xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision cb325ddd)
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 	void __iomem *bounce_iomem_buf;
169 	dma_addr_t bounce_dma_addr;
170 	struct sd_emmc_desc *descs;
171 	dma_addr_t descs_dma_addr;
172 
173 	int irq;
174 
175 	bool vqmmc_enabled;
176 	bool needs_pre_post_req;
177 
178 };
179 
180 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
181 #define CMD_CFG_BLOCK_MODE BIT(9)
182 #define CMD_CFG_R1B BIT(10)
183 #define CMD_CFG_END_OF_CHAIN BIT(11)
184 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
185 #define CMD_CFG_NO_RESP BIT(16)
186 #define CMD_CFG_NO_CMD BIT(17)
187 #define CMD_CFG_DATA_IO BIT(18)
188 #define CMD_CFG_DATA_WR BIT(19)
189 #define CMD_CFG_RESP_NOCRC BIT(20)
190 #define CMD_CFG_RESP_128 BIT(21)
191 #define CMD_CFG_RESP_NUM BIT(22)
192 #define CMD_CFG_DATA_NUM BIT(23)
193 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
194 #define CMD_CFG_ERROR BIT(30)
195 #define CMD_CFG_OWNER BIT(31)
196 
197 #define CMD_DATA_MASK GENMASK(31, 2)
198 #define CMD_DATA_BIG_ENDIAN BIT(1)
199 #define CMD_DATA_SRAM BIT(0)
200 #define CMD_RESP_MASK GENMASK(31, 1)
201 #define CMD_RESP_SRAM BIT(0)
202 
203 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
204 {
205 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
206 
207 	if (!timeout)
208 		return SD_EMMC_CMD_TIMEOUT_DATA;
209 
210 	timeout = roundup_pow_of_two(timeout);
211 
212 	return min(timeout, 32768U); /* max. 2^15 ms */
213 }
214 
215 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
216 {
217 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
218 		return cmd->mrq->cmd;
219 	else if (mmc_op_multi(cmd->opcode) &&
220 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
221 		return cmd->mrq->stop;
222 	else
223 		return NULL;
224 }
225 
226 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
227 					struct mmc_request *mrq)
228 {
229 	struct meson_host *host = mmc_priv(mmc);
230 	struct mmc_data *data = mrq->data;
231 	struct scatterlist *sg;
232 	int i;
233 
234 	/*
235 	 * When Controller DMA cannot directly access DDR memory, disable
236 	 * support for Chain Mode to directly use the internal SRAM using
237 	 * the bounce buffer mode.
238 	 */
239 	if (host->dram_access_quirk)
240 		return;
241 
242 	/* SD_IO_RW_EXTENDED (CMD53) can also use block mode under the hood */
243 	if (data->blocks > 1 || mrq->cmd->opcode == SD_IO_RW_EXTENDED) {
244 		/*
245 		 * In block mode DMA descriptor format, "length" field indicates
246 		 * number of blocks and there is no way to pass DMA size that
247 		 * is not multiple of SDIO block size, making it impossible to
248 		 * tie more than one memory buffer with single SDIO block.
249 		 * Block mode sg buffer size should be aligned with SDIO block
250 		 * size, otherwise chain mode could not be used.
251 		 */
252 		for_each_sg(data->sg, sg, data->sg_len, i) {
253 			if (sg->length % data->blksz) {
254 				dev_warn_once(mmc_dev(mmc),
255 					      "unaligned sg len %u blksize %u, disabling descriptor DMA for transfer\n",
256 					      sg->length, data->blksz);
257 				return;
258 			}
259 		}
260 	}
261 
262 	for_each_sg(data->sg, sg, data->sg_len, i) {
263 		/* check for 8 byte alignment */
264 		if (sg->offset % 8) {
265 			dev_warn_once(mmc_dev(mmc),
266 				      "unaligned sg offset %u, disabling descriptor DMA for transfer\n",
267 				      sg->offset);
268 			return;
269 		}
270 	}
271 
272 	data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
273 }
274 
275 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
276 {
277 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
278 }
279 
280 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
281 {
282 	return data && data->flags & MMC_DATA_READ &&
283 	       !meson_mmc_desc_chain_mode(data);
284 }
285 
286 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
287 {
288 	struct mmc_data *data = mrq->data;
289 
290 	if (!data)
291 		return;
292 
293 	meson_mmc_get_transfer_mode(mmc, mrq);
294 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
295 
296 	if (!meson_mmc_desc_chain_mode(data))
297 		return;
298 
299 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
300                                    mmc_get_dma_dir(data));
301 	if (!data->sg_count)
302 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
303 }
304 
305 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
306 			       int err)
307 {
308 	struct mmc_data *data = mrq->data;
309 
310 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
311 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
312 			     mmc_get_dma_dir(data));
313 }
314 
315 /*
316  * Gating the clock on this controller is tricky.  It seems the mmc clock
317  * is also used by the controller.  It may crash during some operation if the
318  * clock is stopped.  The safest thing to do, whenever possible, is to keep
319  * clock running at stop it at the pad using the pinmux.
