xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision df687341)
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/delay.h>
25 #include <linux/device.h>
26 #include <linux/of_device.h>
27 #include <linux/platform_device.h>
28 #include <linux/ioport.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 #define   ADJUST_ADJ_DELAY_MASK GENMASK(21, 16)
70 #define   ADJUST_DS_EN BIT(15)
71 #define   ADJUST_ADJ_EN BIT(13)
72 
73 #define SD_EMMC_DELAY1 0x4
74 #define SD_EMMC_DELAY2 0x8
75 #define SD_EMMC_V3_ADJUST 0xc
76 
77 #define SD_EMMC_CALOUT 0x10
78 #define SD_EMMC_START 0x40
79 #define   START_DESC_INIT BIT(0)
80 #define   START_DESC_BUSY BIT(1)
81 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
82 
83 #define SD_EMMC_CFG 0x44
84 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
85 #define   CFG_BUS_WIDTH_1 0x0
86 #define   CFG_BUS_WIDTH_4 0x1
87 #define   CFG_BUS_WIDTH_8 0x2
88 #define   CFG_DDR BIT(2)
89 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
90 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
91 #define   CFG_RC_CC_MASK GENMASK(15, 12)
92 #define   CFG_STOP_CLOCK BIT(22)
93 #define   CFG_CLK_ALWAYS_ON BIT(18)
94 #define   CFG_CHK_DS BIT(20)
95 #define   CFG_AUTO_CLK BIT(23)
96 #define   CFG_ERR_ABORT BIT(27)
97 
98 #define SD_EMMC_STATUS 0x48
99 #define   STATUS_BUSY BIT(31)
100 #define   STATUS_DESC_BUSY BIT(30)
101 #define   STATUS_DATI GENMASK(23, 16)
102 
103 #define SD_EMMC_IRQ_EN 0x4c
104 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
105 #define   IRQ_TXD_ERR BIT(8)
106 #define   IRQ_DESC_ERR BIT(9)
107 #define   IRQ_RESP_ERR BIT(10)
108 #define   IRQ_CRC_ERR \
109 	(IRQ_RXD_ERR_MASK | IRQ_TXD_ERR | IRQ_DESC_ERR | IRQ_RESP_ERR)
110 #define   IRQ_RESP_TIMEOUT BIT(11)
111 #define   IRQ_DESC_TIMEOUT BIT(12)
112 #define   IRQ_TIMEOUTS \
113 	(IRQ_RESP_TIMEOUT | IRQ_DESC_TIMEOUT)
114 #define   IRQ_END_OF_CHAIN BIT(13)
115 #define   IRQ_RESP_STATUS BIT(14)
116 #define   IRQ_SDIO BIT(15)
117 #define   IRQ_EN_MASK \
118 	(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
119 	 IRQ_SDIO)
120 
121 #define SD_EMMC_CMD_CFG 0x50
122 #define SD_EMMC_CMD_ARG 0x54
123 #define SD_EMMC_CMD_DAT 0x58
124 #define SD_EMMC_CMD_RSP 0x5c
125 #define SD_EMMC_CMD_RSP1 0x60
126 #define SD_EMMC_CMD_RSP2 0x64
127 #define SD_EMMC_CMD_RSP3 0x68
128 
129 #define SD_EMMC_RXD 0x94
130 #define SD_EMMC_TXD 0x94
131 #define SD_EMMC_LAST_REG SD_EMMC_TXD
132 
133 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
134 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
135 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
136 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
137 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
138 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
139 
140 #define SD_EMMC_PRE_REQ_DONE BIT(0)
141 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
142 
143 #define MUX_CLK_NUM_PARENTS 2
144 
145 struct meson_mmc_data {
146 	unsigned int tx_delay_mask;
147 	unsigned int rx_delay_mask;
148 	unsigned int always_on;
149 	unsigned int adjust;
150 };
151 
152 struct sd_emmc_desc {
153 	u32 cmd_cfg;
154 	u32 cmd_arg;
155 	u32 cmd_data;
156 	u32 cmd_resp;
157 };
158 
159 struct meson_host {
160 	struct	device		*dev;
161 	struct	meson_mmc_data *data;
162 	struct	mmc_host	*mmc;
163 	struct	mmc_command	*cmd;
164 
165 	void __iomem *regs;
166 	struct clk *core_clk;
167 	struct clk *mmc_clk;
168 	struct clk *rx_clk;
169 	struct clk *tx_clk;
170 	unsigned long req_rate;
171 
172 	struct pinctrl *pinctrl;
173 	struct pinctrl_state *pins_default;
174 	struct pinctrl_state *pins_clk_gate;
175 
176 	unsigned int bounce_buf_size;
177 	void *bounce_buf;
178 	dma_addr_t bounce_dma_addr;
179 	struct sd_emmc_desc *descs;
180 	dma_addr_t descs_dma_addr;
181 
182 	bool vqmmc_enabled;
183 };
184 
185 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
186 #define CMD_CFG_BLOCK_MODE BIT(9)
187 #define CMD_CFG_R1B BIT(10)
188 #define CMD_CFG_END_OF_CHAIN BIT(11)
189 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
190 #define CMD_CFG_NO_RESP BIT(16)
191 #define CMD_CFG_NO_CMD BIT(17)
192 #define CMD_CFG_DATA_IO BIT(18)
193 #define CMD_CFG_DATA_WR BIT(19)
194 #define CMD_CFG_RESP_NOCRC BIT(20)
195 #define CMD_CFG_RESP_128 BIT(21)
196 #define CMD_CFG_RESP_NUM BIT(22)
197 #define CMD_CFG_DATA_NUM BIT(23)
198 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
199 #define CMD_CFG_ERROR BIT(30)
200 #define CMD_CFG_OWNER BIT(31)
201 
202 #define CMD_DATA_MASK GENMASK(31, 2)
203 #define CMD_DATA_BIG_ENDIAN BIT(1)
204 #define CMD_DATA_SRAM BIT(0)
205 #define CMD_RESP_MASK GENMASK(31, 1)
206 #define CMD_RESP_SRAM BIT(0)
207 
208 struct meson_mmc_phase {
209 	struct clk_hw hw;
210 	void __iomem *reg;
211 	unsigned long phase_mask;
212 	unsigned long delay_mask;
213 	unsigned int delay_step_ps;
214 };
215 
216 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
217 
218 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
219 {
220 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
221 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
222 	unsigned long period_ps, p, d;
