xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 82e6fdd6)
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 #include <linux/pinctrl/consumer.h>
41 
42 #define DRIVER_NAME "meson-gx-mmc"
43 
44 #define SD_EMMC_CLOCK 0x0
45 #define   CLK_DIV_MASK GENMASK(5, 0)
46 #define   CLK_SRC_MASK GENMASK(7, 6)
47 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
48 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
49 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
50 #define   CLK_TX_DELAY_MASK GENMASK(19, 16)
51 #define   CLK_RX_DELAY_MASK GENMASK(23, 20)
52 #define   CLK_DELAY_STEP_PS 200
53 #define   CLK_PHASE_STEP 30
54 #define   CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
55 #define   CLK_ALWAYS_ON BIT(24)
56 
57 #define SD_EMMC_DELAY 0x4
58 #define SD_EMMC_ADJUST 0x8
59 #define SD_EMMC_CALOUT 0x10
60 #define SD_EMMC_START 0x40
61 #define   START_DESC_INIT BIT(0)
62 #define   START_DESC_BUSY BIT(1)
63 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
64 
65 #define SD_EMMC_CFG 0x44
66 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
67 #define   CFG_BUS_WIDTH_1 0x0
68 #define   CFG_BUS_WIDTH_4 0x1
69 #define   CFG_BUS_WIDTH_8 0x2
70 #define   CFG_DDR BIT(2)
71 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
72 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
73 #define   CFG_RC_CC_MASK GENMASK(15, 12)
74 #define   CFG_STOP_CLOCK BIT(22)
75 #define   CFG_CLK_ALWAYS_ON BIT(18)
76 #define   CFG_CHK_DS BIT(20)
77 #define   CFG_AUTO_CLK BIT(23)
78 
79 #define SD_EMMC_STATUS 0x48
80 #define   STATUS_BUSY BIT(31)
81 #define   STATUS_DATI GENMASK(23, 16)
82 
83 #define SD_EMMC_IRQ_EN 0x4c
84 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
85 #define   IRQ_TXD_ERR BIT(8)
86 #define   IRQ_DESC_ERR BIT(9)
87 #define   IRQ_RESP_ERR BIT(10)
88 #define   IRQ_CRC_ERR \
89 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
90 #define   IRQ_RESP_TIMEOUT BIT(11)
91 #define   IRQ_DESC_TIMEOUT BIT(12)
92 #define   IRQ_TIMEOUTS \
93 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
94 #define   IRQ_END_OF_CHAIN BIT(13)
95 #define   IRQ_RESP_STATUS BIT(14)
96 #define   IRQ_SDIO BIT(15)
97 #define   IRQ_EN_MASK \
98 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
99 	 IRQ_SDIO)
100 
101 #define SD_EMMC_CMD_CFG 0x50
102 #define SD_EMMC_CMD_ARG 0x54
103 #define SD_EMMC_CMD_DAT 0x58
104 #define SD_EMMC_CMD_RSP 0x5c
105 #define SD_EMMC_CMD_RSP1 0x60
106 #define SD_EMMC_CMD_RSP2 0x64
107 #define SD_EMMC_CMD_RSP3 0x68
108 
109 #define SD_EMMC_RXD 0x94
110 #define SD_EMMC_TXD 0x94
111 #define SD_EMMC_LAST_REG SD_EMMC_TXD
112 
113 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
114 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
115 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
116 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
117 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
118 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
119 
120 #define SD_EMMC_PRE_REQ_DONE BIT(0)
121 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
122 
123 #define MUX_CLK_NUM_PARENTS 2
124 
125 struct sd_emmc_desc {
126 	u32 cmd_cfg;
127 	u32 cmd_arg;
128 	u32 cmd_data;
129 	u32 cmd_resp;
130 };
131 
132 struct meson_host {
133 	struct	device		*dev;
134 	struct	mmc_host	*mmc;
135 	struct	mmc_command	*cmd;
136 
137 	spinlock_t lock;
138 	void __iomem *regs;
139 	struct clk *core_clk;
140 	struct clk *mmc_clk;
141 	struct clk *rx_clk;
142 	struct clk *tx_clk;
143 	unsigned long req_rate;
144 
145 	struct pinctrl *pinctrl;
146 	struct pinctrl_state *pins_default;
147 	struct pinctrl_state *pins_clk_gate;
148 
149 	unsigned int bounce_buf_size;
150 	void *bounce_buf;
151 	dma_addr_t bounce_dma_addr;
152 	struct sd_emmc_desc *descs;
153 	dma_addr_t descs_dma_addr;
154 
155 	bool vqmmc_enabled;
156 };
157 
158 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
159 #define CMD_CFG_BLOCK_MODE BIT(9)
160 #define CMD_CFG_R1B BIT(10)
161 #define CMD_CFG_END_OF_CHAIN BIT(11)
162 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
