xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 5b628549)
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 	int irq;
183 
184 	bool vqmmc_enabled;
185 };
186 
187 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
188 #define CMD_CFG_BLOCK_MODE BIT(9)
189 #define CMD_CFG_R1B BIT(10)
190 #define CMD_CFG_END_OF_CHAIN BIT(11)
191 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
192 #define CMD_CFG_NO_RESP BIT(16)
193 #define CMD_CFG_NO_CMD BIT(17)
194 #define CMD_CFG_DATA_IO BIT(18)
195 #define CMD_CFG_DATA_WR BIT(19)
196 #define CMD_CFG_RESP_NOCRC BIT(20)
197 #define CMD_CFG_RESP_128 BIT(21)
198 #define CMD_CFG_RESP_NUM BIT(22)
199 #define CMD_CFG_DATA_NUM BIT(23)
200 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
201 #define CMD_CFG_ERROR BIT(30)
202 #define CMD_CFG_OWNER BIT(31)
203 
204 #define CMD_DATA_MASK GENMASK(31, 2)
205 #define CMD_DATA_BIG_ENDIAN BIT(1)
206 #define CMD_DATA_SRAM BIT(0)
207 #define CMD_RESP_MASK GENMASK(31, 1)
208 #define CMD_RESP_SRAM BIT(0)
209 
210 struct meson_mmc_phase {
211 	struct clk_hw hw;
212 	void __iomem *reg;
213 	unsigned long phase_mask;
214 	unsigned long delay_mask;
215 	unsigned int delay_step_ps;
216 };
217 
218 #define to_meson_mmc_phase(_hw) container_of(_hw, struct meson_mmc_phase, hw)
219 
220 static int meson_mmc_clk_get_phase(struct clk_hw *hw)
221 {
222 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
223 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
224 	unsigned long period_ps, p, d;
225 		int degrees;
226 	u32 val;
227 
228 	val = readl(mmc->reg);
229 	p = (val & mmc->phase_mask) >> __ffs(mmc->phase_mask);
230 	degrees = p * 360 / phase_num;
231 
232 	if (mmc->delay_mask) {
233 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
234 					 clk_get_rate(hw->clk));
235 		d = (val & mmc->delay_mask) >> __ffs(mmc->delay_mask);
236 		degrees += d * mmc->delay_step_ps * 360 / period_ps;
237 		degrees %= 360;
238 	}
239 
240 	return degrees;
241 }
242 
243 static void meson_mmc_apply_phase_delay(struct meson_mmc_phase *mmc,
244 					unsigned int phase,
245 					unsigned int delay)
246 {
247 	u32 val;
248 
249 	val = readl(mmc->reg);
250 	val &= ~mmc->phase_mask;
251 	val |= phase << __ffs(mmc->phase_mask);
252 
253 	if (mmc->delay_mask) {
254 		val &= ~mmc->delay_mask;
255 		val |= delay << __ffs(mmc->delay_mask);
256 	}
257 
258 	writel(val, mmc->reg);
259 }
260 
261 static int meson_mmc_clk_set_phase(struct clk_hw *hw, int degrees)
262 {
263 	struct meson_mmc_phase *mmc = to_meson_mmc_phase(hw);
264 	unsigned int phase_num = 1 <<  hweight_long(mmc->phase_mask);
265 	unsigned long period_ps, d = 0, r;
266 	uint64_t p;
267 
268 	p = degrees % 360;
269 
270 	if (!mmc->delay_mask) {
271 		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
272 	} else {
273 		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
274 					 clk_get_rate(hw->clk));
275 
276 		/* First compute the phase index (p), the remainder (r) is the
277 		 * part we'll try to acheive using the delays (d).
278 		 */
279 		r = do_div(p, 360 / phase_num);
280 		d = DIV_ROUND_CLOSEST(r * period_ps,
281 				      360 * mmc->delay_step_ps);
282 		d = min(d, mmc->delay_mask >> __ffs(mmc->delay_mask));
283 	}
284 
285 	meson_mmc_apply_phase_delay(mmc, p, d);
286 	return 0;
287 }
288 
289 static const struct clk_ops meson_mmc_clk_phase_ops = {
290 	.get_phase = meson_mmc_clk_get_phase,
291 	.set_phase = meson_mmc_clk_set_phase,
292 };
293 
294 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
295 {
296 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
297 
298 	if (!timeout)
299 		return SD_EMMC_CMD_TIMEOUT_DATA;
300 
301 	timeout = roundup_pow_of_two(timeout);
302 
303 	return min(timeout, 32768U); /* max. 2^15 ms */
304 }
305 
306 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
307 {
308 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
309 		return cmd->mrq->cmd;
310 	else if (mmc_op_multi(cmd->opcode) &&
311 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
312 		return cmd->mrq->stop;
313 	else
314 		return NULL;
315 }
316 
317 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
318 					struct mmc_request *mrq)
319 {
320 	struct mmc_data *data = mrq->data;
321 	struct scatterlist *sg;
322 	int i;
323 	bool use_desc_chain_mode = true;
324 
325 	/*
326 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
327 	 * reported. For some strange reason this occurs in descriptor
328 	 * chain mode only. So let's fall back to bounce buffer mode
329 	 * for command SD_IO_RW_EXTENDED.