223 		int degrees;
224 	u32 val;
225 
226 	val = readl(mmc->reg);
227 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
228 	degrees = p * 360 / phase_num;
229 
230 	if (mmc->delay_mask) {
231 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
232 					 clk_get_rate(hw->clk));
233 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
234 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
235 		degrees %= 360;
236 	}
237 
238 	return degrees;
239 }
240 
241 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
242 					unsigned int phase,
243 					unsigned int delay)
244 {
245 	u32 val;
246 
247 	val = readl(mmc->reg);
248 	val &= ~mmc->phase_mask;
249 	val |= phase << __ffs(mmc->phase_mask);
250 
251 	if (mmc->delay_mask) {
252 		val &= ~mmc->delay_mask;
253 		val |= delay << __ffs(mmc->delay_mask);
254 	}
255 
256 	writel(val, mmc->reg);
257 }
258 
259 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
260 {
261 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
262 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
263 	unsigned long period_ps, d = 0, r;
264 	uint64_t p;
265 
266 	p = degrees % 360;
267 
268 	if (!mmc->delay_mask) {
269 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
270 	} else {
271 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
272 					 clk_get_rate(hw->clk));
273 
274 		/* First compute the phase index (p), the remainder (r) is the
275 		 * part we'll try to acheive using the delays (d).
276 		 */
277 		r = do_div(p, 360 / phase_num);
278 		d = DIV_ROUND_CLOSEST(r * period_ps,
279 				      360 * mmc->delay_step_ps);
280 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
281 	}
282 
283 	meson_mmc_apply_phase_delay(mmc, p, d);
284 	return 0;
285 }
286 
287 static const struct clk_ops meson_mmc_clk_phase_ops = {
288 	.get_phase = meson_mmc_clk_get_phase,
289 	.set_phase = meson_mmc_clk_set_phase,
290 };
291 
292 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
293 {
294 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
295 
296 	if (!timeout)
297 		return SD_EMMC_CMD_TIMEOUT_DATA;
298 
299 	timeout = roundup_pow_of_two(timeout);
300 
301 	return min(timeout, 32768U); /* max. 2^15 ms */
302 }
303 
304 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
305 {
306 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
307 		return cmd->mrq->cmd;
308 	else if (mmc_op_multi(cmd->opcode) &&
309 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
310 		return cmd->mrq->stop;
311 	else
312 		return NULL;
313 }
314 
315 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
316 					struct mmc_request *mrq)
317 {
318 	struct mmc_data *data = mrq->data;
319 	struct scatterlist *sg;
320 	int i;
321 	bool use_desc_chain_mode = true;
322 
323 	/*
324 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
325 	 * reported. For some strange reason this occurs in descriptor
326 	 * chain mode only. So let's fall back to bounce buffer mode
327 	 * for command SD_IO_RW_EXTENDED.
328 	 */
329 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
330 		return;
331 
332 	for_each_sg(data->sg, sg, data->sg_len, i)
333 		/* check for 8 byte alignment */
334 		if (sg->offset & 7) {
335 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
336 			use_desc_chain_mode = false;
337 			break;
338 		}
339 
340 	if (use_desc_chain_mode)
341 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
342 }
343 
344 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
345 {
346 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
347 }
348 
349 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
350 {
351 	return data && data->flags & MMC_DATA_READ &&
352 	       !meson_mmc_desc_chain_mode(data);
353 }
354 
355 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
356 {
357 	struct mmc_data *data = mrq->data;
358 
359 	if (!data)
360 		return;
361 
362 	meson_mmc_get_transfer_mode(mmc, mrq);
363 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
364 
365 	if (!meson_mmc_desc_chain_mode(data))
366 		return;
367 
368 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
369                                    mmc_get_dma_dir(data));
370 	if (!data->sg_count)
371 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
372 }
373 
374 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
375 			       int err)
376 {
377 	struct mmc_data *data = mrq->data;
378 
379 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
380 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
381 			     mmc_get_dma_dir(data));
382 }
383 
384 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
385 {
386 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
387 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
388 	    ios->timing == MMC_TIMING_MMC_HS400)
389 		return true;
390 
391 	return false;
392 }
393 
394 /*
395  * Gating the clock on this controller is tricky.  It seems the mmc clock
396  * is also used by the controller.  It may crash during some operation if the
397  * clock is stopped.  The safest thing to do, whenever possible, is to keep
398  * clock running at stop it at the pad using the pinmux.
