xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 711aab1d)
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/interrupt.h>
39 #include <linux/bitfield.h>
40 
41 #define DRIVER_NAME "meson-gx-mmc"
42 
43 #define SD_EMMC_CLOCK 0x0
44 #define   CLK_DIV_MASK GENMASK(5, 0)
45 #define   CLK_SRC_MASK GENMASK(7, 6)
46 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
47 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
48 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
49 #define   CLK_TX_DELAY_MASK GENMASK(19, 16)
50 #define   CLK_RX_DELAY_MASK GENMASK(23, 20)
51 #define   CLK_DELAY_STEP_PS 200
52 #define   CLK_PHASE_STEP 30
53 #define   CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
54 #define   CLK_ALWAYS_ON BIT(24)
55 
56 #define SD_EMMC_DELAY 0x4
57 #define SD_EMMC_ADJUST 0x8
58 #define SD_EMMC_CALOUT 0x10
59 #define SD_EMMC_START 0x40
60 #define   START_DESC_INIT BIT(0)
61 #define   START_DESC_BUSY BIT(1)
62 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
63 
64 #define SD_EMMC_CFG 0x44
65 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
66 #define   CFG_BUS_WIDTH_1 0x0
67 #define   CFG_BUS_WIDTH_4 0x1
68 #define   CFG_BUS_WIDTH_8 0x2
69 #define   CFG_DDR BIT(2)
70 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
71 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
72 #define   CFG_RC_CC_MASK GENMASK(15, 12)
73 #define   CFG_STOP_CLOCK BIT(22)
74 #define   CFG_CLK_ALWAYS_ON BIT(18)
75 #define   CFG_CHK_DS BIT(20)
76 #define   CFG_AUTO_CLK BIT(23)
77 
78 #define SD_EMMC_STATUS 0x48
79 #define   STATUS_BUSY BIT(31)
80 #define   STATUS_DATI GENMASK(23, 16)
81 
82 #define SD_EMMC_IRQ_EN 0x4c
83 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
84 #define   IRQ_TXD_ERR BIT(8)
85 #define   IRQ_DESC_ERR BIT(9)
86 #define   IRQ_RESP_ERR BIT(10)
87 #define   IRQ_CRC_ERR \
88 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
89 #define   IRQ_RESP_TIMEOUT BIT(11)
90 #define   IRQ_DESC_TIMEOUT BIT(12)
91 #define   IRQ_TIMEOUTS \
92 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
93 #define   IRQ_END_OF_CHAIN BIT(13)
94 #define   IRQ_RESP_STATUS BIT(14)
95 #define   IRQ_SDIO BIT(15)
96 #define   IRQ_EN_MASK \
97 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
98 	 IRQ_SDIO)
99 
100 #define SD_EMMC_CMD_CFG 0x50
101 #define SD_EMMC_CMD_ARG 0x54
102 #define SD_EMMC_CMD_DAT 0x58
103 #define SD_EMMC_CMD_RSP 0x5c
104 #define SD_EMMC_CMD_RSP1 0x60
105 #define SD_EMMC_CMD_RSP2 0x64
106 #define SD_EMMC_CMD_RSP3 0x68
107 
108 #define SD_EMMC_RXD 0x94
109 #define SD_EMMC_TXD 0x94
110 #define SD_EMMC_LAST_REG SD_EMMC_TXD
111 
112 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
113 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
114 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
115 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
116 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
117 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
118 
119 #define SD_EMMC_PRE_REQ_DONE BIT(0)
120 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
121 
122 #define MUX_CLK_NUM_PARENTS 2
123 
124 struct sd_emmc_desc {
125 	u32 cmd_cfg;
126 	u32 cmd_arg;
127 	u32 cmd_data;
128 	u32 cmd_resp;
129 };
130 
131 struct meson_host {
132 	struct	device		*dev;
133 	struct	mmc_host	*mmc;
134 	struct	mmc_command	*cmd;
135 
136 	spinlock_t lock;
137 	void __iomem *regs;
138 	struct clk *core_clk;
139 	struct clk *mmc_clk;
140 	struct clk *rx_clk;
141 	struct clk *tx_clk;
142 	unsigned long req_rate;
143 
144 	struct pinctrl *pinctrl;
145 	struct pinctrl_state *pins_default;
146 	struct pinctrl_state *pins_clk_gate;
147 
148 	unsigned int bounce_buf_size;
149 	void *bounce_buf;
150 	dma_addr_t bounce_dma_addr;
151 	struct sd_emmc_desc *descs;
152 	dma_addr_t descs_dma_addr;
153 
154 	bool vqmmc_enabled;
155 };
156 
157 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
158 #define CMD_CFG_BLOCK_MODE BIT(9)
159 #define CMD_CFG_R1B BIT(10)
160 #define CMD_CFG_END_OF_CHAIN BIT(11)
161 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
162 #define CMD_CFG_NO_RESP BIT(16)
163 #define CMD_CFG_NO_CMD BIT(17)
164 #define CMD_CFG_DATA_IO BIT(18)
165 #define CMD_CFG_DATA_WR BIT(19)
166 #define CMD_CFG_RESP_NOCRC BIT(20)
167 #define CMD_CFG_RESP_128 BIT(21)
168 #define CMD_CFG_RESP_NUM BIT(22)
169 #define CMD_CFG_DATA_NUM BIT(23)
170 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
171 #define CMD_CFG_ERROR BIT(30)
172 #define CMD_CFG_OWNER BIT(31)
173 
174 #define CMD_DATA_MASK GENMASK(31, 2)
175 #define CMD_DATA_BIG_ENDIAN BIT(1)
176 #define CMD_DATA_SRAM BIT(0)
177 #define CMD_RESP_MASK GENMASK(31, 1)
178 #define CMD_RESP_SRAM BIT(0)
179 
180 struct meson_mmc_phase {
181 	struct clk_hw hw;
182 	void __iomem *reg;
183 	unsigned long phase_mask;
184 	unsigned long delay_mask;
185 	unsigned int delay_step_ps;
186 };
187 
188 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
189 
190 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
191 {
192 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
193 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
194 	unsigned long period_ps, p, d;
