xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 29c37341)
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 	bool use_desc_chain_mode = true;
231 
232 	/*
233 	 * When Controller DMA cannot directly access DDR memory, disable
234 	 * support for Chain Mode to directly use the internal SRAM using
235 	 * the bounce buffer mode.
236 	 */
237 	if (host->dram_access_quirk)
238 		return;
239 
240 	/*
241 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
242 	 * reported. For some strange reason this occurs in descriptor
243 	 * chain mode only. So let's fall back to bounce buffer mode
244 	 * for command SD_IO_RW_EXTENDED.
245 	 */
246 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
247 		return;
248 
249 	for_each_sg(data->sg, sg, data->sg_len, i)
250 		/* check for 8 byte alignment */
251 		if (sg->offset & 7) {
252 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
253 			use_desc_chain_mode = false;
254 			break;
255 		}
256 
257 	if (use_desc_chain_mode)
258 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
259 }
260 
261 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
262 {
263 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
264 }
265 
266 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
267 {
268 	return data && data->flags & MMC_DATA_READ &&
269 	       !meson_mmc_desc_chain_mode(data);
270 }
271 
272 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
273 {
274 	struct mmc_data *data = mrq->data;
275 
276 	if (!data)
277 		return;
278 
279 	meson_mmc_get_transfer_mode(mmc, mrq);
280 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
281 
282 	if (!meson_mmc_desc_chain_mode(data))
283 		return;
284 
285 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
286                                    mmc_get_dma_dir(data));
287 	if (!data->sg_count)
288 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
289 }
290 
291 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
292 			       int err)
293 {
294 	struct mmc_data *data = mrq->data;
295 
296 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
297 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
298 			     mmc_get_dma_dir(data));
299 }
300 
301 /*
302  * Gating the clock on this controller is tricky.  It seems the mmc clock
303  * is also used by the controller.  It may crash during some operation if the
304  * clock is stopped.  The safest thing to do, whenever possible, is to keep
305  * clock running at stop it at the pad using the pinmux.
306  */
307 static void meson_mmc_clk_gate(struct meson_host *host)
308 {
309 	u32 cfg;
310 
311 	if (host->pins_clk_gate) {
312 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
313 	} else {
314 		/*
315 		 * If the pinmux is not provided - default to the classic and
316 		 * unsafe method
317 		 */
318 		cfg = readl(host->regs + SD_EMMC_CFG);
319 		cfg |= CFG_STOP_CLOCK;
320 		writel(cfg, host->regs + SD_EMMC_CFG);
321 	}
322 }
323 
324 static void meson_mmc_clk_ungate(struct meson_host *host)
325 {
326 	u32 cfg;
327 
328 	if (host->pins_clk_gate)
329 		pinctrl_select_default_state(host->dev);
330 
331 	/* Make sure the clock is not stopped in the controller */
332 	cfg = readl(host->regs + SD_EMMC_CFG);
333 	cfg &= ~CFG_STOP_CLOCK;
334 	writel(cfg, host->regs + SD_EMMC_CFG);
335 }
336 
337 static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
338 			     bool ddr)
339 {
340 	struct mmc_host *mmc = host->mmc;
341 	int ret;
342 	u32 cfg;
343 
344 	/* Same request - bail-out */
345 	if (host->ddr == ddr && host->req_rate == rate)
346 		return 0;
347 
348 	/* stop clock */
349 	meson_mmc_clk_gate(host);
350 	host->req_rate = 0;
351 	mmc->actual_clock = 0;
352 
353 	/* return with clock being stopped */
354 	if (!rate)
355 		return 0;
356 
357 	/* Stop the clock during rate change to avoid glitches */
358 	cfg = readl(host->regs + SD_EMMC_CFG);
359 	cfg |= CFG_STOP_CLOCK;
360 	writel(cfg, host->regs + SD_EMMC_CFG);
361 
362 	if (ddr) {
363 		/* DDR modes require higher module clock */
364 		rate <<= 1;
365 		cfg |= CFG_DDR;
366 	} else {
367 		cfg &= ~CFG_DDR;
368 	}
369 	writel(cfg, host->regs + SD_EMMC_CFG);
370 	host->ddr = ddr;
371 
372 	ret = clk_set_rate(host->mmc_clk, rate);
373 	if (ret) {
374 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
375 			rate, ret);
376 		return ret;
377 	}
378 
379 	host->req_rate = rate;
380 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
381 
382 	/* We should report the real output frequency of the controller */
383 	if (ddr) {
384 		host->req_rate >>= 1;
385 		mmc->actual_clock >>= 1;
386 	}
387 
388 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
389 	if (rate != mmc->actual_clock)
390 		dev_dbg(host->dev, "requested rate was %lu\n", rate);
391 
392 	/* (re)start clock */
393 	meson_mmc_clk_ungate(host);
394 
395 	return 0;
396 }
397 
398 /*
399  * The SD/eMMC IP block has an internal mux and divider used for
400  * generating the MMC clock.  Use the clock framework to create and
401  * manage these clocks.