399  */
400 static void meson_mmc_clk_gate(struct meson_host *host)
401 {
402 	u32 cfg;
403 
404 	if (host->pins_clk_gate) {
405 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
406 	} else {
407 		/*
408 		 * If the pinmux is not provided - default to the classic and
409 		 * unsafe method
410 		 */
411 		cfg = readl(host->regs + SD_EMMC_CFG);
412 		cfg |= CFG_STOP_CLOCK;
413 		writel(cfg, host->regs + SD_EMMC_CFG);
414 	}
415 }
416 
417 static void meson_mmc_clk_ungate(struct meson_host *host)
418 {
419 	u32 cfg;
420 
421 	if (host->pins_clk_gate)
422 		pinctrl_select_state(host->pinctrl, host->pins_default);
423 
424 	/* Make sure the clock is not stopped in the controller */
425 	cfg = readl(host->regs + SD_EMMC_CFG);
426 	cfg &= ~CFG_STOP_CLOCK;
427 	writel(cfg, host->regs + SD_EMMC_CFG);
428 }
429 
430 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
431 {
432 	struct mmc_host *mmc = host->mmc;
433 	unsigned long rate = ios->clock;
434 	int ret;
435 	u32 cfg;
436 
437 	/* DDR modes require higher module clock */
438 	if (meson_mmc_timing_is_ddr(ios))
439 		rate <<= 1;
440 
441 	/* Same request - bail-out */
442 	if (host->req_rate == rate)
443 		return 0;
444 
445 	/* stop clock */
446 	meson_mmc_clk_gate(host);
447 	host->req_rate = 0;
448 
449 	if (!rate) {
450 		mmc->actual_clock = 0;
451 		/* return with clock being stopped */
452 		return 0;
453 	}
454 
455 	/* Stop the clock during rate change to avoid glitches */
456 	cfg = readl(host->regs + SD_EMMC_CFG);
457 	cfg |= CFG_STOP_CLOCK;
458 	writel(cfg, host->regs + SD_EMMC_CFG);
459 
460 	ret = clk_set_rate(host->mmc_clk, rate);
461 	if (ret) {
462 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
463 			rate, ret);
464 		return ret;
465 	}
466 
467 	host->req_rate = rate;
468 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
469 
470 	/* We should report the real output frequency of the controller */
471 	if (meson_mmc_timing_is_ddr(ios))
472 		mmc->actual_clock >>= 1;
473 
474 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
475 	if (ios->clock != mmc->actual_clock)
476 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
477 
478 	/* (re)start clock */
479 	meson_mmc_clk_ungate(host);
480 
481 	return 0;
482 }
483 
484 /*
485  * The SD/eMMC IP block has an internal mux and divider used for
486  * generating the MMC clock.  Use the clock framework to create and
487  * manage these clocks.
488  */
489 static int meson_mmc_clk_init(struct meson_host *host)
490 {
491 	struct clk_init_data init;
492 	struct clk_mux *mux;
493 	struct clk_divider *div;
494 	struct meson_mmc_phase *core, *tx, *rx;
495 	struct clk *clk;
496 	char clk_name[32];
497 	int i, ret = 0;
498 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
499 	const char *clk_parent[1];
500 	u32 clk_reg;
501 
502 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
503 	clk_reg = 0;
504 	clk_reg |= CLK_ALWAYS_ON(host);
505 	clk_reg |= CLK_DIV_MASK;
506 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
507 
508 	/* get the mux parents */
509 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
510 		struct clk *clk;
511 		char name[16];
512 
513 		snprintf(name, sizeof(name), "clkin%d", i);
514 		clk = devm_clk_get(host->dev, name);
515 		if (IS_ERR(clk)) {
516 			if (clk != ERR_PTR(-EPROBE_DEFER))
517 				dev_err(host->dev, "Missing clock %s\n", name);
518 			return PTR_ERR(clk);
519 		}
520 
521 		mux_parent_names[i] = __clk_get_name(clk);
522 	}
523 
524 	/* create the mux */
525 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
526 	if (!mux)
527 		return -ENOMEM;
528 
529 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
530 	init.name = clk_name;
531 	init.ops = &clk_mux_ops;
532 	init.flags = 0;
533 	init.parent_names = mux_parent_names;
534 	init.num_parents = MUX_CLK_NUM_PARENTS;
535 
536 	mux->reg = host->regs + SD_EMMC_CLOCK;
537 	mux->shift = __ffs(CLK_SRC_MASK);
538 	mux->mask = CLK_SRC_MASK >> mux->shift;
539 	mux->hw.init = &init;
540 
541 	clk = devm_clk_register(host->dev, &mux->hw);
542 	if (WARN_ON(IS_ERR(clk)))
543 		return PTR_ERR(clk);
544 
545 	/* create the divider */
546 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
547 	if (!div)
548 		return -ENOMEM;
549 
550 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
551 	init.name = clk_name;
552 	init.ops = &clk_divider_ops;
553 	init.flags = CLK_SET_RATE_PARENT;
554 	clk_parent[0] = __clk_get_name(clk);
555 	init.parent_names = clk_parent;
556 	init.num_parents = 1;
