xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision b737eecd)
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 				WARN_ONCE(1, "unaligned sg len %u blksize %u\n",
251 					  sg->length, data->blksz);
252 				return;
253 			}
254 		}
255 	}
256 
257 	for_each_sg(data->sg, sg, data->sg_len, i) {
258 		/* check for 8 byte alignment */
259 		if (sg->offset % 8) {
260 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
261 			return;
262 		}
263 	}
264 
265 	data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
266 }
267 
268 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
269 {
270 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
271 }
272 
273 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
274 {
275 	return data && data->flags & MMC_DATA_READ &&
276 	       !meson_mmc_desc_chain_mode(data);
277 }
278 
279 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
280 {
281 	struct mmc_data *data = mrq->data;
282 
283 	if (!data)
284 		return;
285 
286 	meson_mmc_get_transfer_mode(mmc, mrq);
287 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
288 
289 	if (!meson_mmc_desc_chain_mode(data))
290 		return;
291 
292 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
293                                    mmc_get_dma_dir(data));
294 	if (!data->sg_count)
295 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
296 }
297 
298 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
299 			       int err)
300 {
301 	struct mmc_data *data = mrq->data;
302 
303 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
304 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
305 			     mmc_get_dma_dir(data));
306 }
307 
308 /*
309  * Gating the clock on this controller is tricky.  It seems the mmc clock
310  * is also used by the controller.  It may crash during some operation if the
311  * clock is stopped.  The safest thing to do, whenever possible, is to keep
312  * clock running at stop it at the pad using the pinmux.
313  */
314 static void meson_mmc_clk_gate(struct meson_host *host)
315 {
316 	u32 cfg;
317 
318 	if (host->pins_clk_gate) {
319 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
320 	} else {
321 		/*
322 		 * If the pinmux is not provided - default to the classic and
323 		 * unsafe method
324 		 */
325 		cfg = readl(host->regs + SD_EMMC_CFG);
326 		cfg |= CFG_STOP_CLOCK;
327 		writel(cfg, host->regs + SD_EMMC_CFG);
328 	}
329 }
330 
331 static void meson_mmc_clk_ungate(struct meson_host *host)
332 {
333 	u32 cfg;
334 
335 	if (host->pins_clk_gate)
336 		pinctrl_select_default_state(host->dev);
337 
338 	/* Make sure the clock is not stopped in the controller */
339 	cfg = readl(host->regs + SD_EMMC_CFG);
340 	cfg &= ~CFG_STOP_CLOCK;
341 	writel(cfg, host->regs + SD_EMMC_CFG);
342 }
343 
344 static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
345 			     bool ddr)
346 {
347 	struct mmc_host *mmc = host->mmc;
348 	int ret;
349 	u32 cfg;
350 
351 	/* Same request - bail-out */
352 	if (host->ddr == ddr && host->req_rate == rate)
353 		return 0;
354 
355 	/* stop clock */
356 	meson_mmc_clk_gate(host);
357 	host->req_rate = 0;
358 	mmc->actual_clock = 0;
359 
360 	/* return with clock being stopped */
361 	if (!rate)
362 		return 0;
363 
364 	/* Stop the clock during rate change to avoid glitches */
365 	cfg = readl(host->regs + SD_EMMC_CFG);
366 	cfg |= CFG_STOP_CLOCK;
367 	writel(cfg, host->regs + SD_EMMC_CFG);
368 
369 	if (ddr) {
370 		/* DDR modes require higher module clock */
371 		rate <<= 1;
372 		cfg |= CFG_DDR;
373 	} else {
374 		cfg &= ~CFG_DDR;
375 	}
376 	writel(cfg, host->regs + SD_EMMC_CFG);
377 	host->ddr = ddr;
378 
379 	ret = clk_set_rate(host->mmc_clk, rate);
380 	if (ret) {
381 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
382 			rate, ret);
383 		return ret;
384 	}
385 
386 	host->req_rate = rate;
387 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
388 
389 	/* We should report the real output frequency of the controller */
390 	if (ddr) {
391 		host->req_rate >>= 1;
392 		mmc->actual_clock >>= 1;
393 	}
394 
395 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
396 	if (rate != mmc->actual_clock)
397 		dev_dbg(host->dev, "requested rate was %lu\n", rate);
398 
399 	/* (re)start clock */
400 	meson_mmc_clk_ungate(host);
401 
402 	return 0;
403 }
404 
405 /*
406  * The SD/eMMC IP block has an internal mux and divider used for
407  * generating the MMC clock.  Use the clock framework to create and
408  * manage these clocks.
