xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision f1575595)
1 /*
2  * Amlogic SD/eMMC driver for the GX/S905 family SoCs
3  *
4  * Copyright (c) 2016 BayLibre, SAS.
5  * Author: Kevin Hilman <khilman@baylibre.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  * The full GNU General Public License is included in this distribution
19  * in the file called COPYING.
20  */
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/ioport.h>
28 #include <linux/spinlock.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/mmc/host.h>
31 #include <linux/mmc/mmc.h>
32 #include <linux/mmc/sdio.h>
33 #include <linux/mmc/slot-gpio.h>
34 #include <linux/io.h>
35 #include <linux/clk.h>
36 #include <linux/clk-provider.h>
37 #include <linux/regulator/consumer.h>
38 #include <linux/reset.h>
39 #include <linux/interrupt.h>
40 #include <linux/bitfield.h>
41 #include <linux/pinctrl/consumer.h>
42 
43 #define DRIVER_NAME "meson-gx-mmc"
44 
45 #define SD_EMMC_CLOCK 0x0
46 #define   CLK_DIV_MASK GENMASK(5, 0)
47 #define   CLK_SRC_MASK GENMASK(7, 6)
48 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
49 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
50 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
51 #define   CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
52 #define   CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
53 #define   CLK_V2_ALWAYS_ON BIT(24)
54 
55 #define   CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
56 #define   CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
57 #define   CLK_V3_ALWAYS_ON BIT(28)
58 
59 #define   CLK_DELAY_STEP_PS 200
60 #define   CLK_PHASE_STEP 30
61 #define   CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
62 
63 #define   CLK_TX_DELAY_MASK(h)		(h->data->tx_delay_mask)
64 #define   CLK_RX_DELAY_MASK(h)		(h->data->rx_delay_mask)
65 #define   CLK_ALWAYS_ON(h)		(h->data->always_on)
66 
67 #define SD_EMMC_DELAY 0x4
68 #define SD_EMMC_ADJUST 0x8
69 
70 #define SD_EMMC_DELAY1 0x4
71 #define SD_EMMC_DELAY2 0x8
72 #define SD_EMMC_V3_ADJUST 0xc
73 
74 #define SD_EMMC_CALOUT 0x10
75 #define SD_EMMC_START 0x40
76 #define   START_DESC_INIT BIT(0)
77 #define   START_DESC_BUSY BIT(1)
78 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
79 
80 #define SD_EMMC_CFG 0x44
81 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
82 #define   CFG_BUS_WIDTH_1 0x0
83 #define   CFG_BUS_WIDTH_4 0x1
84 #define   CFG_BUS_WIDTH_8 0x2
85 #define   CFG_DDR BIT(2)
86 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
87 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
88 #define   CFG_RC_CC_MASK GENMASK(15, 12)
89 #define   CFG_STOP_CLOCK BIT(22)
90 #define   CFG_CLK_ALWAYS_ON BIT(18)
91 #define   CFG_CHK_DS BIT(20)
92 #define   CFG_AUTO_CLK BIT(23)
93 
94 #define SD_EMMC_STATUS 0x48
95 #define   STATUS_BUSY BIT(31)
96 #define   STATUS_DATI GENMASK(23, 16)
97 
98 #define SD_EMMC_IRQ_EN 0x4c
99 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
100 #define   IRQ_TXD_ERR BIT(8)
101 #define   IRQ_DESC_ERR BIT(9)
102 #define   IRQ_RESP_ERR BIT(10)
103 #define   IRQ_CRC_ERR \
104 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
105 #define   IRQ_RESP_TIMEOUT BIT(11)
106 #define   IRQ_DESC_TIMEOUT BIT(12)
107 #define   IRQ_TIMEOUTS \
108 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
109 #define   IRQ_END_OF_CHAIN BIT(13)
110 #define   IRQ_RESP_STATUS BIT(14)
111 #define   IRQ_SDIO BIT(15)
112 #define   IRQ_EN_MASK \
113 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
114 	 IRQ_SDIO)
115 
116 #define SD_EMMC_CMD_CFG 0x50
117 #define SD_EMMC_CMD_ARG 0x54
118 #define SD_EMMC_CMD_DAT 0x58
119 #define SD_EMMC_CMD_RSP 0x5c
120 #define SD_EMMC_CMD_RSP1 0x60
121 #define SD_EMMC_CMD_RSP2 0x64
122 #define SD_EMMC_CMD_RSP3 0x68
123 
124 #define SD_EMMC_RXD 0x94
125 #define SD_EMMC_TXD 0x94
126 #define SD_EMMC_LAST_REG SD_EMMC_TXD
127 
128 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
129 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
130 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
131 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
132 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
133 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
134 
135 #define SD_EMMC_PRE_REQ_DONE BIT(0)
136 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
137 
138 #define MUX_CLK_NUM_PARENTS 2
139 
140 struct meson_mmc_data {
141 	unsigned int tx_delay_mask;
142 	unsigned int rx_delay_mask;
143 	unsigned int always_on;
144 };
145 
146 struct sd_emmc_desc {
147 	u32 cmd_cfg;
148 	u32 cmd_arg;
149 	u32 cmd_data;
150 	u32 cmd_resp;
151 };
152 
153 struct meson_host {
154 	struct	device		*dev;
155 	struct	meson_mmc_data *data;
156 	struct	mmc_host	*mmc;
157 	struct	mmc_command	*cmd;
158 
159 	spinlock_t lock;
160 	void __iomem *regs;
161 	struct clk *core_clk;
162 	struct clk *mmc_clk;
163 	struct clk *rx_clk;
164 	struct clk *tx_clk;
165 	unsigned long req_rate;
166 
167 	struct pinctrl *pinctrl;
168 	struct pinctrl_state *pins_default;
169 	struct pinctrl_state *pins_clk_gate;
170 
171 	unsigned int bounce_buf_size;
172 	void *bounce_buf;
173 	dma_addr_t bounce_dma_addr;
174 	struct sd_emmc_desc *descs;
175 	dma_addr_t descs_dma_addr;
176 
177 	bool vqmmc_enabled;
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 struct meson_mmc_phase {
204 	struct clk_hw hw;
205 	void __iomem *reg;
206 	unsigned long phase_mask;
207 	unsigned long delay_mask;