330 	 */
331 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
332 		return;
333 
334 	for_each_sg(data->sg, sg, data->sg_len, i)
335 		/* check for 8 byte alignment */
336 		if (sg->offset & 7) {
337 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
338 			use_desc_chain_mode = false;
339 			break;
340 		}
341 
342 	if (use_desc_chain_mode)
343 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
344 }
345 
346 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
347 {
348 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
349 }
350 
351 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
352 {
353 	return data && data->flags & MMC_DATA_READ &&
354 	       !meson_mmc_desc_chain_mode(data);
355 }
356 
357 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
358 {
359 	struct mmc_data *data = mrq->data;
360 
361 	if (!data)
362 		return;
363 
364 	meson_mmc_get_transfer_mode(mmc, mrq);
365 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
366 
367 	if (!meson_mmc_desc_chain_mode(data))
368 		return;
369 
370 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
371                                    mmc_get_dma_dir(data));
372 	if (!data->sg_count)
373 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
374 }
375 
376 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
377 			       int err)
378 {
379 	struct mmc_data *data = mrq->data;
380 
381 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
382 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
383 			     mmc_get_dma_dir(data));
384 }
385 
386 static bool meson_mmc_timing_is_ddr(struct mmc_ios *ios)
387 {
388 	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
389 	    ios->timing == MMC_TIMING_UHS_DDR50 ||
390 	    ios->timing == MMC_TIMING_MMC_HS400)
391 		return true;
392 
393 	return false;
394 }
395 
396 /*
397  * Gating the clock on this controller is tricky.  It seems the mmc clock
398  * is also used by the controller.  It may crash during some operation if the
399  * clock is stopped.  The safest thing to do, whenever possible, is to keep
400  * clock running at stop it at the pad using the pinmux.
401  */
402 static void meson_mmc_clk_gate(struct meson_host *host)
403 {
404 	u32 cfg;
405 
406 	if (host->pins_clk_gate) {
407 		pinctrl_select_state(host->pinctrl, host->pins_clk_gate);
408 	} else {
409 		/*
410 		 * If the pinmux is not provided - default to the classic and
411 		 * unsafe method
412 		 */
413 		cfg = readl(host->regs + SD_EMMC_CFG);
414 		cfg |= CFG_STOP_CLOCK;
415 		writel(cfg, host->regs + SD_EMMC_CFG);
416 	}
417 }
418 
419 static void meson_mmc_clk_ungate(struct meson_host *host)
420 {
421 	u32 cfg;
422 
423 	if (host->pins_clk_gate)
424 		pinctrl_select_state(host->pinctrl, host->pins_default);
425 
426 	/* Make sure the clock is not stopped in the controller */
427 	cfg = readl(host->regs + SD_EMMC_CFG);
428 	cfg &= ~CFG_STOP_CLOCK;
429 	writel(cfg, host->regs + SD_EMMC_CFG);
430 }
431 
432 static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
433 {
434 	struct mmc_host *mmc = host->mmc;
435 	unsigned long rate = ios->clock;
436 	int ret;
437 	u32 cfg;
438 
439 	/* DDR modes require higher module clock */
440 	if (meson_mmc_timing_is_ddr(ios))
441 		rate <<= 1;
442 
443 	/* Same request - bail-out */
444 	if (host->req_rate == rate)
445 		return 0;
446 
447 	/* stop clock */
448 	meson_mmc_clk_gate(host);
449 	host->req_rate = 0;
450 
451 	if (!rate) {
452 		mmc->actual_clock = 0;
453 		/* return with clock being stopped */
454 		return 0;
455 	}
456 
457 	/* Stop the clock during rate change to avoid glitches */
458 	cfg = readl(host->regs + SD_EMMC_CFG);
459 	cfg |= CFG_STOP_CLOCK;
460 	writel(cfg, host->regs + SD_EMMC_CFG);
461 
462 	ret = clk_set_rate(host->mmc_clk, rate);
463 	if (ret) {
464 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
465 			rate, ret);
466 		return ret;
467 	}
468 
469 	host->req_rate = rate;
470 	mmc->actual_clock = clk_get_rate(host->mmc_clk);
471 
472 	/* We should report the real output frequency of the controller */
473 	if (meson_mmc_timing_is_ddr(ios))
474 		mmc->actual_clock >>= 1;
475 
476 	dev_dbg(host->dev, "clk rate: %u Hz\n", mmc->actual_clock);
477 	if (ios->clock != mmc->actual_clock)
478 		dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
479 
480 	/* (re)start clock */
481 	meson_mmc_clk_ungate(host);
482 
483 	return 0;
484 }
485 
486 /*
487  * The SD/eMMC IP block has an internal mux and divider used for
488  * generating the MMC clock.  Use the clock framework to create and
489  * manage these clocks.