557 
558 	div->reg = host->regs + SD_EMMC_CLOCK;
559 	div->shift = __ffs(CLK_DIV_MASK);
560 	div->width = __builtin_popcountl(CLK_DIV_MASK);
561 	div->hw.init = &init;
562 	div->flags = CLK_DIVIDER_ONE_BASED;
563 
564 	clk = devm_clk_register(host->dev, &div->hw);
565 	if (WARN_ON(IS_ERR(clk)))
566 		return PTR_ERR(clk);
567 
568 	/* create the mmc core clock */
569 	core = devm_kzalloc(host->dev, sizeof(*core), GFP_KERNEL);
570 	if (!core)
571 		return -ENOMEM;
572 
573 	snprintf(clk_name, sizeof(clk_name), "%s#core", dev_name(host->dev));
574 	init.name = clk_name;
575 	init.ops = &meson_mmc_clk_phase_ops;
576 	init.flags = CLK_SET_RATE_PARENT;
577 	clk_parent[0] = __clk_get_name(clk);
578 	init.parent_names = clk_parent;
579 	init.num_parents = 1;
580 
581 	core->reg = host->regs + SD_EMMC_CLOCK;
582 	core->phase_mask = CLK_CORE_PHASE_MASK;
583 	core->hw.init = &init;
584 
585 	host->mmc_clk = devm_clk_register(host->dev, &core->hw);
586 	if (WARN_ON(PTR_ERR_OR_ZERO(host->mmc_clk)))
587 		return PTR_ERR(host->mmc_clk);
588 
589 	/* create the mmc tx clock */
590 	tx = devm_kzalloc(host->dev, sizeof(*tx), GFP_KERNEL);
591 	if (!tx)
592 		return -ENOMEM;
593 
594 	snprintf(clk_name, sizeof(clk_name), "%s#tx", dev_name(host->dev));
595 	init.name = clk_name;
596 	init.ops = &meson_mmc_clk_phase_ops;
597 	init.flags = 0;
598 	clk_parent[0] = __clk_get_name(host->mmc_clk);
599 	init.parent_names = clk_parent;
600 	init.num_parents = 1;
601 
602 	tx->reg = host->regs + SD_EMMC_CLOCK;
603 	tx->phase_mask = CLK_TX_PHASE_MASK;
604 	tx->delay_mask = CLK_TX_DELAY_MASK(host);
605 	tx->delay_step_ps = CLK_DELAY_STEP_PS;
606 	tx->hw.init = &init;
607 
608 	host->tx_clk = devm_clk_register(host->dev, &tx->hw);
609 	if (WARN_ON(PTR_ERR_OR_ZERO(host->tx_clk)))
610 		return PTR_ERR(host->tx_clk);
611 
612 	/* create the mmc rx clock */
613 	rx = devm_kzalloc(host->dev, sizeof(*rx), GFP_KERNEL);
614 	if (!rx)
615 		return -ENOMEM;
616 
617 	snprintf(clk_name, sizeof(clk_name), "%s#rx", dev_name(host->dev));
618 	init.name = clk_name;
619 	init.ops = &meson_mmc_clk_phase_ops;
620 	init.flags = 0;
621 	clk_parent[0] = __clk_get_name(host->mmc_clk);
622 	init.parent_names = clk_parent;
623 	init.num_parents = 1;
624 
625 	rx->reg = host->regs + SD_EMMC_CLOCK;
626 	rx->phase_mask = CLK_RX_PHASE_MASK;
627 	rx->delay_mask = CLK_RX_DELAY_MASK(host);
628 	rx->delay_step_ps = CLK_DELAY_STEP_PS;
629 	rx->hw.init = &init;
630 
631 	host->rx_clk = devm_clk_register(host->dev, &rx->hw);
632 	if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
633 		return PTR_ERR(host->rx_clk);
634 
635 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
636 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
637 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
638 	if (ret)
639 		return ret;
640 
641 	clk_set_phase(host->mmc_clk, 180);
642 	clk_set_phase(host->tx_clk, 0);
643 	clk_set_phase(host->rx_clk, 0);
644 
645 	return clk_prepare_enable(host->mmc_clk);
646 }
647 
648 static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
649 {
650 	DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
651 	DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
652 
653 	/*
654 	 * shift the bitmap right and reintroduce the dropped bits on the left
655 	 * of the bitmap
656 	 */
657 	bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
658 	bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
659 			  CLK_PHASE_POINT_NUM);
660 	bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
661 }
662 
663 static void meson_mmc_find_next_region(unsigned long *map,
664 				       unsigned long *start,
665 				       unsigned long *stop)
666 {
667 	*start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
668 	*stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
669 }
670 
671 static int meson_mmc_find_tuning_point(unsigned long *test)
672 {
673 	unsigned long shift, stop, offset = 0, start = 0, size = 0;
674 
675 	/* Get the all good/all bad situation out the way */
676 	if (bitmap_full(test, CLK_PHASE_POINT_NUM))
677 		return 0; /* All points are good so point 0 will do */
678 	else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
679 		return -EIO; /* No successful tuning point */
680 
681 	/*
682 	 * Now we know there is a least one region find. Make sure it does
683 	 * not wrap by the shifting the bitmap if necessary
684 	 */
685 	shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
686 	if (shift != 0)
687 		meson_mmc_shift_map(test, shift);