409  */
410 static int meson_mmc_clk_init(struct meson_host *host)
411 {
412 	struct clk_init_data init;
413 	struct clk_mux *mux;
414 	struct clk_divider *div;
415 	char clk_name[32];
416 	int i, ret = 0;
417 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
418 	const char *clk_parent[1];
419 	u32 clk_reg;
420 
421 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
422 	clk_reg = CLK_ALWAYS_ON(host);
423 	clk_reg |= CLK_DIV_MASK;
424 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
425 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
426 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
427 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
428 
429 	/* get the mux parents */
430 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
431 		struct clk *clk;
432 		char name[16];
433 
434 		snprintf(name, sizeof(name), "clkin%d", i);
435 		clk = devm_clk_get(host->dev, name);
436 		if (IS_ERR(clk))
437 			return dev_err_probe(host->dev, PTR_ERR(clk),
438 					     "Missing clock %s\n", name);
439 
440 		mux_parent_names[i] = __clk_get_name(clk);
441 	}
442 
443 	/* create the mux */
444 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
445 	if (!mux)
446 		return -ENOMEM;
447 
448 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
449 	init.name = clk_name;
450 	init.ops = &clk_mux_ops;
451 	init.flags = 0;
452 	init.parent_names = mux_parent_names;
453 	init.num_parents = MUX_CLK_NUM_PARENTS;
454 
455 	mux->reg = host->regs + SD_EMMC_CLOCK;
456 	mux->shift = __ffs(CLK_SRC_MASK);
457 	mux->mask = CLK_SRC_MASK >> mux->shift;
458 	mux->hw.init = &init;
459 
460 	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
461 	if (WARN_ON(IS_ERR(host->mux_clk)))
462 		return PTR_ERR(host->mux_clk);
463 
464 	/* create the divider */
465 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
466 	if (!div)
467 		return -ENOMEM;
468 
469 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
470 	init.name = clk_name;
471 	init.ops = &clk_divider_ops;
472 	init.flags = CLK_SET_RATE_PARENT;
473 	clk_parent[0] = __clk_get_name(host->mux_clk);
474 	init.parent_names = clk_parent;
475 	init.num_parents = 1;
476 
477 	div->reg = host->regs + SD_EMMC_CLOCK;
478 	div->shift = __ffs(CLK_DIV_MASK);
479 	div->width = __builtin_popcountl(CLK_DIV_MASK);
480 	div->hw.init = &init;
481 	div->flags = CLK_DIVIDER_ONE_BASED;
482 
483 	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
484 	if (WARN_ON(IS_ERR(host->mmc_clk)))
485 		return PTR_ERR(host->mmc_clk);
486 
487 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
488 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
489 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
490 	if (ret)
491 		return ret;
492 
493 	return clk_prepare_enable(host->mmc_clk);
494 }
495 
496 static void meson_mmc_disable_resampling(struct meson_host *host)
497 {
498 	unsigned int val = readl(host->regs + host->data->adjust);
499 
500 	val &= ~ADJUST_ADJ_EN;
501 	writel(val, host->regs + host->data->adjust);
502 }
503 
504 static void meson_mmc_reset_resampling(struct meson_host *host)
505 {
506 	unsigned int val;
507 
508 	meson_mmc_disable_resampling(host);
509 
510 	val = readl(host->regs + host->data->adjust);
511 	val &= ~ADJUST_ADJ_DELAY_MASK;
512 	writel(val, host->regs + host->data->adjust);
513 }
514 
515 static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
516 {
517 	struct meson_host *host = mmc_priv(mmc);
518 	unsigned int val, dly, max_dly, i;
519 	int ret;
520 
521 	/* Resampling is done using the source clock */
522 	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
523 			       clk_get_rate(host->mmc_clk));
524 
525 	val = readl(host->regs + host->data->adjust);
526 	val |= ADJUST_ADJ_EN;
527 	writel(val, host->regs + host->data->adjust);
528 