402  */
403 static int meson_mmc_clk_init(struct meson_host *host)
404 {
405 	struct clk_init_data init;
406 	struct clk_mux *mux;
407 	struct clk_divider *div;
408 	char clk_name[32];
409 	int i, ret = 0;
410 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
411 	const char *clk_parent[1];
412 	u32 clk_reg;
413 
414 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
415 	clk_reg = CLK_ALWAYS_ON(host);
416 	clk_reg |= CLK_DIV_MASK;
417 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
418 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
419 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
420 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
421 
422 	/* get the mux parents */
423 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
424 		struct clk *clk;
425 		char name[16];
426 
427 		snprintf(name, sizeof(name), "clkin%d", i);
428 		clk = devm_clk_get(host->dev, name);
429 		if (IS_ERR(clk)) {
430 			if (clk != ERR_PTR(-EPROBE_DEFER))
431 				dev_err(host->dev, "Missing clock %s\n", name);
432 			return PTR_ERR(clk);
433 		}
434 
435 		mux_parent_names[i] = __clk_get_name(clk);
436 	}
437 
438 	/* create the mux */
439 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
440 	if (!mux)
441 		return -ENOMEM;
442 
443 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
444 	init.name = clk_name;
445 	init.ops = &clk_mux_ops;
446 	init.flags = 0;
447 	init.parent_names = mux_parent_names;
448 	init.num_parents = MUX_CLK_NUM_PARENTS;
449 
450 	mux->reg = host->regs + SD_EMMC_CLOCK;
451 	mux->shift = __ffs(CLK_SRC_MASK);
452 	mux->mask = CLK_SRC_MASK >> mux->shift;
453 	mux->hw.init = &init;
454 
455 	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
456 	if (WARN_ON(IS_ERR(host->mux_clk)))
457 		return PTR_ERR(host->mux_clk);
458 
459 	/* create the divider */
460 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
461 	if (!div)
462 		return -ENOMEM;
463 
464 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
465 	init.name = clk_name;
466 	init.ops = &clk_divider_ops;
467 	init.flags = CLK_SET_RATE_PARENT;
468 	clk_parent[0] = __clk_get_name(host->mux_clk);
469 	init.parent_names = clk_parent;
470 	init.num_parents = 1;
471 
472 	div->reg = host->regs + SD_EMMC_CLOCK;
473 	div->shift = __ffs(CLK_DIV_MASK);
474 	div->width = __builtin_popcountl(CLK_DIV_MASK);
475 	div->hw.init = &init;
476 	div->flags = CLK_DIVIDER_ONE_BASED;
477 
478 	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
479 	if (WARN_ON(IS_ERR(host->mmc_clk)))
480 		return PTR_ERR(host->mmc_clk);
481 
482 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
483 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
484 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
485 	if (ret)
486 		return ret;
487 
488 	return clk_prepare_enable(host->mmc_clk);
489 }
490 
491 static void meson_mmc_disable_resampling(struct meson_host *host)
492 {
493 	unsigned int val = readl(host->regs + host->data->adjust);
494 
495 	val &= ~ADJUST_ADJ_EN;
496 	writel(val, host->regs + host->data->adjust);
497 }
498 
499 static void meson_mmc_reset_resampling(struct meson_host *host)
500 {
501 	unsigned int val;
502 
503 	meson_mmc_disable_resampling(host);
504 
505 	val = readl(host->regs + host->data->adjust);
506 	val &= ~ADJUST_ADJ_DELAY_MASK;
507 	writel(val, host->regs + host->data->adjust);
508 }
509 
510 static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
511 {
512 	struct meson_host *host = mmc_priv(mmc);
513 	unsigned int val, dly, max_dly, i;
514 	int ret;
515 
516 	/* Resampling is done using the source clock */
517 	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
518 			       clk_get_rate(host->mmc_clk));
519 
520 	val = readl(host->regs + host->data->adjust);
521 	val |= ADJUST_ADJ_EN;