208 	unsigned int delay_step_ps;
209 };
210 
211 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
212 
213 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
214 {
215 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
216 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
217 	unsigned long period_ps, p, d;
218 		int degrees;
219 	u32 val;
220 
221 	val = readl(mmc->reg);
222 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
223 	degrees = p * 360 / phase_num;
224 
225 	if (mmc->delay_mask) {
226 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
227 					 clk_get_rate(hw->clk));
228 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
229 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
230 		degrees %= 360;
231 	}
232 
233 	return degrees;
234 }
235 
236 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
237 					unsigned int phase,
238 					unsigned int delay)
239 {
240 	u32 val;
241 
242 	val = readl(mmc->reg);
243 	val &= ~mmc->phase_mask;
244 	val |= phase << __ffs(mmc->phase_mask);
245 
246 	if (mmc->delay_mask) {
247 		val &= ~mmc->delay_mask;
248 		val |= delay << __ffs(mmc->delay_mask);
249 	}
250 
251 	writel(val, mmc->reg);
252 }
253 
254 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
255 {
256 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
257 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
258 	unsigned long period_ps, d = 0, r;
259 	uint64_t p;
260 
261 	p = degrees % 360;
262 
263 	if (!mmc->delay_mask) {
264 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
265 	} else {
266 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
267 					 clk_get_rate(hw->clk));
268 
269 		/* First compute the phase index (p), the remainder (r) is the
270 		 * part we'll try to acheive using the delays (d).
271 		 */
272 		r = do_div(p, 360 / phase_num);
273 		d = DIV_ROUND_CLOSEST(r * period_ps,
274 				      360 * mmc->delay_step_ps);
275 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
276 	}
277 
278 	meson_mmc_apply_phase_delay(mmc, p, d);
279 	return 0;
280 }
281 
282 static const struct clk_ops meson_mmc_clk_phase_ops = {
283 	.get_phase = meson_mmc_clk_get_phase,
284 	.set_phase = meson_mmc_clk_set_phase,
285 };
286 
287 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
288 {
289 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
290 
291 	if (!timeout)
292 		return SD_EMMC_CMD_TIMEOUT_DATA;
293 
294 	timeout = roundup_pow_of_two(timeout);
295 
296 	return min(timeout, 32768U); /* max. 2^15 ms */
297 }
298 
299 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
300 {
301 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
302 		return cmd->mrq->cmd;
303 	else if (mmc_op_multi(cmd->opcode) &&
304 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
305 		return cmd->mrq->stop;
306 	else
307 		return NULL;
308 }
309 
310 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
311 					struct mmc_request *mrq)
312 {
313 	struct mmc_data *data = mrq->data;
314 	struct scatterlist *sg;
315 	int i;
316 	bool use_desc_chain_mode = true;
317 
318 	/*
319 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
320 	 * reported. For some strange reason this occurs in descriptor
321 	 * chain mode only. So let's fall back to bounce buffer mode
322 	 * for command SD_IO_RW_EXTENDED.
323 	 */
324 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
325 		return;
326 
327 	for_each_sg(data->sg, sg, data->sg_len, i)
328 		/* check for 8 byte alignment */
329 		if (sg->offset & 7) {
330 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
331 			use_desc_chain_mode = false;
332 			break;
333 		}
334 
335 	if (use_desc_chain_mode)
336 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
337 }
338 
339 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
340 {
341 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
342 }
343 
344 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
345 {
346 	return data && data->flags & MMC_DATA_READ &&
347 	       !meson_mmc_desc_chain_mode(data);
348 }
349 
350 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
351 {
352 	struct mmc_data *data = mrq->data;
353 
354 	if (!data)
355 		return;
356 
357 	meson_mmc_get_transfer_mode(mmc, mrq);
358 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
359 
360 	if (!meson_mmc_desc_chain_mode(data))
361 		return;
362 
363 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
364                                    mmc_get_dma_dir(data));
365 	if (!data->sg_count)
366 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
367 }
368 
369 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
370 			       int err)
371 {
372 	struct mmc_data *data = mrq->data;
373 
374 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
375 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
376 			     mmc_get_dma_dir(data));
377 }
378 
379 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
380 {
381 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
382 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
383 	    ios->timing == MMC_TIMING_MMC_HS400)
384 		return true;
385 
386 	return false;
387 }
388 
389 /*
390  * Gating the clock on this controller is tricky.  It seems the mmc clock
391  * is also used by the controller.  It may crash during some operation if the
392  * clock is stopped.  The safest thing to do, whenever possible, is to keep
393  * clock running at stop it at the pad using the pinmux.