529 	if (mmc_doing_retune(mmc))
530 		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
531 	else
532 		dly = 0;
533 
534 	for (i = 0; i < max_dly; i++) {
535 		val &= ~ADJUST_ADJ_DELAY_MASK;
536 		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
537 		writel(val, host->regs + host->data->adjust);
538 
539 		ret = mmc_send_tuning(mmc, opcode, NULL);
540 		if (!ret) {
541 			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
542 				(dly + i) % max_dly);
543 			return 0;
544 		}
545 	}
546 
547 	meson_mmc_reset_resampling(host);
548 	return -EIO;
549 }
550 
551 static int meson_mmc_prepare_ios_clock(struct meson_host *host,
552 				       struct mmc_ios *ios)
553 {
554 	bool ddr;
555 
556 	switch (ios->timing) {
557 	case MMC_TIMING_MMC_DDR52:
558 	case MMC_TIMING_UHS_DDR50:
559 		ddr = true;
560 		break;
561 
562 	default:
563 		ddr = false;
564 		break;
565 	}
566 
567 	return meson_mmc_clk_set(host, ios->clock, ddr);
568 }
569 
570 static void meson_mmc_check_resampling(struct meson_host *host,
571 				       struct mmc_ios *ios)
572 {
573 	switch (ios->timing) {
574 	case MMC_TIMING_LEGACY:
575 	case MMC_TIMING_MMC_HS:
576 	case MMC_TIMING_SD_HS:
577 	case MMC_TIMING_MMC_DDR52:
578 		meson_mmc_disable_resampling(host);
579 		break;
580 	}
581 }
582 
583 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
584 {
585 	struct meson_host *host = mmc_priv(mmc);
586 	u32 bus_width, val;
587 	int err;
588 
589 	/*
590 	 * GPIO regulator, only controls switching between 1v8 and
591 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
592 	 */
593 	switch (ios->power_mode) {
594 	case MMC_POWER_OFF:
595 		if (!IS_ERR(mmc->supply.vmmc))
596 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
597 
598 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
599 			regulator_disable(mmc->supply.vqmmc);
600 			host->vqmmc_enabled = false;
601 		}
602 
603 		break;
604 
605 	case MMC_POWER_UP:
606 		if (!IS_ERR(mmc->supply.vmmc))
607 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
608 
609 		break;
610 
611 	case MMC_POWER_ON:
612 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
613 			int ret = regulator_enable(mmc->supply.vqmmc);
614 
615 			if (ret < 0)
616 				dev_err(host->dev,
617 					"failed to enable vqmmc regulator\n");
618 			else
619 				host->vqmmc_enabled = true;
620 		}
621 
622 		break;
623 	}
624 
625 	/* Bus width */
626 	switch (ios->bus_width) {
627 	case MMC_BUS_WIDTH_1:
628 		bus_width = CFG_BUS_WIDTH_1;
629 		break;
630 	case MMC_BUS_WIDTH_4:
631 		bus_width = CFG_BUS_WIDTH_4;
632 		break;
633 	case MMC_BUS_WIDTH_8:
634 		bus_width = CFG_BUS_WIDTH_8;
635 		break;
636 	default:
637 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
638 			ios->bus_width);
639 		bus_width = CFG_BUS_WIDTH_4;
640 	}
641 
642 	val = readl(host->regs + SD_EMMC_CFG);
643 	val &= ~CFG_BUS_WIDTH_MASK;
644 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
645 	writel(val, host->regs + SD_EMMC_CFG);
646 
647 	meson_mmc_check_resampling(host, ios);
648 	err = meson_mmc_prepare_ios_clock(host, ios);
649 	if (err)
650 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
651 
652 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
653 }
654 
655 static void meson_mmc_request_done(struct mmc_host *mmc,
656 				   struct mmc_request *mrq)
657 {
658 	struct meson_host *host = mmc_priv(mmc);
659 
660 	host->cmd = NULL;
661 	mmc_request_done(host->mmc, mrq);
662 }
663 
664 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
665 {
666 	struct meson_host *host = mmc_priv(mmc);
667 	u32 cfg, blksz_old;
668 
669 	cfg = readl(host->regs + SD_EMMC_CFG);
670 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
671 
672 	if (!is_power_of_2(blksz))
673 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
674 