163 #define CMD_CFG_NO_RESP BIT(16)
164 #define CMD_CFG_NO_CMD BIT(17)
165 #define CMD_CFG_DATA_IO BIT(18)
166 #define CMD_CFG_DATA_WR BIT(19)
167 #define CMD_CFG_RESP_NOCRC BIT(20)
168 #define CMD_CFG_RESP_128 BIT(21)
169 #define CMD_CFG_RESP_NUM BIT(22)
170 #define CMD_CFG_DATA_NUM BIT(23)
171 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
172 #define CMD_CFG_ERROR BIT(30)
173 #define CMD_CFG_OWNER BIT(31)
174 
175 #define CMD_DATA_MASK GENMASK(31, 2)
176 #define CMD_DATA_BIG_ENDIAN BIT(1)
177 #define CMD_DATA_SRAM BIT(0)
178 #define CMD_RESP_MASK GENMASK(31, 1)
179 #define CMD_RESP_SRAM BIT(0)
180 
181 struct meson_mmc_phase {
182 	struct clk_hw hw;
183 	void __iomem *reg;
184 	unsigned long phase_mask;
185 	unsigned long delay_mask;
186 	unsigned int delay_step_ps;
187 };
188 
189 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
190 
191 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
192 {
193 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
194 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
195 	unsigned long period_ps, p, d;
196 		int degrees;
197 	u32 val;
198 
199 	val = readl(mmc->reg);
200 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
201 	degrees = p * 360 / phase_num;
202 
203 	if (mmc->delay_mask) {
204 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
205 					 clk_get_rate(hw->clk));
206 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
207 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
208 		degrees %= 360;
209 	}
210 
211 	return degrees;
212 }
213 
214 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
215 					unsigned int phase,
216 					unsigned int delay)
217 {
218 	u32 val;
219 
220 	val = readl(mmc->reg);
221 	val &= ~mmc->phase_mask;
222 	val |= phase << __ffs(mmc->phase_mask);
223 
224 	if (mmc->delay_mask) {
225 		val &= ~mmc->delay_mask;
226 		val |= delay << __ffs(mmc->delay_mask);
227 	}
228 
229 	writel(val, mmc->reg);
230 }
231 
232 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
233 {
234 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
235 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
236 	unsigned long period_ps, d = 0, r;
237 	uint64_t p;
238 
239 	p = degrees % 360;
240 
241 	if (!mmc->delay_mask) {
242 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
243 	} else {
244 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
245 					 clk_get_rate(hw->clk));
246 
247 		/* First compute the phase index (p), the remainder (r) is the
248 		 * part we'll try to acheive using the delays (d).
249 		 */
250 		r = do_div(p, 360 / phase_num);
251 		d = DIV_ROUND_CLOSEST(r * period_ps,
252 				      360 * mmc->delay_step_ps);
253 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
254 	}
255 
256 	meson_mmc_apply_phase_delay(mmc, p, d);
257 	return 0;
258 }
259 
260 static const struct clk_ops meson_mmc_clk_phase_ops = {
261 	.get_phase = meson_mmc_clk_get_phase,
262 	.set_phase = meson_mmc_clk_set_phase,
263 };
264 
265 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
266 {
267 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
268 
269 	if (!timeout)
270 		return SD_EMMC_CMD_TIMEOUT_DATA;
271 
272 	timeout = roundup_pow_of_two(timeout);
273 
274 	return min(timeout, 32768U); /* max. 2^15 ms */
275 }
276 
277 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
278 {
279 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
280 		return cmd->mrq->cmd;
281 	else if (mmc_op_multi(cmd->opcode) &&
282 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
283 		return cmd->mrq->stop;
284 	else
285 		return NULL;
286 }
287 
288 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
289 					struct mmc_request *mrq)
290 {
291 	struct mmc_data *data = mrq->data;
292 	struct scatterlist *sg;
293 	int i;
294 	bool use_desc_chain_mode = true;
295 
296 	/*
297 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
298 	 * reported. For some strange reason this occurs in descriptor
299 	 * chain mode only. So let's fall back to bounce buffer mode
300 	 * for command SD_IO_RW_EXTENDED.
