xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 249592bf)
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 	if (data->blocks > 1) {
240 		/*
241 		 * In block mode DMA descriptor format, "length" field indicates
242 		 * number of blocks and there is no way to pass DMA size that
243 		 * is not multiple of SDIO block size, making it impossible to
244 		 * tie more than one memory buffer with single SDIO block.
245 		 * Block mode sg buffer size should be aligned with SDIO block
246 		 * size, otherwise chain mode could not be used.
247 		 */
248 		for_each_sg(data->sg, sg, data->sg_len, i) {
249 			if (sg->length % data->blksz) {
250 				dev_warn_once(mmc_dev(mmc),
251 					      "unaligned sg len %u blksize %u, disabling descriptor DMA for transfer\n",
252 					      sg->length, data->blksz);
253 				return;
254 			}
255 		}
256 	}
257 
258 	for_each_sg(data->sg, sg, data->sg_len, i) {
259 		/* check for 8 byte alignment */
260 		if (sg->offset % 8) {
261 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
262 			return;
263 		}
264 	}
265 
266 	data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
267 }
268 
269 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
270 {
271 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
272 }
273 
274 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
275 {
276 	return data && data->flags & MMC_DATA_READ &&
277 	       !meson_mmc_desc_chain_mode(data);
278 }
279 
280 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
281 {
282 	struct mmc_data *data = mrq->data;
283 
284 	if (!data)
285 		return;
286 
287 	meson_mmc_get_transfer_mode(mmc, mrq);
288 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
289 
290 	if (!meson_mmc_desc_chain_mode(data))
291 		return;
292 
293 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
294                                    mmc_get_dma_dir(data));
295 	if (!data->sg_count)
296 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
297 }
298 
299 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
300 			       int err)
301 {
302 	struct mmc_data *data = mrq->data;
303 
304 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
305 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
306 			     mmc_get_dma_dir(data));
307 }
308 
309 /*
310  * Gating the clock on this controller is tricky.  It seems the mmc clock
311  * is also used by the controller.  It may crash during some operation if the
312  * clock is stopped.  The safest thing to do, whenever possible, is to keep
313  * clock running at stop it at the pad using the pinmux.
314  */
315 static void meson_mmc_clk_gate(struct meson_host *host)
316 {
317 	u32 cfg;
318 
319 	if (host->pins_clk_gate) {
320 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
321 	} else {
322 		/*
323 		 * If the pinmux is not provided - default to the classic and
324 		 * unsafe method
325 		 */
326 		cfg = readl(host->regs + SD_EMMC_CFG);
327 		cfg |= CFG_STOP_CLOCK;
328 		writel(cfg, host->regs + SD_EMMC_CFG);
329 	}
330 }
331 
332 static void meson_mmc_clk_ungate(struct meson_host *host)
333 {
334 	u32 cfg;
335 
336 	if (host->pins_clk_gate)
337 		pinctrl_select_default_state(host->dev);
338 
339 	/* Make sure the clock is not stopped in the controller */
340 	cfg = readl(host->regs + SD_EMMC_CFG);
341 	cfg &= ~CFG_STOP_CLOCK;
342 	writel(cfg, host->regs + SD_EMMC_CFG);
343 }
344 
345 static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
346 			     bool ddr)
347 {
348 	struct mmc_host *mmc = host->mmc;
349 	int ret;
350 	u32 cfg;
351 
352 	/* Same request - bail-out */
353 	if (host->ddr == ddr && host->req_rate == rate)
354 		return 0;
355 
356 	/* stop clock */
357 	meson_mmc_clk_gate(host);
358 	host->req_rate = 0;
359 	mmc->actual_clock = 0;
360 
361 	/* return with clock being stopped */
362 	if (!rate)
363 		return 0;
364 
365 	/* Stop the clock during rate change to avoid glitches */
366 	cfg = readl(host->regs + SD_EMMC_CFG);
367 	cfg |= CFG_STOP_CLOCK;
368 	writel(cfg, host->regs + SD_EMMC_CFG);
369 
370 	if (ddr) {
371 		/* DDR modes require higher module clock */
372 		rate <<= 1;
373 		cfg |= CFG_DDR;
374 	} else {
375 		cfg &= ~CFG_DDR;
376 	}
377 	writel(cfg, host->regs + SD_EMMC_CFG);
378 	host->ddr = ddr;
379 
380 	ret = clk_set_rate(host->mmc_clk, rate);
381 	if (ret) {
382 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
383 			rate, ret);
384 		return ret;
385 	}
386 
387 	host->req_rate = rate;
388 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
389 
390 	/* We should report the real output frequency of the controller */
391 	if (ddr) {
392 		host->req_rate >>= 1;
393 		mmc->actual_clock >>= 1;
394 	}
395 
396 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
397 	if (rate != mmc->actual_clock)
398 		dev_dbg(host->dev, "requested rate was %lu\n", rate);
399 
400 	/* (re)start clock */
401 	meson_mmc_clk_ungate(host);
402 
403 	return 0;
404 }
405 
406 /*
407  * The SD/eMMC IP block has an internal mux and divider used for
408  * generating the MMC clock.  Use the clock framework to create and
409  * manage these clocks.