490  */
491 static int meson_mmc_clk_init(struct meson_host *host)
492 {
493 	struct clk_init_data init;
494 	struct clk_mux *mux;
495 	struct clk_divider *div;
496 	struct meson_mmc_phase *core, *tx, *rx;
497 	struct clk *clk;
498 	char clk_name[32];
499 	int i, ret = 0;
500 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
501 	const char *clk_parent[1];
502 	u32 clk_reg;
503 
504 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
505 	clk_reg = 0;
506 	clk_reg |= CLK_ALWAYS_ON(host);
507 	clk_reg |= CLK_DIV_MASK;
508 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
509 
510 	/* get the mux parents */
511 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
512 		struct clk *clk;
513 		char name[16];
514 
515 		snprintf(name, sizeof(name), "clkin%d", i);
516 		clk = devm_clk_get(host->dev, name);
517 		if (IS_ERR(clk)) {
518 			if (clk != ERR_PTR(-EPROBE_DEFER))
519 				dev_err(host->dev, "Missing clock %s\n", name);
520 			return PTR_ERR(clk);
521 		}
522 
523 		mux_parent_names[i] = __clk_get_name(clk);
524 	}
525 
526 	/* create the mux */
527 	mux = devm_kzalloc(host->dev, sizeof(*mux), GFP_KERNEL);
528 	if (!mux)
529 		return -ENOMEM;
530 
531 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
532 	init.name = clk_name;
533 	init.ops = &clk_mux_ops;
534 	init.flags = 0;
535 	init.parent_names = mux_parent_names;
536 	init.num_parents = MUX_CLK_NUM_PARENTS;
537 
538 	mux->reg = host->regs + SD_EMMC_CLOCK;
539 	mux->shift = __ffs(CLK_SRC_MASK);
540 	mux->mask = CLK_SRC_MASK >> mux->shift;
541 	mux->hw.init = &init;
542 
543 	clk = devm_clk_register(host->dev, &mux->hw);
544 	if (WARN_ON(IS_ERR(clk)))
545 		return PTR_ERR(clk);
546 
547 	/* create the divider */
548 	div = devm_kzalloc(host->dev, sizeof(*div), GFP_KERNEL);
549 	if (!div)
550 		return -ENOMEM;
551 
552 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
553 	init.name = clk_name;
554 	init.ops = &clk_divider_ops;
555 	init.flags = CLK_SET_RATE_PARENT;
556 	clk_parent[0] = __clk_get_name(clk);
557 	init.parent_names = clk_parent;
558 	init.num_parents = 1;
559 
560 	div->reg = host->regs + SD_EMMC_CLOCK;
561 	div->shift = __ffs(CLK_DIV_MASK);
562 	div->width = __builtin_popcountl(CLK_DIV_MASK);
563 	div->hw.init = &init;
564 	div->flags = CLK_DIVIDER_ONE_BASED;
565 
566 	clk = devm_clk_register(host->dev, &div->hw);
567 	if (WARN_ON(IS_ERR(clk)))
568 		return PTR_ERR(clk);
569 
570 	/* create the mmc core clock */
571 	core = devm_kzalloc(host->dev, sizeof(*core), GFP_KERNEL);
572 	if (!core)
573 		return -ENOMEM;
574 
575 	snprintf(clk_name, sizeof(clk_name), "%s#core", dev_name(host->dev));
576 	init.name = clk_name;
577 	init.ops = &meson_mmc_clk_phase_ops;
578 	init.flags = CLK_SET_RATE_PARENT;
579 	clk_parent[0] = __clk_get_name(clk);
580 	init.parent_names = clk_parent;
581 	init.num_parents = 1;
582 
583 	core->reg = host->regs + SD_EMMC_CLOCK;
584 	core->phase_mask = CLK_CORE_PHASE_MASK;
585 	core->hw.init = &init;
586 
587 	host->mmc_clk = devm_clk_register(host->dev, &core->hw);
588 	if (WARN_ON(PTR_ERR_OR_ZERO(host->mmc_clk)))
589 		return PTR_ERR(host->mmc_clk);
590 
591 	/* create the mmc tx clock */
592 	tx = devm_kzalloc(host->dev, sizeof(*tx), GFP_KERNEL);
593 	if (!tx)
594 		return -ENOMEM;
595 
596 	snprintf(clk_name, sizeof(clk_name), "%s#tx", dev_name(host->dev));
597 	init.name = clk_name;
598 	init.ops = &meson_mmc_clk_phase_ops;
599 	init.flags = 0;
600 	clk_parent[0] = __clk_get_name(host->mmc_clk);
601 	init.parent_names = clk_parent;
602 	init.num_parents = 1;
603 
604 	tx->reg = host->regs + SD_EMMC_CLOCK;
605 	tx->phase_mask = CLK_TX_PHASE_MASK;
606 	tx->delay_mask = CLK_TX_DELAY_MASK(host);
607 	tx->delay_step_ps = CLK_DELAY_STEP_PS;
608 	tx->hw.init = &init;
609 
610 	host->tx_clk = devm_clk_register(host->dev, &tx->hw);
611 	if (WARN_ON(PTR_ERR_OR_ZERO(host->tx_clk)))
612 		return PTR_ERR(host->tx_clk);
613 
614 	/* create the mmc rx clock */
615 	rx = devm_kzalloc(host->dev, sizeof(*rx), GFP_KERNEL);
616 	if (!rx)
617 		return -ENOMEM;
618 
619 	snprintf(clk_name, sizeof(clk_name), "%s#rx", dev_name(host->dev));
620 	init.name = clk_name;
621 	init.ops = &meson_mmc_clk_phase_ops;
622 	init.flags = 0;
623 	clk_parent[0] = __clk_get_name(host->mmc_clk);
624 	init.parent_names = clk_parent;
625 	init.num_parents = 1;
626 
627 	rx->reg = host->regs + SD_EMMC_CLOCK;
628 	rx->phase_mask = CLK_RX_PHASE_MASK;
629 	rx->delay_mask = CLK_RX_DELAY_MASK(host);
630 	rx->delay_step_ps = CLK_DELAY_STEP_PS;
631 	rx->hw.init = &init;
632 
633 	host->rx_clk = devm_clk_register(host->dev, &rx->hw);
634 	if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
635 		return PTR_ERR(host->rx_clk);
636 
637 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
638 	host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
639 	ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
640 	if (ret)
641 		return ret;
642 
643 	clk_set_phase(host->mmc_clk, 180);
644 	clk_set_phase(host->tx_clk, 0);
645 	clk_set_phase(host->rx_clk, 0);
646 
647 	return clk_prepare_enable(host->mmc_clk);