301 	 */
302 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
303 		return;
304 
305 	for_each_sg(data->sg, sg, data->sg_len, i)
306 		/* check for 8 byte alignment */
307 		if (sg->offset & 7) {
308 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
309 			use_desc_chain_mode = false;
310 			break;
311 		}
312 
313 	if (use_desc_chain_mode)
314 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
315 }
316 
317 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
318 {
319 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
320 }
321 
322 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
323 {
324 	return data && data->flags & MMC_DATA_READ &&
325 	       !meson_mmc_desc_chain_mode(data);
326 }
327 
328 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
329 {
330 	struct mmc_data *data = mrq->data;
331 
332 	if (!data)
333 		return;
334 
335 	meson_mmc_get_transfer_mode(mmc, mrq);
336 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
337 
338 	if (!meson_mmc_desc_chain_mode(data))
339 		return;
340 
341 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
342                                    mmc_get_dma_dir(data));
343 	if (!data->sg_count)
344 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
345 }
346 
347 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
348 			       int err)
349 {
350 	struct mmc_data *data = mrq->data;
351 
352 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
353 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
354 			     mmc_get_dma_dir(data));
355 }
356 
357 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
358 {
359 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
360 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
361 	    ios->timing == MMC_TIMING_MMC_HS400)
362 		return true;
363 
364 	return false;
365 }
366 
367 /*
368  * Gating the clock on this controller is tricky.  It seems the mmc clock
369  * is also used by the controller.  It may crash during some operation if the
370  * clock is stopped.  The safest thing to do, whenever possible, is to keep
371  * clock running at stop it at the pad using the pinmux.
372  */
373 static void meson_mmc_clk_gate(struct meson_host *host)
374 {
375 	u32 cfg;
376 
377 	if (host->pins_clk_gate) {
378 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
379 	} else {
380 		/*
381 		 * If the pinmux is not provided - default to the classic and
382 		 * unsafe method
383 		 */
384 		cfg = readl(host->regs + SD_EMMC_CFG);
385 		cfg |= CFG_STOP_CLOCK;
386 		writel(cfg, host->regs + SD_EMMC_CFG);
387 	}
388 }
389 
390 static void meson_mmc_clk_ungate(struct meson_host *host)
391 {
392 	u32 cfg;
393 
394 	if (host->pins_clk_gate)
395 		pinctrl_select_state(host->pinctrl, host->pins_default);
396 
397 	/* Make sure the clock is not stopped in the controller */
398 	cfg = readl(host->regs + SD_EMMC_CFG);
399 	cfg &= ~CFG_STOP_CLOCK;
400 	writel(cfg, host->regs + SD_EMMC_CFG);
401 }
402 
403 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
404 {
405 	struct mmc_host *mmc = host->mmc;
406 	unsigned long rate = ios->clock;
407 	int ret;
408 	u32 cfg;
409 
410 	/* DDR modes require higher module clock */
411 	if (meson_mmc_timing_is_ddr(ios))
412 		rate <<= 1;
413 
414 	/* Same request - bail-out */
415 	if (host->req_rate == rate)
416 		return 0;
417 
418 	/* stop clock */
419 	meson_mmc_clk_gate(host);
420 	host->req_rate = 0;
421 
422 	if (!rate) {
423 		mmc->actual_clock = 0;
424 		/* return with clock being stopped */
425 		return 0;
426 	}
427 
428 	/* Stop the clock during rate change to avoid glitches */
429 	cfg = readl(host->regs + SD_EMMC_CFG);
430 	cfg |= CFG_STOP_CLOCK;
431 	writel(cfg, host->regs + SD_EMMC_CFG);
432 
433 	ret = clk_set_rate(host->mmc_clk, rate);
434 	if (ret) {
435 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
436 			rate, ret);
437 		return ret;
438 	}
439 
440 	host->req_rate = rate;
441 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
442 
443 	/* We should report the real output frequency of the controller */
444 	if (meson_mmc_timing_is_ddr(ios))
445 		mmc->actual_clock >>= 1;
446 
447 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
448 	if (ios->clock != mmc->actual_clock)
449 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
450 
451 	/* (re)start clock */
452 	meson_mmc_clk_ungate(host);
453 
454 	return 0;
455 }
456 
457 /*
458  * The SD/eMMC IP block has an internal mux and divider used for
459  * generating the MMC clock.  Use the clock framework to create and
460  * manage these clocks.