410  */
411 static int meson_mmc_clk_init(struct meson_host *host)
412 {
413 	struct clk_init_data init;
414 	struct clk_mux *mux;
415 	struct clk_divider *div;
416 	char clk_name[32];
417 	int i, ret = 0;
418 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
419 	const char *clk_parent[1];
420 	u32 clk_reg;
421 
422 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
423 	clk_reg = CLK_ALWAYS_ON(host);
424 	clk_reg |= CLK_DIV_MASK;
425 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
426 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
427 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
428 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
429 
430 	/* get the mux parents */
431 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
432 		struct clk *clk;
433 		char name[16];
434 
435 		snprintf(name, sizeof(name), "clkin%d", i);
436 		clk = devm_clk_get(host->dev, name);
437 		if (IS_ERR(clk))
438 			return dev_err_probe(host->dev, PTR_ERR(clk),
439 					     "Missing clock %s\n", name);
440 
441 		mux_parent_names[i] = __clk_get_name(clk);
442 	}
443 
444 	/* create the mux */
445 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
446 	if (!mux)
447 		return -ENOMEM;
448 
449 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
450 	init.name = clk_name;
451 	init.ops = &clk_mux_ops;
452 	init.flags = 0;
453 	init.parent_names = mux_parent_names;
454 	init.num_parents = MUX_CLK_NUM_PARENTS;
455 
456 	mux->reg = host->regs + SD_EMMC_CLOCK;
457 	mux->shift = __ffs(CLK_SRC_MASK);
458 	mux->mask = CLK_SRC_MASK >> mux->shift;
459 	mux->hw.init = &init;
460 
461 	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
462 	if (WARN_ON(IS_ERR(host->mux_clk)))
463 		return PTR_ERR(host->mux_clk);
464 
465 	/* create the divider */
466 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
467 	if (!div)
468 		return -ENOMEM;
469 
470 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
471 	init.name = clk_name;
472 	init.ops = &clk_divider_ops;
473 	init.flags = CLK_SET_RATE_PARENT;
474 	clk_parent[0] = __clk_get_name(host->mux_clk);
475 	init.parent_names = clk_parent;
476 	init.num_parents = 1;
477 
478 	div->reg = host->regs + SD_EMMC_CLOCK;
479 	div->shift = __ffs(CLK_DIV_MASK);
480 	div->width = __builtin_popcountl(CLK_DIV_MASK);
481 	div->hw.init = &init;
482 	div->flags = CLK_DIVIDER_ONE_BASED;
483 
484 	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
485 	if (WARN_ON(IS_ERR(host->mmc_clk)))
486 		return PTR_ERR(host->mmc_clk);
487 
488 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
489 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
490 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
491 	if (ret)
492 		return ret;
493 
494 	return clk_prepare_enable(host->mmc_clk);
495 }
496 
497 static void meson_mmc_disable_resampling(struct meson_host *host)
498 {
499 	unsigned int val = readl(host->regs + host->data->adjust);
500 
501 	val &= ~ADJUST_ADJ_EN;
502 	writel(val, host->regs + host->data->adjust);
503 }
504 
505 static void meson_mmc_reset_resampling(struct meson_host *host)
506 {
507 	unsigned int val;
508 
509 	meson_mmc_disable_resampling(host);
510 
511 	val = readl(host->regs + host->data->adjust);
512 	val &= ~ADJUST_ADJ_DELAY_MASK;
513 	writel(val, host->regs + host->data->adjust);
514 }
515 
516 static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
517 {
518 	struct meson_host *host = mmc_priv(mmc);
519 	unsigned int val, dly, max_dly, i;
520 	int ret;
521 
522 	/* Resampling is done using the source clock */
523 	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
524 			       clk_get_rate(host->mmc_clk));
525 
526 	val = readl(host->regs + host->data->adjust);
527 	val |= ADJUST_ADJ_EN;
528 	writel(val, host->regs + host->data->adjust);
529 