522 	writel(val, host->regs + host->data->adjust);
523 
524 	if (mmc->doing_retune)
525 		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
526 	else
527 		dly = 0;
528 
529 	for (i = 0; i < max_dly; i++) {
530 		val &= ~ADJUST_ADJ_DELAY_MASK;
531 		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
532 		writel(val, host->regs + host->data->adjust);
533 
534 		ret = mmc_send_tuning(mmc, opcode, NULL);
535 		if (!ret) {
536 			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
537 				(dly + i) % max_dly);
538 			return 0;
539 		}
540 	}
541 
542 	meson_mmc_reset_resampling(host);
543 	return -EIO;
544 }
545 
546 static int meson_mmc_prepare_ios_clock(struct meson_host *host,
547 				       struct mmc_ios *ios)
548 {
549 	bool ddr;
550 
551 	switch (ios->timing) {
552 	case MMC_TIMING_MMC_DDR52:
553 	case MMC_TIMING_UHS_DDR50:
554 		ddr = true;
555 		break;
556 
557 	default:
558 		ddr = false;
559 		break;
560 	}
561 
562 	return meson_mmc_clk_set(host, ios->clock, ddr);
563 }
564 
565 static void meson_mmc_check_resampling(struct meson_host *host,
566 				       struct mmc_ios *ios)
567 {
568 	switch (ios->timing) {
569 	case MMC_TIMING_LEGACY:
570 	case MMC_TIMING_MMC_HS:
571 	case MMC_TIMING_SD_HS:
572 	case MMC_TIMING_MMC_DDR52:
573 		meson_mmc_disable_resampling(host);
574 		break;
575 	}
576 }
577 
578 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
579 {
580 	struct meson_host *host = mmc_priv(mmc);
581 	u32 bus_width, val;
582 	int err;
583 
584 	/*
585 	 * GPIO regulator, only controls switching between 1v8 and
586 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
587 	 */
588 	switch (ios->power_mode) {
589 	case MMC_POWER_OFF:
590 		if (!IS_ERR(mmc->supply.vmmc))
591 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
592 
593 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
594 			regulator_disable(mmc->supply.vqmmc);
595 			host->vqmmc_enabled = false;
596 		}
597 
598 		break;
599 
600 	case MMC_POWER_UP:
601 		if (!IS_ERR(mmc->supply.vmmc))
602 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
603 
604 		break;
605 
606 	case MMC_POWER_ON:
607 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
608 			int ret = regulator_enable(mmc->supply.vqmmc);
609 
610 			if (ret < 0)
611 				dev_err(host->dev,
612 					"failed to enable vqmmc regulator\n");
613 			else
614 				host->vqmmc_enabled = true;
615 		}
616 
617 		break;
618 	}
619 
620 	/* Bus width */
621 	switch (ios->bus_width) {
622 	case MMC_BUS_WIDTH_1:
623 		bus_width = CFG_BUS_WIDTH_1;
624 		break;
625 	case MMC_BUS_WIDTH_4:
626 		bus_width = CFG_BUS_WIDTH_4;
627 		break;
628 	case MMC_BUS_WIDTH_8:
629 		bus_width = CFG_BUS_WIDTH_8;
630 		break;
631 	default:
632 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
633 			ios->bus_width);
634 		bus_width = CFG_BUS_WIDTH_4;
635 	}
636 
637 	val = readl(host->regs + SD_EMMC_CFG);
638 	val &= ~CFG_BUS_WIDTH_MASK;
639 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
640 	writel(val, host->regs + SD_EMMC_CFG);
641 
642 	meson_mmc_check_resampling(host, ios);
643 	err = meson_mmc_prepare_ios_clock(host, ios);
644 	if (err)
645 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
646 
647 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
648 }
649 
650 static void meson_mmc_request_done(struct mmc_host *mmc,
651 				   struct mmc_request *mrq)
652 {
653 	struct meson_host *host = mmc_priv(mmc);
654 
655 	host->cmd = NULL;
656 	mmc_request_done(host->mmc, mrq);
657 }
658 
659 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
660 {
661 	struct meson_host *host = mmc_priv(mmc);
662 	u32 cfg, blksz_old;
663 
664 	cfg = readl(host->regs + SD_EMMC_CFG);
665 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
666 
667 	if (!is_power_of_2(blksz))
668 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