461  */
462 static int meson_mmc_clk_init(struct meson_host *host)
463 {
464 	struct clk_init_data init;
465 	struct clk_mux *mux;
466 	struct clk_divider *div;
467 	struct meson_mmc_phase *core, *tx, *rx;
468 	struct clk *clk;
469 	char clk_name[32];
470 	int i, ret = 0;
471 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
472 	const char *clk_parent[1];
473 	u32 clk_reg;
474 
475 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
476 	clk_reg = 0;
477 	clk_reg |= CLK_ALWAYS_ON;
478 	clk_reg |= CLK_DIV_MASK;
479 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
480 
481 	/* get the mux parents */
482 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
483 		struct clk *clk;
484 		char name[16];
485 
486 		snprintf(name, sizeof(name), "clkin%d", i);
487 		clk = devm_clk_get(host->dev, name);
488 		if (IS_ERR(clk)) {
489 			if (clk != ERR_PTR(-EPROBE_DEFER))
490 				dev_err(host->dev, "Missing clock %s\n", name);
491 			return PTR_ERR(clk);
492 		}
493 
494 		mux_parent_names[i] = __clk_get_name(clk);
495 	}
496 
497 	/* create the mux */
498 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
499 	if (!mux)
500 		return -ENOMEM;
501 
502 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
503 	init.name = clk_name;
504 	init.ops = &clk_mux_ops;
505 	init.flags = 0;
506 	init.parent_names = mux_parent_names;
507 	init.num_parents = MUX_CLK_NUM_PARENTS;
508 
509 	mux->reg = host->regs + SD_EMMC_CLOCK;
510 	mux->shift = __ffs(CLK_SRC_MASK);
511 	mux->mask = CLK_SRC_MASK >> mux->shift;
512 	mux->hw.init = &init;
513 
514 	clk = devm_clk_register(host->dev, &mux->hw);
515 	if (WARN_ON(IS_ERR(clk)))
516 		return PTR_ERR(clk);
517 
518 	/* create the divider */
519 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
520 	if (!div)
521 		return -ENOMEM;
522 
523 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
524 	init.name = clk_name;
525 	init.ops = &clk_divider_ops;
526 	init.flags = CLK_SET_RATE_PARENT;
527 	clk_parent[0] = __clk_get_name(clk);
528 	init.parent_names = clk_parent;
529 	init.num_parents = 1;
530 
531 	div->reg = host->regs + SD_EMMC_CLOCK;
532 	div->shift = __ffs(CLK_DIV_MASK);
533 	div->width = __builtin_popcountl(CLK_DIV_MASK);
534 	div->hw.init = &init;
535 	div->flags = CLK_DIVIDER_ONE_BASED;
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 
750 		/* Reset rx phase */
751 		clk_set_phase(host->rx_clk, 0);
752 
753 		break;
754 
755 	case MMC_POWER_ON:
756 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
757 			int ret = regulator_enable(mmc->supply.vqmmc);
758 
759 			if (ret < 0)
760 				dev_err(host->dev,
761 					"failed to enable vqmmc regulator\n");
762 			else
763 				host->vqmmc_enabled = true;
764 		}
765 
766 		break;
767 	}
768 
769 	/* Bus width */
770 	switch (ios->bus_width) {
771 	case MMC_BUS_WIDTH_1:
772 		bus_width = CFG_BUS_WIDTH_1;
773 		break;
774 	case MMC_BUS_WIDTH_4:
775 		bus_width = CFG_BUS_WIDTH_4;
776 		break;
777 	case MMC_BUS_WIDTH_8:
778 		bus_width = CFG_BUS_WIDTH_8;
779 		break;
780 	default:
781 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
782 			ios->bus_width);
783 		bus_width = CFG_BUS_WIDTH_4;
784 	}
785 
786 	val = readl(host->regs + SD_EMMC_CFG);
787 	val &= ~CFG_BUS_WIDTH_MASK;
788 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
789 
790 	val &= ~CFG_DDR;
791 	if (meson_mmc_timing_is_ddr(ios))
792 		val |= CFG_DDR;
793 
794 	val &= ~CFG_CHK_DS;
795 	if (ios->timing == MMC_TIMING_MMC_HS400)
796 		val |= CFG_CHK_DS;
797 
798 	err = meson_mmc_clk_set(host, ios);
799 	if (err)
800 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
801 
802 	writel(val, host->regs + SD_EMMC_CFG);
803 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
804 }
805 
806 static void meson_mmc_request_done(struct mmc_host *mmc,
807 				   struct mmc_request *mrq)
808 {
809 	struct meson_host *host = mmc_priv(mmc);
810 
811 	host->cmd = NULL;
812 	mmc_request_done(host->mmc, mrq);
813 }
814 
815 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
816 {
817 	struct meson_host *host = mmc_priv(mmc);
818 	u32 cfg, blksz_old;
819 
