux parents */
434 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
435 		struct clk *clk;
436 		char name[16];
437 
438 		snprintf(name, sizeof(name), "clkin%d", i);
439 		clk = devm_clk_get(host->dev, name);
440 		if (IS_ERR(clk))
441 			return dev_err_probe(host->dev, PTR_ERR(clk),
442 					     "Missing clock %s\n", name);
443 
444 		mux_parent_names[i] = __clk_get_name(clk);
445 	}
446 
447 	/* create the mux */
448 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
449 	if (!mux)
450 		return -ENOMEM;
451 
452 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
453 	init.name = clk_name;
454 	init.ops = &clk_mux_ops;
455 	init.flags = 0;
456 	init.parent_names = mux_parent_names;
457 	init.num_parents = MUX_CLK_NUM_PARENTS;
458 
459 	mux->reg = host->regs + SD_EMMC_CLOCK;
460 	mux->shift = __ffs(CLK_SRC_MASK);
461 	mux->mask = CLK_SRC_MASK >> mux->shift;
462 	mux->hw.init = &init;
463 
464 	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
465 	if (WARN_ON(IS_ERR(host->mux_clk)))
466 		return PTR_ERR(host->mux_clk);
467 
468 	/* create the divider */
469 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
470 	if (!div)
471 		return -ENOMEM;
472 
473 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
474 	init.name = clk_name;
475 	init.ops = &clk_divider_ops;
476 	init.flags = CLK_SET_RATE_PARENT;
477 	clk_parent[0] = __clk_get_name(host->mux_clk);
478 	init.parent_names = clk_parent;
479 	init.num_parents = 1;
480 
481 	div->reg = host->regs + SD_EMMC_CLOCK;
482 	div->shift = __ffs(CLK_DIV_MASK);
483 	div->width = __builtin_popcountl(CLK_DIV_MASK);
484 	div->hw.init = &init;
485 	div->flags = CLK_DIVIDER_ONE_BASED;
486 
487 	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
488 	if (WARN_ON(IS_ERR(host->mmc_clk)))
489 		return PTR_ERR(host->mmc_clk);
490 
491 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
492 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
493 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
494 	if (ret)
495 		return ret;
496 
497 	return clk_prepare_enable(host->mmc_clk);
498 }
499 
500 static void meson_mmc_disable_resampling(struct meson_host *host)
501 {
502 	unsigned int val = readl(host->regs + host->data->adjust);
503 
504 	val &= ~ADJUST_ADJ_EN;
505 	writel(val, host->regs + host->data->adjust);
506 }
507 
508 static void meson_mmc_reset_resampling(struct meson_host *host)
509 {
510 	unsigned int val;
511 
512 	meson_mmc_disable_resampling(host);
513 
514 	val = readl(host->regs + host->data->adjust);
515 	val &= ~ADJUST_ADJ_DELAY_MASK;
516 	writel(val, host->regs + host->data->adjust);
517 }
518 
519 static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
520 {
521 	struct meson_host *host = mmc_priv(mmc);
522 	unsigned int val, dly, max_dly, i;
523 	int ret;
524 
525 	/* Resampling is done using the source clock */
526 	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
527 			       clk_get_rate(host->mmc_clk));
528 
529 	val = readl(host->regs + host->data->adjust);
530 	val |= ADJUST_ADJ_EN;
531 	writel(val, host->regs + host->data->adjust);
532 
533 	if (mmc_doing_retune(mmc))
534 		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
535 	else
536 		dly = 0;
537 
538 	for (i = 0; i < max_dly; i++) {
539 		val &= ~ADJUST_ADJ_DELAY_MASK;
540 		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
541 		writel(val, host->regs + host->data->adjust);
542 
543 		ret = mmc_send_tuning(mmc, opcode, NULL);
544 		if (!ret) {
545 			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
546 				(dly + i) % max_dly);
547 			return 0;
548 		}
549 	}
550 