675 	blksz = ilog2(blksz);
676 
677 	/* check if block-size matches, if not update */
678 	if (blksz == blksz_old)
679 		return;
680 
681 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
682 		blksz_old, blksz);
683 
684 	cfg &= ~CFG_BLK_LEN_MASK;
685 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
686 	writel(cfg, host->regs + SD_EMMC_CFG);
687 }
688 
689 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
690 {
691 	if (cmd->flags & MMC_RSP_PRESENT) {
692 		if (cmd->flags & MMC_RSP_136)
693 			*cmd_cfg |= CMD_CFG_RESP_128;
694 		*cmd_cfg |= CMD_CFG_RESP_NUM;
695 
696 		if (!(cmd->flags & MMC_RSP_CRC))
697 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
698 
699 		if (cmd->flags & MMC_RSP_BUSY)
700 			*cmd_cfg |= CMD_CFG_R1B;
701 	} else {
702 		*cmd_cfg |= CMD_CFG_NO_RESP;
703 	}
704 }
705 
706 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
707 {
708 	struct meson_host *host = mmc_priv(mmc);
709 	struct sd_emmc_desc *desc = host->descs;
710 	struct mmc_data *data = host->cmd->data;
711 	struct scatterlist *sg;
712 	u32 start;
713 	int i;
714 
715 	if (data->flags & MMC_DATA_WRITE)
716 		cmd_cfg |= CMD_CFG_DATA_WR;
717 
718 	if (data->blocks > 1) {
719 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
720 		meson_mmc_set_blksz(mmc, data->blksz);
721 	}
722 
723 	for_each_sg(data->sg, sg, data->sg_count, i) {
724 		unsigned int len = sg_dma_len(sg);
725 
726 		if (data->blocks > 1)
727 			len /= data->blksz;
728 
729 		desc[i].cmd_cfg = cmd_cfg;
730 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
731 		if (i > 0)
732 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
733 		desc[i].cmd_arg = host->cmd->arg;
734 		desc[i].cmd_resp = 0;
735 		desc[i].cmd_data = sg_dma_address(sg);
736 	}
737 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
738 
739 	dma_wmb(); /* ensure descriptor is written before kicked */
740 	start = host->descs_dma_addr | START_DESC_BUSY;
741 	writel(start, host->regs + SD_EMMC_START);
742 }
743 
744 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
745 {
746 	struct meson_host *host = mmc_priv(mmc);
747 	struct mmc_data *data = cmd->data;
748 	u32 cmd_cfg = 0, cmd_data = 0;
749 	unsigned int xfer_bytes = 0;
750 
751 	/* Setup descriptors */
752 	dma_rmb();
753 
754 	host->cmd = cmd;
755 
756 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
757 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
758 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
759 
760 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
761 
762 	/* data? */
763 	if (data) {
764 		data->bytes_xfered = 0;
765 		cmd_cfg |= CMD_CFG_DATA_IO;
766 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
767 				      ilog2(meson_mmc_get_timeout_msecs(data)));
768 
769 		if (meson_mmc_desc_chain_mode(data)) {
770 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
771 			return;
772 		}
773 
774 		if (data->blocks > 1) {
775 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
776 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
777 					      data->blocks);
778 			meson_mmc_set_blksz(mmc, data->blksz);
779 		} else {
780 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
781 		}
782 
783 		xfer_bytes = data->blksz * data->blocks;
784 		if (data->flags & MMC_DATA_WRITE) {
785 			cmd_cfg |= CMD_CFG_DATA_WR;
786 			WARN_ON(xfer_bytes > host->bounce_buf_size);
787 			sg_copy_to_buffer(data->sg, data->sg_len,
788 					  host->bounce_buf, xfer_bytes);
789 			dma_wmb();
790 		}
791 
792 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
793 	} else {
794 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
795 				      ilog2(SD_EMMC_CMD_TIMEOUT));
796 	}
797 
798 	/* Last descriptor */
799 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