820 	cfg = readl(host->regs + SD_EMMC_CFG);
821 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
822 
823 	if (!is_power_of_2(blksz))
824 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
825 
826 	blksz = ilog2(blksz);
827 
828 	/* check if block-size matches, if not update */
829 	if (blksz == blksz_old)
830 		return;
831 
832 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
833 		blksz_old, blksz);
834 
835 	cfg &= ~CFG_BLK_LEN_MASK;
836 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
837 	writel(cfg, host->regs + SD_EMMC_CFG);
838 }
839 
840 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
841 {
842 	if (cmd->flags & MMC_RSP_PRESENT) {
843 		if (cmd->flags & MMC_RSP_136)
844 			*cmd_cfg |= CMD_CFG_RESP_128;
845 		*cmd_cfg |= CMD_CFG_RESP_NUM;
846 
847 		if (!(cmd->flags & MMC_RSP_CRC))
848 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
849 
850 		if (cmd->flags & MMC_RSP_BUSY)
851 			*cmd_cfg |= CMD_CFG_R1B;
852 	} else {
853 		*cmd_cfg |= CMD_CFG_NO_RESP;
854 	}
855 }
856 
857 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
858 {
859 	struct meson_host *host = mmc_priv(mmc);
860 	struct sd_emmc_desc *desc = host->descs;
861 	struct mmc_data *data = host->cmd->data;
862 	struct scatterlist *sg;
863 	u32 start;
864 	int i;
865 
866 	if (data->flags & MMC_DATA_WRITE)
867 		cmd_cfg |= CMD_CFG_DATA_WR;
868 
869 	if (data->blocks > 1) {
870 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
871 		meson_mmc_set_blksz(mmc, data->blksz);
872 	}
873 
874 	for_each_sg(data->sg, sg, data->sg_count, i) {
875 		unsigned int len = sg_dma_len(sg);
876 
877 		if (data->blocks > 1)
878 			len /= data->blksz;
879 
880 		desc[i].cmd_cfg = cmd_cfg;
881 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
882 		if (i > 0)
883 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
884 		desc[i].cmd_arg = host->cmd->arg;
885 		desc[i].cmd_resp = 0;
886 		desc[i].cmd_data = sg_dma_address(sg);
887 	}
888 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
889 
890 	dma_wmb(); /* ensure descriptor is written before kicked */
891 	start = host->descs_dma_addr | START_DESC_BUSY;
892 	writel(start, host->regs + SD_EMMC_START);
893 }
894 
895 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
896 {
897 	struct meson_host *host = mmc_priv(mmc);
898 	struct mmc_data *data = cmd->data;
899 	u32 cmd_cfg = 0, cmd_data = 0;
900 	unsigned int xfer_bytes = 0;
901 
902 	/* Setup descriptors */
903 	dma_rmb();
904 
905 	host->cmd = cmd;
906 
907 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
908 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
909 
910 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
911 
912 	/* data? */
913 	if (data) {
914 		data->bytes_xfered = 0;
915 		cmd_cfg |= CMD_CFG_DATA_IO;
916 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
917 				      ilog2(meson_mmc_get_timeout_msecs(data)));
918 
919 		if (meson_mmc_desc_chain_mode(data)) {
920 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
921 			return;
922 		}
923 
924 		if (data->blocks > 1) {
925 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
926 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
927 					      data->blocks);
928 			meson_mmc_set_blksz(mmc, data->blksz);
929 		} else {
930 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
931 		}
932 
933 		xfer_bytes = data->blksz * data->blocks;
934 		if (data->flags & MMC_DATA_WRITE) {
935 			cmd_cfg |= CMD_CFG_DATA_WR;
936 			WARN_ON(xfer_bytes > host->bounce_buf_size);
937 			sg_copy_to_buffer(data->sg, data->sg_len,
938 					  host->bounce_buf, xfer_bytes);
939 			dma_wmb();
940 		}
941 
942 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
943 	} else {
944 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
945 				      ilog2(SD_EMMC_CMD_TIMEOUT));
946 	}
947 
948 	/* Last descriptor */
949 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
950 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
951 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
952 	writel(0, host->regs + SD_EMMC_CMD_RSP);