530 	if (mmc_doing_retune(mmc))
531 		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
532 	else
533 		dly = 0;
534 
535 	for (i = 0; i < max_dly; i++) {
536 		val &= ~ADJUST_ADJ_DELAY_MASK;
537 		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
538 		writel(val, host->regs + host->data->adjust);
539 
540 		ret = mmc_send_tuning(mmc, opcode, NULL);
541 		if (!ret) {
542 			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
543 				(dly + i) % max_dly);
544 			return 0;
545 		}
546 	}
547 
548 	meson_mmc_reset_resampling(host);
549 	return -EIO;
550 }
551 
552 static int meson_mmc_prepare_ios_clock(struct meson_host *host,
553 				       struct mmc_ios *ios)
554 {
555 	bool ddr;
556 
557 	switch (ios->timing) {
558 	case MMC_TIMING_MMC_DDR52:
559 	case MMC_TIMING_UHS_DDR50:
560 		ddr = true;
561 		break;
562 
563 	default:
564 		ddr = false;
565 		break;
566 	}
567 
568 	return meson_mmc_clk_set(host, ios->clock, ddr);
569 }
570 
571 static void meson_mmc_check_resampling(struct meson_host *host,
572 				       struct mmc_ios *ios)
573 {
574 	switch (ios->timing) {
575 	case MMC_TIMING_LEGACY:
576 	case MMC_TIMING_MMC_HS:
577 	case MMC_TIMING_SD_HS:
578 	case MMC_TIMING_MMC_DDR52:
579 		meson_mmc_disable_resampling(host);
580 		break;
581 	}
582 }
583 
584 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
585 {
586 	struct meson_host *host = mmc_priv(mmc);
587 	u32 bus_width, val;
588 	int err;
589 
590 	/*
591 	 * GPIO regulator, only controls switching between 1v8 and
592 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
593 	 */
594 	switch (ios->power_mode) {
595 	case MMC_POWER_OFF:
596 		if (!IS_ERR(mmc->supply.vmmc))
597 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
598 
599 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
600 			regulator_disable(mmc->supply.vqmmc);
601 			host->vqmmc_enabled = false;
602 		}
603 
604 		break;
605 
606 	case MMC_POWER_UP:
607 		if (!IS_ERR(mmc->supply.vmmc))
608 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
609 
610 		break;
611 
612 	case MMC_POWER_ON:
613 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
614 			int ret = regulator_enable(mmc->supply.vqmmc);
615 
616 			if (ret < 0)
617 				dev_err(host->dev,
618 					"failed to enable vqmmc regulator\n");
619 			else
620 				host->vqmmc_enabled = true;
621 		}
622 
623 		break;
624 	}
625 
626 	/* Bus width */
627 	switch (ios->bus_width) {
628 	case MMC_BUS_WIDTH_1:
629 		bus_width = CFG_BUS_WIDTH_1;
630 		break;
631 	case MMC_BUS_WIDTH_4:
632 		bus_width = CFG_BUS_WIDTH_4;
633 		break;
634 	case MMC_BUS_WIDTH_8:
635 		bus_width = CFG_BUS_WIDTH_8;
636 		break;
637 	default:
638 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
639 			ios->bus_width);
640 		bus_width = CFG_BUS_WIDTH_4;
641 	}
642 
643 	val = readl(host->regs + SD_EMMC_CFG);
644 	val &= ~CFG_BUS_WIDTH_MASK;
645 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
646 	writel(val, host->regs + SD_EMMC_CFG);
647 
648 	meson_mmc_check_resampling(host, ios);
649 	err = meson_mmc_prepare_ios_clock(host, ios);
650 	if (err)
651 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
652 
653 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
654 }
655 
656 static void meson_mmc_request_done(struct mmc_host *mmc,
657 				   struct mmc_request *mrq)
658 {
659 	struct meson_host *host = mmc_priv(mmc);
660 
661 	host->cmd = NULL;
662 	mmc_request_done(host->mmc, mrq);
663 }
664 
665 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
666 {
667 	struct meson_host *host = mmc_priv(mmc);
668 	u32 cfg, blksz_old;
669 
670 	cfg = readl(host->regs + SD_EMMC_CFG);
671 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
672 
673 	if (!is_power_of_2(blksz))
674 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
675 