800 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
801 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
802 	writel(0, host->regs + SD_EMMC_CMD_RSP);
803 	wmb(); /* ensure descriptor is written before kicked */
804 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
805 }
806 
807 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
808 {
809 	struct meson_host *host = mmc_priv(mmc);
810 	bool needs_pre_post_req = mrq->data &&
811 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
812 
813 	if (needs_pre_post_req) {
814 		meson_mmc_get_transfer_mode(mmc, mrq);
815 		if (!meson_mmc_desc_chain_mode(mrq->data))
816 			needs_pre_post_req = false;
817 	}
818 
819 	if (needs_pre_post_req)
820 		meson_mmc_pre_req(mmc, mrq);
821 
822 	/* Stop execution */
823 	writel(0, host->regs + SD_EMMC_START);
824 
825 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
826 
827 	if (needs_pre_post_req)
828 		meson_mmc_post_req(mmc, mrq, 0);
829 }
830 
831 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
832 {
833 	struct meson_host *host = mmc_priv(mmc);
834 
835 	if (cmd->flags & MMC_RSP_136) {
836 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
837 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
838 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
839 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
840 	} else if (cmd->flags & MMC_RSP_PRESENT) {
841 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
842 	}
843 }
844 
845 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
846 {
847 	struct meson_host *host = dev_id;
848 	struct mmc_command *cmd;
849 	struct mmc_data *data;
850 	u32 irq_en, status, raw_status;
851 	irqreturn_t ret = IRQ_NONE;
852 
853 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
854 	raw_status = readl(host->regs + SD_EMMC_STATUS);
855 	status = raw_status & irq_en;
856 
857 	if (!status) {
858 		dev_dbg(host->dev,
859 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
860 			 irq_en, raw_status);
861 		return IRQ_NONE;
862 	}
863 
864 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
865 		return IRQ_NONE;
866 
867 	/* ack all raised interrupts */
868 	writel(status, host->regs + SD_EMMC_STATUS);
869 
870 	cmd = host->cmd;
871 	data = cmd->data;
872 	cmd->error = 0;
873 	if (status & IRQ_CRC_ERR) {
874 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
875 		cmd->error = -EILSEQ;
876 		ret = IRQ_WAKE_THREAD;
877 		goto out;
878 	}
879 
880 	if (status & IRQ_TIMEOUTS) {
881 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
882 		cmd->error = -ETIMEDOUT;
883 		ret = IRQ_WAKE_THREAD;
884 		goto out;
885 	}
886 
887 	meson_mmc_read_resp(host->mmc, cmd);
888 
889 	if (status & IRQ_SDIO) {
890 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
891 		ret = IRQ_HANDLED;
892 	}
893 
894 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
895 		if (data && !cmd->error)
896 			data->bytes_xfered = data->blksz * data->blocks;
897 		if (meson_mmc_bounce_buf_read(data) ||
898 		    meson_mmc_get_next_command(cmd))
899 			ret = IRQ_WAKE_THREAD;
900 		else
901 			ret = IRQ_HANDLED;
902 	}
903 
904 out:
905 	if (cmd->error) {
906 		/* Stop desc in case of errors */
907 		u32 start = readl(host->regs + SD_EMMC_START);
908 
909 		start &= ~START_DESC_BUSY;
910 		writel(start, host->regs + SD_EMMC_START);
911 	}
912 
913 	if (ret == IRQ_HANDLED)
914 		meson_mmc_request_done(host->mmc, cmd->mrq);
915 
916 	return ret;
917 }
918 
919 static int meson_mmc_wait_desc_stop(struct meson_host *host)
920 {
921 	u32 status;
922 
923 	/*
924 	 * It may sometimes take a while for it to actually halt. Here, we
925 	 * are giving it 5ms to comply
926 	 *
927 	 * If we don't confirm the descriptor is stopped, it might raise new
928 	 * IRQs after we have called mmc_request_done() which is bad.