394  */
395 static void meson_mmc_clk_gate(struct meson_host *host)
396 {
397 	u32 cfg;
398 
399 	if (host->pins_clk_gate) {
400 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
401 	} else {
402 		/*
403 		 * If the pinmux is not provided - default to the classic and
404 		 * unsafe method
405 		 */
406 		cfg = readl(host->regs + SD_EMMC_CFG);
407 		cfg |= CFG_STOP_CLOCK;
408 		writel(cfg, host->regs + SD_EMMC_CFG);
409 	}
410 }
411 
412 static void meson_mmc_clk_ungate(struct meson_host *host)
413 {
414 	u32 cfg;
415 
416 	if (host->pins_clk_gate)
417 		pinctrl_select_state(host->pinctrl, host->pins_default);
418 
419 	/* Make sure the clock is not stopped in the controller */
420 	cfg = readl(host->regs + SD_EMMC_CFG);
421 	cfg &= ~CFG_STOP_CLOCK;
422 	writel(cfg, host->regs + SD_EMMC_CFG);
423 }
424 
425 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
426 {
427 	struct mmc_host *mmc = host->mmc;
428 	unsigned long rate = ios->clock;
429 	int ret;
430 	u32 cfg;
431 
432 	/* DDR modes require higher module clock */
433 	if (meson_mmc_timing_is_ddr(ios))
434 		rate <<= 1;
435 
436 	/* Same request - bail-out */
437 	if (host->req_rate == rate)
438 		return 0;
439 
440 	/* stop clock */
441 	meson_mmc_clk_gate(host);
442 	host->req_rate = 0;
443 
444 	if (!rate) {
445 		mmc->actual_clock = 0;
446 		/* return with clock being stopped */
447 		return 0;
448 	}
449 
450 	/* Stop the clock during rate change to avoid glitches */
451 	cfg = readl(host->regs + SD_EMMC_CFG);
452 	cfg |= CFG_STOP_CLOCK;
453 	writel(cfg, host->regs + SD_EMMC_CFG);
454 
455 	ret = clk_set_rate(host->mmc_clk, rate);
456 	if (ret) {
457 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
458 			rate, ret);
459 		return ret;
460 	}
461 
462 	host->req_rate = rate;
463 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
464 
465 	/* We should report the real output frequency of the controller */
466 	if (meson_mmc_timing_is_ddr(ios))
467 		mmc->actual_clock >>= 1;
468 
469 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
470 	if (ios->clock != mmc->actual_clock)
471 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
472 
473 	/* (re)start clock */
474 	meson_mmc_clk_ungate(host);
475 
476 	return 0;
477 }
478 
479 /*
480  * The SD/eMMC IP block has an internal mux and divider used for
481  * generating the MMC clock.  Use the clock framework to create and
482  * manage these clocks.
483  */
484 static int meson_mmc_clk_init(struct meson_host *host)
485 {
486 	struct clk_init_data init;
487 	struct clk_mux *mux;
488 	struct clk_divider *div;
489 	struct meson_mmc_phase *core, *tx, *rx;
490 	struct clk *clk;
491 	char clk_name[32];
492 	int i, ret = 0;
493 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
494 	const char *clk_parent[1];
495 	u32 clk_reg;
496 
497 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
498 	clk_reg = 0;
499 	clk_reg |= CLK_ALWAYS_ON(host);
500 	clk_reg |= CLK_DIV_MASK;
501 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
502 
503 	/* get the mux parents */
504 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
505 		struct clk *clk;
506 		char name[16];
507 
508 		snprintf(name, sizeof(name), "clkin%d", i);
509 		clk = devm_clk_get(host->dev, name);
510 		if (IS_ERR(clk)) {
511 			if (clk != ERR_PTR(-EPROBE_DEFER))
512 				dev_err(host->dev, "Missing clock %s\n", name);
513 			return PTR_ERR(clk);
514 		}
515 
516 		mux_parent_names[i] = __clk_get_name(clk);
517 	}
518 
519 	/* create the mux */
520 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
521 	if (!mux)
522 		return -ENOMEM;
523 
524 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
525 	init.name = clk_name;
526 	init.ops = &clk_mux_ops;
527 	init.flags = 0;
528 	init.parent_names = mux_parent_names;
529 	init.num_parents = MUX_CLK_NUM_PARENTS;