676 	blksz = ilog2(blksz);
677 
678 	/* check if block-size matches, if not update */
679 	if (blksz == blksz_old)
680 		return;
681 
682 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
683 		blksz_old, blksz);
684 
685 	cfg &= ~CFG_BLK_LEN_MASK;
686 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
687 	writel(cfg, host->regs + SD_EMMC_CFG);
688 }
689 
690 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
691 {
692 	if (cmd->flags & MMC_RSP_PRESENT) {
693 		if (cmd->flags & MMC_RSP_136)
694 			*cmd_cfg |= CMD_CFG_RESP_128;
695 		*cmd_cfg |= CMD_CFG_RESP_NUM;
696 
697 		if (!(cmd->flags & MMC_RSP_CRC))
698 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
699 
700 		if (cmd->flags & MMC_RSP_BUSY)
701 			*cmd_cfg |= CMD_CFG_R1B;
702 	} else {
703 		*cmd_cfg |= CMD_CFG_NO_RESP;
704 	}
705 }
706 
707 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
708 {
709 	struct meson_host *host = mmc_priv(mmc);
710 	struct sd_emmc_desc *desc = host->descs;
711 	struct mmc_data *data = host->cmd->data;
712 	struct scatterlist *sg;
713 	u32 start;
714 	int i;
715 
716 	if (data->flags & MMC_DATA_WRITE)
717 		cmd_cfg |= CMD_CFG_DATA_WR;
718 
719 	if (data->blocks > 1) {
720 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
721 		meson_mmc_set_blksz(mmc, data->blksz);
722 	}
723 
724 	for_each_sg(data->sg, sg, data->sg_count, i) {
725 		unsigned int len = sg_dma_len(sg);
726 
727 		if (data->blocks > 1)
728 			len /= data->blksz;
729 
730 		desc[i].cmd_cfg = cmd_cfg;
731 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
732 		if (i > 0)
733 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
734 		desc[i].cmd_arg = host->cmd->arg;
735 		desc[i].cmd_resp = 0;
736 		desc[i].cmd_data = sg_dma_address(sg);
737 	}
738 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
739 
740 	dma_wmb(); /* ensure descriptor is written before kicked */
741 	start = host->descs_dma_addr | START_DESC_BUSY;
742 	writel(start, host->regs + SD_EMMC_START);
743 }
744 
745 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
746 {
747 	struct meson_host *host = mmc_priv(mmc);
748 	struct mmc_data *data = cmd->data;
749 	u32 cmd_cfg = 0, cmd_data = 0;
750 	unsigned int xfer_bytes = 0;
751 
752 	/* Setup descriptors */
753 	dma_rmb();
754 
755 	host->cmd = cmd;
756 
757 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
758 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
759 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
760 
761 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
762 
763 	/* data? */
764 	if (data) {
765 		data->bytes_xfered = 0;
766 		cmd_cfg |= CMD_CFG_DATA_IO;
767 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
768 				      ilog2(meson_mmc_get_timeout_msecs(data)));
769 
770 		if (meson_mmc_desc_chain_mode(data)) {
771 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
772 			return;
773 		}
774 
775 		if (data->blocks > 1) {
776 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
777 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
778 					      data->blocks);
779 			meson_mmc_set_blksz(mmc, data->blksz);
780 		} else {
781 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
782 		}
783 
784 		xfer_bytes = data->blksz * data->blocks;
785 		if (data->flags & MMC_DATA_WRITE) {
786 			cmd_cfg |= CMD_CFG_DATA_WR;
787 			WARN_ON(xfer_bytes > host->bounce_buf_size);
788 			sg_copy_to_buffer(data->sg, data->sg_len,
789 					  host->bounce_buf, xfer_bytes);
790 			dma_wmb();
791 		}
792 
793 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
794 	} else {
795 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
796 				      ilog2(SD_EMMC_CMD_TIMEOUT));
797 	}
798 
799 	/* Last descriptor */
800 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