929 	 */
930 
931 	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
932 				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
933 				  100, 5000);
934 }
935 
936 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
937 {
938 	struct meson_host *host = dev_id;
939 	struct mmc_command *next_cmd, *cmd = host->cmd;
940 	struct mmc_data *data;
941 	unsigned int xfer_bytes;
942 
943 	if (WARN_ON(!cmd))
944 		return IRQ_NONE;
945 
946 	if (cmd->error) {
947 		meson_mmc_wait_desc_stop(host);
948 		meson_mmc_request_done(host->mmc, cmd->mrq);
949 
950 		return IRQ_HANDLED;
951 	}
952 
953 	data = cmd->data;
954 	if (meson_mmc_bounce_buf_read(data)) {
955 		xfer_bytes = data->blksz * data->blocks;
956 		WARN_ON(xfer_bytes > host->bounce_buf_size);
957 		sg_copy_from_buffer(data->sg, data->sg_len,
958 				    host->bounce_buf, xfer_bytes);
959 	}
960 
961 	next_cmd = meson_mmc_get_next_command(cmd);
962 	if (next_cmd)
963 		meson_mmc_start_cmd(host->mmc, next_cmd);
964 	else
965 		meson_mmc_request_done(host->mmc, cmd->mrq);
966 
967 	return IRQ_HANDLED;
968 }
969 
970 /*
971  * NOTE: we only need this until the GPIO/pinctrl driver can handle
972  * interrupts.  For now, the MMC core will use this for polling.
973  */
974 static int meson_mmc_get_cd(struct mmc_host *mmc)
975 {
976 	int status = mmc_gpio_get_cd(mmc);
977 
978 	if (status == -ENOSYS)
979 		return 1; /* assume present */
980 
981 	return status;
982 }
983 
984 static void meson_mmc_cfg_init(struct meson_host *host)
985 {
986 	u32 cfg = 0;
987 
988 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
989 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
990 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
991 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
992 
993 	/* abort chain on R/W errors */
994 	cfg |= CFG_ERR_ABORT;
995 
996 	writel(cfg, host->regs + SD_EMMC_CFG);
997 }
998 
999 static int meson_mmc_card_busy(struct mmc_host *mmc)
1000 {
1001 	struct meson_host *host = mmc_priv(mmc);
1002 	u32 regval;
1003 
1004 	regval = readl(host->regs + SD_EMMC_STATUS);
1005 
1006 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1007 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1008 }
1009 
1010 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1011 {
1012 	int ret;
1013 
1014 	/* vqmmc regulator is available */
1015 	if (!IS_ERR(mmc->supply.vqmmc)) {
1016 		/*
1017 		 * The usual amlogic setup uses a GPIO to switch from one
1018 		 * regulator to the other. While the voltage ramp up is
1019 		 * pretty fast, care must be taken when switching from 3.3v
1020 		 * to 1.8v. Please make sure the regulator framework is aware
1021 		 * of your own regulator constraints
1022 		 */
1023 		ret = mmc_regulator_set_vqmmc(mmc, ios);
1024 		return ret < 0 ? ret : 0;
1025 	}
1026 
1027 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1028 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1029 		return 0;
1030 
1031 	return -EINVAL;
1032 }
1033 
1034 static const struct mmc_host_ops meson_mmc_ops = {
1035 	.request	= meson_mmc_request,
1036 	.set_ios	= meson_mmc_set_ios,
1037 	.get_cd         = meson_mmc_get_cd,
1038 	.pre_req	= meson_mmc_pre_req,
1039 	.post_req	= meson_mmc_post_req,
1040 	.execute_tuning = meson_mmc_resampling_tuning,
1041 	.card_busy	= meson_mmc_card_busy,
1042 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1043 };
1044 
1045 static int meson_mmc_probe(struct platform_device *pdev)
1046 {
1047 	struct resource *res;
1048 	struct meson_host *host;
1049 	struct mmc_host *mmc;