669 
670 	blksz = ilog2(blksz);
671 
672 	/* check if block-size matches, if not update */
673 	if (blksz == blksz_old)
674 		return;
675 
676 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
677 		blksz_old, blksz);
678 
679 	cfg &= ~CFG_BLK_LEN_MASK;
680 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
681 	writel(cfg, host->regs + SD_EMMC_CFG);
682 }
683 
684 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
685 {
686 	if (cmd->flags & MMC_RSP_PRESENT) {
687 		if (cmd->flags & MMC_RSP_136)
688 			*cmd_cfg |= CMD_CFG_RESP_128;
689 		*cmd_cfg |= CMD_CFG_RESP_NUM;
690 
691 		if (!(cmd->flags & MMC_RSP_CRC))
692 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
693 
694 		if (cmd->flags & MMC_RSP_BUSY)
695 			*cmd_cfg |= CMD_CFG_R1B;
696 	} else {
697 		*cmd_cfg |= CMD_CFG_NO_RESP;
698 	}
699 }
700 
701 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
702 {
703 	struct meson_host *host = mmc_priv(mmc);
704 	struct sd_emmc_desc *desc = host->descs;
705 	struct mmc_data *data = host->cmd->data;
706 	struct scatterlist *sg;
707 	u32 start;
708 	int i;
709 
710 	if (data->flags & MMC_DATA_WRITE)
711 		cmd_cfg |= CMD_CFG_DATA_WR;
712 
713 	if (data->blocks > 1) {
714 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
715 		meson_mmc_set_blksz(mmc, data->blksz);
716 	}
717 
718 	for_each_sg(data->sg, sg, data->sg_count, i) {
719 		unsigned int len = sg_dma_len(sg);
720 
721 		if (data->blocks > 1)
722 			len /= data->blksz;
723 
724 		desc[i].cmd_cfg = cmd_cfg;
725 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
726 		if (i > 0)
727 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
728 		desc[i].cmd_arg = host->cmd->arg;
729 		desc[i].cmd_resp = 0;
730 		desc[i].cmd_data = sg_dma_address(sg);
731 	}
732 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
733 
734 	dma_wmb(); /* ensure descriptor is written before kicked */
735 	start = host->descs_dma_addr | START_DESC_BUSY;
736 	writel(start, host->regs + SD_EMMC_START);
737 }
738 
739 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
740 {
741 	struct meson_host *host = mmc_priv(mmc);
742 	struct mmc_data *data = cmd->data;
743 	u32 cmd_cfg = 0, cmd_data = 0;
744 	unsigned int xfer_bytes = 0;
745 
746 	/* Setup descriptors */
747 	dma_rmb();
748 
749 	host->cmd = cmd;
750 
751 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
752 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
753 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
754 
755 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
756 
757 	/* data? */
758 	if (data) {
759 		data->bytes_xfered = 0;
760 		cmd_cfg |= CMD_CFG_DATA_IO;
761 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
762 				      ilog2(meson_mmc_get_timeout_msecs(data)));
763 
764 		if (meson_mmc_desc_chain_mode(data)) {
765 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
766 			return;
767 		}
768 
769 		if (data->blocks > 1) {
770 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
771 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
772 					      data->blocks);
773 			meson_mmc_set_blksz(mmc, data->blksz);
774 		} else {
775 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
776 		}
777 
778 		xfer_bytes = data->blksz * data->blocks;
779 		if (data->flags & MMC_DATA_WRITE) {
780 			cmd_cfg |= CMD_CFG_DATA_WR;
781 			WARN_ON(xfer_bytes > host->bounce_buf_size);
782 			sg_copy_to_buffer(data->sg, data->sg_len,
783 					  host->bounce_buf, xfer_bytes);
784 			dma_wmb();
785 		}
786 
787 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
788 	} else {
789 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
790 				      ilog2(SD_EMMC_CMD_TIMEOUT));
791 	}
792 
793 	/* Last descriptor */
794 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