801 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
802 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
803 	writel(0, host->regs + SD_EMMC_CMD_RSP);
804 	wmb(); /* ensure descriptor is written before kicked */
805 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
806 }
807 
808 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
809 {
810 	struct meson_host *host = mmc_priv(mmc);
811 	bool needs_pre_post_req = mrq->data &&
812 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
813 
814 	if (needs_pre_post_req) {
815 		meson_mmc_get_transfer_mode(mmc, mrq);
816 		if (!meson_mmc_desc_chain_mode(mrq->data))
817 			needs_pre_post_req = false;
818 	}
819 
820 	if (needs_pre_post_req)
821 		meson_mmc_pre_req(mmc, mrq);
822 
823 	/* Stop execution */
824 	writel(0, host->regs + SD_EMMC_START);
825 
826 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
827 
828 	if (needs_pre_post_req)
829 		meson_mmc_post_req(mmc, mrq, 0);
830 }
831 
832 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
833 {
834 	struct meson_host *host = mmc_priv(mmc);
835 
836 	if (cmd->flags & MMC_RSP_136) {
837 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
838 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
839 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
840 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
841 	} else if (cmd->flags & MMC_RSP_PRESENT) {
842 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
843 	}
844 }
845 
846 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
847 {
848 	struct meson_host *host = dev_id;
849 	struct mmc_command *cmd;
850 	struct mmc_data *data;
851 	u32 irq_en, status, raw_status;
852 	irqreturn_t ret = IRQ_NONE;
853 
854 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
855 	raw_status = readl(host->regs + SD_EMMC_STATUS);
856 	status = raw_status & irq_en;
857 
858 	if (!status) {
859 		dev_dbg(host->dev,
860 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
861 			 irq_en, raw_status);
862 		return IRQ_NONE;
863 	}
864 
865 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
866 		return IRQ_NONE;
867 
868 	/* ack all raised interrupts */
869 	writel(status, host->regs + SD_EMMC_STATUS);
870 
871 	cmd = host->cmd;
872 	data = cmd->data;
873 	cmd->error = 0;
874 	if (status & IRQ_CRC_ERR) {
875 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
876 		cmd->error = -EILSEQ;
877 		ret = IRQ_WAKE_THREAD;
878 		goto out;
879 	}
880 
881 	if (status & IRQ_TIMEOUTS) {
882 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
883 		cmd->error = -ETIMEDOUT;
884 		ret = IRQ_WAKE_THREAD;
885 		goto out;
886 	}
887 
888 	meson_mmc_read_resp(host->mmc, cmd);
889 
890 	if (status & IRQ_SDIO) {
891 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
892 		ret = IRQ_HANDLED;
893 	}
894 
895 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
896 		if (data && !cmd->error)
897 			data->bytes_xfered = data->blksz * data->blocks;
898 		if (meson_mmc_bounce_buf_read(data) ||
899 		    meson_mmc_get_next_command(cmd))
900 			ret = IRQ_WAKE_THREAD;
901 		else
902 			ret = IRQ_HANDLED;
903 	}
904 
905 out:
906 	if (cmd->error) {
907 		/* Stop desc in case of errors */
908 		u32 start = readl(host->regs + SD_EMMC_START);
909 
910 		start &= ~START_DESC_BUSY;
911 		writel(start, host->regs + SD_EMMC_START);
912 	}
913 
914 	if (ret == IRQ_HANDLED)
915 		meson_mmc_request_done(host->mmc, cmd->mrq);
916 
917 	return ret;
918 }
919 
920 static int meson_mmc_wait_desc_stop(struct meson_host *host)
921 {
922 	u32 status;
923 
924 	/*
925 	 * It may sometimes take a while for it to actually halt. Here, we
926 	 * are giving it 5ms to comply
927 	 *
928 	 * If we don't confirm the descriptor is stopped, it might raise new
929 	 * IRQs after we have called mmc_request_done() which is bad.