530 
531 	mux->reg = host->regs + SD_EMMC_CLOCK;
532 	mux->shift = __ffs(CLK_SRC_MASK);
533 	mux->mask = CLK_SRC_MASK >> mux->shift;
534 	mux->hw.init = &init;
535 
536 	clk = devm_clk_register(host->dev, &mux->hw);
537 	if (WARN_ON(IS_ERR(clk)))
538 		return PTR_ERR(clk);
539 
540 	/* create the divider */
541 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
542 	if (!div)
543 		return -ENOMEM;
544 
545 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
546 	init.name = clk_name;
547 	init.ops = &clk_divider_ops;
548 	init.flags = CLK_SET_RATE_PARENT;
549 	clk_parent[0] = __clk_get_name(clk);
550 	init.parent_names = clk_parent;
551 	init.num_parents = 1;
552 
553 	div->reg = host->regs + SD_EMMC_CLOCK;
554 	div->shift = __ffs(CLK_DIV_MASK);
555 	div->width = __builtin_popcountl(CLK_DIV_MASK);
556 	div->hw.init = &init;
557 	div->flags = CLK_DIVIDER_ONE_BASED;
558 
559 	clk = devm_clk_register(host->dev, &div->hw);
560 	if (WARN_ON(IS_ERR(clk)))
561 		return PTR_ERR(clk);
562 
563 	/* create the mmc core clock */
564 	core = devm_kzalloc(host->dev, sizeof(*core), GFP_KERNEL);
565 	if (!core)
566 		return -ENOMEM;
567 
568 	snprintf(clk_name, sizeof(clk_name), "%s#core", dev_name(host->dev));
569 	init.name = clk_name;
570 	init.ops = &meson_mmc_clk_phase_ops;
571 	init.flags = CLK_SET_RATE_PARENT;
572 	clk_parent[0] = __clk_get_name(clk);
573 	init.parent_names = clk_parent;
574 	init.num_parents = 1;
575 
576 	core->reg = host->regs + SD_EMMC_CLOCK;
577 	core->phase_mask = CLK_CORE_PHASE_MASK;
578 	core->hw.init = &init;
579 
580 	host->mmc_clk = devm_clk_register(host->dev, &core->hw);
581 	if (WARN_ON(PTR_ERR_OR_ZERO(host->mmc_clk)))
582 		return PTR_ERR(host->mmc_clk);
583 
584 	/* create the mmc tx clock */
585 	tx = devm_kzalloc(host->dev, sizeof(*tx), GFP_KERNEL);
586 	if (!tx)
587 		return -ENOMEM;
588 
589 	snprintf(clk_name, sizeof(clk_name), "%s#tx", dev_name(host->dev));
590 	init.name = clk_name;
591 	init.ops = &meson_mmc_clk_phase_ops;
592 	init.flags = 0;
593 	clk_parent[0] = __clk_get_name(host->mmc_clk);
594 	init.parent_names = clk_parent;
595 	init.num_parents = 1;
596 
597 	tx->reg = host->regs + SD_EMMC_CLOCK;
598 	tx->phase_mask = CLK_TX_PHASE_MASK;
599 	tx->delay_mask = CLK_TX_DELAY_MASK(host);
600 	tx->delay_step_ps = CLK_DELAY_STEP_PS;
601 	tx->hw.init = &init;
602 
603 	host->tx_clk = devm_clk_register(host->dev, &tx->hw);
604 	if (WARN_ON(PTR_ERR_OR_ZERO(host->tx_clk)))
605 		return PTR_ERR(host->tx_clk);
606 
607 	/* create the mmc rx clock */
608 	rx = devm_kzalloc(host->dev, sizeof(*rx), GFP_KERNEL);
609 	if (!rx)
610 		return -ENOMEM;
611 
612 	snprintf(clk_name, sizeof(clk_name), "%s#rx", dev_name(host->dev));
613 	init.name = clk_name;
614 	init.ops = &meson_mmc_clk_phase_ops;
615 	init.flags = 0;
616 	clk_parent[0] = __clk_get_name(host->mmc_clk);
617 	init.parent_names = clk_parent;
618 	init.num_parents = 1;
619 
620 	rx->reg = host->regs + SD_EMMC_CLOCK;
621 	rx->phase_mask = CLK_RX_PHASE_MASK;
622 	rx->delay_mask = CLK_RX_DELAY_MASK(host);
623 	rx->delay_step_ps = CLK_DELAY_STEP_PS;
624 	rx->hw.init = &init;
625 
626 	host->rx_clk = devm_clk_register(host->dev, &rx->hw);
627 	if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
628 		return PTR_ERR(host->rx_clk);
629 
630 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
631 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
632 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
633 	if (ret)
634 		return ret;
635 
636 	/*
637 	 * Set phases : These values are mostly the datasheet recommended ones
638 	 * except for the Tx phase. Datasheet recommends 180 but some cards
639 	 * fail at initialisation with it. 270 works just fine, it fixes these
640 	 * initialisation issues and enable eMMC DDR52 mode.