195 		int degrees;
196 	u32 val;
197 
198 	val = readl(mmc->reg);
199 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
200 	degrees = p * 360 / phase_num;
201 
202 	if (mmc->delay_mask) {
203 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
204 					 clk_get_rate(hw->clk));
205 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
206 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
207 		degrees %= 360;
208 	}
209 
210 	return degrees;
211 }
212 
213 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
214 					unsigned int phase,
215 					unsigned int delay)
216 {
217 	u32 val;
218 
219 	val = readl(mmc->reg);
220 	val &= ~mmc->phase_mask;
221 	val |= phase << __ffs(mmc->phase_mask);
222 
223 	if (mmc->delay_mask) {
224 		val &= ~mmc->delay_mask;
225 		val |= delay << __ffs(mmc->delay_mask);
226 	}
227 
228 	writel(val, mmc->reg);
229 }
230 
231 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
232 {
233 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
234 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
235 	unsigned long period_ps, d = 0, r;
236 	uint64_t p;
237 
238 	p = degrees % 360;
239 
240 	if (!mmc->delay_mask) {
241 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
242 	} else {
243 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
244 					 clk_get_rate(hw->clk));
245 
246 		/* First compute the phase index (p), the remainder (r) is the
247 		 * part we'll try to acheive using the delays (d).
248 		 */
249 		r = do_div(p, 360 / phase_num);
250 		d = DIV_ROUND_CLOSEST(r * period_ps,
251 				      360 * mmc->delay_step_ps);
252 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
253 	}
254 
255 	meson_mmc_apply_phase_delay(mmc, p, d);
256 	return 0;
257 }
258 
259 static const struct clk_ops meson_mmc_clk_phase_ops = {
260 	.get_phase = meson_mmc_clk_get_phase,
261 	.set_phase = meson_mmc_clk_set_phase,
262 };
263 
264 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
265 {
266 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
267 
268 	if (!timeout)
269 		return SD_EMMC_CMD_TIMEOUT_DATA;
270 
271 	timeout = roundup_pow_of_two(timeout);
272 
273 	return min(timeout, 32768U); /* max. 2^15 ms */
274 }
275 
276 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
277 {
278 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
279 		return cmd->mrq->cmd;
280 	else if (mmc_op_multi(cmd->opcode) &&
281 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
282 		return cmd->mrq->stop;
283 	else
284 		return NULL;
285 }
286 
287 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
288 					struct mmc_request *mrq)
289 {
290 	struct mmc_data *data = mrq->data;
291 	struct scatterlist *sg;
292 	int i;
293 	bool use_desc_chain_mode = true;
294 
295 	/*
296 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
297 	 * reported. For some strange reason this occurs in descriptor
298 	 * chain mode only. So let's fall back to bounce buffer mode
299 	 * for command SD_IO_RW_EXTENDED.
300 	 */
301 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
302 		return;
303 
304 	for_each_sg(data->sg, sg, data->sg_len, i)
305 		/* check for 8 byte alignment */
306 		if (sg->offset & 7) {
307 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
308 			use_desc_chain_mode = false;
309 			break;
310 		}
311 
312 	if (use_desc_chain_mode)
313 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
314 }
315 
316 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
317 {
318 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
319 }
320 
321 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
322 {
323 	return data && data->flags & MMC_DATA_READ &&
324 	       !meson_mmc_desc_chain_mode(data);
325 }
326 
327 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
328 {
329 	struct mmc_data *data = mrq->data;
330 
331 	if (!data)
332 		return;
333 
334 	meson_mmc_get_transfer_mode(mmc, mrq);
335 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
336 
337 	if (!meson_mmc_desc_chain_mode(data))
338 		return;
339 
340 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
341                                    mmc_get_dma_dir(data));
342 	if (!data->sg_count)
343 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
344 }
345 
346 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
347 			       int err)
348 {
349 	struct mmc_data *data = mrq->data;
350 
351 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
352 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
353 			     mmc_get_dma_dir(data));
354 }
355 
356 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
357 {
358 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
359 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
360 	    ios->timing == MMC_TIMING_MMC_HS400)
361 		return true;
362 
363 	return false;
364 }
365 
366 /*
367  * Gating the clock on this controller is tricky.  It seems the mmc clock
368  * is also used by the controller.  It may crash during some operation if the
369  * clock is stopped.  The safest thing to do, whenever possible, is to keep
370  * clock running at stop it at the pad using the pinmux.