930 	 */
931 
932 	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
933 				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
934 				  100, 5000);
935 }
936 
937 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
938 {
939 	struct meson_host *host = dev_id;
940 	struct mmc_command *next_cmd, *cmd = host->cmd;
941 	struct mmc_data *data;
942 	unsigned int xfer_bytes;
943 
944 	if (WARN_ON(!cmd))
945 		return IRQ_NONE;
946 
947 	if (cmd->error) {
948 		meson_mmc_wait_desc_stop(host);
949 		meson_mmc_request_done(host->mmc, cmd->mrq);
950 
951 		return IRQ_HANDLED;
952 	}
953 
954 	data = cmd->data;
955 	if (meson_mmc_bounce_buf_read(data)) {
956 		xfer_bytes = data->blksz * data->blocks;
957 		WARN_ON(xfer_bytes > host->bounce_buf_size);
958 		sg_copy_from_buffer(data->sg, data->sg_len,
959 				    host->bounce_buf, xfer_bytes);
960 	}
961 
962 	next_cmd = meson_mmc_get_next_command(cmd);
963 	if (next_cmd)
964 		meson_mmc_start_cmd(host->mmc, next_cmd);
965 	else
966 		meson_mmc_request_done(host->mmc, cmd->mrq);
967 
968 	return IRQ_HANDLED;
969 }
970 
971 /*
972  * NOTE: we only need this until the GPIO/pinctrl driver can handle
973  * interrupts.  For now, the MMC core will use this for polling.
974  */
975 static int meson_mmc_get_cd(struct mmc_host *mmc)
976 {
977 	int status = mmc_gpio_get_cd(mmc);
978 
979 	if (status == -ENOSYS)
980 		return 1; /* assume present */
981 
982 	return status;
983 }
984 
985 static void meson_mmc_cfg_init(struct meson_host *host)
986 {
987 	u32 cfg = 0;
988 
989 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
990 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
991 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
992 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
993 
994 	/* abort chain on R/W errors */
995 	cfg |= CFG_ERR_ABORT;
996 
997 	writel(cfg, host->regs + SD_EMMC_CFG);
998 }
999 
1000 static int meson_mmc_card_busy(struct mmc_host *mmc)
1001 {
1002 	struct meson_host *host = mmc_priv(mmc);
1003 	u32 regval;
1004 
1005 	regval = readl(host->regs + SD_EMMC_STATUS);
1006 
1007 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1008 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1009 }
1010 
1011 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1012 {
1013 	int ret;
1014 
1015 	/* vqmmc regulator is available */
1016 	if (!IS_ERR(mmc->supply.vqmmc)) {
1017 		/*
1018 		 * The usual amlogic setup uses a GPIO to switch from one
1019 		 * regulator to the other. While the voltage ramp up is
1020 		 * pretty fast, care must be taken when switching from 3.3v
1021 		 * to 1.8v. Please make sure the regulator framework is aware
1022 		 * of your own regulator constraints
1023 		 */
1024 		ret = mmc_regulator_set_vqmmc(mmc, ios);
1025 		return ret < 0 ? ret : 0;
1026 	}
1027 
1028 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1029 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1030 		return 0;
1031 
1032 	return -EINVAL;
1033 }
1034 
1035 static const struct mmc_host_ops meson_mmc_ops = {
1036 	.request	= meson_mmc_request,
1037 	.set_ios	= meson_mmc_set_ios,
1038 	.get_cd         = meson_mmc_get_cd,
1039 	.pre_req	= meson_mmc_pre_req,
1040 	.post_req	= meson_mmc_post_req,
1041 	.execute_tuning = meson_mmc_resampling_tuning,
1042 	.card_busy	= meson_mmc_card_busy,
1043 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1044 };
1045 
1046 static int meson_mmc_probe(struct platform_device *pdev)
1047 {
1048 	struct resource *res;
1049 	struct meson_host *host;
1050 	struct mmc_host *mmc;