641 	 */
642 	clk_set_phase(host->mmc_clk, 180);
643 	clk_set_phase(host->tx_clk, 270);
644 	clk_set_phase(host->rx_clk, 0);
645 
646 	return clk_prepare_enable(host->mmc_clk);
647 }
648 
649 static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
650 {
651 	DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
652 	DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
653 
654 	/*
655 	 * shift the bitmap right and reintroduce the dropped bits on the left
656 	 * of the bitmap
657 	 */
658 	bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
659 	bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
660 			  CLK_PHASE_POINT_NUM);
661 	bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
662 }
663 
664 static void meson_mmc_find_next_region(unsigned long *map,
665 				       unsigned long *start,
666 				       unsigned long *stop)
667 {
668 	*start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
669 	*stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
670 }
671 
672 static int meson_mmc_find_tuning_point(unsigned long *test)
673 {
674 	unsigned long shift, stop, offset = 0, start = 0, size = 0;
675 
676 	/* Get the all good/all bad situation out the way */
677 	if (bitmap_full(test, CLK_PHASE_POINT_NUM))
678 		return 0; /* All points are good so point 0 will do */
679 	else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
680 		return -EIO; /* No successful tuning point */
681 
682 	/*
683 	 * Now we know there is a least one region find. Make sure it does
684 	 * not wrap by the shifting the bitmap if necessary
685 	 */
686 	shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
687 	if (shift != 0)
688 		meson_mmc_shift_map(test, shift);
689 
690 	while (start < CLK_PHASE_POINT_NUM) {
691 		meson_mmc_find_next_region(test, &start, &stop);
692 
693 		if ((stop - start) > size) {
694 			offset = start;
695 			size = stop - start;
696 		}
697 
698 		start = stop;
699 	}
700 
701 	/* Get the center point of the region */
702 	offset += (size / 2);
703 
704 	/* Shift the result back */
705 	offset = (offset + shift) % CLK_PHASE_POINT_NUM;
706 
707 	return offset;
708 }
709 
710 static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
711 				      struct clk *clk)
712 {
713 	int point, ret;
714 	DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
715 
716 	dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
717 		__clk_get_name(clk));
718 	bitmap_zero(test, CLK_PHASE_POINT_NUM);
719 
720 	/* Explore tuning points */
721 	for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
722 		clk_set_phase(clk, point * CLK_PHASE_STEP);
723 		ret = mmc_send_tuning(mmc, opcode, NULL);
724 		if (!ret)
725 			set_bit(point, test);
726 	}
727 
728 	/* Find the optimal tuning point and apply it */
729 	point = meson_mmc_find_tuning_point(test);
730 	if (point < 0)
731 		return point; /* tuning failed */
732 
733 	clk_set_phase(clk, point * CLK_PHASE_STEP);
734 	dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
735 		clk_get_phase(clk));
736 	return 0;
737 }
738 
739 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
740 {
741 	struct meson_host *host = mmc_priv(mmc);
742 
743 	return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
744 }
745 
746 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
747 {
748 	struct meson_host *host = mmc_priv(mmc);
749 	u32 bus_width, val;
750 	int err;
751 
752 	/*
753 	 * GPIO regulator, only controls switching between 1v8 and
754 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
755 	 */
756 	switch (ios->power_mode) {
757 	case MMC_POWER_OFF:
758 		if (!IS_ERR(mmc->supply.vmmc))
759 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
760 
761 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
762 			regulator_disable(mmc->supply.vqmmc);
763 			host->vqmmc_enabled = false;
764 		}
765 
766 		break;
767 
768 	case MMC_POWER_UP:
769 		if (!IS_ERR(mmc->supply.vmmc))
770 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
771 
772 		/* Reset rx phase */
773 		clk_set_phase(host->rx_clk, 0);
774 
775 		break;
776 
777 	case MMC_POWER_ON:
778 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
779 			int ret = regulator_enable(mmc->supply.vqmmc);
780 
781 			if (ret < 0)
782 				dev_err(host->dev,
783 					"failed to enable vqmmc regulator\n");
784 			else
785 				host->vqmmc_enabled = true;
786 		}
787 
788 		break;
789 	}
790 
791 	/* Bus width */
792 	switch (ios->bus_width) {
793 	case MMC_BUS_WIDTH_1:
794 		bus_width = CFG_BUS_WIDTH_1;
795 		break;
796 	case MMC_BUS_WIDTH_4:
797 		bus_width = CFG_BUS_WIDTH_4;
798 		break;
799 	case MMC_BUS_WIDTH_8:
800 		bus_width = CFG_BUS_WIDTH_8;
801 		break;
802 	default:
803 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
804 			ios->bus_width);
805 		bus_width = CFG_BUS_WIDTH_4;
806 	}
807 
808 	val = readl(host->regs + SD_EMMC_CFG);
809 	val &= ~CFG_BUS_WIDTH_MASK;
810 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
811 
812 	val &= ~CFG_DDR;
813 	if (meson_mmc_timing_is_ddr(ios))
814 		val |= CFG_DDR;
815 
816 	val &= ~CFG_CHK_DS;
817 	if (ios->timing == MMC_TIMING_MMC_HS400)
818 		val |= CFG_CHK_DS;
819 
820 	err = meson_mmc_clk_set(host, ios);
821 	if (err)
822 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
823 
824 	writel(val, host->regs + SD_EMMC_CFG);
825 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
826 }
827 
828 static void meson_mmc_request_done(struct mmc_host *mmc,
829 				   struct mmc_request *mrq)
830 {
831 	struct meson_host *host = mmc_priv(mmc);
832 
833 	host->cmd = NULL;
834 	mmc_request_done(host->mmc, mrq);
835 }
836 