371  */
372 static void meson_mmc_clk_gate(struct meson_host *host)
373 {
374 	u32 cfg;
375 
376 	if (host->pins_clk_gate) {
377 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
378 	} else {
379 		/*
380 		 * If the pinmux is not provided - default to the classic and
381 		 * unsafe method
382 		 */
383 		cfg = readl(host->regs + SD_EMMC_CFG);
384 		cfg |= CFG_STOP_CLOCK;
385 		writel(cfg, host->regs + SD_EMMC_CFG);
386 	}
387 }
388 
389 static void meson_mmc_clk_ungate(struct meson_host *host)
390 {
391 	u32 cfg;
392 
393 	if (host->pins_clk_gate)
394 		pinctrl_select_state(host->pinctrl, host->pins_default);
395 
396 	/* Make sure the clock is not stopped in the controller */
397 	cfg = readl(host->regs + SD_EMMC_CFG);
398 	cfg &= ~CFG_STOP_CLOCK;
399 	writel(cfg, host->regs + SD_EMMC_CFG);
400 }
401 
402 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
403 {
404 	struct mmc_host *mmc = host->mmc;
405 	unsigned long rate = ios->clock;
406 	int ret;
407 	u32 cfg;
408 
409 	/* DDR modes require higher module clock */
410 	if (meson_mmc_timing_is_ddr(ios))
411 		rate <<= 1;
412 
413 	/* Same request - bail-out */
414 	if (host->req_rate == rate)
415 		return 0;
416 
417 	/* stop clock */
418 	meson_mmc_clk_gate(host);
419 	host->req_rate = 0;
420 
421 	if (!rate) {
422 		mmc->actual_clock = 0;
423 		/* return with clock being stopped */
424 		return 0;
425 	}
426 
427 	/* Stop the clock during rate change to avoid glitches */
428 	cfg = readl(host->regs + SD_EMMC_CFG);
429 	cfg |= CFG_STOP_CLOCK;
430 	writel(cfg, host->regs + SD_EMMC_CFG);
431 
432 	ret = clk_set_rate(host->mmc_clk, rate);
433 	if (ret) {
434 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
435 			rate, ret);
436 		return ret;
437 	}
438 
439 	host->req_rate = rate;
440 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
441 
442 	/* We should report the real output frequency of the controller */
443 	if (meson_mmc_timing_is_ddr(ios))
444 		mmc->actual_clock >>= 1;
445 
446 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
447 	if (ios->clock != mmc->actual_clock)
448 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
449 
450 	/* (re)start clock */
451 	meson_mmc_clk_ungate(host);
452 
453 	return 0;
454 }
455 
456 /*
457  * The SD/eMMC IP block has an internal mux and divider used for
458  * generating the MMC clock.  Use the clock framework to create and
459  * manage these clocks.
460  */
461 static int meson_mmc_clk_init(struct meson_host *host)
462 {
463 	struct clk_init_data init;
464 	struct clk_mux *mux;
465 	struct clk_divider *div;
466 	struct meson_mmc_phase *core, *tx, *rx;
467 	struct clk *clk;
468 	char clk_name[32];
469 	int i, ret = 0;
470 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
471 	const char *clk_parent[1];
472 	u32 clk_reg;
473 
474 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
475 	clk_reg = 0;
476 	clk_reg |= CLK_ALWAYS_ON;
477 	clk_reg |= CLK_DIV_MASK;
478 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
479 
480 	/* get the mux parents */
481 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
482 		struct clk *clk;
483 		char name[16];
484 
485 		snprintf(name, sizeof(name), "clkin%d", i);
486 		clk = devm_clk_get(host->dev, name);
487 		if (IS_ERR(clk)) {
488 			if (clk != ERR_PTR(-EPROBE_DEFER))
489 				dev_err(host->dev, "Missing clock %s\n", name);
490 			return PTR_ERR(clk);
491 		}
492 
493 		mux_parent_names[i] = __clk_get_name(clk);
494 	}
495 
496 	/* create the mux */
497 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
498 	if (!mux)
499 		return -ENOMEM;
500 
501 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
502 	init.name = clk_name;
503 	init.ops = &clk_mux_ops;
504 	init.flags = 0;
505 	init.parent_names = mux_parent_names;
506 	init.num_parents = MUX_CLK_NUM_PARENTS;