320  */
321 static void meson_mmc_clk_gate(struct meson_host *host)
322 {
323 	u32 cfg;
324 
325 	if (host->pins_clk_gate) {
326 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
327 	} else {
328 		/*
329 		 * If the pinmux is not provided - default to the classic and
330 		 * unsafe method
331 		 */
332 		cfg = readl(host->regs + SD_EMMC_CFG);
333 		cfg |= CFG_STOP_CLOCK;
334 		writel(cfg, host->regs + SD_EMMC_CFG);
335 	}
336 }
337 
338 static void meson_mmc_clk_ungate(struct meson_host *host)
339 {
340 	u32 cfg;
341 
342 	if (host->pins_clk_gate)
343 		pinctrl_select_default_state(host->dev);
344 
345 	/* Make sure the clock is not stopped in the controller */
346 	cfg = readl(host->regs + SD_EMMC_CFG);
347 	cfg &= ~CFG_STOP_CLOCK;
348 	writel(cfg, host->regs + SD_EMMC_CFG);
349 }
350 
351 static int meson_mmc_clk_set(struct meson_host *host, unsigned long rate,
352 			     bool ddr)
353 {
354 	struct mmc_host *mmc = host->mmc;
355 	int ret;
356 	u32 cfg;
357 
358 	/* Same request - bail-out */
359 	if (host->ddr == ddr && host->req_rate == rate)
360 		return 0;
361 
362 	/* stop clock */
363 	meson_mmc_clk_gate(host);
364 	host->req_rate = 0;
365 	mmc->actual_clock = 0;
366 
367 	/* return with clock being stopped */
368 	if (!rate)
369 		return 0;
370 
371 	/* Stop the clock during rate change to avoid glitches */
372 	cfg = readl(host->regs + SD_EMMC_CFG);
373 	cfg |= CFG_STOP_CLOCK;
374 	writel(cfg, host->regs + SD_EMMC_CFG);
375 
376 	if (ddr) {
377 		/* DDR modes require higher module clock */
378 		rate <<= 1;
379 		cfg |= CFG_DDR;
380 	} else {
381 		cfg &= ~CFG_DDR;
382 	}
383 	writel(cfg, host->regs + SD_EMMC_CFG);
384 	host->ddr = ddr;
385 
386 	ret = clk_set_rate(host->mmc_clk, rate);
387 	if (ret) {
388 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
389 			rate, ret);
390 		return ret;
391 	}
392 
393 	host->req_rate = rate;
394 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
395 
396 	/* We should report the real output frequency of the controller */
397 	if (ddr) {
398 		host->req_rate >>= 1;
399 		mmc->actual_clock >>= 1;
400 	}
401 
402 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
403 	if (rate != mmc->actual_clock)
404 		dev_dbg(host->dev, "requested rate was %lu\n", rate);
405 
406 	/* (re)start clock */
407 	meson_mmc_clk_ungate(host);
408 
409 	return 0;
410 }
411 
412 /*
413  * The SD/eMMC IP block has an internal mux and divider used for
414  * generating the MMC clock.  Use the clock framework to create and
415  * manage these clocks.
416  */
417 static int meson_mmc_clk_init(struct meson_host *host)
418 {
419 	struct clk_init_data init;
420 	struct clk_mux *mux;
421 	struct clk_divider *div;
422 	char clk_name[32];
423 	int i, ret = 0;
424 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
425 	const char *clk_parent[1];
426 	u32 clk_reg;
427 
428 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
429 	clk_reg = CLK_ALWAYS_ON(host);
430 	clk_reg |= CLK_DIV_MASK;
431 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
432 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
433 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
434 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
435 
436 	/* get the mux parents */
437 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
438 		struct clk *clk;
439 		char name[16];
440 
441 		snprintf(name, sizeof(name), "clkin%d", i);
442 		clk = devm_clk_get(host->dev, name);
443 		if (IS_ERR(clk))
444 			return dev_err_probe(host->dev, PTR_ERR(clk),
445 					     "Missing clock %s\n", name);
446 
447 		mux_parent_names[i] = __clk_get_name(clk);
448 	}
449 
450 	/* create the mux */
451 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
452 	if (!mux)
453 		return -ENOMEM;
454 
455 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
456 	init.name = clk_name;
457 	init.ops = &clk_mux_ops;
458 	init.flags = 0;
459 	init.parent_names = mux_parent_names;
460 	init.num_parents = MUX_CLK_NUM_PARENTS;
461 
462 	mux->reg = host->regs + SD_EMMC_CLOCK;
463 	mux->shift = __ffs(CLK_SRC_MASK);
464 	mux->mask = CLK_SRC_MASK >> mux->shift;
465 	mux->hw.init = &init;