648 }
649 
650 static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
651 {
652 	DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
653 	DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
654 
655 	/*
656 	 * shift the bitmap right and reintroduce the dropped bits on the left
657 	 * of the bitmap
658 	 */
659 	bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
660 	bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
661 			  CLK_PHASE_POINT_NUM);
662 	bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
663 }
664 
665 static void meson_mmc_find_next_region(unsigned long *map,
666 				       unsigned long *start,
667 				       unsigned long *stop)
668 {
669 	*start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
670 	*stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
671 }
672 
673 static int meson_mmc_find_tuning_point(unsigned long *test)
674 {
675 	unsigned long shift, stop, offset = 0, start = 0, size = 0;
676 
677 	/* Get the all good/all bad situation out the way */
678 	if (bitmap_full(test, CLK_PHASE_POINT_NUM))
679 		return 0; /* All points are good so point 0 will do */
680 	else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
681 		return -EIO; /* No successful tuning point */
682 
683 	/*
684 	 * Now we know there is a least one region find. Make sure it does
685 	 * not wrap by the shifting the bitmap if necessary
686 	 */
687 	shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
688 	if (shift != 0)
689 		meson_mmc_shift_map(test, shift);
690 
691 	while (start < CLK_PHASE_POINT_NUM) {
692 		meson_mmc_find_next_region(test, &start, &stop);
693 
694 		if ((stop - start) > size) {
695 			offset = start;
696 			size = stop - start;
697 		}
698 
699 		start = stop;
700 	}
701 
702 	/* Get the center point of the region */
703 	offset += (size / 2);
704 
705 	/* Shift the result back */
706 	offset = (offset + shift) % CLK_PHASE_POINT_NUM;
707 
708 	return offset;
709 }
710 
711 static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
712 				      struct clk *clk)
713 {
714 	int point, ret;
715 	DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
716 
717 	dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
718 		__clk_get_name(clk));
719 	bitmap_zero(test, CLK_PHASE_POINT_NUM);
720 
721 	/* Explore tuning points */
722 	for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
723 		clk_set_phase(clk, point * CLK_PHASE_STEP);
724 		ret = mmc_send_tuning(mmc, opcode, NULL);
725 		if (!ret)
726 			set_bit(point, test);
727 	}
728 
729 	/* Find the optimal tuning point and apply it */
730 	point = meson_mmc_find_tuning_point(test);
731 	if (point < 0)
732 		return point; /* tuning failed */
733 
734 	clk_set_phase(clk, point * CLK_PHASE_STEP);
735 	dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
736 		clk_get_phase(clk));
737 	return 0;
738 }
739 
740 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
741 {
742 	struct meson_host *host = mmc_priv(mmc);
743 	int adj = 0;
744 
745 	/* enable signal resampling w/o delay */
746 	adj = ADJUST_ADJ_EN;
747 	writel(adj, host->regs + host->data->adjust);
748 
749 	return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
750 }
751 
752 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
753 {
754 	struct meson_host *host = mmc_priv(mmc);
755 	u32 bus_width, val;
756 	int err;
757 
758 	/*
759 	 * GPIO regulator, only controls switching between 1v8 and
760 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
761 	 */
762 	switch (ios->power_mode) {
763 	case MMC_POWER_OFF:
764 		if (!IS_ERR(mmc->supply.vmmc))
765 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
766 
767 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
768 			regulator_disable(mmc->supply.vqmmc);
769 			host->vqmmc_enabled = false;
770 		}
771 
772 		break;
773 
774 	case MMC_POWER_UP:
775 		if (!IS_ERR(mmc->supply.vmmc))
776 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
777 
778 		/* disable signal resampling */
779 		writel(0, host->regs + host->data->adjust);
780 
781 		/* Reset rx phase */
782 		clk_set_phase(host->rx_clk, 0);
783 
784 		break;
785 
786 	case MMC_POWER_ON:
787 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
788 			int ret = regulator_enable(mmc->supply.vqmmc);
789 
790 			if (ret < 0)
791 				dev_err(host->dev,
792 					"failed to enable vqmmc regulator\n");
793 			else
794 				host->vqmmc_enabled = true;
795 		}
796 
797 		break;
798 	}
799 
800 	/* Bus width */
801 	switch (ios->bus_width) {
802 	case MMC_BUS_WIDTH_1:
803 		bus_width = CFG_BUS_WIDTH_1;
804 		break;
805 	case MMC_BUS_WIDTH_4:
806 		bus_width = CFG_BUS_WIDTH_4;
807 		break;
808 	case MMC_BUS_WIDTH_8:
809 		bus_width = CFG_BUS_WIDTH_8;
810 		break;
811 	default:
812 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
813 			ios->bus_width);
814 		bus_width = CFG_BUS_WIDTH_4;
815 	}
816 
817 	val = readl(host->regs + SD_EMMC_CFG);
818 	val &= ~CFG_BUS_WIDTH_MASK;
819 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
820 
821 	val &= ~CFG_DDR;
822 	if (meson_mmc_timing_is_ddr(ios))