1050 	int ret;
1051 
1052 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1053 	if (!mmc)
1054 		return -ENOMEM;
1055 	host = mmc_priv(mmc);
1056 	host->mmc = mmc;
1057 	host->dev = &pdev->dev;
1058 	dev_set_drvdata(&pdev->dev, host);
1059 
1060 	/* The G12A SDIO Controller needs an SRAM bounce buffer */
1061 	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
1062 					"amlogic,dram-access-quirk");
1063 
1064 	/* Get regulators and the supported OCR mask */
1065 	host->vqmmc_enabled = false;
1066 	ret = mmc_regulator_get_supply(mmc);
1067 	if (ret)
1068 		goto free_host;
1069 
1070 	ret = mmc_of_parse(mmc);
1071 	if (ret) {
1072 		if (ret != -EPROBE_DEFER)
1073 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1074 		goto free_host;
1075 	}
1076 
1077 	host->data = (struct meson_mmc_data *)
1078 		of_device_get_match_data(&pdev->dev);
1079 	if (!host->data) {
1080 		ret = -EINVAL;
1081 		goto free_host;
1082 	}
1083 
1084 	ret = device_reset_optional(&pdev->dev);
1085 	if (ret)
1086 		return dev_err_probe(&pdev->dev, ret, "device reset failed\n");
1087 
1088 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1089 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1090 	if (IS_ERR(host->regs)) {
1091 		ret = PTR_ERR(host->regs);
1092 		goto free_host;
1093 	}
1094 
1095 	host->irq = platform_get_irq(pdev, 0);
1096 	if (host->irq <= 0) {
1097 		ret = -EINVAL;
1098 		goto free_host;
1099 	}
1100 
1101 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1102 	if (IS_ERR(host->pinctrl)) {
1103 		ret = PTR_ERR(host->pinctrl);
1104 		goto free_host;
1105 	}
1106 
1107 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1108 						   "clk-gate");
1109 	if (IS_ERR(host->pins_clk_gate)) {
1110 		dev_warn(&pdev->dev,
1111 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1112 		host->pins_clk_gate = NULL;
1113 	}
1114 
1115 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1116 	if (IS_ERR(host->core_clk)) {
1117 		ret = PTR_ERR(host->core_clk);
1118 		goto free_host;
1119 	}
1120 
1121 	ret = clk_prepare_enable(host->core_clk);
1122 	if (ret)
1123 		goto free_host;
1124 
1125 	ret = meson_mmc_clk_init(host);
1126 	if (ret)
1127 		goto err_core_clk;
1128 
1129 	/* set config to sane default */
1130 	meson_mmc_cfg_init(host);
1131 
1132 	/* Stop execution */
1133 	writel(0, host->regs + SD_EMMC_START);
1134 
1135 	/* clear, ack and enable interrupts */
1136 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1137 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1138 	       host->regs + SD_EMMC_STATUS);
1139 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1140 	       host->regs + SD_EMMC_IRQ_EN);
1141 
1142 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1143 				   meson_mmc_irq_thread, IRQF_ONESHOT,
1144 				   dev_name(&pdev->dev), host);
1145 	if (ret)
1146 		goto err_init_clk;
1147 
1148 	mmc->caps |= MMC_CAP_CMD23;
1149 	if (host->dram_access_quirk) {
1150 		/* Limit segments to 1 due to low available sram memory */
1151 		mmc->max_segs = 1;
1152 		/* Limit to the available sram memory */
1153 		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
1154 				     mmc->max_blk_size;
1155 	} else {
1156 		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1157 		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
1158 				sizeof(struct sd_emmc_desc);
1159 	}
1160 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1161 	mmc->max_seg_size = mmc->max_req_size;
1162 
1163 	/*
1164 	 * At the moment, we don't know how to reliably enable HS400.