1051 	int ret;
1052 
1053 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1054 	if (!mmc)
1055 		return -ENOMEM;
1056 	host = mmc_priv(mmc);
1057 	host->mmc = mmc;
1058 	host->dev = &pdev->dev;
1059 	dev_set_drvdata(&pdev->dev, host);
1060 
1061 	/* The G12A SDIO Controller needs an SRAM bounce buffer */
1062 	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
1063 					"amlogic,dram-access-quirk");
1064 
1065 	/* Get regulators and the supported OCR mask */
1066 	host->vqmmc_enabled = false;
1067 	ret = mmc_regulator_get_supply(mmc);
1068 	if (ret)
1069 		goto free_host;
1070 
1071 	ret = mmc_of_parse(mmc);
1072 	if (ret) {
1073 		if (ret != -EPROBE_DEFER)
1074 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1075 		goto free_host;
1076 	}
1077 
1078 	host->data = (struct meson_mmc_data *)
1079 		of_device_get_match_data(&pdev->dev);
1080 	if (!host->data) {
1081 		ret = -EINVAL;
1082 		goto free_host;
1083 	}
1084 
1085 	ret = device_reset_optional(&pdev->dev);
1086 	if (ret)
1087 		return dev_err_probe(&pdev->dev, ret, "device reset failed\n");
1088 
1089 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1090 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1091 	if (IS_ERR(host->regs)) {
1092 		ret = PTR_ERR(host->regs);
1093 		goto free_host;
1094 	}
1095 
1096 	host->irq = platform_get_irq(pdev, 0);
1097 	if (host->irq <= 0) {
1098 		ret = -EINVAL;
1099 		goto free_host;
1100 	}
1101 
1102 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1103 	if (IS_ERR(host->pinctrl)) {
1104 		ret = PTR_ERR(host->pinctrl);
1105 		goto free_host;
1106 	}
1107 
1108 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1109 						   "clk-gate");
1110 	if (IS_ERR(host->pins_clk_gate)) {
1111 		dev_warn(&pdev->dev,
1112 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1113 		host->pins_clk_gate = NULL;
1114 	}
1115 
1116 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1117 	if (IS_ERR(host->core_clk)) {
1118 		ret = PTR_ERR(host->core_clk);
1119 		goto free_host;
1120 	}
1121 
1122 	ret = clk_prepare_enable(host->core_clk);
1123 	if (ret)
1124 		goto free_host;
1125 
1126 	ret = meson_mmc_clk_init(host);
1127 	if (ret)
1128 		goto err_core_clk;
1129 
1130 	/* set config to sane default */
1131 	meson_mmc_cfg_init(host);
1132 
1133 	/* Stop execution */
1134 	writel(0, host->regs + SD_EMMC_START);
1135 
1136 	/* clear, ack and enable interrupts */
1137 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1138 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1139 	       host->regs + SD_EMMC_STATUS);
1140 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1141 	       host->regs + SD_EMMC_IRQ_EN);
1142 
1143 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1144 				   meson_mmc_irq_thread, IRQF_ONESHOT,
1145 				   dev_name(&pdev->dev), host);
1146 	if (ret)
1147 		goto err_init_clk;
1148 
1149 	mmc->caps |= MMC_CAP_CMD23;
1150 	if (host->dram_access_quirk) {
1151 		/* Limit segments to 1 due to low available sram memory */
1152 		mmc->max_segs = 1;
1153 		/* Limit to the available sram memory */
1154 		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
1155 				     mmc->max_blk_size;
1156 	} else {
1157 		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1158 		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
1159 				sizeof(struct sd_emmc_desc);
1160 	}
1161 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1162 	mmc->max_seg_size = mmc->max_req_size;
1163 
1164 	/*
1165 	 * At the moment, we don't know how to reliably enable HS400.