466 
467 	host->mux_clk = devm_clk_register(host->dev, &mux->hw);
468 	if (WARN_ON(IS_ERR(host->mux_clk)))
469 		return PTR_ERR(host->mux_clk);
470 
471 	/* create the divider */
472 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
473 	if (!div)
474 		return -ENOMEM;
475 
476 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
477 	init.name = clk_name;
478 	init.ops = &clk_divider_ops;
479 	init.flags = CLK_SET_RATE_PARENT;
480 	clk_parent[0] = __clk_get_name(host->mux_clk);
481 	init.parent_names = clk_parent;
482 	init.num_parents = 1;
483 
484 	div->reg = host->regs + SD_EMMC_CLOCK;
485 	div->shift = __ffs(CLK_DIV_MASK);
486 	div->width = __builtin_popcountl(CLK_DIV_MASK);
487 	div->hw.init = &init;
488 	div->flags = CLK_DIVIDER_ONE_BASED;
489 
490 	host->mmc_clk = devm_clk_register(host->dev, &div->hw);
491 	if (WARN_ON(IS_ERR(host->mmc_clk)))
492 		return PTR_ERR(host->mmc_clk);
493 
494 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
495 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
496 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
497 	if (ret)
498 		return ret;
499 
500 	return clk_prepare_enable(host->mmc_clk);
501 }
502 
503 static void meson_mmc_disable_resampling(struct meson_host *host)
504 {
505 	unsigned int val = readl(host->regs + host->data->adjust);
506 
507 	val &= ~ADJUST_ADJ_EN;
508 	writel(val, host->regs + host->data->adjust);
509 }
510 
511 static void meson_mmc_reset_resampling(struct meson_host *host)
512 {
513 	unsigned int val;
514 
515 	meson_mmc_disable_resampling(host);
516 
517 	val = readl(host->regs + host->data->adjust);
518 	val &= ~ADJUST_ADJ_DELAY_MASK;
519 	writel(val, host->regs + host->data->adjust);
520 }
521 
522 static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode)
523 {
524 	struct meson_host *host = mmc_priv(mmc);
525 	unsigned int val, dly, max_dly, i;
526 	int ret;
527 
528 	/* Resampling is done using the source clock */
529 	max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk),
530 			       clk_get_rate(host->mmc_clk));
531 
532 	val = readl(host->regs + host->data->adjust);
533 	val |= ADJUST_ADJ_EN;
534 	writel(val, host->regs + host->data->adjust);
535 
536 	if (mmc_doing_retune(mmc))
537 		dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1;
538 	else
539 		dly = 0;
540 
541 	for (i = 0; i < max_dly; i++) {
542 		val &= ~ADJUST_ADJ_DELAY_MASK;
543 		val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly);
544 		writel(val, host->regs + host->data->adjust);
545 
546 		ret = mmc_send_tuning(mmc, opcode, NULL);
547 		if (!ret) {
548 			dev_dbg(mmc_dev(mmc), "resampling delay: %u\n",
549 				(dly + i) % max_dly);
550 			return 0;
551 		}
552 	}
553 
554 	meson_mmc_reset_resampling(host);
555 	return -EIO;
556 }
557 
558 static int meson_mmc_prepare_ios_clock(struct meson_host *host,
559 				       struct mmc_ios *ios)
560 {
561 	bool ddr;
562 
563 	switch (ios->timing) {
564 	case MMC_TIMING_MMC_DDR52:
565 	case MMC_TIMING_UHS_DDR50:
566 		ddr = true;
567 		break;
568 
569 	default:
570 		ddr = false;
571 		break;
572 	}
573 
574 	return meson_mmc_clk_set(host, ios->clock, ddr);
575 }
576 
577 static void meson_mmc_check_resampling(struct meson_host *host,
578 				       struct mmc_ios *ios)
579 {
580 	switch (ios->timing) {
581 	case MMC_TIMING_LEGACY:
582 	case MMC_TIMING_MMC_HS:
583 	case MMC_TIMING_SD_HS:
584 	case MMC_TIMING_MMC_DDR52:
585 		meson_mmc_disable_resampling(host);
586 		break;
587 	}
588 }
589 
590 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
591 {
592 	struct meson_host *host = mmc_priv(mmc);
593 	u32 bus_width, val;
594 	int err;
595 
596 	/*
597 	 * GPIO regulator, only controls switching between 1v8 and
598 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
599 	 */
600 	switch (ios->power_mode) {
601 	case MMC_POWER_OFF:
602 		if (!IS_ERR(mmc->supply.vmmc))
603 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
604 
605 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
606 			regulator_disable(mmc->supply.vqmmc);
607 			host->vqmmc_enabled = false;
608 		}
609 
610 		break;
611 
612 	case MMC_POWER_UP:
613 		if (!IS_ERR(mmc->supply.vmmc))
614 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
615 
616 		break;
617 
618 	case MMC_POWER_ON:
619 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
620 			int ret = regulator_enable(mmc->supply.vqmmc);
621 
622 			if (ret < 0)
623 				dev_err(host->dev,
624 					"failed to enable vqmmc regulator\n");
625 			else
626 				host->vqmmc_enabled = true;
627 		}
628 
629 		break;
630 	}
631 
632 	/* Bus width */
633 	switch (ios->bus_width) {
634 	case MMC_BUS_WIDTH_1:
635 		bus_width = CFG_BUS_WIDTH_1;
636 		break;
637 	case MMC_BUS_WIDTH_4:
638 		bus_width = CFG_BUS_WIDTH_4;
639 		break;
640 	case MMC_BUS_WIDTH_8:
641 		bus_width = CFG_BUS_WIDTH_8;
642 		break;
643 	default:
644 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
645 			ios->bus_width);
646 		bus_width = CFG_BUS_WIDTH_4;
647 	}
648 
649 	val = readl(host->regs + SD_EMMC_CFG);
650 	val &= ~CFG_BUS_WIDTH_MASK;
651 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
652 	writel(val, host->regs + SD_EMMC_CFG);
653 
654 	meson_mmc_check_resampling(host, ios);
655 	err = meson_mmc_prepare_ios_clock(host, ios);
656 	if (err)
657 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
658 
659 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
660 }
661 
662 static void meson_mmc_request_done(struct mmc_host *mmc,
663 				   struct mmc_request *mrq)
664 {
665 	struct meson_host *host = mmc_priv(mmc);
666 
667 	host->cmd = NULL;
668 	if (host->needs_pre_post_req)
669 		meson_mmc_post_req(mmc, mrq, 0);
670 	mmc_request_done(host->mmc, mrq);
671 }
672 
673 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
674 {
675 	struct meson_host *host = mmc_priv(mmc);
676 	u32 cfg, blksz_old;
677 
678 	cfg = readl(host->regs + SD_EMMC_CFG);
679 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
680 
681 	if (!is_power_of_2(blksz))
682 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
683 
684 	blksz = ilog2(blksz);
685 
686 	/* check if block-size matches, if not update */
687 	if (blksz == blksz_old)
688 		return;
689 
690 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
691 		blksz_old, blksz);
692 
693 	cfg &= ~CFG_BLK_LEN_MASK;
694 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
695 	writel(cfg, host->regs + SD_EMMC_CFG);
696 }
697 
698 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
699 {
700 	if (cmd->flags & MMC_RSP_PRESENT) {
701 		if (cmd->flags & MMC_RSP_136)
702 			*cmd_cfg |= CMD_CFG_RESP_128;
703 		*cmd_cfg |= CMD_CFG_RESP_NUM;
704 
705 		if (!(cmd->flags & MMC_RSP_CRC))
706 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
707 
708 		if (cmd->flags & MMC_RSP_BUSY)
709 			*cmd_cfg |= CMD_CFG_R1B;
710 	} else {
711 		*cmd_cfg |= CMD_CFG_NO_RESP;
712 	}
713 }
714 
715 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
716 {
717 	struct meson_host *host = mmc_priv(mmc);
718 	struct sd_emmc_desc *desc = host->descs;
719 	struct mmc_data *data = host->cmd->data;
720 	struct scatterlist *sg;
721 	u32 start;
722 	int i;
723 
724 	if (data->flags & MMC_DATA_WRITE)
725 		cmd_cfg |= CMD_CFG_DATA_WR;
726 
727 	if (data->blocks > 1) {
728 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
729 		meson_mmc_set_blksz(mmc, data->blksz);
730 	}
731 
732 	for_each_sg(data->sg, sg, data->sg_count, i) {
733 		unsigned int len = sg_dma_len(sg);
734 
735 		if (data->blocks > 1)
736 			len /= data->blksz;
737 
738 		desc[i].cmd_cfg = cmd_cfg;
739 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
740 		if (i > 0)
741 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
742 		desc[i].cmd_arg = host->cmd->arg;
743 		desc[i].cmd_resp = 0;
744 		desc[i].cmd_data = sg_dma_address(sg);
745 	}
746 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
747 
748 	dma_wmb(); /* ensure descriptor is written before kicked */
749 	start = host->descs_dma_addr | START_DESC_BUSY;
750 	writel(start, host->regs + SD_EMMC_START);
751 }
752 
753 /* local sg copy for dram_access_quirk */
754 static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data,
755 				  size_t buflen, bool to_buffer)
756 {
757 	unsigned int sg_flags = SG_MITER_ATOMIC;