551 	meson_mmc_reset_resampling(host);
552 	return -EIO;
553 }
554 
555 static int meson_mmc_prepare_ios_clock(struct meson_host *host,
556 				       struct mmc_ios *ios)
557 {
558 	bool ddr;
559 
560 	switch (ios->timing) {
561 	case MMC_TIMING_MMC_DDR52:
562 	case MMC_TIMING_UHS_DDR50:
563 		ddr = true;
564 		break;
565 
566 	default:
567 		ddr = false;
568 		break;
569 	}
570 
571 	return meson_mmc_clk_set(host, ios->clock, ddr);
572 }
573 
574 static void meson_mmc_check_resampling(struct meson_host *host,
575 				       struct mmc_ios *ios)
576 {
577 	switch (ios->timing) {
578 	case MMC_TIMING_LEGACY:
579 	case MMC_TIMING_MMC_HS:
580 	case MMC_TIMING_SD_HS:
581 	case MMC_TIMING_MMC_DDR52:
582 		meson_mmc_disable_resampling(host);
583 		break;
584 	}
585 }
586 
587 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
588 {
589 	struct meson_host *host = mmc_priv(mmc);
590 	u32 bus_width, val;
591 	int err;
592 
593 	/*
594 	 * GPIO regulator, only controls switching between 1v8 and
595 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
596 	 */
597 	switch (ios->power_mode) {
598 	case MMC_POWER_OFF:
599 		if (!IS_ERR(mmc->supply.vmmc))
600 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
601 
602 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
603 			regulator_disable(mmc->supply.vqmmc);
604 			host->vqmmc_enabled = false;
605 		}
606 
607 		break;
608 
609 	case MMC_POWER_UP:
610 		if (!IS_ERR(mmc->supply.vmmc))
611 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
612 
613 		break;
614 
615 	case MMC_POWER_ON:
616 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
617 			int ret = regulator_enable(mmc->supply.vqmmc);
618 
619 			if (ret < 0)
620 				dev_err(host->dev,
621 					"failed to enable vqmmc regulator\n");
622 			else
623 				host->vqmmc_enabled = true;
624 		}
625 
626 		break;
627 	}
628 
629 	/* Bus width */
630 	switch (ios->bus_width) {
631 	case MMC_BUS_WIDTH_1:
632 		bus_width = CFG_BUS_WIDTH_1;
633 		break;
634 	case MMC_BUS_WIDTH_4:
635 		bus_width = CFG_BUS_WIDTH_4;
636 		break;
637 	case MMC_BUS_WIDTH_8:
638 		bus_width = CFG_BUS_WIDTH_8;
639 		break;
640 	default:
641 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
642 			ios->bus_width);
643 		bus_width = CFG_BUS_WIDTH_4;
644 	}
645 
646 	val = readl(host->regs + SD_EMMC_CFG);
647 	val &= ~CFG_BUS_WIDTH_MASK;
648 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
649 	writel(val, host->regs + SD_EMMC_CFG);
650 
651 	meson_mmc_check_resampling(host, ios);
652 	err = meson_mmc_prepare_ios_clock(host, ios);
653 	if (err)
654 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
655 
656 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
657 }
658 
659 static void meson_mmc_request_done(struct mmc_host *mmc,
660 				   struct mmc_request *mrq)
661 {
662 	struct meson_host *host = mmc_priv(mmc);
663 
664 	host->cmd = NULL;
665 	mmc_request_done(host->mmc, mrq);
666 }
667 
668 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
669 {
670 	struct meson_host *host = mmc_priv(mmc);
671 	u32 cfg, blksz_old;
672 
673 	cfg = readl(host->regs + SD_EMMC_CFG);
674 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
675 
676 	if (!is_power_of_2(blksz))
677 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
678 
679 	blksz = ilog2(blksz);
680 
681 	/* check if block-size matches, if not update */
682 	if (blksz == blksz_old)
683 		return;
684 
685 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
686 		blksz_old, blksz);
687 
688 	cfg &= ~CFG_BLK_LEN_MASK;
689 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
690 	writel(cfg, host->regs + SD_EMMC_CFG);