795 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
796 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
797 	writel(0, host->regs + SD_EMMC_CMD_RSP);
798 	wmb(); /* ensure descriptor is written before kicked */
799 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
800 }
801 
802 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
803 {
804 	struct meson_host *host = mmc_priv(mmc);
805 	bool needs_pre_post_req = mrq->data &&
806 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
807 
808 	if (needs_pre_post_req) {
809 		meson_mmc_get_transfer_mode(mmc, mrq);
810 		if (!meson_mmc_desc_chain_mode(mrq->data))
811 			needs_pre_post_req = false;
812 	}
813 
814 	if (needs_pre_post_req)
815 		meson_mmc_pre_req(mmc, mrq);
816 
817 	/* Stop execution */
818 	writel(0, host->regs + SD_EMMC_START);
819 
820 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
821 
822 	if (needs_pre_post_req)
823 		meson_mmc_post_req(mmc, mrq, 0);
824 }
825 
826 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
827 {
828 	struct meson_host *host = mmc_priv(mmc);
829 
830 	if (cmd->flags & MMC_RSP_136) {
831 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
832 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
833 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
834 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
835 	} else if (cmd->flags & MMC_RSP_PRESENT) {
836 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
837 	}
838 }
839 
840 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
841 {
842 	struct meson_host *host = dev_id;
843 	struct mmc_command *cmd;
844 	struct mmc_data *data;
845 	u32 irq_en, status, raw_status;
846 	irqreturn_t ret = IRQ_NONE;
847 
848 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
849 	raw_status = readl(host->regs + SD_EMMC_STATUS);
850 	status = raw_status & irq_en;
851 
852 	if (!status) {
853 		dev_dbg(host->dev,
854 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
855 			 irq_en, raw_status);
856 		return IRQ_NONE;
857 	}
858 
859 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
860 		return IRQ_NONE;
861 
862 	/* ack all raised interrupts */
863 	writel(status, host->regs + SD_EMMC_STATUS);
864 
865 	cmd = host->cmd;
866 	data = cmd->data;
867 	cmd->error = 0;
868 	if (status & IRQ_CRC_ERR) {
869 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
870 		cmd->error = -EILSEQ;
871 		ret = IRQ_WAKE_THREAD;
872 		goto out;
873 	}
874 
875 	if (status & IRQ_TIMEOUTS) {
876 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
877 		cmd->error = -ETIMEDOUT;
878 		ret = IRQ_WAKE_THREAD;
879 		goto out;
880 	}
881 
882 	meson_mmc_read_resp(host->mmc, cmd);
883 
884 	if (status & IRQ_SDIO) {
885 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
886 		ret = IRQ_HANDLED;
887 	}
888 
889 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
890 		if (data && !cmd->error)
891 			data->bytes_xfered = data->blksz * data->blocks;
892 		if (meson_mmc_bounce_buf_read(data) ||
893 		    meson_mmc_get_next_command(cmd))
894 			ret = IRQ_WAKE_THREAD;
895 		else
896 			ret = IRQ_HANDLED;
897 	}
898 
899 out:
900 	if (cmd->error) {
901 		/* Stop desc in case of errors */
902 		u32 start = readl(host->regs + SD_EMMC_START);
903 
904 		start &= ~START_DESC_BUSY;
905 		writel(start, host->regs + SD_EMMC_START);
906 	}
907 
908 	if (ret == IRQ_HANDLED)
909 		meson_mmc_request_done(host->mmc, cmd->mrq);
910 
911 	return ret;
912 }
913 
914 static int meson_mmc_wait_desc_stop(struct meson_host *host)
915 {
916 	u32 status;
917 
918 	/*
919 	 * It may sometimes take a while for it to actually halt. Here, we
920 	 * are giving it 5ms to comply
921 	 *
922 	 * If we don't confirm the descriptor is stopped, it might raise new
923 	 * IRQs after we have called mmc_request_done() which is bad.