837 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
838 {
839 	struct meson_host *host = mmc_priv(mmc);
840 	u32 cfg, blksz_old;
841 
842 	cfg = readl(host->regs + SD_EMMC_CFG);
843 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
844 
845 	if (!is_power_of_2(blksz))
846 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
847 
848 	blksz = ilog2(blksz);
849 
850 	/* check if block-size matches, if not update */
851 	if (blksz == blksz_old)
852 		return;
853 
854 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
855 		blksz_old, blksz);
856 
857 	cfg &= ~CFG_BLK_LEN_MASK;
858 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
859 	writel(cfg, host->regs + SD_EMMC_CFG);
860 }
861 
862 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
863 {
864 	if (cmd->flags & MMC_RSP_PRESENT) {
865 		if (cmd->flags & MMC_RSP_136)
866 			*cmd_cfg |= CMD_CFG_RESP_128;
867 		*cmd_cfg |= CMD_CFG_RESP_NUM;
868 
869 		if (!(cmd->flags & MMC_RSP_CRC))
870 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
871 
872 		if (cmd->flags & MMC_RSP_BUSY)
873 			*cmd_cfg |= CMD_CFG_R1B;
874 	} else {
875 		*cmd_cfg |= CMD_CFG_NO_RESP;
876 	}
877 }
878 
879 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
880 {
881 	struct meson_host *host = mmc_priv(mmc);
882 	struct sd_emmc_desc *desc = host->descs;
883 	struct mmc_data *data = host->cmd->data;
884 	struct scatterlist *sg;
885 	u32 start;
886 	int i;
887 
888 	if (data->flags & MMC_DATA_WRITE)
889 		cmd_cfg |= CMD_CFG_DATA_WR;
890 
891 	if (data->blocks > 1) {
892 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
893 		meson_mmc_set_blksz(mmc, data->blksz);
894 	}
895 
896 	for_each_sg(data->sg, sg, data->sg_count, i) {
897 		unsigned int len = sg_dma_len(sg);
898 
899 		if (data->blocks > 1)
900 			len /= data->blksz;
901 
902 		desc[i].cmd_cfg = cmd_cfg;
903 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
904 		if (i > 0)
905 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
906 		desc[i].cmd_arg = host->cmd->arg;
907 		desc[i].cmd_resp = 0;
908 		desc[i].cmd_data = sg_dma_address(sg);
909 	}
910 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
911 
912 	dma_wmb(); /* ensure descriptor is written before kicked */
913 	start = host->descs_dma_addr | START_DESC_BUSY;
914 	writel(start, host->regs + SD_EMMC_START);
915 }
916 
917 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
918 {
919 	struct meson_host *host = mmc_priv(mmc);
920 	struct mmc_data *data = cmd->data;
921 	u32 cmd_cfg = 0, cmd_data = 0;
922 	unsigned int xfer_bytes = 0;
923 
924 	/* Setup descriptors */
925 	dma_rmb();
926 
927 	host->cmd = cmd;
928 
929 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
930 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
931 
932 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
933 
934 	/* data? */
935 	if (data) {
936 		data->bytes_xfered = 0;
937 		cmd_cfg |= CMD_CFG_DATA_IO;
938 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
939 				      ilog2(meson_mmc_get_timeout_msecs(data)));
940 
941 		if (meson_mmc_desc_chain_mode(data)) {
942 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
943 			return;
944 		}
945 
946 		if (data->blocks > 1) {
947 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
948 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
949 					      data->blocks);
950 			meson_mmc_set_blksz(mmc, data->blksz);
951 		} else {
952 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
953 		}
954 
955 		xfer_bytes = data->blksz * data->blocks;
956 		if (data->flags & MMC_DATA_WRITE) {
957 			cmd_cfg |= CMD_CFG_DATA_WR;
958 			WARN_ON(xfer_bytes > host->bounce_buf_size);
959 			sg_copy_to_buffer(data->sg, data->sg_len,
960 					  host->bounce_buf, xfer_bytes);
961 			dma_wmb();
962 		}
963 
964 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
965 	} else {
966 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
967 				      ilog2(SD_EMMC_CMD_TIMEOUT));
968 	}
969 
970 	/* Last descriptor */
971 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
972 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
973 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
974 	writel(0, host->regs + SD_EMMC_CMD_RSP);
975 	wmb(); /* ensure descriptor is written before kicked */
976 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
977 }
978 
979 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
980 {
981 	struct meson_host *host = mmc_priv(mmc);
982 	bool needs_pre_post_req = mrq->data &&
983 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
984 
985 	if (needs_pre_post_req) {
986 		meson_mmc_get_transfer_mode(mmc, mrq);
987 		if (!meson_mmc_desc_chain_mode(mrq->data))
988 			needs_pre_post_req = false;
989 	}
990 
991 	if (needs_pre_post_req)
992 		meson_mmc_pre_req(mmc, mrq);
993 
994 	/* Stop execution */
995 	writel(0, host->regs + SD_EMMC_START);
996 
997 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
998 
999 	if (needs_pre_post_req)
1000 		meson_mmc_post_req(mmc, mrq, 0);
1001 }
1002 
1003 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
1004 {
1005 	struct meson_host *host = mmc_priv(mmc);
1006 
1007 	if (cmd->flags & MMC_RSP_136) {
1008 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
1009 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
1010 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
1011 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
1012 	} else if (cmd->flags & MMC_RSP_PRESENT) {
1013 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
1014 	}
1015 }
1016 
1017 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
1018 {
1019 	struct meson_host *host = dev_id;