688 
689 	while (start < CLK_PHASE_POINT_NUM) {
690 		meson_mmc_find_next_region(test, &start, &stop);
691 
692 		if ((stop - start) > size) {
693 			offset = start;
694 			size = stop - start;
695 		}
696 
697 		start = stop;
698 	}
699 
700 	/* Get the center point of the region */
701 	offset += (size / 2);
702 
703 	/* Shift the result back */
704 	offset = (offset + shift) % CLK_PHASE_POINT_NUM;
705 
706 	return offset;
707 }
708 
709 static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
710 				      struct clk *clk)
711 {
712 	int point, ret;
713 	DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
714 
715 	dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
716 		__clk_get_name(clk));
717 	bitmap_zero(test, CLK_PHASE_POINT_NUM);
718 
719 	/* Explore tuning points */
720 	for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
721 		clk_set_phase(clk, point * CLK_PHASE_STEP);
722 		ret = mmc_send_tuning(mmc, opcode, NULL);
723 		if (!ret)
724 			set_bit(point, test);
725 	}
726 
727 	/* Find the optimal tuning point and apply it */
728 	point = meson_mmc_find_tuning_point(test);
729 	if (point < 0)
730 		return point; /* tuning failed */
731 
732 	clk_set_phase(clk, point * CLK_PHASE_STEP);
733 	dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
734 		clk_get_phase(clk));
735 	return 0;
736 }
737 
738 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
739 {
740 	struct meson_host *host = mmc_priv(mmc);
741 
742 	return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
743 }
744 
745 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
746 {
747 	struct meson_host *host = mmc_priv(mmc);
748 	u32 bus_width, val;
749 	int err;
750 
751 	/*
752 	 * GPIO regulator, only controls switching between 1v8 and
753 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
754 	 */
755 	switch (ios->power_mode) {
756 	case MMC_POWER_OFF:
757 		if (!IS_ERR(mmc->supply.vmmc))
758 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
759 
760 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
761 			regulator_disable(mmc->supply.vqmmc);
762 			host->vqmmc_enabled = false;
763 		}
764 
765 		break;
766 
767 	case MMC_POWER_UP:
768 		if (!IS_ERR(mmc->supply.vmmc))
769 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
770 
771 		/* Reset rx phase */
772 		clk_set_phase(host->rx_clk, 0);
773 
774 		break;
775 
776 	case MMC_POWER_ON:
777 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
778 			int ret = regulator_enable(mmc->supply.vqmmc);
779 
780 			if (ret < 0)
781 				dev_err(host->dev,
782 					"failed to enable vqmmc regulator\n");
783 			else
784 				host->vqmmc_enabled = true;
785 		}
786 
787 		break;
788 	}
789 
790 	/* Bus width */
791 	switch (ios->bus_width) {
792 	case MMC_BUS_WIDTH_1:
793 		bus_width = CFG_BUS_WIDTH_1;
794 		break;
795 	case MMC_BUS_WIDTH_4:
796 		bus_width = CFG_BUS_WIDTH_4;
797 		break;
798 	case MMC_BUS_WIDTH_8:
799 		bus_width = CFG_BUS_WIDTH_8;
800 		break;
801 	default:
802 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
803 			ios->bus_width);
804 		bus_width = CFG_BUS_WIDTH_4;
805 	}
806 
807 	val = readl(host->regs + SD_EMMC_CFG);
808 	val &= ~CFG_BUS_WIDTH_MASK;
809 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
810 
811 	val &= ~CFG_DDR;
812 	if (meson_mmc_timing_is_ddr(ios))
813 		val |= CFG_DDR;
814 
815 	val &= ~CFG_CHK_DS;
816 	if (ios->timing == MMC_TIMING_MMC_HS400)
817 		val |= CFG_CHK_DS;
818 
819 	err = meson_mmc_clk_set(host, ios);
820 	if (err)
821 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
822 
823 	writel(val, host->regs + SD_EMMC_CFG);
824 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
825 }
826 
827 static void meson_mmc_request_done(struct mmc_host *mmc,
828 				   struct mmc_request *mrq)
829 {
830 	struct meson_host *host = mmc_priv(mmc);
831 
832 	host->cmd = NULL;
833 	mmc_request_done(host->mmc, mrq);
834 }
835 
836 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
837 {
838 	struct meson_host *host = mmc_priv(mmc);
839 	u32 cfg, blksz_old;
840 
841 	cfg = readl(host->regs + SD_EMMC_CFG);
842 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
843 
844 	if (!is_power_of_2(blksz))
845 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
846 
847 	blksz = ilog2(blksz);
848 
849 	/* check if block-size matches, if not update */
850 	if (blksz == blksz_old)
851 		return;
852 
853 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
854 		blksz_old, blksz);
855 