507 
508 	mux->reg = host->regs + SD_EMMC_CLOCK;
509 	mux->shift = __ffs(CLK_SRC_MASK);
510 	mux->mask = CLK_SRC_MASK >> mux->shift;
511 	mux->hw.init = &init;
512 
513 	clk = devm_clk_register(host->dev, &mux->hw);
514 	if (WARN_ON(IS_ERR(clk)))
515 		return PTR_ERR(clk);
516 
517 	/* create the divider */
518 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
519 	if (!div)
520 		return -ENOMEM;
521 
522 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
523 	init.name = clk_name;
524 	init.ops = &clk_divider_ops;
525 	init.flags = CLK_SET_RATE_PARENT;
526 	clk_parent[0] = __clk_get_name(clk);
527 	init.parent_names = clk_parent;
528 	init.num_parents = 1;
529 
530 	div->reg = host->regs + SD_EMMC_CLOCK;
531 	div->shift = __ffs(CLK_DIV_MASK);
532 	div->width = __builtin_popcountl(CLK_DIV_MASK);
533 	div->hw.init = &init;
534 	div->flags = (CLK_DIVIDER_ONE_BASED |
535 		      CLK_DIVIDER_ROUND_CLOSEST);
536 
537 	clk = devm_clk_register(host->dev, &div->hw);
538 	if (WARN_ON(IS_ERR(clk)))
539 		return PTR_ERR(clk);
540 
541 	/* create the mmc core clock */
542 	core = devm_kzalloc(host->dev, sizeof(*core), GFP_KERNEL);
543 	if (!core)
544 		return -ENOMEM;
545 
546 	snprintf(clk_name, sizeof(clk_name), "%s#core", dev_name(host->dev));
547 	init.name = clk_name;
548 	init.ops = &meson_mmc_clk_phase_ops;
549 	init.flags = CLK_SET_RATE_PARENT;
550 	clk_parent[0] = __clk_get_name(clk);
551 	init.parent_names = clk_parent;
552 	init.num_parents = 1;
553 
554 	core->reg = host->regs + SD_EMMC_CLOCK;
555 	core->phase_mask = CLK_CORE_PHASE_MASK;
556 	core->hw.init = &init;
557 
558 	host->mmc_clk = devm_clk_register(host->dev, &core->hw);
559 	if (WARN_ON(PTR_ERR_OR_ZERO(host->mmc_clk)))
560 		return PTR_ERR(host->mmc_clk);
561 
562 	/* create the mmc tx clock */
563 	tx = devm_kzalloc(host->dev, sizeof(*tx), GFP_KERNEL);
564 	if (!tx)
565 		return -ENOMEM;
566 
567 	snprintf(clk_name, sizeof(clk_name), "%s#tx", dev_name(host->dev));
568 	init.name = clk_name;
569 	init.ops = &meson_mmc_clk_phase_ops;
570 	init.flags = 0;
571 	clk_parent[0] = __clk_get_name(host->mmc_clk);
572 	init.parent_names = clk_parent;
573 	init.num_parents = 1;
574 
575 	tx->reg = host->regs + SD_EMMC_CLOCK;
576 	tx->phase_mask = CLK_TX_PHASE_MASK;
577 	tx->delay_mask = CLK_TX_DELAY_MASK;
578 	tx->delay_step_ps = CLK_DELAY_STEP_PS;
579 	tx->hw.init = &init;
580 
581 	host->tx_clk = devm_clk_register(host->dev, &tx->hw);
582 	if (WARN_ON(PTR_ERR_OR_ZERO(host->tx_clk)))
583 		return PTR_ERR(host->tx_clk);
584 
585 	/* create the mmc rx clock */
586 	rx = devm_kzalloc(host->dev, sizeof(*rx), GFP_KERNEL);
587 	if (!rx)
588 		return -ENOMEM;
589 
590 	snprintf(clk_name, sizeof(clk_name), "%s#rx", dev_name(host->dev));
591 	init.name = clk_name;
592 	init.ops = &meson_mmc_clk_phase_ops;
593 	init.flags = 0;
594 	clk_parent[0] = __clk_get_name(host->mmc_clk);
595 	init.parent_names = clk_parent;
596 	init.num_parents = 1;
597 
598 	rx->reg = host->regs + SD_EMMC_CLOCK;
599 	rx->phase_mask = CLK_RX_PHASE_MASK;
600 	rx->delay_mask = CLK_RX_DELAY_MASK;
601 	rx->delay_step_ps = CLK_DELAY_STEP_PS;
602 	rx->hw.init = &init;
603 
604 	host->rx_clk = devm_clk_register(host->dev, &rx->hw);
605 	if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
606 		return PTR_ERR(host->rx_clk);
607 
608 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
609 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
610 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
611 	if (ret)
612 		return ret;
613 
614 	/*
615 	 * Set phases : These values are mostly the datasheet recommended ones
616 	 * except for the Tx phase. Datasheet recommends 180 but some cards
617 	 * fail at initialisation with it. 270 works just fine, it fixes these
618 	 * initialisation issues and enable eMMC DDR52 mode.