1020 	struct mmc_command *cmd;
1021 	struct mmc_data *data;
1022 	u32 irq_en, status, raw_status;
1023 	irqreturn_t ret = IRQ_NONE;
1024 
1025 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1026 		return IRQ_NONE;
1027 
1028 	spin_lock(&host->lock);
1029 
1030 	cmd = host->cmd;
1031 	data = cmd->data;
1032 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1033 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1034 	status = raw_status & irq_en;
1035 
1036 	cmd->error = 0;
1037 	if (status & IRQ_CRC_ERR) {
1038 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1039 		cmd->error = -EILSEQ;
1040 		ret = IRQ_HANDLED;
1041 		goto out;
1042 	}
1043 
1044 	if (status & IRQ_TIMEOUTS) {
1045 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1046 		cmd->error = -ETIMEDOUT;
1047 		ret = IRQ_HANDLED;
1048 		goto out;
1049 	}
1050 
1051 	meson_mmc_read_resp(host->mmc, cmd);
1052 
1053 	if (status & IRQ_SDIO) {
1054 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1055 		ret = IRQ_HANDLED;
1056 	}
1057 
1058 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1059 		if (data && !cmd->error)
1060 			data->bytes_xfered = data->blksz * data->blocks;
1061 		if (meson_mmc_bounce_buf_read(data) ||
1062 		    meson_mmc_get_next_command(cmd))
1063 			ret = IRQ_WAKE_THREAD;
1064 		else
1065 			ret = IRQ_HANDLED;
1066 	}
1067 
1068 out:
1069 	/* ack all enabled interrupts */
1070 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1071 
1072 	if (ret == IRQ_HANDLED)
1073 		meson_mmc_request_done(host->mmc, cmd->mrq);
1074 	else if (ret == IRQ_NONE)
1075 		dev_warn(host->dev,
1076 			 "Unexpected IRQ! status=0x%08x, irq_en=0x%08x\n",
1077 			 raw_status, irq_en);
1078 
1079 	spin_unlock(&host->lock);
1080 	return ret;
1081 }
1082 
1083 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1084 {
1085 	struct meson_host *host = dev_id;
1086 	struct mmc_command *next_cmd, *cmd = host->cmd;
1087 	struct mmc_data *data;
1088 	unsigned int xfer_bytes;
1089 
1090 	if (WARN_ON(!cmd))
1091 		return IRQ_NONE;
1092 
1093 	data = cmd->data;
1094 	if (meson_mmc_bounce_buf_read(data)) {
1095 		xfer_bytes = data->blksz * data->blocks;
1096 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1097 		sg_copy_from_buffer(data->sg, data->sg_len,
1098 				    host->bounce_buf, xfer_bytes);
1099 	}
1100 
1101 	next_cmd = meson_mmc_get_next_command(cmd);
1102 	if (next_cmd)
1103 		meson_mmc_start_cmd(host->mmc, next_cmd);
1104 	else
1105 		meson_mmc_request_done(host->mmc, cmd->mrq);
1106 
1107 	return IRQ_HANDLED;
1108 }
1109 
1110 /*
1111  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1112  * interrupts.  For now, the MMC core will use this for polling.
1113  */
1114 static int meson_mmc_get_cd(struct mmc_host *mmc)
1115 {
1116 	int status = mmc_gpio_get_cd(mmc);
1117 
1118 	if (status == -ENOSYS)
1119 		return 1; /* assume present */
1120 
1121 	return status;
1122 }
1123 
1124 static void meson_mmc_cfg_init(struct meson_host *host)
1125 {
1126 	u32 cfg = 0;
1127 
1128 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1129 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1130 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1131 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1132 
1133 	writel(cfg, host->regs + SD_EMMC_CFG);
1134 }
1135 
1136 static int meson_mmc_card_busy(struct mmc_host *mmc)
1137 {
1138 	struct meson_host *host = mmc_priv(mmc);
1139 	u32 regval;
1140 
1141 	regval = readl(host->regs + SD_EMMC_STATUS);
1142 
1143 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1144 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1145 }
1146 
1147 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1148 {
1149 	/* vqmmc regulator is available */
1150 	if (!IS_ERR(mmc->supply.vqmmc)) {
1151 		/*
1152 		 * The usual amlogic setup uses a GPIO to switch from one
1153 		 * regulator to the other. While the voltage ramp up is
1154 		 * pretty fast, care must be taken when switching from 3.3v
1155 		 * to 1.8v. Please make sure the regulator framework is aware
1156 		 * of your own regulator constraints
1157 		 */
1158 		return mmc_regulator_set_vqmmc(mmc, ios);
1159 	}
1160 
1161 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1162 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1163 		return 0;
1164 
1165 	return -EINVAL;
1166 }
1167 
1168 static const struct mmc_host_ops meson_mmc_ops = {
1169 	.request	= meson_mmc_request,
1170 	.set_ios	= meson_mmc_set_ios,
1171 	.get_cd         = meson_mmc_get_cd,
1172 	.pre_req	= meson_mmc_pre_req,
1173 	.post_req	= meson_mmc_post_req,
1174 	.execute_tuning = meson_mmc_execute_tuning,
1175 	.card_busy	= meson_mmc_card_busy,
1176 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1177 };
1178 
1179 static int meson_mmc_probe(struct platform_device *pdev)
1180 {
1181 	struct resource *res;
1182 	struct meson_host *host;
1183 	struct mmc_host *mmc;
1184 	int ret, irq;
1185 
1186 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1187 	if (!mmc)
1188 		return -ENOMEM;
1189 	host = mmc_priv(mmc);
1190 	host->mmc = mmc;
1191 	host->dev = &pdev->dev;
1192 	dev_set_drvdata(&pdev->dev, host);
1193 
1194 	spin_lock_init(&host->lock);
1195 
1196 	/* Get regulators and the supported OCR mask */
1197 	host->vqmmc_enabled = false;
1198 	ret = mmc_regulator_get_supply(mmc);
1199 	if (ret)
1200 		goto free_host;
1201 
1202 	ret = mmc_of_parse(mmc);
1203 	if (ret) {
1204 		if (ret != -EPROBE_DEFER)
1205 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1206 		goto free_host;
1207 	}
1208 
1209 	host->data = (struct meson_mmc_data *)
1210 		of_device_get_match_data(&pdev->dev);