856 	cfg &= ~CFG_BLK_LEN_MASK;
857 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
858 	writel(cfg, host->regs + SD_EMMC_CFG);
859 }
860 
861 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
862 {
863 	if (cmd->flags & MMC_RSP_PRESENT) {
864 		if (cmd->flags & MMC_RSP_136)
865 			*cmd_cfg |= CMD_CFG_RESP_128;
866 		*cmd_cfg |= CMD_CFG_RESP_NUM;
867 
868 		if (!(cmd->flags & MMC_RSP_CRC))
869 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
870 
871 		if (cmd->flags & MMC_RSP_BUSY)
872 			*cmd_cfg |= CMD_CFG_R1B;
873 	} else {
874 		*cmd_cfg |= CMD_CFG_NO_RESP;
875 	}
876 }
877 
878 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
879 {
880 	struct meson_host *host = mmc_priv(mmc);
881 	struct sd_emmc_desc *desc = host->descs;
882 	struct mmc_data *data = host->cmd->data;
883 	struct scatterlist *sg;
884 	u32 start;
885 	int i;
886 
887 	if (data->flags & MMC_DATA_WRITE)
888 		cmd_cfg |= CMD_CFG_DATA_WR;
889 
890 	if (data->blocks > 1) {
891 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
892 		meson_mmc_set_blksz(mmc, data->blksz);
893 	}
894 
895 	for_each_sg(data->sg, sg, data->sg_count, i) {
896 		unsigned int len = sg_dma_len(sg);
897 
898 		if (data->blocks > 1)
899 			len /= data->blksz;
900 
901 		desc[i].cmd_cfg = cmd_cfg;
902 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
903 		if (i > 0)
904 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
905 		desc[i].cmd_arg = host->cmd->arg;
906 		desc[i].cmd_resp = 0;
907 		desc[i].cmd_data = sg_dma_address(sg);
908 	}
909 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
910 
911 	dma_wmb(); /* ensure descriptor is written before kicked */
912 	start = host->descs_dma_addr | START_DESC_BUSY;
913 	writel(start, host->regs + SD_EMMC_START);
914 }
915 
916 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
917 {
918 	struct meson_host *host = mmc_priv(mmc);
919 	struct mmc_data *data = cmd->data;
920 	u32 cmd_cfg = 0, cmd_data = 0;
921 	unsigned int xfer_bytes = 0;
922 
923 	/* Setup descriptors */
924 	dma_rmb();
925 
926 	host->cmd = cmd;
927 
928 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
929 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
930 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
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 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1026 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1027 	status = raw_status & irq_en;
1028 
1029 	if (!status) {
1030 		dev_dbg(host->dev,
1031 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
1032 			 irq_en, raw_status);
1033 		return IRQ_NONE;
1034 	}
1035 
1036 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1037 		return IRQ_NONE;
1038 
1039 	cmd = host->cmd;
1040 	data = cmd->data;
1041 	cmd->error = 0;
1042 	if (status & IRQ_CRC_ERR) {
1043 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1044 		cmd->error = -EILSEQ;
1045 		ret = IRQ_WAKE_THREAD;
1046 		goto out;
1047 	}
1048 
1049 	if (status & IRQ_TIMEOUTS) {
1050 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1051 		cmd->error = -ETIMEDOUT;
1052 		ret = IRQ_WAKE_THREAD;
1053 		goto out;
1054 	}
1055 
1056 	meson_mmc_read_resp(host->mmc, cmd);
1057 
1058 	if (status & IRQ_SDIO) {
1059 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1060 		ret = IRQ_HANDLED;
1061 	}
1062 
1063 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1064 		if (data && !cmd->error)
1065 			data->bytes_xfered = data->blksz * data->blocks;
1066 		if (meson_mmc_bounce_buf_read(data) ||
1067 		    meson_mmc_get_next_command(cmd))
1068 			ret = IRQ_WAKE_THREAD;
1069 		else
1070 			ret = IRQ_HANDLED;
1071 	}
1072 
1073 out:
1074 	/* ack all enabled interrupts */
1075 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1076 
1077 	if (cmd->error) {
1078 		/* Stop desc in case of errors */
1079 		u32 start = readl(host->regs + SD_EMMC_START);
1080 
1081 		start &= ~START_DESC_BUSY;
1082 		writel(start, host->regs + SD_EMMC_START);
1083 	}
1084 
1085 	if (ret == IRQ_HANDLED)
1086 		meson_mmc_request_done(host->mmc, cmd->mrq);
1087 
1088 	return ret;
1089 }
1090 
1091 static int meson_mmc_wait_desc_stop(struct meson_host *host)
1092 {
1093 	int loop;
1094 	u32 status;
1095 
1096 	/*
1097 	 * It may sometimes take a while for it to actually halt. Here, we
1098 	 * are giving it 5ms to comply
1099 	 *
1100 	 * If we don't confirm the descriptor is stopped, it might raise new
1101 	 * IRQs after we have called mmc_request_done() which is bad.