619 	 */
620 	clk_set_phase(host->mmc_clk, 180);
621 	clk_set_phase(host->tx_clk, 270);
622 	clk_set_phase(host->rx_clk, 0);
623 
624 	return clk_prepare_enable(host->mmc_clk);
625 }
626 
627 static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
628 {
629 	DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
630 	DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
631 
632 	/*
633 	 * shift the bitmap right and reintroduce the dropped bits on the left
634 	 * of the bitmap
635 	 */
636 	bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
637 	bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
638 			  CLK_PHASE_POINT_NUM);
639 	bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
640 }
641 
642 static void meson_mmc_find_next_region(unsigned long *map,
643 				       unsigned long *start,
644 				       unsigned long *stop)
645 {
646 	*start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
647 	*stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
648 }
649 
650 static int meson_mmc_find_tuning_point(unsigned long *test)
651 {
652 	unsigned long shift, stop, offset = 0, start = 0, size = 0;
653 
654 	/* Get the all good/all bad situation out the way */
655 	if (bitmap_full(test, CLK_PHASE_POINT_NUM))
656 		return 0; /* All points are good so point 0 will do */
657 	else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
658 		return -EIO; /* No successful tuning point */
659 
660 	/*
661 	 * Now we know there is a least one region find. Make sure it does
662 	 * not wrap by the shifting the bitmap if necessary
663 	 */
664 	shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
665 	if (shift != 0)
666 		meson_mmc_shift_map(test, shift);
667 
668 	while (start < CLK_PHASE_POINT_NUM) {
669 		meson_mmc_find_next_region(test, &start, &stop);
670 
671 		if ((stop - start) > size) {
672 			offset = start;
673 			size = stop - start;
674 		}
675 
676 		start = stop;
677 	}
678 
679 	/* Get the center point of the region */
680 	offset += (size / 2);
681 
682 	/* Shift the result back */
683 	offset = (offset + shift) % CLK_PHASE_POINT_NUM;
684 
685 	return offset;
686 }
687 
688 static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
689 				      struct clk *clk)
690 {
691 	int point, ret;
692 	DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
693 
694 	dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
695 		__clk_get_name(clk));
696 	bitmap_zero(test, CLK_PHASE_POINT_NUM);
697 
698 	/* Explore tuning points */
699 	for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
700 		clk_set_phase(clk, point * CLK_PHASE_STEP);
701 		ret = mmc_send_tuning(mmc, opcode, NULL);
702 		if (!ret)
703 			set_bit(point, test);
704 	}
705 
706 	/* Find the optimal tuning point and apply it */
707 	point = meson_mmc_find_tuning_point(test);
708 	if (point < 0)
709 		return point; /* tuning failed */
710 
711 	clk_set_phase(clk, point * CLK_PHASE_STEP);
712 	dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
713 		clk_get_phase(clk));
714 	return 0;
715 }
716 
717 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
718 {
719 	struct meson_host *host = mmc_priv(mmc);
720 
721 	return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
722 }
723 
724 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
725 {
726 	struct meson_host *host = mmc_priv(mmc);
727 	u32 bus_width, val;
728 	int err;
729 
730 	/*
731 	 * GPIO regulator, only controls switching between 1v8 and
732 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
733 	 */
734 	switch (ios->power_mode) {
735 	case MMC_POWER_OFF:
736 		if (!IS_ERR(mmc->supply.vmmc))
737 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
738 
739 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
740 			regulator_disable(mmc->supply.vqmmc);
741 			host->vqmmc_enabled = false;
742 		}
743 
744 		break;
745 
746 	case MMC_POWER_UP:
747 		if (!IS_ERR(mmc->supply.vmmc))
748 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
749 		break;
750 
751 	case MMC_POWER_ON:
752 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
753 			int ret = regulator_enable(mmc->supply.vqmmc);
754 
755 			if (ret < 0)
756 				dev_err(host->dev,
757 					"failed to enable vqmmc regulator\n");
758 			else
759 				host->vqmmc_enabled = true;
760 		}
761 
762 		/* Reset rx phase */
763 		clk_set_phase(host->rx_clk, 0);
764 		break;
765 	}
766 
767 	/* Bus width */
768 	switch (ios->bus_width) {
769 	case MMC_BUS_WIDTH_1:
770 		bus_width = CFG_BUS_WIDTH_1;
771 		break;
772 	case MMC_BUS_WIDTH_4:
773 		bus_width = CFG_BUS_WIDTH_4;
774 		break;
775 	case MMC_BUS_WIDTH_8:
776 		bus_width = CFG_BUS_WIDTH_8;
777 		break;
778 	default:
779 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
780 			ios->bus_width);
781 		bus_width = CFG_BUS_WIDTH_4;
782 	}
783 
784 	val = readl(host->regs + SD_EMMC_CFG);
785 	val &= ~CFG_BUS_WIDTH_MASK;
786 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
787 
788 	val &= ~CFG_DDR;
789 	if (meson_mmc_timing_is_ddr(ios))
790 		val |= CFG_DDR;
791 
792 	val &= ~CFG_CHK_DS;
793 	if (ios->timing == MMC_TIMING_MMC_HS400)
794 		val |= CFG_CHK_DS;
795 
796 	err = meson_mmc_clk_set(host, ios);
797 	if (err)
798 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
799 
800 	writel(val, host->regs + SD_EMMC_CFG);
801 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
802 }
803 