924 	 */
925 
926 	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
927 				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
928 				  100, 5000);
929 }
930 
931 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
932 {
933 	struct meson_host *host = dev_id;
934 	struct mmc_command *next_cmd, *cmd = host->cmd;
935 	struct mmc_data *data;
936 	unsigned int xfer_bytes;
937 
938 	if (WARN_ON(!cmd))
939 		return IRQ_NONE;
940 
941 	if (cmd->error) {
942 		meson_mmc_wait_desc_stop(host);
943 		meson_mmc_request_done(host->mmc, cmd->mrq);
944 
945 		return IRQ_HANDLED;
946 	}
947 
948 	data = cmd->data;
949 	if (meson_mmc_bounce_buf_read(data)) {
950 		xfer_bytes = data->blksz * data->blocks;
951 		WARN_ON(xfer_bytes > host->bounce_buf_size);
952 		sg_copy_from_buffer(data->sg, data->sg_len,
953 				    host->bounce_buf, xfer_bytes);
954 	}
955 
956 	next_cmd = meson_mmc_get_next_command(cmd);
957 	if (next_cmd)
958 		meson_mmc_start_cmd(host->mmc, next_cmd);
959 	else
960 		meson_mmc_request_done(host->mmc, cmd->mrq);
961 
962 	return IRQ_HANDLED;
963 }
964 
965 /*
966  * NOTE: we only need this until the GPIO/pinctrl driver can handle
967  * interrupts.  For now, the MMC core will use this for polling.
968  */
969 static int meson_mmc_get_cd(struct mmc_host *mmc)
970 {
971 	int status = mmc_gpio_get_cd(mmc);
972 
973 	if (status == -ENOSYS)
974 		return 1; /* assume present */
975 
976 	return status;
977 }
978 
979 static void meson_mmc_cfg_init(struct meson_host *host)
980 {
981 	u32 cfg = 0;
982 
983 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
984 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
985 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
986 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
987 
988 	/* abort chain on R/W errors */
989 	cfg |= CFG_ERR_ABORT;
990 
991 	writel(cfg, host->regs + SD_EMMC_CFG);
992 }
993 
994 static int meson_mmc_card_busy(struct mmc_host *mmc)
995 {
996 	struct meson_host *host = mmc_priv(mmc);
997 	u32 regval;
998 
999 	regval = readl(host->regs + SD_EMMC_STATUS);
1000 
1001 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1002 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1003 }
1004 
1005 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1006 {
1007 	int ret;
1008 
1009 	/* vqmmc regulator is available */
1010 	if (!IS_ERR(mmc->supply.vqmmc)) {
1011 		/*
1012 		 * The usual amlogic setup uses a GPIO to switch from one
1013 		 * regulator to the other. While the voltage ramp up is
1014 		 * pretty fast, care must be taken when switching from 3.3v
1015 		 * to 1.8v. Please make sure the regulator framework is aware
1016 		 * of your own regulator constraints
1017 		 */
1018 		ret = mmc_regulator_set_vqmmc(mmc, ios);
1019 		return ret < 0 ? ret : 0;
1020 	}
1021 
1022 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1023 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1024 		return 0;
1025 
1026 	return -EINVAL;
1027 }
1028 
1029 static const struct mmc_host_ops meson_mmc_ops = {
1030 	.request	= meson_mmc_request,
1031 	.set_ios	= meson_mmc_set_ios,
1032 	.get_cd         = meson_mmc_get_cd,
1033 	.pre_req	= meson_mmc_pre_req,
1034 	.post_req	= meson_mmc_post_req,
1035 	.execute_tuning = meson_mmc_resampling_tuning,
1036 	.card_busy	= meson_mmc_card_busy,
1037 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1038 };
1039 
1040 static int meson_mmc_probe(struct platform_device *pdev)
1041 {
1042 	struct resource *res;
1043 	struct meson_host *host;
1044 	struct mmc_host *mmc;
1045 	int ret;
1046 