823 		val |= CFG_DDR;
824 
825 	val &= ~CFG_CHK_DS;
826 	if (ios->timing == MMC_TIMING_MMC_HS400)
827 		val |= CFG_CHK_DS;
828 
829 	err = meson_mmc_clk_set(host, ios);
830 	if (err)
831 		dev_err(host->dev, "Failed to set clock: %d\n,", err);
832 
833 	writel(val, host->regs + SD_EMMC_CFG);
834 	dev_dbg(host->dev, "SD_EMMC_CFG:  0x%08x\n", val);
835 }
836 
837 static void meson_mmc_request_done(struct mmc_host *mmc,
838 				   struct mmc_request *mrq)
839 {
840 	struct meson_host *host = mmc_priv(mmc);
841 
842 	host->cmd = NULL;
843 	mmc_request_done(host->mmc, mrq);
844 }
845 
846 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
847 {
848 	struct meson_host *host = mmc_priv(mmc);
849 	u32 cfg, blksz_old;
850 
851 	cfg = readl(host->regs + SD_EMMC_CFG);
852 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
853 
854 	if (!is_power_of_2(blksz))
855 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
856 
857 	blksz = ilog2(blksz);
858 
859 	/* check if block-size matches, if not update */
860 	if (blksz == blksz_old)
861 		return;
862 
863 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
864 		blksz_old, blksz);
865 
866 	cfg &= ~CFG_BLK_LEN_MASK;
867 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
868 	writel(cfg, host->regs + SD_EMMC_CFG);
869 }
870 
871 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
872 {
873 	if (cmd->flags & MMC_RSP_PRESENT) {
874 		if (cmd->flags & MMC_RSP_136)
875 			*cmd_cfg |= CMD_CFG_RESP_128;
876 		*cmd_cfg |= CMD_CFG_RESP_NUM;
877 
878 		if (!(cmd->flags & MMC_RSP_CRC))
879 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
880 
881 		if (cmd->flags & MMC_RSP_BUSY)
882 			*cmd_cfg |= CMD_CFG_R1B;
883 	} else {
884 		*cmd_cfg |= CMD_CFG_NO_RESP;
885 	}
886 }
887 
888 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
889 {
890 	struct meson_host *host = mmc_priv(mmc);
891 	struct sd_emmc_desc *desc = host->descs;
892 	struct mmc_data *data = host->cmd->data;
893 	struct scatterlist *sg;
894 	u32 start;
895 	int i;
896 
897 	if (data->flags & MMC_DATA_WRITE)
898 		cmd_cfg |= CMD_CFG_DATA_WR;
899 
900 	if (data->blocks > 1) {
901 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
902 		meson_mmc_set_blksz(mmc, data->blksz);
903 	}
904 
905 	for_each_sg(data->sg, sg, data->sg_count, i) {
906 		unsigned int len = sg_dma_len(sg);
907 
908 		if (data->blocks > 1)
909 			len /= data->blksz;
910 
911 		desc[i].cmd_cfg = cmd_cfg;
912 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
913 		if (i > 0)
914 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
915 		desc[i].cmd_arg = host->cmd->arg;
916 		desc[i].cmd_resp = 0;
917 		desc[i].cmd_data = sg_dma_address(sg);
918 	}
919 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
920 
921 	dma_wmb(); /* ensure descriptor is written before kicked */
922 	start = host->descs_dma_addr | START_DESC_BUSY;
923 	writel(start, host->regs + SD_EMMC_START);
924 }
925 
926 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
927 {
928 	struct meson_host *host = mmc_priv(mmc);
929 	struct mmc_data *data = cmd->data;
930 	u32 cmd_cfg = 0, cmd_data = 0;
931 	unsigned int xfer_bytes = 0;
932 
933 	/* Setup descriptors */
934 	dma_rmb();
935 
936 	host->cmd = cmd;
937 
938 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
939 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
940 	cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
941 
942 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
943 
944 	/* data? */
945 	if (data) {
946 		data->bytes_xfered = 0;
947 		cmd_cfg |= CMD_CFG_DATA_IO;
948 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
949 				      ilog2(meson_mmc_get_timeout_msecs(data)));
950 
951 		if (meson_mmc_desc_chain_mode(data)) {
952 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
953 			return;
954 		}
955 
956 		if (data->blocks > 1) {
957 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
958 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
959 					      data->blocks);
960 			meson_mmc_set_blksz(mmc, data->blksz);
961 		} else {
962 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
963 		}
964 
965 		xfer_bytes = data->blksz * data->blocks;
966 		if (data->flags & MMC_DATA_WRITE) {
967 			cmd_cfg |= CMD_CFG_DATA_WR;
968 			WARN_ON(xfer_bytes > host->bounce_buf_size);
969 			sg_copy_to_buffer(data->sg, data->sg_len,
970 					  host->bounce_buf, xfer_bytes);
971 			dma_wmb();
972 		}
973 
974 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
975 	} else {
976 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
977 				      ilog2(SD_EMMC_CMD_TIMEOUT));
978 	}
979 
980 	/* Last descriptor */
981 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
982 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
983 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
984 	writel(0, host->regs + SD_EMMC_CMD_RSP);
985 	wmb(); /* ensure descriptor is written before kicked */
986 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
987 }
988 
989 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
990 {