804 static void meson_mmc_request_done(struct mmc_host *mmc,
805 				   struct mmc_request *mrq)
806 {
807 	struct meson_host *host = mmc_priv(mmc);
808 
809 	host->cmd = NULL;
810 	mmc_request_done(host->mmc, mrq);
811 }
812 
813 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
814 {
815 	struct meson_host *host = mmc_priv(mmc);
816 	u32 cfg, blksz_old;
817 
818 	cfg = readl(host->regs + SD_EMMC_CFG);
819 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
820 
821 	if (!is_power_of_2(blksz))
822 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
823 
824 	blksz = ilog2(blksz);
825 
826 	/* check if block-size matches, if not update */
827 	if (blksz == blksz_old)
828 		return;
829 
830 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
831 		blksz_old, blksz);
832 
833 	cfg &= ~CFG_BLK_LEN_MASK;
834 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
835 	writel(cfg, host->regs + SD_EMMC_CFG);
836 }
837 
838 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
839 {
840 	if (cmd->flags & MMC_RSP_PRESENT) {
841 		if (cmd->flags & MMC_RSP_136)
842 			*cmd_cfg |= CMD_CFG_RESP_128;
843 		*cmd_cfg |= CMD_CFG_RESP_NUM;
844 
845 		if (!(cmd->flags & MMC_RSP_CRC))
846 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
847 
848 		if (cmd->flags & MMC_RSP_BUSY)
849 			*cmd_cfg |= CMD_CFG_R1B;
850 	} else {
851 		*cmd_cfg |= CMD_CFG_NO_RESP;
852 	}
853 }
854 
855 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
856 {
857 	struct meson_host *host = mmc_priv(mmc);
858 	struct sd_emmc_desc *desc = host->descs;
859 	struct mmc_data *data = host->cmd->data;
860 	struct scatterlist *sg;
861 	u32 start;
862 	int i;
863 
864 	if (data->flags & MMC_DATA_WRITE)
865 		cmd_cfg |= CMD_CFG_DATA_WR;
866 
867 	if (data->blocks > 1) {
868 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
869 		meson_mmc_set_blksz(mmc, data->blksz);
870 	}
871 
872 	for_each_sg(data->sg, sg, data->sg_count, i) {
873 		unsigned int len = sg_dma_len(sg);
874 
875 		if (data->blocks > 1)
876 			len /= data->blksz;
877 
878 		desc[i].cmd_cfg = cmd_cfg;
879 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
880 		if (i > 0)
881 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
882 		desc[i].cmd_arg = host->cmd->arg;
883 		desc[i].cmd_resp = 0;
884 		desc[i].cmd_data = sg_dma_address(sg);
885 	}
886 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
887 
888 	dma_wmb(); /* ensure descriptor is written before kicked */
889 	start = host->descs_dma_addr | START_DESC_BUSY;
890 	writel(start, host->regs + SD_EMMC_START);
891 }
892 
893 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
894 {
895 	struct meson_host *host = mmc_priv(mmc);
896 	struct mmc_data *data = cmd->data;
897 	u32 cmd_cfg = 0, cmd_data = 0;
898 	unsigned int xfer_bytes = 0;
899 
900 	/* Setup descriptors */
901 	dma_rmb();
902 
903 	host->cmd = cmd;
904 
905 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
906 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
907 
908 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
909 
910 	/* data? */
911 	if (data) {
912 		data->bytes_xfered = 0;
913 		cmd_cfg |= CMD_CFG_DATA_IO;
914 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
915 				      ilog2(meson_mmc_get_timeout_msecs(data)));
916 
917 		if (meson_mmc_desc_chain_mode(data)) {
918 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
919 			return;
920 		}
921 
922 		if (data->blocks > 1) {
923 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
924 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
925 					      data->blocks);
926 			meson_mmc_set_blksz(mmc, data->blksz);
927 		} else {
928 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
929 		}
930 
931 		xfer_bytes = data->blksz * data->blocks;
932 		if (data->flags & MMC_DATA_WRITE) {
933 			cmd_cfg |= CMD_CFG_DATA_WR;
934 			WARN_ON(xfer_bytes > host->bounce_buf_size);
935 			sg_copy_to_buffer(data->sg, data->sg_len,
936 					  host->bounce_buf, xfer_bytes);
937 			dma_wmb();
938 		}
939 
940 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
941 	} else {
942 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
943 				      ilog2(SD_EMMC_CMD_TIMEOUT));
944 	}
945 
946 	/* Last descriptor */
947 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
948 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
949 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
950 	writel(0, host->regs + SD_EMMC_CMD_RSP);
951 	wmb(); /* ensure descriptor is written before kicked */
952 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
953 }
954 
955 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
956 {
957 	struct meson_host *host = mmc_priv(mmc);
958 	bool needs_pre_post_req = mrq->data &&
959 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
960 
961 	if (needs_pre_post_req) {
962 		meson_mmc_get_transfer_mode(mmc, mrq);
963 		if (!meson_mmc_desc_chain_mode(mrq->data))
964 			needs_pre_post_req = false;
965 	}
966 
967 	if (needs_pre_post_req)
968 		meson_mmc_pre_req(mmc, mrq);
969 
970 	/* Stop execution */
971 	writel(0, host->regs + SD_EMMC_START);
972 
973 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
974 
975 	if (needs_pre_post_req)
976 		meson_mmc_post_req(mmc, mrq, 0);
977 }
978 
979 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
980 {
981 	struct meson_host *host = mmc_priv(mmc);
982 
983 	if (cmd->flags & MMC_RSP_136) {