691 }
692 
693 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
694 {
695 	if (cmd->flags & MMC_RSP_PRESENT) {
696 		if (cmd->flags & MMC_RSP_136)
697 			*cmd_cfg |= CMD_CFG_RESP_128;
698 		*cmd_cfg |= CMD_CFG_RESP_NUM;
699 
700 		if (!(cmd->flags & MMC_RSP_CRC))
701 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
702 
703 		if (cmd->flags & MMC_RSP_BUSY)
704 			*cmd_cfg |= CMD_CFG_R1B;
705 	} else {
706 		*cmd_cfg |= CMD_CFG_NO_RESP;
707 	}
708 }
709 
710 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
711 {
712 	struct meson_host *host = mmc_priv(mmc);
713 	struct sd_emmc_desc *desc = host->descs;
714 	struct mmc_data *data = host->cmd->data;
715 	struct scatterlist *sg;
716 	u32 start;
717 	int i;
718 
719 	if (data->flags & MMC_DATA_WRITE)
720 		cmd_cfg |= CMD_CFG_DATA_WR;
721 
722 	if (data->blocks > 1) {
723 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
724 		meson_mmc_set_blksz(mmc, data->blksz);
725 	}
726 
727 	for_each_sg(data->sg, sg, data->sg_count, i) {
728 		unsigned int len = sg_dma_len(sg);
729 
730 		if (data->blocks > 1)
731 			len /= data->blksz;
732 
733 		desc[i].cmd_cfg = cmd_cfg;
734 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
735 		if (i > 0)
736 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
737 		desc[i].cmd_arg = host->cmd->arg;
738 		desc[i].cmd_resp = 0;
739 		desc[i].cmd_data = sg_dma_address(sg);
740 	}
741 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
742 
743 	dma_wmb(); /* ensure descriptor is written before kicked */
744 	start = host->descs_dma_addr | START_DESC_BUSY;
745 	writel(start, host->regs + SD_EMMC_START);
746 }
747 
748 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
749 {
750 	struct meson_host *host = mmc_priv(mmc);
751 	struct mmc_data *data = cmd->data;
752 	u32 cmd_cfg = 0, cmd_data = 0;
753 	unsigned int xfer_bytes = 0;
754 
755 	/* Setup descriptors */
756 	dma_rmb();
757 
758 	host->cmd = cmd;
759 
760 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
761 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
762 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
763 
764 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
765 
766 	/* data? */
767 	if (data) {
768 		data->bytes_xfered = 0;
769 		cmd_cfg |= CMD_CFG_DATA_IO;
770 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
771 				      ilog2(meson_mmc_get_timeout_msecs(data)));
772 
773 		if (meson_mmc_desc_chain_mode(data)) {
774 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
775 			return;
776 		}
777 
778 		if (data->blocks > 1) {
779 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
780 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
781 					      data->blocks);
782 			meson_mmc_set_blksz(mmc, data->blksz);
783 		} else {
784 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
785 		}
786 
787 		xfer_bytes = data->blksz * data->blocks;
788 		if (data->flags & MMC_DATA_WRITE) {
789 			cmd_cfg |= CMD_CFG_DATA_WR;
790 			WARN_ON(xfer_bytes > host->bounce_buf_size);
791 			sg_copy_to_buffer(data->sg, data->sg_len,
792 					  host->bounce_buf, xfer_bytes);
793 			dma_wmb();
794 		}
795 
796 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
797 	} else {
798 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
799 				      ilog2(SD_EMMC_CMD_TIMEOUT));
800 	}
801 
802 	/* Last descriptor */
803 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
804 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
805 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
806 	writel(0, host->regs + SD_EMMC_CMD_RSP);
807 	wmb(); /* ensure descriptor is written before kicked */