991 	struct meson_host *host = mmc_priv(mmc);
992 	bool needs_pre_post_req = mrq->data &&
993 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
994 
995 	if (needs_pre_post_req) {
996 		meson_mmc_get_transfer_mode(mmc, mrq);
997 		if (!meson_mmc_desc_chain_mode(mrq->data))
998 			needs_pre_post_req = false;
999 	}
1000 
1001 	if (needs_pre_post_req)
1002 		meson_mmc_pre_req(mmc, mrq);
1003 
1004 	/* Stop execution */
1005 	writel(0, host->regs + SD_EMMC_START);
1006 
1007 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
1008 
1009 	if (needs_pre_post_req)
1010 		meson_mmc_post_req(mmc, mrq, 0);
1011 }
1012 
1013 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
1014 {
1015 	struct meson_host *host = mmc_priv(mmc);
1016 
1017 	if (cmd->flags & MMC_RSP_136) {
1018 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
1019 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
1020 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
1021 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
1022 	} else if (cmd->flags & MMC_RSP_PRESENT) {
1023 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
1024 	}
1025 }
1026 
1027 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
1028 {
1029 	struct meson_host *host = dev_id;
1030 	struct mmc_command *cmd;
1031 	struct mmc_data *data;
1032 	u32 irq_en, status, raw_status;
1033 	irqreturn_t ret = IRQ_NONE;
1034 
1035 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
1036 	raw_status = readl(host->regs + SD_EMMC_STATUS);
1037 	status = raw_status & irq_en;
1038 
1039 	if (!status) {
1040 		dev_dbg(host->dev,
1041 			"Unexpected IRQ! irq_en 0x%08x - status 0x%08x\n",
1042 			 irq_en, raw_status);
1043 		return IRQ_NONE;
1044 	}
1045 
1046 	if (WARN_ON(!host) || WARN_ON(!host->cmd))
1047 		return IRQ_NONE;
1048 
1049 	cmd = host->cmd;
1050 	data = cmd->data;
1051 	cmd->error = 0;
1052 	if (status & IRQ_CRC_ERR) {
1053 		dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
1054 		cmd->error = -EILSEQ;
1055 		ret = IRQ_WAKE_THREAD;
1056 		goto out;
1057 	}
1058 
1059 	if (status & IRQ_TIMEOUTS) {
1060 		dev_dbg(host->dev, "Timeout - status 0x%08x\n", status);
1061 		cmd->error = -ETIMEDOUT;
1062 		ret = IRQ_WAKE_THREAD;
1063 		goto out;
1064 	}
1065 
1066 	meson_mmc_read_resp(host->mmc, cmd);
1067 
1068 	if (status & IRQ_SDIO) {
1069 		dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
1070 		ret = IRQ_HANDLED;
1071 	}
1072 
1073 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
1074 		if (data && !cmd->error)
1075 			data->bytes_xfered = data->blksz * data->blocks;
1076 		if (meson_mmc_bounce_buf_read(data) ||
1077 		    meson_mmc_get_next_command(cmd))
1078 			ret = IRQ_WAKE_THREAD;
1079 		else
1080 			ret = IRQ_HANDLED;
1081 	}
1082 
1083 out:
1084 	/* ack all enabled interrupts */
1085 	writel(irq_en, host->regs + SD_EMMC_STATUS);
1086 
1087 	if (cmd->error) {
1088 		/* Stop desc in case of errors */
1089 		u32 start = readl(host->regs + SD_EMMC_START);
1090 
1091 		start &= ~START_DESC_BUSY;
1092 		writel(start, host->regs + SD_EMMC_START);
1093 	}
1094 
1095 	if (ret == IRQ_HANDLED)
1096 		meson_mmc_request_done(host->mmc, cmd->mrq);
1097 
1098 	return ret;
1099 }
1100 
1101 static int meson_mmc_wait_desc_stop(struct meson_host *host)
1102 {
1103 	int loop;
1104 	u32 status;
1105 
1106 	/*
1107 	 * It may sometimes take a while for it to actually halt. Here, we
1108 	 * are giving it 5ms to comply
1109 	 *
1110 	 * If we don't confirm the descriptor is stopped, it might raise new
1111 	 * IRQs after we have called mmc_request_done() which is bad.
1112 	 */
1113 	for (loop = 50; loop; loop--) {
1114 		status = readl(host->regs + SD_EMMC_STATUS);
1115 		if (status & (STATUS_BUSY | STATUS_DESC_BUSY))
1116 			udelay(100);
1117 		else
1118 			break;
1119 	}
1120 
1121 	if (status & (STATUS_BUSY | STATUS_DESC_BUSY)) {
1122 		dev_err(host->dev, "Timed out waiting for host to stop\n");
1123 		return -ETIMEDOUT;
1124 	}
1125 
1126 	return 0;
1127 }
1128 
1129 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
1130 {
1131 	struct meson_host *host = dev_id;
1132 	struct mmc_command *next_cmd, *cmd = host->cmd;
1133 	struct mmc_data *data;
1134 	unsigned int xfer_bytes;
1135 
1136 	if (WARN_ON(!cmd))
1137 		return IRQ_NONE;
1138 
1139 	if (cmd->error) {
1140 		meson_mmc_wait_desc_stop(host);
1141 		meson_mmc_request_done(host->mmc, cmd->mrq);
1142 
1143 		return IRQ_HANDLED;
1144 	}
1145 
1146 	data = cmd->data;
1147 	if (meson_mmc_bounce_buf_read(data)) {
1148 		xfer_bytes = data->blksz * data->blocks;
1149 		WARN_ON(xfer_bytes > host->bounce_buf_size);
1150 		sg_copy_from_buffer(data->sg, data->sg_len,
1151 				    host->bounce_buf, xfer_bytes);
1152 	}
1153 
1154 	next_cmd = meson_mmc_get_next_command(cmd);
1155 	if (next_cmd)
1156 		meson_mmc_start_cmd(host->mmc, next_cmd);
1157 	else
1158 		meson_mmc_request_done(host->mmc, cmd->mrq);
1159 
1160 	return IRQ_HANDLED;
1161 }
1162 
1163 /*
1164  * NOTE: we only need this until the GPIO/pinctrl driver can handle
1165  * interrupts.  For now, the MMC core will use this for polling.