758 	struct scatterlist *sgl = data->sg;
759 	unsigned int nents = data->sg_len;
760 	struct sg_mapping_iter miter;
761 	unsigned int offset = 0;
762 
763 	if (to_buffer)
764 		sg_flags |= SG_MITER_FROM_SG;
765 	else
766 		sg_flags |= SG_MITER_TO_SG;
767 
768 	sg_miter_start(&miter, sgl, nents, sg_flags);
769 
770 	while ((offset < buflen) && sg_miter_next(&miter)) {
771 		unsigned int buf_offset = 0;
772 		unsigned int len, left;
773 		u32 *buf = miter.addr;
774 
775 		len = min(miter.length, buflen - offset);
776 		left = len;
777 
778 		if (to_buffer) {
779 			do {
780 				writel(*buf++, host->bounce_iomem_buf + offset + buf_offset);
781 
782 				buf_offset += 4;
783 				left -= 4;
784 			} while (left);
785 		} else {
786 			do {
787 				*buf++ = readl(host->bounce_iomem_buf + offset + buf_offset);
788 
789 				buf_offset += 4;
790 				left -= 4;
791 			} while (left);
792 		}
793 
794 		offset += len;
795 	}
796 
797 	sg_miter_stop(&miter);
798 }
799 
800 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
801 {
802 	struct meson_host *host = mmc_priv(mmc);
803 	struct mmc_data *data = cmd->data;
804 	u32 cmd_cfg = 0, cmd_data = 0;
805 	unsigned int xfer_bytes = 0;
806 
807 	/* Setup descriptors */
808 	dma_rmb();
809 
810 	host->cmd = cmd;
811 
812 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
813 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
814 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
815 
816 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
817 
818 	/* data? */
819 	if (data) {
820 		data->bytes_xfered = 0;
821 		cmd_cfg |= CMD_CFG_DATA_IO;
822 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
823 				      ilog2(meson_mmc_get_timeout_msecs(data)));
824 
825 		if (meson_mmc_desc_chain_mode(data)) {
826 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
827 			return;
828 		}
829 
830 		if (data->blocks > 1) {
831 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
832 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
833 					      data->blocks);
834 			meson_mmc_set_blksz(mmc, data->blksz);
835 		} else {
836 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
837 		}
838 
839 		xfer_bytes = data->blksz * data->blocks;
840 		if (data->flags & MMC_DATA_WRITE) {
841 			cmd_cfg |= CMD_CFG_DATA_WR;
842 			WARN_ON(xfer_bytes > host->bounce_buf_size);
843 			if (host->dram_access_quirk)
844 				meson_mmc_copy_buffer(host, data, xfer_bytes, true);
845 			else
846 				sg_copy_to_buffer(data->sg, data->sg_len,
847 						  host->bounce_buf, xfer_bytes);
848 			dma_wmb();
849 		}
850 
851 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
852 	} else {
853 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
854 				      ilog2(SD_EMMC_CMD_TIMEOUT));
855 	}
856 
857 	/* Last descriptor */
858 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
859 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
860 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
861 	writel(0, host->regs + SD_EMMC_CMD_RSP);
862 	wmb(); /* ensure descriptor is written before kicked */
863 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
864 }
865 
866 static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data *data)
867 {
868 	struct scatterlist *sg;
869 	int i;
870 
871 	/* Reject request if any element offset or size is not 32bit aligned */
872 	for_each_sg(data->sg, sg, data->sg_len, i) {
873 		if (!IS_ALIGNED(sg->offset, sizeof(u32)) ||
874 		    !IS_ALIGNED(sg->length, sizeof(u32))) {
875 			dev_err(mmc_dev(mmc), "unaligned sg offset %u len %u\n",
876 				data->sg->offset, data->sg->length);
877 			return -EINVAL;
878 		}
879 	}
880 
881 	return 0;
882 }
883 
884 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
885 {
886 	struct meson_host *host = mmc_priv(mmc);
887 	host->needs_pre_post_req = mrq->data &&
888 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
889 
890 	/*
891 	 * The memory at the end of the controller used as bounce buffer for
892 	 * the dram_access_quirk only accepts 32bit read/write access,
893 	 * check the aligment and length of the data before starting the request.