808 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
809 }
810 
811 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
812 {
813 	struct meson_host *host = mmc_priv(mmc);
814 	bool needs_pre_post_req = mrq->data &&
815 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
816 
817 	if (needs_pre_post_req) {
818 		meson_mmc_get_transfer_mode(mmc, mrq);
819 		if (!meson_mmc_desc_chain_mode(mrq->data))
820 			needs_pre_post_req = false;
821 	}
822 
823 	if (needs_pre_post_req)
824 		meson_mmc_pre_req(mmc, mrq);
825 
826 	/* Stop execution */
827 	writel(0, host->regs + SD_EMMC_START);
828 
829 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
830 
831 	if (needs_pre_post_req)
832 		meson_mmc_post_req(mmc, mrq, 0);
833 }
834 
835 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
836 {
837 	struct meson_host *host = mmc_priv(mmc);
838 
839 	if (cmd->flags & MMC_RSP_136) {
840 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
841 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
842 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
843 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
844 	} else if (cmd->flags & MMC_RSP_PRESENT) {
845 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
846 	}
847 }
848 
849 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
850 {
851 	struct meson_host *host = dev_id;
852 	struct mmc_command *cmd;
853 	struct mmc_data *data;
854 	u32 irq_en, status, raw_status;
855 	irqreturn_t ret = IRQ_NONE;
856 
857 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
858 	raw_status = readl(host->regs + SD_EMMC_STATUS);
859 	status = raw_status & irq_en;
860 
861 	if (!status) {
862 		dev_dbg(host->dev,
863 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
864 			 irq_en, raw_status);
865 		return IRQ_NONE;
866 	}
867 
868 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
869 		return IRQ_NONE;
870 
871 	/* ack all raised interrupts */
872 	writel(status, host->regs + SD_EMMC_STATUS);
873 
874 	cmd = host->cmd;
875 	data = cmd->data;
876 	cmd->error = 0;
877 	if (status & IRQ_CRC_ERR) {
878 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
879 		cmd->error = -EILSEQ;
880 		ret = IRQ_WAKE_THREAD;
881 		goto out;
882 	}
883 
884 	if (status & IRQ_TIMEOUTS) {
885 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
886 		cmd->error = -ETIMEDOUT;
887 		ret = IRQ_WAKE_THREAD;
888 		goto out;
889 	}
890 
891 	meson_mmc_read_resp(host->mmc, cmd);
892 
893 	if (status & IRQ_SDIO) {
894 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
895 		ret = IRQ_HANDLED;
896 	}
897 
898 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
899 		if (data && !cmd->error)
900 			data->bytes_xfered = data->blksz * data->blocks;
901 		if (meson_mmc_bounce_buf_read(data) ||
902 		    meson_mmc_get_next_command(cmd))
903 			ret = IRQ_WAKE_THREAD;
904 		else
905 			ret = IRQ_HANDLED;
906 	}
907 
908 out:
909 	if (cmd->error) {
910 		/* Stop desc in case of errors */
911 		u32 start = readl(host->regs + SD_EMMC_START);
912 
913 		start &= ~START_DESC_BUSY;
914 		writel(start, host->regs + SD_EMMC_START);
915 	}
916 
917 	if (ret == IRQ_HANDLED)
918 		meson_mmc_request_done(host->mmc, cmd->mrq);
919 
920 	return ret;
921 }
922 
923 static int meson_mmc_wait_desc_stop(struct meson_host *host)
924 {
925 	u32 status;
926 
927 	/*
928 	 * It may sometimes take a while for it to actually halt. Here, we
929 	 * are giving it 5ms to comply
930 	 *
931 	 * If we don't confirm the descriptor is stopped, it might raise new
932 	 * IRQs after we have called mmc_request_done() which is bad.