984 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
985 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
986 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
987 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
988 	} else if (cmd->flags & MMC_RSP_PRESENT) {
989 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
990 	}
991 }
992 
993 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
994 {
995 	struct meson_host *host = dev_id;
996 	struct mmc_command *cmd;
997 	struct mmc_data *data;
998 	u32 irq_en, status, raw_status;
999 	irqreturn_t ret = IRQ_NONE;
1000 
1001 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1002 		return IRQ_NONE;
1003 
1004 	spin_lock(&host->lock);
1005 
1006 	cmd = host->cmd;
1007 	data = cmd->data;
1008 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1009 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1010 	status = raw_status & irq_en;
1011 
1012 	cmd->error = 0;
1013 	if (status & IRQ_CRC_ERR) {
1014 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1015 		cmd->error = -EILSEQ;
1016 		ret = IRQ_HANDLED;
1017 		goto out;
1018 	}
1019 
1020 	if (status & IRQ_TIMEOUTS) {
1021 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1022 		cmd->error = -ETIMEDOUT;
1023 		ret = IRQ_HANDLED;
1024 		goto out;
1025 	}
1026 
1027 	meson_mmc_read_resp(host->mmc, cmd);
1028 
1029 	if (status & IRQ_SDIO) {
1030 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1031 		ret = IRQ_HANDLED;
1032 	}
1033 
1034 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1035 		if (data && !cmd->error)
1036 			data->bytes_xfered = data->blksz * data->blocks;
1037 		if (meson_mmc_bounce_buf_read(data) ||
1038 		    meson_mmc_get_next_command(cmd))
1039 			ret = IRQ_WAKE_THREAD;
1040 		else
1041 			ret = IRQ_HANDLED;
1042 	}
1043 
1044 out:
1045 	/* ack all enabled interrupts */
1046 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1047 
1048 	if (ret == IRQ_HANDLED)
1049 		meson_mmc_request_done(host->mmc, cmd->mrq);
1050 	else if (ret == IRQ_NONE)
1051 		dev_warn(host->dev,
1052 			 "Unexpected IRQ! status=0x%08x, irq_en=0x%08x\n",
1053 			 raw_status, irq_en);
1054 
1055 	spin_unlock(&host->lock);
1056 	return ret;
1057 }
1058 
1059 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1060 {
1061 	struct meson_host *host = dev_id;
1062 	struct mmc_command *next_cmd, *cmd = host->cmd;
1063 	struct mmc_data *data;
1064 	unsigned int xfer_bytes;
1065 
1066 	if (WARN_ON(!cmd))
1067 		return IRQ_NONE;
1068 
1069 	data = cmd->data;
1070 	if (meson_mmc_bounce_buf_read(data)) {
1071 		xfer_bytes = data->blksz * data->blocks;
1072 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1073 		sg_copy_from_buffer(data->sg, data->sg_len,
1074 				    host->bounce_buf, xfer_bytes);
1075 	}
1076 
1077 	next_cmd = meson_mmc_get_next_command(cmd);
1078 	if (next_cmd)
1079 		meson_mmc_start_cmd(host->mmc, next_cmd);
1080 	else
1081 		meson_mmc_request_done(host->mmc, cmd->mrq);
1082 
1083 	return IRQ_HANDLED;
1084 }
1085 
1086 /*
1087  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1088  * interrupts.  For now, the MMC core will use this for polling.
1089  */
1090 static int meson_mmc_get_cd(struct mmc_host *mmc)
1091 {
1092 	int status = mmc_gpio_get_cd(mmc);
1093 
1094 	if (status == -ENOSYS)
1095 		return 1; /* assume present */
1096 
1097 	return status;
1098 }
1099 
1100 static void meson_mmc_cfg_init(struct meson_host *host)
1101 {
1102 	u32 cfg = 0;
1103 
1104 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1105 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1106 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1107 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1108 
1109 	writel(cfg, host->regs + SD_EMMC_CFG);
1110 }
1111 
1112 static int meson_mmc_card_busy(struct mmc_host *mmc)
1113 {
1114 	struct meson_host *host = mmc_priv(mmc);
1115 	u32 regval;
1116 
1117 	regval = readl(host->regs + SD_EMMC_STATUS);
1118 
1119 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1120 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1121 }
1122 
1123 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1124 {
1125 	/* vqmmc regulator is available */
1126 	if (!IS_ERR(mmc->supply.vqmmc)) {
1127 		/*
1128 		 * The usual amlogic setup uses a GPIO to switch from one
1129 		 * regulator to the other. While the voltage ramp up is
1130 		 * pretty fast, care must be taken when switching from 3.3v
1131 		 * to 1.8v. Please make sure the regulator framework is aware
1132 		 * of your own regulator constraints
1133 		 */
1134 		return mmc_regulator_set_vqmmc(mmc, ios);
1135 	}
1136 
1137 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1138 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1139 		return 0;
1140 
1141 	return -EINVAL;
1142 }
1143 
1144 static const struct mmc_host_ops meson_mmc_ops = {
1145 	.request	= meson_mmc_request,
1146 	.set_ios	= meson_mmc_set_ios,
1147 	.get_cd         = meson_mmc_get_cd,
1148 	.pre_req	= meson_mmc_pre_req,
1149 	.post_req	= meson_mmc_post_req,
1150 	.execute_tuning = meson_mmc_execute_tuning,
1151 	.card_busy	= meson_mmc_card_busy,
1152 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1153 };
1154 
1155 static int meson_mmc_probe(struct platform_device *pdev)
1156 {
1157 	struct resource *res;
1158 	struct meson_host *host;
1159 	struct mmc_host *mmc;
1160 	int ret, irq;
1161 