1047 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1048 	if (!mmc)
1049 		return -ENOMEM;
1050 	host = mmc_priv(mmc);
1051 	host->mmc = mmc;
1052 	host->dev = &pdev->dev;
1053 	dev_set_drvdata(&pdev->dev, host);
1054 
1055 	/* The G12A SDIO Controller needs an SRAM bounce buffer */
1056 	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
1057 					"amlogic,dram-access-quirk");
1058 
1059 	/* Get regulators and the supported OCR mask */
1060 	host->vqmmc_enabled = false;
1061 	ret = mmc_regulator_get_supply(mmc);
1062 	if (ret)
1063 		goto free_host;
1064 
1065 	ret = mmc_of_parse(mmc);
1066 	if (ret) {
1067 		if (ret != -EPROBE_DEFER)
1068 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1069 		goto free_host;
1070 	}
1071 
1072 	host->data = (struct meson_mmc_data *)
1073 		of_device_get_match_data(&pdev->dev);
1074 	if (!host->data) {
1075 		ret = -EINVAL;
1076 		goto free_host;
1077 	}
1078 
1079 	ret = device_reset_optional(&pdev->dev);
1080 	if (ret) {
1081 		if (ret != -EPROBE_DEFER)
1082 			dev_err(&pdev->dev, "device reset failed: %d\n", ret);
1083 
1084 		return ret;
1085 	}
1086 
1087 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1088 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1089 	if (IS_ERR(host->regs)) {
1090 		ret = PTR_ERR(host->regs);
1091 		goto free_host;
1092 	}
1093 
1094 	host->irq = platform_get_irq(pdev, 0);
1095 	if (host->irq <= 0) {
1096 		ret = -EINVAL;
1097 		goto free_host;
1098 	}
1099 
1100 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1101 	if (IS_ERR(host->pinctrl)) {
1102 		ret = PTR_ERR(host->pinctrl);
1103 		goto free_host;
1104 	}
1105 
1106 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1107 						   "clk-gate");
1108 	if (IS_ERR(host->pins_clk_gate)) {
1109 		dev_warn(&pdev->dev,
1110 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1111 		host->pins_clk_gate = NULL;
1112 	}
1113 
1114 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1115 	if (IS_ERR(host->core_clk)) {
1116 		ret = PTR_ERR(host->core_clk);
1117 		goto free_host;
1118 	}
1119 
1120 	ret = clk_prepare_enable(host->core_clk);
1121 	if (ret)
1122 		goto free_host;
1123 
1124 	ret = meson_mmc_clk_init(host);
1125 	if (ret)
1126 		goto err_core_clk;
1127 
1128 	/* set config to sane default */
1129 	meson_mmc_cfg_init(host);
1130 
1131 	/* Stop execution */
1132 	writel(0, host->regs + SD_EMMC_START);
1133 
1134 	/* clear, ack and enable interrupts */
1135 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1136 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1137 	       host->regs + SD_EMMC_STATUS);
1138 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1139 	       host->regs + SD_EMMC_IRQ_EN);
1140 
1141 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1142 				   meson_mmc_irq_thread, IRQF_ONESHOT,
1143 				   dev_name(&pdev->dev), host);
1144 	if (ret)
1145 		goto err_init_clk;
1146 
1147 	mmc->caps |= MMC_CAP_CMD23;
1148 	if (host->dram_access_quirk) {
1149 		/* Limit segments to 1 due to low available sram memory */
1150 		mmc->max_segs = 1;
1151 		/* Limit to the available sram memory */
1152 		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
1153 				     mmc->max_blk_size;
1154 	} else {
1155 		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1156 		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
1157 				sizeof(struct sd_emmc_desc);
1158 	}
1159 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1160 	mmc->max_seg_size = mmc->max_req_size;
1161 
1162 	/*
1163 	 * At the moment, we don't know how to reliably enable HS400.