953 	wmb(); /* ensure descriptor is written before kicked */
954 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
955 }
956 
957 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
958 {
959 	struct meson_host *host = mmc_priv(mmc);
960 	bool needs_pre_post_req = mrq->data &&
961 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
962 
963 	if (needs_pre_post_req) {
964 		meson_mmc_get_transfer_mode(mmc, mrq);
965 		if (!meson_mmc_desc_chain_mode(mrq->data))
966 			needs_pre_post_req = false;
967 	}
968 
969 	if (needs_pre_post_req)
970 		meson_mmc_pre_req(mmc, mrq);
971 
972 	/* Stop execution */
973 	writel(0, host->regs + SD_EMMC_START);
974 
975 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
976 
977 	if (needs_pre_post_req)
978 		meson_mmc_post_req(mmc, mrq, 0);
979 }
980 
981 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
982 {
983 	struct meson_host *host = mmc_priv(mmc);
984 
985 	if (cmd->flags & MMC_RSP_136) {
986 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
987 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
988 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
989 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
990 	} else if (cmd->flags & MMC_RSP_PRESENT) {
991 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
992 	}
993 }
994 
995 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
996 {
997 	struct meson_host *host = dev_id;
998 	struct mmc_command *cmd;
999 	struct mmc_data *data;
1000 	u32 irq_en, status, raw_status;
1001 	irqreturn_t ret = IRQ_NONE;
1002 
1003 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1004 		return IRQ_NONE;
1005 
1006 	spin_lock(&host->lock);
1007 
1008 	cmd = host->cmd;
1009 	data = cmd->data;
1010 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1011 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1012 	status = raw_status & irq_en;
1013 
1014 	cmd->error = 0;
1015 	if (status & IRQ_CRC_ERR) {
1016 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1017 		cmd->error = -EILSEQ;
1018 		ret = IRQ_HANDLED;
1019 		goto out;
1020 	}
1021 
1022 	if (status & IRQ_TIMEOUTS) {
1023 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1024 		cmd->error = -ETIMEDOUT;
1025 		ret = IRQ_HANDLED;
1026 		goto out;
1027 	}
1028 
1029 	meson_mmc_read_resp(host->mmc, cmd);
1030 
1031 	if (status & IRQ_SDIO) {
1032 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1033 		ret = IRQ_HANDLED;
1034 	}
1035 
1036 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1037 		if (data && !cmd->error)
1038 			data->bytes_xfered = data->blksz * data->blocks;
1039 		if (meson_mmc_bounce_buf_read(data) ||
1040 		    meson_mmc_get_next_command(cmd))
1041 			ret = IRQ_WAKE_THREAD;
1042 		else
1043 			ret = IRQ_HANDLED;
1044 	}
1045 
1046 out:
1047 	/* ack all enabled interrupts */
1048 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1049 
1050 	if (ret == IRQ_HANDLED)
1051 		meson_mmc_request_done(host->mmc, cmd->mrq);
1052 	else if (ret == IRQ_NONE)
1053 		dev_warn(host->dev,
1054 			 "Unexpected IRQ! status=0x%08x, irq_en=0x%08x\n",
1055 			 raw_status, irq_en);
1056 
1057 	spin_unlock(&host->lock);
1058 	return ret;
1059 }
1060 
1061 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1062 {
1063 	struct meson_host *host = dev_id;
1064 	struct mmc_command *next_cmd, *cmd = host->cmd;
1065 	struct mmc_data *data;
1066 	unsigned int xfer_bytes;
1067 
1068 	if (WARN_ON(!cmd))
1069 		return IRQ_NONE;
1070 
1071 	data = cmd->data;
1072 	if (meson_mmc_bounce_buf_read(data)) {
1073 		xfer_bytes = data->blksz * data->blocks;
1074 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1075 		sg_copy_from_buffer(data->sg, data->sg_len,
1076 				    host->bounce_buf, xfer_bytes);
1077 	}
1078 
1079 	next_cmd = meson_mmc_get_next_command(cmd);
1080 	if (next_cmd)
1081 		meson_mmc_start_cmd(host->mmc, next_cmd);
1082 	else
1083 		meson_mmc_request_done(host->mmc, cmd->mrq);
1084 
1085 	return IRQ_HANDLED;
1086 }
1087 
1088 /*
1089  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1090  * interrupts.  For now, the MMC core will use this for polling.