1166  */
1167 static int meson_mmc_get_cd(struct mmc_host *mmc)
1168 {
1169 	int status = mmc_gpio_get_cd(mmc);
1170 
1171 	if (status == -ENOSYS)
1172 		return 1; /* assume present */
1173 
1174 	return status;
1175 }
1176 
1177 static void meson_mmc_cfg_init(struct meson_host *host)
1178 {
1179 	u32 cfg = 0;
1180 
1181 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
1182 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
1183 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
1184 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
1185 
1186 	/* abort chain on R/W errors */
1187 	cfg |= CFG_ERR_ABORT;
1188 
1189 	writel(cfg, host->regs + SD_EMMC_CFG);
1190 }
1191 
1192 static int meson_mmc_card_busy(struct mmc_host *mmc)
1193 {
1194 	struct meson_host *host = mmc_priv(mmc);
1195 	u32 regval;
1196 
1197 	regval = readl(host->regs + SD_EMMC_STATUS);
1198 
1199 	/* We are only interrested in lines 0 to 3, so mask the other ones */
1200 	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
1201 }
1202 
1203 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
1204 {
1205 	/* vqmmc regulator is available */
1206 	if (!IS_ERR(mmc->supply.vqmmc)) {
1207 		/*
1208 		 * The usual amlogic setup uses a GPIO to switch from one
1209 		 * regulator to the other. While the voltage ramp up is
1210 		 * pretty fast, care must be taken when switching from 3.3v
1211 		 * to 1.8v. Please make sure the regulator framework is aware
1212 		 * of your own regulator constraints
1213 		 */
1214 		return mmc_regulator_set_vqmmc(mmc, ios);
1215 	}
1216 
1217 	/* no vqmmc regulator, assume fixed regulator at 3/3.3V */
1218 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
1219 		return 0;
1220 
1221 	return -EINVAL;
1222 }
1223 
1224 static const struct mmc_host_ops meson_mmc_ops = {
1225 	.request	= meson_mmc_request,
1226 	.set_ios	= meson_mmc_set_ios,
1227 	.get_cd         = meson_mmc_get_cd,
1228 	.pre_req	= meson_mmc_pre_req,
1229 	.post_req	= meson_mmc_post_req,
1230 	.execute_tuning = meson_mmc_execute_tuning,
1231 	.card_busy	= meson_mmc_card_busy,
1232 	.start_signal_voltage_switch = meson_mmc_voltage_switch,
1233 };
1234 
1235 static int meson_mmc_probe(struct platform_device *pdev)
1236 {
1237 	struct resource *res;
1238 	struct meson_host *host;
1239 	struct mmc_host *mmc;
1240 	int ret;
1241 
1242 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
1243 	if (!mmc)
1244 		return -ENOMEM;
1245 	host = mmc_priv(mmc);
1246 	host->mmc = mmc;
1247 	host->dev = &pdev->dev;
1248 	dev_set_drvdata(&pdev->dev, host);
1249 
1250 	/* Get regulators and the supported OCR mask */
1251 	host->vqmmc_enabled = false;
1252 	ret = mmc_regulator_get_supply(mmc);
1253 	if (ret)
1254 		goto free_host;
1255 
1256 	ret = mmc_of_parse(mmc);
1257 	if (ret) {
1258 		if (ret != -EPROBE_DEFER)
1259 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
1260 		goto free_host;
1261 	}
1262 
1263 	host->data = (struct meson_mmc_data *)
1264 		of_device_get_match_data(&pdev->dev);
1265 	if (!host->data) {
1266 		ret = -EINVAL;
1267 		goto free_host;
1268 	}
1269 
1270 	ret = device_reset_optional(&pdev->dev);
1271 	if (ret) {
1272 		if (ret != -EPROBE_DEFER)
1273 			dev_err(&pdev->dev, "device reset failed: %d\n", ret);
1274 
1275 		return ret;
1276 	}
1277 
1278 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1279 	host->regs = devm_ioremap_resource(&pdev->dev, res);
1280 	if (IS_ERR(host->regs)) {
1281 		ret = PTR_ERR(host->regs);
1282 		goto free_host;
1283 	}
1284 
1285 	host->irq = platform_get_irq(pdev, 0);
1286 	if (host->irq <= 0) {
1287 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
1288 		ret = -EINVAL;
1289 		goto free_host;
1290 	}
1291 
1292 	host->pinctrl = devm_pinctrl_get(&pdev->dev);
1293 	if (IS_ERR(host->pinctrl)) {
1294 		ret = PTR_ERR(host->pinctrl);
1295 		goto free_host;
1296 	}
1297 
1298 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1299 						  PINCTRL_STATE_DEFAULT);
1300 	if (IS_ERR(host->pins_default)) {
1301 		ret = PTR_ERR(host->pins_default);
1302 		goto free_host;
1303 	}
1304 
1305 	host->pins_clk_gate = pinctrl_lookup_state(host->pinctrl,
1306 						   "clk-gate");
1307 	if (IS_ERR(host->pins_clk_gate)) {
1308 		dev_warn(&pdev->dev,
1309 			 "can't get clk-gate pinctrl, using clk_stop bit\n");
1310 		host->pins_clk_gate = NULL;
1311 	}
1312 
1313 	host->core_clk = devm_clk_get(&pdev->dev, "core");