894 	 */
895 	if (host->dram_access_quirk && mrq->data) {
896 		mrq->cmd->error = meson_mmc_validate_dram_access(mmc, mrq->data);
897 		if (mrq->cmd->error) {
898 			mmc_request_done(mmc, mrq);
899 			return;
900 		}
901 	}
902 
903 	if (host->needs_pre_post_req) {
904 		meson_mmc_get_transfer_mode(mmc, mrq);
905 		if (!meson_mmc_desc_chain_mode(mrq->data))
906 			host->needs_pre_post_req = false;
907 	}
908 
909 	if (host->needs_pre_post_req)
910 		meson_mmc_pre_req(mmc, mrq);
911 
912 	/* Stop execution */
913 	writel(0, host->regs + SD_EMMC_START);
914 
915 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
916 }
917 
918 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
919 {
920 	struct meson_host *host = mmc_priv(mmc);
921 
922 	if (cmd->flags & MMC_RSP_136) {
923 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
924 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
925 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
926 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
927 	} else if (cmd->flags & MMC_RSP_PRESENT) {
928 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
929 	}
930 }
931 
932 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
933 {
934 	struct meson_host *host = dev_id;
935 	struct mmc_command *cmd;
936 	struct mmc_data *data;
937 	u32 irq_en, status, raw_status;
938 	irqreturn_t ret = IRQ_NONE;
939 
940 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
941 	raw_status = readl(host->regs + SD_EMMC_STATUS);
942 	status = raw_status & irq_en;
943 
944 	if (!status) {
945 		dev_dbg(host->dev,
946 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
947 			 irq_en, raw_status);
948 		return IRQ_NONE;
949 	}
950 
951 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
952 		return IRQ_NONE;
953 
954 	/* ack all raised interrupts */
955 	writel(status, host->regs + SD_EMMC_STATUS);
956 
957 	cmd = host->cmd;
958 	data = cmd->data;
959 	cmd->error = 0;
960 	if (status & IRQ_CRC_ERR) {
961 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
962 		cmd->error = -EILSEQ;
963 		ret = IRQ_WAKE_THREAD;
964 		goto out;
965 	}
966 
967 	if (status & IRQ_TIMEOUTS) {
968 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
969 		cmd->error = -ETIMEDOUT;
970 		ret = IRQ_WAKE_THREAD;
971 		goto out;
972 	}
973 
974 	meson_mmc_read_resp(host->mmc, cmd);
975 
976 	if (status & IRQ_SDIO) {
977 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
978 		ret = IRQ_HANDLED;
979 	}
980 
981 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
982 		if (data && !cmd->error)
983 			data->bytes_xfered = data->blksz * data->blocks;
984 		if (meson_mmc_bounce_buf_read(data) ||
985 		    meson_mmc_get_next_command(cmd))
986 			ret = IRQ_WAKE_THREAD;
987 		else
988 			ret = IRQ_HANDLED;
989 	}
990 
991 out:
992 	if (cmd->error) {
993 		/* Stop desc in case of errors */
994 		u32 start = readl(host->regs + SD_EMMC_START);
995 
996 		start &= ~START_DESC_BUSY;
997 		writel(start, host->regs + SD_EMMC_START);
998 	}
999 
1000 	if (ret == IRQ_HANDLED)
1001 		meson_mmc_request_done(host->mmc, cmd->mrq);
1002 
1003 	return ret;
1004 }
1005 
1006 static int meson_mmc_wait_desc_stop(struct meson_host *host)
1007 {
1008 	u32 status;
1009 
1010 	/*
1011 	 * It may sometimes take a while for it to actually halt. Here, we
1012 	 * are giving it 5ms to comply
1013 	 *
1014 	 * If we don't confirm the descriptor is stopped, it might raise new
1015 	 * IRQs after we have called mmc_request_done() which is bad.
1016 	 */
1017 
1018 	return readl_poll_timeout(host->regs + SD_EMMC_STATUS, status,
1019 				  !(status & (STATUS_BUSY | STATUS_DESC_BUSY)),
1020 				  100, 5000);
1021 }
1022 
1023 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1024 {
1025 	struct meson_host *host = dev_id;
1026 	struct mmc_command *next_cmd, *cmd = host->cmd;
1027 	struct mmc_data *data;
1028 	unsigned int xfer_bytes;
1029 
1030 	if (WARN_ON(!cmd))
1031 		return IRQ_NONE;
1032 
1033 	if (cmd->error) {
1034 		meson_mmc_wait_desc_stop(host);
1035 		meson_mmc_request_done(host->mmc, cmd->mrq);
1036 
1037 		return IRQ_HANDLED;
1038 	}
1039 
1040 	data = cmd->data;
1041 	if (meson_mmc_bounce_buf_read(data)) {
1042 		xfer_bytes = data->blksz * data->blocks;
1043 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1044 		if (host->dram_access_quirk)
1045 			meson_mmc_copy_buffer(host, data, xfer_bytes, false);
1046 		else
1047 			sg_copy_from_buffer(data->sg, data->sg_len,
1048 					    host->bounce_buf, xfer_bytes);
1049 	}
1050 
1051 	next_cmd = meson_mmc_get_next_command(cmd);
1052 	if (next_cmd)
1053 		meson_mmc_start_cmd(host->mmc, next_cmd);
1054 	else
1055 		meson_mmc_request_done(host->mmc, cmd->mrq);
1056 
1057 	return IRQ_HANDLED;
1058 }
1059 
1060 /*
1061  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1062  * interrupts.  For now, the MMC core will use this for polling.