1162 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1163 	if (!mmc)
1164 		return -ENOMEM;
1165 	host = mmc_priv(mmc);
1166 	host->mmc = mmc;
1167 	host->dev = &pdev->dev;
1168 	dev_set_drvdata(&pdev->dev, host);
1169 
1170 	spin_lock_init(&host->lock);
1171 
1172 	/* Get regulators and the supported OCR mask */
1173 	host->vqmmc_enabled = false;
1174 	ret = mmc_regulator_get_supply(mmc);
1175 	if (ret == -EPROBE_DEFER)
1176 		goto free_host;
1177 
1178 	ret = mmc_of_parse(mmc);
1179 	if (ret) {
1180 		if (ret != -EPROBE_DEFER)
1181 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1182 		goto free_host;
1183 	}
1184 
1185 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1186 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1187 	if (IS_ERR(host->regs)) {
1188 		ret = PTR_ERR(host->regs);
1189 		goto free_host;
1190 	}
1191 
1192 	irq = platform_get_irq(pdev, 0);
1193 	if (!irq) {
1194 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1195 		ret = -EINVAL;
1196 		goto free_host;
1197 	}
1198 
1199 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1200 	if (IS_ERR(host->pinctrl)) {
1201 		ret = PTR_ERR(host->pinctrl);
1202 		goto free_host;
1203 	}
1204 
1205 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1206 						  PINCTRL_STATE_DEFAULT);
1207 	if (IS_ERR(host->pins_default)) {
1208 		ret = PTR_ERR(host->pins_default);
1209 		goto free_host;
1210 	}
1211 
1212 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1213 						   "clk-gate");
1214 	if (IS_ERR(host->pins_clk_gate)) {
1215 		dev_warn(&pdev->dev,
1216 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1217 		host->pins_clk_gate = NULL;
1218 	}
1219 
1220 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1221 	if (IS_ERR(host->core_clk)) {
1222 		ret = PTR_ERR(host->core_clk);
1223 		goto free_host;
1224 	}
1225 
1226 	ret = clk_prepare_enable(host->core_clk);
1227 	if (ret)
1228 		goto free_host;
1229 
1230 	ret = meson_mmc_clk_init(host);
1231 	if (ret)
1232 		goto err_core_clk;
1233 
1234 	/* set config to sane default */
1235 	meson_mmc_cfg_init(host);
1236 
1237 	/* Stop execution */
1238 	writel(0, host->regs + SD_EMMC_START);
1239 
1240 	/* clear, ack and enable interrupts */
1241 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1242 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1243 	       host->regs + SD_EMMC_STATUS);
1244 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1245 	       host->regs + SD_EMMC_IRQ_EN);
1246 
1247 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
1248 					meson_mmc_irq_thread, IRQF_SHARED,
1249 					NULL, host);
1250 	if (ret)
1251 		goto err_init_clk;
1252 
1253 	mmc->caps |= MMC_CAP_CMD23;
1254 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1255 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1256 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1257 	mmc->max_seg_size = mmc->max_req_size;
1258 
1259 	/* data bounce buffer */
1260 	host->bounce_buf_size = mmc->max_req_size;
1261 	host->bounce_buf =
1262 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1263 				   &host->bounce_dma_addr, GFP_KERNEL);
1264 	if (host->bounce_buf == NULL) {
1265 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1266 		ret = -ENOMEM;
1267 		goto err_init_clk;
1268 	}
1269 
1270 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1271 		      &host->descs_dma_addr, GFP_KERNEL);
1272 	if (!host->descs) {
1273 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1274 		ret = -ENOMEM;
1275 		goto err_bounce_buf;
1276 	}
1277 
1278 	mmc->ops = &meson_mmc_ops;
1279 	mmc_add_host(mmc);
1280 
1281 	return 0;
1282 
1283 err_bounce_buf:
1284 	dma_free_coherent(host->dev, host->bounce_buf_size,
1285 			  host->bounce_buf, host->bounce_dma_addr);
1286 err_init_clk:
1287 	clk_disable_unprepare(host->mmc_clk);
1288 err_core_clk:
1289 	clk_disable_unprepare(host->core_clk);
1290 free_host:
1291 	mmc_free_host(mmc);
1292 	return ret;
1293 }
1294 
1295 static int meson_mmc_remove(struct platform_device *pdev)
1296 {
1297 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1298 
1299 	mmc_remove_host(host->mmc);
1300 
1301 	/* disable interrupts */
1302 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1303 
1304 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1305 			  host->descs, host->descs_dma_addr);
1306 	dma_free_coherent(host->dev, host->bounce_buf_size,
1307 			  host->bounce_buf, host->bounce_dma_addr);
1308 
1309 	clk_disable_unprepare(host->mmc_clk);
1310 	clk_disable_unprepare(host->core_clk);
1311 
1312 	mmc_free_host(host->mmc);
1313 	return 0;
1314 }
1315 
1316 static const struct of_device_id meson_mmc_of_match[] = {
1317 	{ .compatible = "amlogic,meson-gx-mmc", },
1318 	{ .compatible = "amlogic,meson-gxbb-mmc", },
1319 	{ .compatible = "amlogic,meson-gxl-mmc", },
1320 	{ .compatible = "amlogic,meson-gxm-mmc", },
1321 	{}
1322 };
1323 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1324 
1325 static struct platform_driver meson_mmc_driver = {
1326 	.probe		= meson_mmc_probe,
1327 	.remove		= meson_mmc_remove,
1328 	.driver		= {
1329 		.name = DRIVER_NAME,
1330 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1331 	},
1332 };
1333 
1334 module_platform_driver(meson_mmc_driver);
1335 
1336 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
1337 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1338 MODULE_LICENSE("GPL v2");
1339