1091  */
1092 static int meson_mmc_get_cd(struct mmc_host *mmc)
1093 {
1094 	int status = mmc_gpio_get_cd(mmc);
1095 
1096 	if (status == -ENOSYS)
1097 		return 1; /* assume present */
1098 
1099 	return status;
1100 }
1101 
1102 static void meson_mmc_cfg_init(struct meson_host *host)
1103 {
1104 	u32 cfg = 0;
1105 
1106 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1107 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1108 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1109 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1110 
1111 	writel(cfg, host->regs + SD_EMMC_CFG);
1112 }
1113 
1114 static int meson_mmc_card_busy(struct mmc_host *mmc)
1115 {
1116 	struct meson_host *host = mmc_priv(mmc);
1117 	u32 regval;
1118 
1119 	regval = readl(host->regs + SD_EMMC_STATUS);
1120 
1121 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1122 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1123 }
1124 
1125 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1126 {
1127 	/* vqmmc regulator is available */
1128 	if (!IS_ERR(mmc->supply.vqmmc)) {
1129 		/*
1130 		 * The usual amlogic setup uses a GPIO to switch from one
1131 		 * regulator to the other. While the voltage ramp up is
1132 		 * pretty fast, care must be taken when switching from 3.3v
1133 		 * to 1.8v. Please make sure the regulator framework is aware
1134 		 * of your own regulator constraints
1135 		 */
1136 		return mmc_regulator_set_vqmmc(mmc, ios);
1137 	}
1138 
1139 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1140 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1141 		return 0;
1142 
1143 	return -EINVAL;
1144 }
1145 
1146 static const struct mmc_host_ops meson_mmc_ops = {
1147 	.request	= meson_mmc_request,
1148 	.set_ios	= meson_mmc_set_ios,
1149 	.get_cd         = meson_mmc_get_cd,
1150 	.pre_req	= meson_mmc_pre_req,
1151 	.post_req	= meson_mmc_post_req,
1152 	.execute_tuning = meson_mmc_execute_tuning,
1153 	.card_busy	= meson_mmc_card_busy,
1154 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1155 };
1156 
1157 static int meson_mmc_probe(struct platform_device *pdev)
1158 {
1159 	struct resource *res;
1160 	struct meson_host *host;
1161 	struct mmc_host *mmc;
1162 	int ret, irq;
1163 
1164 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1165 	if (!mmc)
1166 		return -ENOMEM;
1167 	host = mmc_priv(mmc);
1168 	host->mmc = mmc;
1169 	host->dev = &pdev->dev;
1170 	dev_set_drvdata(&pdev->dev, host);
1171 
1172 	spin_lock_init(&host->lock);
1173 
1174 	/* Get regulators and the supported OCR mask */
1175 	host->vqmmc_enabled = false;
1176 	ret = mmc_regulator_get_supply(mmc);
1177 	if (ret)
1178 		goto free_host;
1179 
1180 	ret = mmc_of_parse(mmc);
1181 	if (ret) {
1182 		if (ret != -EPROBE_DEFER)
1183 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1184 		goto free_host;
1185 	}
1186 
1187 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1188 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1189 	if (IS_ERR(host->regs)) {
1190 		ret = PTR_ERR(host->regs);
1191 		goto free_host;
1192 	}
1193 
1194 	irq = platform_get_irq(pdev, 0);
1195 	if (irq <= 0) {
1196 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1197 		ret = -EINVAL;
1198 		goto free_host;
1199 	}
1200 
1201 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1202 	if (IS_ERR(host->pinctrl)) {
1203 		ret = PTR_ERR(host->pinctrl);
1204 		goto free_host;
1205 	}
1206 
1207 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1208 						  PINCTRL_STATE_DEFAULT);
1209 	if (IS_ERR(host->pins_default)) {
1210 		ret = PTR_ERR(host->pins_default);
1211 		goto free_host;
1212 	}
1213 
1214 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1215 						   "clk-gate");
1216 	if (IS_ERR(host->pins_clk_gate)) {
1217 		dev_warn(&pdev->dev,