1063  */
1064 static int meson_mmc_get_cd(struct mmc_host *mmc)
1065 {
1066 	int status = mmc_gpio_get_cd(mmc);
1067 
1068 	if (status == -ENOSYS)
1069 		return 1; /* assume present */
1070 
1071 	return status;
1072 }
1073 
1074 static void meson_mmc_cfg_init(struct meson_host *host)
1075 {
1076 	u32 cfg = 0;
1077 
1078 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1079 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1080 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1081 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1082 
1083 	/* abort chain on R/W errors */
1084 	cfg |= CFG_ERR_ABORT;
1085 
1086 	writel(cfg, host->regs + SD_EMMC_CFG);
1087 }
1088 
1089 static int meson_mmc_card_busy(struct mmc_host *mmc)
1090 {
1091 	struct meson_host *host = mmc_priv(mmc);
1092 	u32 regval;
1093 
1094 	regval = readl(host->regs + SD_EMMC_STATUS);
1095 
1096 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1097 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1098 }
1099 
1100 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1101 {
1102 	int ret;
1103 
1104 	/* vqmmc regulator is available */
1105 	if (!IS_ERR(mmc->supply.vqmmc)) {
1106 		/*
1107 		 * The usual amlogic setup uses a GPIO to switch from one
1108 		 * regulator to the other. While the voltage ramp up is
1109 		 * pretty fast, care must be taken when switching from 3.3v
1110 		 * to 1.8v. Please make sure the regulator framework is aware
1111 		 * of your own regulator constraints
1112 		 */
1113 		ret = mmc_regulator_set_vqmmc(mmc, ios);
1114 		return ret < 0 ? ret : 0;
1115 	}
1116 
1117 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1118 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1119 		return 0;
1120 
1121 	return -EINVAL;
1122 }
1123 
1124 static const struct mmc_host_ops meson_mmc_ops = {
1125 	.request	= meson_mmc_request,
1126 	.set_ios	= meson_mmc_set_ios,
1127 	.get_cd         = meson_mmc_get_cd,
1128 	.pre_req	= meson_mmc_pre_req,
1129 	.post_req	= meson_mmc_post_req,
1130 	.execute_tuning = meson_mmc_resampling_tuning,
1131 	.card_busy	= meson_mmc_card_busy,
1132 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1133 };
1134 
1135 static int meson_mmc_probe(struct platform_device *pdev)
1136 {
1137 	struct resource *res;
1138 	struct meson_host *host;
1139 	struct mmc_host *mmc;
1140 	int ret;
1141 
1142 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1143 	if (!mmc)
1144 		return -ENOMEM;
1145 	host = mmc_priv(mmc);
1146 	host->mmc = mmc;
1147 	host->dev = &pdev->dev;
1148 	dev_set_drvdata(&pdev->dev, host);
1149 
1150 	/* The G12A SDIO Controller needs an SRAM bounce buffer */
1151 	host->dram_access_quirk = device_property_read_bool(&pdev->dev,
1152 					"amlogic,dram-access-quirk");
1153 
1154 	/* Get regulators and the supported OCR mask */
1155 	host->vqmmc_enabled = false;
1156 	ret = mmc_regulator_get_supply(mmc);
1157 	if (ret)
1158 		goto free_host;
1159 
1160 	ret = mmc_of_parse(mmc);
1161 	if (ret) {
1162 		if (ret != -EPROBE_DEFER)
1163 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1164 		goto free_host;
1165 	}
1166 
1167 	host->data = (struct meson_mmc_data *)
1168 		of_device_get_match_data(&pdev->dev);
1169 	if (!host->data) {
1170 		ret = -EINVAL;
1171 		goto free_host;
1172 	}
1173 
1174 	ret = device_reset_optional(&pdev->dev);
1175 	if (ret)
1176 		return dev_err_probe(&pdev->dev, ret, "device reset failed\n");
1177 
1178 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1179 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1180 	if (IS_ERR(host->regs)) {
1181 		ret = PTR_ERR(host->regs);
1182 		goto free_host;
1183 	}
1184 
1185 	host->irq = platform_get_irq(pdev, 0);
1186 	if (host->irq <= 0) {
1187 		ret = -EINVAL;
1188 		goto free_host;
1189 	}
1190 
1191 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1192 	if (IS_ERR(host->pinctrl)) {
1193 		ret = PTR_ERR(host->pinctrl);
1194 		goto free_host;
1195 	}
1196 
1197 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1198 						   "clk-gate");
1199 	if (IS_ERR(host->pins_clk_gate)) {
1200 		dev_warn(&pdev->dev,
1201 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1202 		host->pins_clk_gate = NULL;
1203 	}
1204 
1205 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1206 	if (IS_ERR(host->core_clk)) {
1207 		ret = PTR_ERR(host->core_clk);
1208 		goto free_host;
1209 	}
1210 
1211 	ret = clk_prepare_enable(host->core_clk);
1212 	if (ret)
1213 		goto free_host;
1214 
1215 	ret = meson_mmc_clk_init(host);
1216 	if (ret)
1217 		goto err_core_clk;
1218 
1219 	/* set config to sane default */
1220 	meson_mmc_cfg_init(host);
1221 
1222 	/* Stop execution */
1223 	writel(0, host->regs + SD_EMMC_START);
1224 
1225 	/* clear, ack and enable interrupts */
1226 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1227 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1228 	       host->regs + SD_EMMC_STATUS);
1229 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1230 	       host->regs + SD_EMMC_IRQ_EN);
1231 
1232 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1233 				   meson_mmc_irq_thread, IRQF_ONESHOT,
1234 				   dev_name(&pdev->dev), host);
1235 	if (ret)
1236 		goto err_init_clk;
1237 
1238 	mmc->caps |= MMC_CAP_CMD23;
1239 	if (host->dram_access_quirk) {
1240 		/* Limit segments to 1 due to low available sram memory */
1241 		mmc->max_segs = 1;
1242 		/* Limit to the available sram memory */
1243 		mmc->max_blk_count = SD_EMMC_SRAM_DATA_BUF_LEN /
1244 				     mmc->max_blk_size;
1245 	} else {
1246 		mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1247 		mmc->max_segs = SD_EMMC_DESC_BUF_LEN /
1248 				sizeof(struct sd_emmc_desc);
1249 	}
1250 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1251 	mmc->max_seg_size = mmc->max_req_size;
1252 
1253 	/*
1254 	 * At the moment, we don't know how to reliably enable HS400.