1165 	 * From the different datasheets, it is not even clear if this mode
1166 	 * is officially supported by any of the SoCs
1167 	 */
1168 	mmc->caps2 &= ~MMC_CAP2_HS400;
1169 
1170 	if (host->dram_access_quirk) {
1171 		/*
1172 		 * The MMC Controller embeds 1,5KiB of internal SRAM
1173 		 * that can be used to be used as bounce buffer.
1174 		 * In the case of the G12A SDIO controller, use these
1175 		 * instead of the DDR memory
1176 		 */
1177 		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
1178 		host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
1179 		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
1180 	} else {
1181 		/* data bounce buffer */
1182 		host->bounce_buf_size = mmc->max_req_size;
1183 		host->bounce_buf =
1184 			dma_alloc_coherent(host->dev, host->bounce_buf_size,
1185 					   &host->bounce_dma_addr, GFP_KERNEL);
1186 		if (host->bounce_buf == NULL) {
1187 			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1188 			ret = -ENOMEM;
1189 			goto err_free_irq;
1190 		}
1191 	}
1192 
1193 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1194 		      &host->descs_dma_addr, GFP_KERNEL);
1195 	if (!host->descs) {
1196 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1197 		ret = -ENOMEM;
1198 		goto err_bounce_buf;
1199 	}
1200 
1201 	mmc->ops = &meson_mmc_ops;
1202 	mmc_add_host(mmc);
1203 
1204 	return 0;
1205 
1206 err_bounce_buf:
1207 	if (!host->dram_access_quirk)
1208 		dma_free_coherent(host->dev, host->bounce_buf_size,
1209 				  host->bounce_buf, host->bounce_dma_addr);
1210 err_free_irq:
1211 	free_irq(host->irq, host);
1212 err_init_clk:
1213 	clk_disable_unprepare(host->mmc_clk);
1214 err_core_clk:
1215 	clk_disable_unprepare(host->core_clk);
1216 free_host:
1217 	mmc_free_host(mmc);
1218 	return ret;
1219 }
1220 
1221 static int meson_mmc_remove(struct platform_device *pdev)
1222 {
1223 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1224 
1225 	mmc_remove_host(host->mmc);
1226 
1227 	/* disable interrupts */
1228 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1229 	free_irq(host->irq, host);
1230 
1231 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1232 			  host->descs, host->descs_dma_addr);
1233 
1234 	if (!host->dram_access_quirk)
1235 		dma_free_coherent(host->dev, host->bounce_buf_size,
1236 				  host->bounce_buf, host->bounce_dma_addr);
1237 
1238 	clk_disable_unprepare(host->mmc_clk);
1239 	clk_disable_unprepare(host->core_clk);
1240 
1241 	mmc_free_host(host->mmc);
1242 	return 0;
1243 }
1244 
1245 static const struct meson_mmc_data meson_gx_data = {
1246 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1247 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1248 	.always_on	= CLK_V2_ALWAYS_ON,
1249 	.adjust		= SD_EMMC_ADJUST,
1250 };
1251 
1252 static const struct meson_mmc_data meson_axg_data = {
1253 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1254 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1255 	.always_on	= CLK_V3_ALWAYS_ON,
1256 	.adjust		= SD_EMMC_V3_ADJUST,
1257 };
1258 
1259 static const struct of_device_id meson_mmc_of_match[] = {
1260 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1261 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1262 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1263 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1264 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1265 	{}
1266 };
1267 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1268 
1269 static struct platform_driver meson_mmc_driver = {
1270 	.probe		= meson_mmc_probe,
1271 	.remove		= meson_mmc_remove,
1272 	.driver		= {
1273 		.name = DRIVER_NAME,
1274 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1275 		.of_match_table = meson_mmc_of_match,
1276 	},
1277 };
1278 
1279 module_platform_driver(meson_mmc_driver);
1280 
1281 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1282 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1283 MODULE_LICENSE("GPL v2");
1284