1102 	 */
1103 	for (loop = 50; loop; loop--) {
1104 		status = readl(host->regs + SD_EMMC_STATUS);
1105 		if (status & (STATUS_BUSY | STATUS_DESC_BUSY))
1106 			udelay(100);
1107 		else
1108 			break;
1109 	}
1110 
1111 	if (status & (STATUS_BUSY | STATUS_DESC_BUSY)) {
1112 		dev_err(host->dev, "Timed out waiting for host to stop\n");
1113 		return -ETIMEDOUT;
1114 	}
1115 
1116 	return 0;
1117 }
1118 
1119 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1120 {
1121 	struct meson_host *host = dev_id;
1122 	struct mmc_command *next_cmd, *cmd = host->cmd;
1123 	struct mmc_data *data;
1124 	unsigned int xfer_bytes;
1125 
1126 	if (WARN_ON(!cmd))
1127 		return IRQ_NONE;
1128 
1129 	if (cmd->error) {
1130 		meson_mmc_wait_desc_stop(host);
1131 		meson_mmc_request_done(host->mmc, cmd->mrq);
1132 
1133 		return IRQ_HANDLED;
1134 	}
1135 
1136 	data = cmd->data;
1137 	if (meson_mmc_bounce_buf_read(data)) {
1138 		xfer_bytes = data->blksz * data->blocks;
1139 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1140 		sg_copy_from_buffer(data->sg, data->sg_len,
1141 				    host->bounce_buf, xfer_bytes);
1142 	}
1143 
1144 	next_cmd = meson_mmc_get_next_command(cmd);
1145 	if (next_cmd)
1146 		meson_mmc_start_cmd(host->mmc, next_cmd);
1147 	else
1148 		meson_mmc_request_done(host->mmc, cmd->mrq);
1149 
1150 	return IRQ_HANDLED;
1151 }
1152 
1153 /*
1154  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1155  * interrupts.  For now, the MMC core will use this for polling.
1156  */
1157 static int meson_mmc_get_cd(struct mmc_host *mmc)
1158 {
1159 	int status = mmc_gpio_get_cd(mmc);
1160 
1161 	if (status == -ENOSYS)
1162 		return 1; /* assume present */
1163 
1164 	return status;
1165 }
1166 
1167 static void meson_mmc_cfg_init(struct meson_host *host)
1168 {
1169 	u32 cfg = 0, adj = 0;
1170 
1171 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1172 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1173 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1174 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1175 
1176 	/* abort chain on R/W errors */
1177 	cfg |= CFG_ERR_ABORT;
1178 
1179 	writel(cfg, host->regs + SD_EMMC_CFG);
1180 
1181 	/* enable signal resampling w/o delay */
1182 	adj = ADJUST_ADJ_EN;
1183 	writel(adj, host->regs + host->data->adjust);
1184 }
1185 
1186 static int meson_mmc_card_busy(struct mmc_host *mmc)
1187 {
1188 	struct meson_host *host = mmc_priv(mmc);
1189 	u32 regval;
1190 
1191 	regval = readl(host->regs + SD_EMMC_STATUS);
1192 
1193 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1194 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1195 }
1196 
1197 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1198 {
1199 	/* vqmmc regulator is available */
1200 	if (!IS_ERR(mmc->supply.vqmmc)) {
1201 		/*
1202 		 * The usual amlogic setup uses a GPIO to switch from one
1203 		 * regulator to the other. While the voltage ramp up is
1204 		 * pretty fast, care must be taken when switching from 3.3v
1205 		 * to 1.8v. Please make sure the regulator framework is aware
1206 		 * of your own regulator constraints
1207 		 */
1208 		return mmc_regulator_set_vqmmc(mmc, ios);
1209 	}
1210 
1211 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1212 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1213 		return 0;
1214 
1215 	return -EINVAL;
1216 }
1217 
1218 static const struct mmc_host_ops meson_mmc_ops = {
1219 	.request	= meson_mmc_request,
1220 	.set_ios	= meson_mmc_set_ios,
1221 	.get_cd         = meson_mmc_get_cd,
1222 	.pre_req	= meson_mmc_pre_req,
1223 	.post_req	= meson_mmc_post_req,
1224 	.execute_tuning = meson_mmc_execute_tuning,
1225 	.card_busy	= meson_mmc_card_busy,
1226 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1227 };
1228 
1229 static int meson_mmc_probe(struct platform_device *pdev)
1230 {
1231 	struct resource *res;
1232 	struct meson_host *host;
1233 	struct mmc_host *mmc;
1234 	int ret, irq;
1235 
1236 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1237 	if (!mmc)
1238 		return -ENOMEM;
1239 	host = mmc_priv(mmc);
1240 	host->mmc = mmc;
1241 	host->dev = &pdev->dev;
1242 	dev_set_drvdata(&pdev->dev, host);
1243 
1244 	/* Get regulators and the supported OCR mask */
1245 	host->vqmmc_enabled = false;
1246 	ret = mmc_regulator_get_supply(mmc);
1247 	if (ret)
1248 		goto free_host;
1249 
1250 	ret = mmc_of_parse(mmc);
1251 	if (ret) {
1252 		if (ret != -EPROBE_DEFER)
1253 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1254 		goto free_host;
1255 	}
1256 
1257 	host->data = (struct meson_mmc_data *)
1258 		of_device_get_match_data(&pdev->dev);
1259 	if (!host->data) {
1260 		ret = -EINVAL;
1261 		goto free_host;
1262 	}
1263 
1264 	ret = device_reset_optional(&pdev->dev);
1265 	if (ret) {
1266 		if (ret != -EPROBE_DEFER)
1267 			dev_err(&pdev->dev, "device reset failed: %d\n", ret);
1268 
1269 		return ret;
1270 	}
1271 
1272 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1273 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1274 	if (IS_ERR(host->regs)) {
1275 		ret = PTR_ERR(host->regs);
1276 		goto free_host;
1277 	}
1278 
1279 	irq = platform_get_irq(pdev, 0);