1164 	 * From the different datasheets, it is not even clear if this mode
1165 	 * is officially supported by any of the SoCs
1166 	 */
1167 	mmc->caps2 &= ~MMC_CAP2_HS400;
1168 
1169 	if (host->dram_access_quirk) {
1170 		/*
1171 		 * The MMC Controller embeds 1,5KiB of internal SRAM
1172 		 * that can be used to be used as bounce buffer.
1173 		 * In the case of the G12A SDIO controller, use these
1174 		 * instead of the DDR memory
1175 		 */
1176 		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
1177 		host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
1178 		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
1179 	} else {
1180 		/* data bounce buffer */
1181 		host->bounce_buf_size = mmc->max_req_size;
1182 		host->bounce_buf =
1183 			dma_alloc_coherent(host->dev, host->bounce_buf_size,
1184 					   &host->bounce_dma_addr, GFP_KERNEL);
1185 		if (host->bounce_buf == NULL) {
1186 			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1187 			ret = -ENOMEM;
1188 			goto err_free_irq;
1189 		}
1190 	}
1191 
1192 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1193 		      &host->descs_dma_addr, GFP_KERNEL);
1194 	if (!host->descs) {
1195 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1196 		ret = -ENOMEM;
1197 		goto err_bounce_buf;
1198 	}
1199 
1200 	mmc->ops = &meson_mmc_ops;
1201 	mmc_add_host(mmc);
1202 
1203 	return 0;
1204 
1205 err_bounce_buf:
1206 	if (!host->dram_access_quirk)
1207 		dma_free_coherent(host->dev, host->bounce_buf_size,
1208 				  host->bounce_buf, host->bounce_dma_addr);
1209 err_free_irq:
1210 	free_irq(host->irq, host);
1211 err_init_clk:
1212 	clk_disable_unprepare(host->mmc_clk);
1213 err_core_clk:
1214 	clk_disable_unprepare(host->core_clk);
1215 free_host:
1216 	mmc_free_host(mmc);
1217 	return ret;
1218 }
1219 
1220 static int meson_mmc_remove(struct platform_device *pdev)
1221 {
1222 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1223 
1224 	mmc_remove_host(host->mmc);
1225 
1226 	/* disable interrupts */
1227 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1228 	free_irq(host->irq, host);
1229 
1230 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1231 			  host->descs, host->descs_dma_addr);
1232 
1233 	if (!host->dram_access_quirk)
1234 		dma_free_coherent(host->dev, host->bounce_buf_size,
1235 				  host->bounce_buf, host->bounce_dma_addr);
1236 
1237 	clk_disable_unprepare(host->mmc_clk);
1238 	clk_disable_unprepare(host->core_clk);
1239 
1240 	mmc_free_host(host->mmc);
1241 	return 0;
1242 }
1243 
1244 static const struct meson_mmc_data meson_gx_data = {
1245 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1246 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1247 	.always_on	= CLK_V2_ALWAYS_ON,
1248 	.adjust		= SD_EMMC_ADJUST,
1249 };
1250 
1251 static const struct meson_mmc_data meson_axg_data = {
1252 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1253 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1254 	.always_on	= CLK_V3_ALWAYS_ON,
1255 	.adjust		= SD_EMMC_V3_ADJUST,
1256 };
1257 
1258 static const struct of_device_id meson_mmc_of_match[] = {
1259 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1260 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1261 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1262 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1263 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1264 	{}
1265 };
1266 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1267 
1268 static struct platform_driver meson_mmc_driver = {
1269 	.probe		= meson_mmc_probe,
1270 	.remove		= meson_mmc_remove,
1271 	.driver		= {
1272 		.name = DRIVER_NAME,
1273 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1274 	},
1275 };
1276 
1277 module_platform_driver(meson_mmc_driver);
1278 
1279 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1280 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1281 MODULE_LICENSE("GPL v2");
1282