933 	 */
934 
935 	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
936 				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
937 				  100, 5000);
938 }
939 
940 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
941 {
942 	struct meson_host *host = dev_id;
943 	struct mmc_command *next_cmd, *cmd = host->cmd;
944 	struct mmc_data *data;
945 	unsigned int xfer_bytes;
946 
947 	if (WARN_ON(!cmd))
948 		return IRQ_NONE;
949 
950 	if (cmd->error) {
951 		meson_mmc_wait_desc_stop(host);
952 		meson_mmc_request_done(host->mmc, cmd->mrq);
953 
954 		return IRQ_HANDLED;
955 	}
956 
957 	data = cmd->data;
958 	if (meson_mmc_bounce_buf_read(data)) {
959 		xfer_bytes = data->blksz * data->blocks;
960 		WARN_ON(xfer_bytes > host->bounce_buf_size);
961 		sg_copy_from_buffer(data->sg, data->sg_len,
962 				    host->bounce_buf, xfer_bytes);
963 	}
964 
965 	next_cmd = meson_mmc_get_next_command(cmd);
966 	if (next_cmd)
967 		meson_mmc_start_cmd(host->mmc, next_cmd);
968 	else
969 		meson_mmc_request_done(host->mmc, cmd->mrq);
970 
971 	return IRQ_HANDLED;
972 }
973 
974 /*
975  * NOTE: we only need this until the GPIO/pinctrl driver can handle
976  * interrupts.  For now, the MMC core will use this for polling.
977  */
978 static int meson_mmc_get_cd(struct mmc_host *mmc)
979 {
980 	int status = mmc_gpio_get_cd(mmc);
981 
982 	if (status == -ENOSYS)
983 		return 1; /* assume present */
984 
985 	return status;
986 }
987 
988 static void meson_mmc_cfg_init(struct meson_host *host)
989 {
990 	u32 cfg = 0;
991 
992 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
993 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
994 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
995 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
996 
997 	/* abort chain on R/W errors */
998 	cfg |= CFG_ERR_ABORT;
999 
1000 	writel(cfg, host->regs + SD_EMMC_CFG);
1001 }
1002 
1003 static int meson_mmc_card_busy(struct mmc_host *mmc)
1004 {
1005 	struct meson_host *host = mmc_priv(mmc);
1006 	u32 regval;
1007 
1008 	regval = readl(host->regs + SD_EMMC_STATUS);
1009 
1010 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1011 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1012 }
1013 
1014 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1015 {
1016 	int ret;
1017 
1018 	/* vqmmc regulator is available */
1019 	if (!IS_ERR(mmc->supply.vqmmc)) {
1020 		/*
1021 		 * The usual amlogic setup uses a GPIO to switch from one
1022 		 * regulator to the other. While the voltage ramp up is
1023 		 * pretty fast, care must be taken when switching from 3.3v
1024 		 * to 1.8v. Please make sure the regulator framework is aware
1025 		 * of your own regulator constraints
1026 		 */
1027 		ret = mmc_regulator_set_vqmmc(mmc, ios);
1028 		return ret < 0 ? ret : 0;
1029 	}
1030 
1031 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1032 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1033 		return 0;
1034 
1035 	return -EINVAL;
1036 }
1037 
1038 static const struct mmc_host_ops meson_mmc_ops = {
1039 	.request	= meson_mmc_request,
1040 	.set_ios	= meson_mmc_set_ios,
1041 	.get_cd         = meson_mmc_get_cd,
1042 	.pre_req	= meson_mmc_pre_req,
1043 	.post_req	= meson_mmc_post_req,
1044 	.execute_tuning = meson_mmc_resampling_tuning,
1045 	.card_busy	= meson_mmc_card_busy,
1046 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1047 };
1048 
1049 static int meson_mmc_probe(struct platform_device *pdev)
1050 {
1051 	struct resource *res;
1052 	struct meson_host *host;
1053 	struct mmc_host *mmc;