1166 	 * From the different datasheets, it is not even clear if this mode
1167 	 * is officially supported by any of the SoCs
1168 	 */
1169 	mmc->caps2 &= ~MMC_CAP2_HS400;
1170 
1171 	if (host->dram_access_quirk) {
1172 		/*
1173 		 * The MMC Controller embeds 1,5KiB of internal SRAM
1174 		 * that can be used to be used as bounce buffer.
1175 		 * In the case of the G12A SDIO controller, use these
1176 		 * instead of the DDR memory
1177 		 */
1178 		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
1179 		host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
1180 		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
1181 	} else {
1182 		/* data bounce buffer */
1183 		host->bounce_buf_size = mmc->max_req_size;
1184 		host->bounce_buf =
1185 			dma_alloc_coherent(host->dev, host->bounce_buf_size,
1186 					   &host->bounce_dma_addr, GFP_KERNEL);
1187 		if (host->bounce_buf == NULL) {
1188 			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1189 			ret = -ENOMEM;
1190 			goto err_free_irq;
1191 		}
1192 	}
1193 
1194 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1195 		      &host->descs_dma_addr, GFP_KERNEL);
1196 	if (!host->descs) {
1197 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1198 		ret = -ENOMEM;
1199 		goto err_bounce_buf;
1200 	}
1201 
1202 	mmc->ops = &meson_mmc_ops;
1203 	mmc_add_host(mmc);
1204 
1205 	return 0;
1206 
1207 err_bounce_buf:
1208 	if (!host->dram_access_quirk)
1209 		dma_free_coherent(host->dev, host->bounce_buf_size,
1210 				  host->bounce_buf, host->bounce_dma_addr);
1211 err_free_irq:
1212 	free_irq(host->irq, host);
1213 err_init_clk:
1214 	clk_disable_unprepare(host->mmc_clk);
1215 err_core_clk:
1216 	clk_disable_unprepare(host->core_clk);
1217 free_host:
1218 	mmc_free_host(mmc);
1219 	return ret;
1220 }
1221 
1222 static int meson_mmc_remove(struct platform_device *pdev)
1223 {
1224 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1225 
1226 	mmc_remove_host(host->mmc);
1227 
1228 	/* disable interrupts */
1229 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1230 	free_irq(host->irq, host);
1231 
1232 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1233 			  host->descs, host->descs_dma_addr);
1234 
1235 	if (!host->dram_access_quirk)
1236 		dma_free_coherent(host->dev, host->bounce_buf_size,
1237 				  host->bounce_buf, host->bounce_dma_addr);
1238 
1239 	clk_disable_unprepare(host->mmc_clk);
1240 	clk_disable_unprepare(host->core_clk);
1241 
1242 	mmc_free_host(host->mmc);
1243 	return 0;
1244 }
1245 
1246 static const struct meson_mmc_data meson_gx_data = {
1247 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1248 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1249 	.always_on	= CLK_V2_ALWAYS_ON,
1250 	.adjust		= SD_EMMC_ADJUST,
1251 };
1252 
1253 static const struct meson_mmc_data meson_axg_data = {
1254 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1255 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1256 	.always_on	= CLK_V3_ALWAYS_ON,
1257 	.adjust		= SD_EMMC_V3_ADJUST,
1258 };
1259 
1260 static const struct of_device_id meson_mmc_of_match[] = {
1261 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1262 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1263 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1264 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1265 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1266 	{}
1267 };
1268 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1269 
1270 static struct platform_driver meson_mmc_driver = {
1271 	.probe		= meson_mmc_probe,
1272 	.remove		= meson_mmc_remove,
1273 	.driver		= {
1274 		.name = DRIVER_NAME,
1275 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1276 		.of_match_table = meson_mmc_of_match,
1277 	},
1278 };
1279 
1280 module_platform_driver(meson_mmc_driver);
1281 
1282 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1283 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1284 MODULE_LICENSE("GPL v2");
1285