1314 	if (IS_ERR(host->core_clk)) {
1315 		ret = PTR_ERR(host->core_clk);
1316 		goto free_host;
1317 	}
1318 
1319 	ret = clk_prepare_enable(host->core_clk);
1320 	if (ret)
1321 		goto free_host;
1322 
1323 	ret = meson_mmc_clk_init(host);
1324 	if (ret)
1325 		goto err_core_clk;
1326 
1327 	/* set config to sane default */
1328 	meson_mmc_cfg_init(host);
1329 
1330 	/* Stop execution */
1331 	writel(0, host->regs + SD_EMMC_START);
1332 
1333 	/* clear, ack and enable interrupts */
1334 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1335 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1336 	       host->regs + SD_EMMC_STATUS);
1337 	writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
1338 	       host->regs + SD_EMMC_IRQ_EN);
1339 
1340 	ret = request_threaded_irq(host->irq, meson_mmc_irq,
1341 				   meson_mmc_irq_thread, IRQF_SHARED,
1342 				   dev_name(&pdev->dev), host);
1343 	if (ret)
1344 		goto err_init_clk;
1345 
1346 	mmc->caps |= MMC_CAP_CMD23;
1347 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
1348 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1349 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
1350 	mmc->max_seg_size = mmc->max_req_size;
1351 
1352 	/* data bounce buffer */
1353 	host->bounce_buf_size = mmc->max_req_size;
1354 	host->bounce_buf =
1355 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
1356 				   &host->bounce_dma_addr, GFP_KERNEL);
1357 	if (host->bounce_buf == NULL) {
1358 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
1359 		ret = -ENOMEM;
1360 		goto err_free_irq;
1361 	}
1362 
1363 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1364 		      &host->descs_dma_addr, GFP_KERNEL);
1365 	if (!host->descs) {
1366 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1367 		ret = -ENOMEM;
1368 		goto err_bounce_buf;
1369 	}
1370 
1371 	mmc->ops = &meson_mmc_ops;
1372 	mmc_add_host(mmc);
1373 
1374 	return 0;
1375 
1376 err_bounce_buf:
1377 	dma_free_coherent(host->dev, host->bounce_buf_size,
1378 			  host->bounce_buf, host->bounce_dma_addr);
1379 err_free_irq:
1380 	free_irq(host->irq, host);
1381 err_init_clk:
1382 	clk_disable_unprepare(host->mmc_clk);
1383 err_core_clk:
1384 	clk_disable_unprepare(host->core_clk);
1385 free_host:
1386 	mmc_free_host(mmc);
1387 	return ret;
1388 }
1389 
1390 static int meson_mmc_remove(struct platform_device *pdev)
1391 {
1392 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1393 
1394 	mmc_remove_host(host->mmc);
1395 
1396 	/* disable interrupts */
1397 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1398 	free_irq(host->irq, host);
1399 
1400 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1401 			  host->descs, host->descs_dma_addr);
1402 	dma_free_coherent(host->dev, host->bounce_buf_size,
1403 			  host->bounce_buf, host->bounce_dma_addr);
1404 
1405 	clk_disable_unprepare(host->mmc_clk);
1406 	clk_disable_unprepare(host->core_clk);
1407 
1408 	mmc_free_host(host->mmc);
1409 	return 0;
1410 }
1411 
1412 static const struct meson_mmc_data meson_gx_data = {
1413 	.tx_delay_mask	= CLK_V2_TX_DELAY_MASK,
1414 	.rx_delay_mask	= CLK_V2_RX_DELAY_MASK,
1415 	.always_on	= CLK_V2_ALWAYS_ON,
1416 	.adjust		= SD_EMMC_ADJUST,
1417 };
1418 
1419 static const struct meson_mmc_data meson_axg_data = {
1420 	.tx_delay_mask	= CLK_V3_TX_DELAY_MASK,
1421 	.rx_delay_mask	= CLK_V3_RX_DELAY_MASK,
1422 	.always_on	= CLK_V3_ALWAYS_ON,
1423 	.adjust		= SD_EMMC_V3_ADJUST,
1424 };
1425 
1426 static const struct of_device_id meson_mmc_of_match[] = {
1427 	{ .compatible = "amlogic,meson-gx-mmc",		.data = &meson_gx_data },
1428 	{ .compatible = "amlogic,meson-gxbb-mmc", 	.data = &meson_gx_data },
1429 	{ .compatible = "amlogic,meson-gxl-mmc",	.data = &meson_gx_data },
1430 	{ .compatible = "amlogic,meson-gxm-mmc",	.data = &meson_gx_data },
1431 	{ .compatible = "amlogic,meson-axg-mmc",	.data = &meson_axg_data },
1432 	{}
1433 };
1434 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1435 
1436 static struct platform_driver meson_mmc_driver = {
1437 	.probe		= meson_mmc_probe,
1438 	.remove		= meson_mmc_remove,
1439 	.driver		= {
1440 		.name = DRIVER_NAME,
1441 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1442 	},
1443 };
1444 
1445 module_platform_driver(meson_mmc_driver);
1446 
1447 MODULE_DESCRIPTION("Amlogic S905*/GX*/AXG SD/eMMC driver");
1448 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1449 MODULE_LICENSE("GPL v2");
1450