1054 	int ret;
1055 
1056 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1057 	if (!mmc)
1058 		return -ENOMEM;
1059 	host = mmc_priv(mmc);
1060 	host->mmc = mmc;
1061 	host->dev = &pdev->dev;
1062 	dev_set_drvdata(&pdev->dev, host);
1063 
1064 	/* The G12A SDIO Controller needs an SRAM bounce buffer */
1065 	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
1066 					"amlogic,dram-access-quirk");
1067 
1068 	/* Get regulators and the supported OCR mask */
1069 	host->vqmmc_enabled = false;
1070 	ret = mmc_regulator_get_supply(mmc);
1071 	if (ret)
1072 		goto free_host;
1073 
1074 	ret = mmc_of_parse(mmc);
1075 	if (ret) {
1076 		if (ret != -EPROBE_DEFER)
1077 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1078 		goto free_host;
1079 	}
1080 
1081 	host->data = (struct meson_mmc_data *)
1082 		of_device_get_match_data(&pdev->dev);
1083 	if (!host->data) {
1084 		ret = -EINVAL;
1085 		goto free_host;
1086 	}
1087 
1088 	ret = device_reset_optional(&pdev->dev);
1089 	if (ret)
1090 		return dev_err_probe(&pdev->dev, ret, "device reset failed\n");
1091 
1092 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1093 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1094 	if (IS_ERR(host->regs)) {
1095 		ret = PTR_ERR(host->regs);
1096 		goto free_host;
1097 	}
1098 
1099 	host->irq = platform_get_irq(pdev, 0);
1100 	if (host->irq <= 0) {
1101 		ret = -EINVAL;
1102 		goto free_host;
1103 	}
1104 
1105 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1106 	if (IS_ERR(host->pinctrl)) {
1107 		ret = PTR_ERR(host->pinctrl);
1108 		goto free_host;
1109 	}
1110 
1111 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1112 						   "clk-gate");
1113 	if (IS_ERR(host->pins_clk_gate)) {
1114 		dev_warn(&pdev->dev,
1115 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1116 		host->pins_clk_gate = NULL;
1117 	}
1118 
1119 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1120 	if (IS_ERR(host->core_clk)) {
1121 		ret = PTR_ERR(host->core_clk);
1122 		goto free_host;
1123 	}
1124 
1125 	ret = clk_prepare_enable(host->core_clk);
1126 	if (ret)
1127 		goto free_host;
1128 
1129 	ret = meson_mmc_clk_init(host);
1130 	if (ret)
1131 		goto err_core_clk;
1132 
1133 	/* set config to sane default */
1134 	meson_mmc_cfg_init(host);
1135 
1136 	/* Stop execution */
1137 	writel(0, host->regs + SD_EMMC_START);
1138 
1139 	/* clear, ack and enable interrupts */
1140 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1141 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1142 	       host->regs + SD_EMMC_STATUS);
1143 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1144 	       host->regs + SD_EMMC_IRQ_EN);
1145 
1146 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1147 				   meson_mmc_irq_thread, IRQF_ONESHOT,
1148 				   dev_name(&pdev->dev), host);
1149 	if (ret)
1150 		goto err_init_clk;
1151 
1152 	mmc->caps |= MMC_CAP_CMD23;
1153 	if (host->dram_access_quirk) {
1154 		/* Limit segments to 1 due to low available sram memory */
1155 		mmc->max_segs = 1;
1156 		/* Limit to the available sram memory */
1157 		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
1158 				     mmc->max_blk_size;
1159 	} else {
1160 		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1161 		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
1162 				sizeof(struct sd_emmc_desc);
1163 	}
1164 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1165 	mmc->max_seg_size = mmc->max_req_size;
1166 
1167 	/*
1168 	 * At the moment, we don't know how to reliably enable HS400.