1280 	if (irq <= 0) {
1281 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1282 		ret = -EINVAL;
1283 		goto free_host;
1284 	}
1285 
1286 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1287 	if (IS_ERR(host->pinctrl)) {
1288 		ret = PTR_ERR(host->pinctrl);
1289 		goto free_host;
1290 	}
1291 
1292 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1293 						  PINCTRL_STATE_DEFAULT);
1294 	if (IS_ERR(host->pins_default)) {
1295 		ret = PTR_ERR(host->pins_default);
1296 		goto free_host;
1297 	}
1298 
1299 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1300 						   "clk-gate");
1301 	if (IS_ERR(host->pins_clk_gate)) {
1302 		dev_warn(&pdev->dev,
1303 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1304 		host->pins_clk_gate = NULL;
1305 	}
1306 
1307 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1308 	if (IS_ERR(host->core_clk)) {
1309 		ret = PTR_ERR(host->core_clk);
1310 		goto free_host;
1311 	}
1312 
1313 	ret = clk_prepare_enable(host->core_clk);
1314 	if (ret)
1315 		goto free_host;
1316 
1317 	ret = meson_mmc_clk_init(host);
1318 	if (ret)
1319 		goto err_core_clk;
1320 
1321 	/* set config to sane default */
1322 	meson_mmc_cfg_init(host);
1323 
1324 	/* Stop execution */
1325 	writel(0, host->regs + SD_EMMC_START);
1326 
1327 	/* clear, ack and enable interrupts */
1328 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1329 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1330 	       host->regs + SD_EMMC_STATUS);
1331 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1332 	       host->regs + SD_EMMC_IRQ_EN);
1333 
1334 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
1335 					meson_mmc_irq_thread, IRQF_SHARED,
1336 					NULL, host);
1337 	if (ret)
1338 		goto err_init_clk;
1339 
1340 	mmc->caps |= MMC_CAP_CMD23;
1341 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1342 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1343 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1344 	mmc->max_seg_size = mmc->max_req_size;
1345 
1346 	/* data bounce buffer */
1347 	host->bounce_buf_size = mmc->max_req_size;
1348 	host->bounce_buf =
1349 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1350 				   &host->bounce_dma_addr, GFP_KERNEL);
1351 	if (host->bounce_buf == NULL) {
1352 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1353 		ret = -ENOMEM;
1354 		goto err_init_clk;
1355 	}
1356 
1357 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1358 		      &host->descs_dma_addr, GFP_KERNEL);
1359 	if (!host->descs) {
1360 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1361 		ret = -ENOMEM;
1362 		goto err_bounce_buf;
1363 	}
1364 
1365 	mmc->ops = &meson_mmc_ops;
1366 	mmc_add_host(mmc);
1367 
1368 	return 0;
1369 
1370 err_bounce_buf:
1371 	dma_free_coherent(host->dev, host->bounce_buf_size,
1372 			  host->bounce_buf, host->bounce_dma_addr);
1373 err_init_clk:
1374 	clk_disable_unprepare(host->mmc_clk);
1375 err_core_clk:
1376 	clk_disable_unprepare(host->core_clk);
1377 free_host:
1378 	mmc_free_host(mmc);
1379 	return ret;
1380 }
1381 
1382 static int meson_mmc_remove(struct platform_device *pdev)
1383 {
1384 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1385 
1386 	mmc_remove_host(host->mmc);
1387 
1388 	/* disable interrupts */
1389 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1390 
1391 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1392 			  host->descs, host->descs_dma_addr);
1393 	dma_free_coherent(host->dev, host->bounce_buf_size,
1394 			  host->bounce_buf, host->bounce_dma_addr);
1395 
1396 	clk_disable_unprepare(host->mmc_clk);
1397 	clk_disable_unprepare(host->core_clk);
1398 
1399 	mmc_free_host(host->mmc);
1400 	return 0;
1401 }
1402 
1403 static const struct meson_mmc_data meson_gx_data = {
1404 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1405 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1406 	.always_on	= CLK_V2_ALWAYS_ON,
1407 	.adjust		= SD_EMMC_ADJUST,
1408 };
1409 
1410 static const struct meson_mmc_data meson_axg_data = {
1411 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1412 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1413 	.always_on	= CLK_V3_ALWAYS_ON,
1414 	.adjust		= SD_EMMC_V3_ADJUST,
1415 };
1416 
1417 static const struct of_device_id meson_mmc_of_match[] = {
1418 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1419 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1420 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1421 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1422 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1423 	{}
1424 };
1425 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1426 
1427 static struct platform_driver meson_mmc_driver = {
1428 	.probe		= meson_mmc_probe,
1429 	.remove		= meson_mmc_remove,
1430 	.driver		= {
1431 		.name = DRIVER_NAME,
1432 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1433 	},
1434 };
1435 
1436 module_platform_driver(meson_mmc_driver);
1437 
1438 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1439 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1440 MODULE_LICENSE("GPL v2");
1441