1255 	 * From the different datasheets, it is not even clear if this mode
1256 	 * is officially supported by any of the SoCs
1257 	 */
1258 	mmc->caps2 &= ~MMC_CAP2_HS400;
1259 
1260 	if (host->dram_access_quirk) {
1261 		/*
1262 		 * The MMC Controller embeds 1,5KiB of internal SRAM
1263 		 * that can be used to be used as bounce buffer.
1264 		 * In the case of the G12A SDIO controller, use these
1265 		 * instead of the DDR memory
1266 		 */
1267 		host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN;
1268 		host->bounce_iomem_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF;
1269 		host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF;
1270 	} else {
1271 		/* data bounce buffer */
1272 		host->bounce_buf_size = mmc->max_req_size;
1273 		host->bounce_buf =
1274 			dma_alloc_coherent(host->dev, host->bounce_buf_size,
1275 					   &host->bounce_dma_addr, GFP_KERNEL);
1276 		if (host->bounce_buf == NULL) {
1277 			dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1278 			ret = -ENOMEM;
1279 			goto err_free_irq;
1280 		}
1281 	}
1282 
1283 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1284 		      &host->descs_dma_addr, GFP_KERNEL);
1285 	if (!host->descs) {
1286 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1287 		ret = -ENOMEM;
1288 		goto err_bounce_buf;
1289 	}
1290 
1291 	mmc->ops = &meson_mmc_ops;
1292 	mmc_add_host(mmc);
1293 
1294 	return 0;
1295 
1296 err_bounce_buf:
1297 	if (!host->dram_access_quirk)
1298 		dma_free_coherent(host->dev, host->bounce_buf_size,
1299 				  host->bounce_buf, host->bounce_dma_addr);
1300 err_free_irq:
1301 	free_irq(host->irq, host);
1302 err_init_clk:
1303 	clk_disable_unprepare(host->mmc_clk);
1304 err_core_clk:
1305 	clk_disable_unprepare(host->core_clk);
1306 free_host:
1307 	mmc_free_host(mmc);
1308 	return ret;
1309 }
1310 
1311 static int meson_mmc_remove(struct platform_device *pdev)
1312 {
1313 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1314 
1315 	mmc_remove_host(host->mmc);
1316 
1317 	/* disable interrupts */
1318 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1319 	free_irq(host->irq, host);
1320 
1321 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1322 			  host->descs, host->descs_dma_addr);
1323 
1324 	if (!host->dram_access_quirk)
1325 		dma_free_coherent(host->dev, host->bounce_buf_size,
1326 				  host->bounce_buf, host->bounce_dma_addr);
1327 
1328 	clk_disable_unprepare(host->mmc_clk);
1329 	clk_disable_unprepare(host->core_clk);
1330 
1331 	mmc_free_host(host->mmc);
1332 	return 0;
1333 }
1334 
1335 static const struct meson_mmc_data meson_gx_data = {
1336 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1337 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1338 	.always_on	= CLK_V2_ALWAYS_ON,
1339 	.adjust		= SD_EMMC_ADJUST,
1340 };
1341 
1342 static const struct meson_mmc_data meson_axg_data = {
1343 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1344 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1345 	.always_on	= CLK_V3_ALWAYS_ON,
1346 	.adjust		= SD_EMMC_V3_ADJUST,
1347 };
1348 
1349 static const struct of_device_id meson_mmc_of_match[] = {
1350 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1351 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1352 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1353 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1354 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1355 	{}
1356 };
1357 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1358 
1359 static struct platform_driver meson_mmc_driver = {
1360 	.probe		= meson_mmc_probe,
1361 	.remove		= meson_mmc_remove,
1362 	.driver		= {
1363 		.name = DRIVER_NAME,
1364 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1365 		.of_match_table = meson_mmc_of_match,
1366 	},
1367 };
1368 
1369 module_platform_driver(meson_mmc_driver);
1370 
1371 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1372 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1373 MODULE_LICENSE("GPL v2");
1374