1169 	 * From the different datasheets, it is not even clear if this mode
1170 	 * is officially supported by any of the SoCs
1171 	 */
1172 	mmc->caps2 &= ~MMC_CAP2_HS400;
1173 
1174 	if (host->dram_access_quirk) {
1175 		/*
1176 		 * The MMC Controller embeds 1,5KiB of internal SRAM
1177 		 * that can be used to be used as bounce buffer.
1178 		 * In the case of the G12A SDIO controller, use these
1179 		 * instead of the DDR memory
1180 		 */
1181 		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
1182 		host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
1183 		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
1184 	} else {
1185 		/* data bounce buffer */
1186 		host->bounce_buf_size = mmc->max_req_size;
1187 		host->bounce_buf =
1188 			dma_alloc_coherent(host->dev, host->bounce_buf_size,
1189 					   &host->bounce_dma_addr, GFP_KERNEL);
1190 		if (host->bounce_buf == NULL) {
1191 			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1192 			ret = -ENOMEM;
1193 			goto err_free_irq;
1194 		}
1195 	}
1196 
1197 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1198 		      &host->descs_dma_addr, GFP_KERNEL);
1199 	if (!host->descs) {
1200 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1201 		ret = -ENOMEM;
1202 		goto err_bounce_buf;
1203 	}
1204 
1205 	mmc->ops = &meson_mmc_ops;
1206 	mmc_add_host(mmc);
1207 
1208 	return 0;
1209 
1210 err_bounce_buf:
1211 	if (!host->dram_access_quirk)
1212 		dma_free_coherent(host->dev, host->bounce_buf_size,
1213 				  host->bounce_buf, host->bounce_dma_addr);
1214 err_free_irq:
1215 	free_irq(host->irq, host);
1216 err_init_clk:
1217 	clk_disable_unprepare(host->mmc_clk);
1218 err_core_clk:
1219 	clk_disable_unprepare(host->core_clk);
1220 free_host:
1221 	mmc_free_host(mmc);
1222 	return ret;
1223 }
1224 
1225 static int meson_mmc_remove(struct platform_device *pdev)
1226 {
1227 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1228 
1229 	mmc_remove_host(host->mmc);
1230 
1231 	/* disable interrupts */
1232 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1233 	free_irq(host->irq, host);
1234 
1235 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1236 			  host->descs, host->descs_dma_addr);
1237 
1238 	if (!host->dram_access_quirk)
1239 		dma_free_coherent(host->dev, host->bounce_buf_size,
1240 				  host->bounce_buf, host->bounce_dma_addr);
1241 
1242 	clk_disable_unprepare(host->mmc_clk);
1243 	clk_disable_unprepare(host->core_clk);
1244 
1245 	mmc_free_host(host->mmc);
1246 	return 0;
1247 }
1248 
1249 static const struct meson_mmc_data meson_gx_data = {
1250 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1251 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1252 	.always_on	= CLK_V2_ALWAYS_ON,
1253 	.adjust		= SD_EMMC_ADJUST,
1254 };
1255 
1256 static const struct meson_mmc_data meson_axg_data = {
1257 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1258 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1259 	.always_on	= CLK_V3_ALWAYS_ON,
1260 	.adjust		= SD_EMMC_V3_ADJUST,
1261 };
1262 
1263 static const struct of_device_id meson_mmc_of_match[] = {
1264 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1265 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1266 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1267 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1268 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1269 	{}
1270 };
1271 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1272 
1273 static struct platform_driver meson_mmc_driver = {
1274 	.probe		= meson_mmc_probe,
1275 	.remove		= meson_mmc_remove,
1276 	.driver		= {
1277 		.name = DRIVER_NAME,
1278 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1279 		.of_match_table = meson_mmc_of_match,
1280 	},
1281 };
1282 
1283 module_platform_driver(meson_mmc_driver);
1284 
1285 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1286 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1287 MODULE_LICENSE("GPL v2");
1288