1211 	if (!host->data) {
1212 		ret = -EINVAL;
1213 		goto free_host;
1214 	}
1215 
1216 	ret = device_reset_optional(&pdev->dev);
1217 	if (ret) {
1218 		if (ret != -EPROBE_DEFER)
1219 			dev_err(&pdev->dev, "device reset failed: %d\n", ret);
1220 
1221 		return ret;
1222 	}
1223 
1224 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1225 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1226 	if (IS_ERR(host->regs)) {
1227 		ret = PTR_ERR(host->regs);
1228 		goto free_host;
1229 	}
1230 
1231 	irq = platform_get_irq(pdev, 0);
1232 	if (irq <= 0) {
1233 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1234 		ret = -EINVAL;
1235 		goto free_host;
1236 	}
1237 
1238 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1239 	if (IS_ERR(host->pinctrl)) {
1240 		ret = PTR_ERR(host->pinctrl);
1241 		goto free_host;
1242 	}
1243 
1244 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1245 						  PINCTRL_STATE_DEFAULT);
1246 	if (IS_ERR(host->pins_default)) {
1247 		ret = PTR_ERR(host->pins_default);
1248 		goto free_host;
1249 	}
1250 
1251 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1252 						   "clk-gate");
1253 	if (IS_ERR(host->pins_clk_gate)) {
1254 		dev_warn(&pdev->dev,
1255 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1256 		host->pins_clk_gate = NULL;
1257 	}
1258 
1259 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1260 	if (IS_ERR(host->core_clk)) {
1261 		ret = PTR_ERR(host->core_clk);
1262 		goto free_host;
1263 	}
1264 
1265 	ret = clk_prepare_enable(host->core_clk);
1266 	if (ret)
1267 		goto free_host;
1268 
1269 	ret = meson_mmc_clk_init(host);
1270 	if (ret)
1271 		goto err_core_clk;
1272 
1273 	/* set config to sane default */
1274 	meson_mmc_cfg_init(host);
1275 
1276 	/* Stop execution */
1277 	writel(0, host->regs + SD_EMMC_START);
1278 
1279 	/* clear, ack and enable interrupts */
1280 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1281 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1282 	       host->regs + SD_EMMC_STATUS);
1283 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1284 	       host->regs + SD_EMMC_IRQ_EN);
1285 
1286 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
1287 					meson_mmc_irq_thread, IRQF_SHARED,
1288 					NULL, host);
1289 	if (ret)
1290 		goto err_init_clk;
1291 
1292 	mmc->caps |= MMC_CAP_CMD23;
1293 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1294 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1295 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1296 	mmc->max_seg_size = mmc->max_req_size;
1297 
1298 	/* data bounce buffer */
1299 	host->bounce_buf_size = mmc->max_req_size;
1300 	host->bounce_buf =
1301 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1302 				   &host->bounce_dma_addr, GFP_KERNEL);
1303 	if (host->bounce_buf == NULL) {
1304 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1305 		ret = -ENOMEM;
1306 		goto err_init_clk;
1307 	}
1308 
1309 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1310 		      &host->descs_dma_addr, GFP_KERNEL);
1311 	if (!host->descs) {
1312 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1313 		ret = -ENOMEM;
1314 		goto err_bounce_buf;
1315 	}
1316 
1317 	mmc->ops = &meson_mmc_ops;
1318 	mmc_add_host(mmc);
1319 
1320 	return 0;
1321 
1322 err_bounce_buf:
1323 	dma_free_coherent(host->dev, host->bounce_buf_size,
1324 			  host->bounce_buf, host->bounce_dma_addr);
1325 err_init_clk:
1326 	clk_disable_unprepare(host->mmc_clk);
1327 err_core_clk:
1328 	clk_disable_unprepare(host->core_clk);
1329 free_host:
1330 	mmc_free_host(mmc);
1331 	return ret;
1332 }
1333 
1334 static int meson_mmc_remove(struct platform_device *pdev)
1335 {
1336 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1337 
1338 	mmc_remove_host(host->mmc);
1339 
1340 	/* disable interrupts */
1341 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1342 
1343 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1344 			  host->descs, host->descs_dma_addr);
1345 	dma_free_coherent(host->dev, host->bounce_buf_size,
1346 			  host->bounce_buf, host->bounce_dma_addr);
1347 
1348 	clk_disable_unprepare(host->mmc_clk);
1349 	clk_disable_unprepare(host->core_clk);
1350 
1351 	mmc_free_host(host->mmc);
1352 	return 0;
1353 }
1354 
1355 static const struct meson_mmc_data meson_gx_data = {
1356 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1357 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1358 	.always_on	= CLK_V2_ALWAYS_ON,
1359 };
1360 
1361 static const struct meson_mmc_data meson_axg_data = {
1362 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1363 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1364 	.always_on	= CLK_V3_ALWAYS_ON,
1365 };
1366 
1367 static const struct of_device_id meson_mmc_of_match[] = {
1368 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1369 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1370 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1371 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1372 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1373 	{}
1374 };
1375 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1376 
1377 static struct platform_driver meson_mmc_driver = {
1378 	.probe		= meson_mmc_probe,
1379 	.remove		= meson_mmc_remove,
1380 	.driver		= {
1381 		.name = DRIVER_NAME,
1382 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1383 	},
1384 };
1385 
1386 module_platform_driver(meson_mmc_driver);
1387 
1388 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1389 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1390 MODULE_LICENSE("GPL v2");
1391