1218 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1219 		host->pins_clk_gate = NULL;
1220 	}
1221 
1222 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1223 	if (IS_ERR(host->core_clk)) {
1224 		ret = PTR_ERR(host->core_clk);
1225 		goto free_host;
1226 	}
1227 
1228 	ret = clk_prepare_enable(host->core_clk);
1229 	if (ret)
1230 		goto free_host;
1231 
1232 	ret = meson_mmc_clk_init(host);
1233 	if (ret)
1234 		goto err_core_clk;
1235 
1236 	/* set config to sane default */
1237 	meson_mmc_cfg_init(host);
1238 
1239 	/* Stop execution */
1240 	writel(0, host->regs + SD_EMMC_START);
1241 
1242 	/* clear, ack and enable interrupts */
1243 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1244 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1245 	       host->regs + SD_EMMC_STATUS);
1246 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1247 	       host->regs + SD_EMMC_IRQ_EN);
1248 
1249 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
1250 					meson_mmc_irq_thread, IRQF_SHARED,
1251 					NULL, host);
1252 	if (ret)
1253 		goto err_init_clk;
1254 
1255 	mmc->caps |= MMC_CAP_CMD23;
1256 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1257 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1258 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1259 	mmc->max_seg_size = mmc->max_req_size;
1260 
1261 	/* data bounce buffer */
1262 	host->bounce_buf_size = mmc->max_req_size;
1263 	host->bounce_buf =
1264 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1265 				   &host->bounce_dma_addr, GFP_KERNEL);
1266 	if (host->bounce_buf == NULL) {
1267 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1268 		ret = -ENOMEM;
1269 		goto err_init_clk;
1270 	}
1271 
1272 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1273 		      &host->descs_dma_addr, GFP_KERNEL);
1274 	if (!host->descs) {
1275 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1276 		ret = -ENOMEM;
1277 		goto err_bounce_buf;
1278 	}
1279 
1280 	mmc->ops = &meson_mmc_ops;
1281 	mmc_add_host(mmc);
1282 
1283 	return 0;
1284 
1285 err_bounce_buf:
1286 	dma_free_coherent(host->dev, host->bounce_buf_size,
1287 			  host->bounce_buf, host->bounce_dma_addr);
1288 err_init_clk:
1289 	clk_disable_unprepare(host->mmc_clk);
1290 err_core_clk:
1291 	clk_disable_unprepare(host->core_clk);
1292 free_host:
1293 	mmc_free_host(mmc);
1294 	return ret;
1295 }
1296 
1297 static int meson_mmc_remove(struct platform_device *pdev)
1298 {
1299 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1300 
1301 	mmc_remove_host(host->mmc);
1302 
1303 	/* disable interrupts */
1304 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1305 
1306 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1307 			  host->descs, host->descs_dma_addr);
1308 	dma_free_coherent(host->dev, host->bounce_buf_size,
1309 			  host->bounce_buf, host->bounce_dma_addr);
1310 
1311 	clk_disable_unprepare(host->mmc_clk);
1312 	clk_disable_unprepare(host->core_clk);
1313 
1314 	mmc_free_host(host->mmc);
1315 	return 0;
1316 }
1317 
1318 static const struct of_device_id meson_mmc_of_match[] = {
1319 	{ .compatible = "amlogic,meson-gx-mmc", },
1320 	{ .compatible = "amlogic,meson-gxbb-mmc", },
1321 	{ .compatible = "amlogic,meson-gxl-mmc", },
1322 	{ .compatible = "amlogic,meson-gxm-mmc", },
1323 	{}
1324 };
1325 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1326 
1327 static struct platform_driver meson_mmc_driver = {
1328 	.probe		= meson_mmc_probe,
1329 	.remove		= meson_mmc_remove,
1330 	.driver		= {
1331 		.name = DRIVER_NAME,
1332 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1333 	},
1334 };
1335 
1336 module_platform_driver(meson_mmc_driver);
1337 
1338 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
1339 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1340 MODULE_LICENSE("GPL v2");
1341