xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision 4a5f8ae5)
1 /*
2  * Amlogic SD/eMMC driver for the GX/S905 family SoCs
3  *
4  * Copyright (c) 2016 BayLibre, SAS.
5  * Author: Kevin Hilman <khilman@baylibre.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  * The full GNU General Public License is included in this distribution
19  * in the file called COPYING.
20  */
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/ioport.h>
28 #include <linux/spinlock.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/mmc/host.h>
31 #include <linux/mmc/mmc.h>
32 #include <linux/mmc/sdio.h>
33 #include <linux/mmc/slot-gpio.h>
34 #include <linux/io.h>
35 #include <linux/clk.h>
36 #include <linux/clk-provider.h>
37 #include <linux/regulator/consumer.h>
38 #include <linux/interrupt.h>
39 #include <linux/bitfield.h>
40 
41 #define DRIVER_NAME "meson-gx-mmc"
42 
43 #define SD_EMMC_CLOCK 0x0
44 #define   CLK_DIV_MASK GENMASK(5, 0)
45 #define   CLK_DIV_MAX 63
46 #define   CLK_SRC_MASK GENMASK(7, 6)
47 #define   CLK_SRC_XTAL 0   /* external crystal */
48 #define   CLK_SRC_XTAL_RATE 24000000
49 #define   CLK_SRC_PLL 1    /* FCLK_DIV2 */
50 #define   CLK_SRC_PLL_RATE 1000000000
51 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
52 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
53 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
54 #define   CLK_PHASE_0 0
55 #define   CLK_PHASE_90 1
56 #define   CLK_PHASE_180 2
57 #define   CLK_PHASE_270 3
58 #define   CLK_ALWAYS_ON BIT(24)
59 
60 #define SD_EMMC_DElAY 0x4
61 #define SD_EMMC_ADJUST 0x8
62 #define SD_EMMC_CALOUT 0x10
63 #define SD_EMMC_START 0x40
64 #define   START_DESC_INIT BIT(0)
65 #define   START_DESC_BUSY BIT(1)
66 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
67 
68 #define SD_EMMC_CFG 0x44
69 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
70 #define   CFG_BUS_WIDTH_1 0x0
71 #define   CFG_BUS_WIDTH_4 0x1
72 #define   CFG_BUS_WIDTH_8 0x2
73 #define   CFG_DDR BIT(2)
74 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
75 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
76 #define   CFG_RC_CC_MASK GENMASK(15, 12)
77 #define   CFG_STOP_CLOCK BIT(22)
78 #define   CFG_CLK_ALWAYS_ON BIT(18)
79 #define   CFG_CHK_DS BIT(20)
80 #define   CFG_AUTO_CLK BIT(23)
81 
82 #define SD_EMMC_STATUS 0x48
83 #define   STATUS_BUSY BIT(31)
84 
85 #define SD_EMMC_IRQ_EN 0x4c
86 #define   IRQ_EN_MASK GENMASK(13, 0)
87 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
88 #define   IRQ_TXD_ERR BIT(8)
89 #define   IRQ_DESC_ERR BIT(9)
90 #define   IRQ_RESP_ERR BIT(10)
91 #define   IRQ_RESP_TIMEOUT BIT(11)
92 #define   IRQ_DESC_TIMEOUT BIT(12)
93 #define   IRQ_END_OF_CHAIN BIT(13)
94 #define   IRQ_RESP_STATUS BIT(14)
95 #define   IRQ_SDIO BIT(15)
96 
97 #define SD_EMMC_CMD_CFG 0x50
98 #define SD_EMMC_CMD_ARG 0x54
99 #define SD_EMMC_CMD_DAT 0x58
100 #define SD_EMMC_CMD_RSP 0x5c
101 #define SD_EMMC_CMD_RSP1 0x60
102 #define SD_EMMC_CMD_RSP2 0x64
103 #define SD_EMMC_CMD_RSP3 0x68
104 
105 #define SD_EMMC_RXD 0x94
106 #define SD_EMMC_TXD 0x94
107 #define SD_EMMC_LAST_REG SD_EMMC_TXD
108 
109 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
110 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
111 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
112 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
113 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
114 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
115 
116 #define SD_EMMC_PRE_REQ_DONE BIT(0)
117 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
118 
119 #define MUX_CLK_NUM_PARENTS 2
120 
121 struct meson_tuning_params {
122 	u8 core_phase;
123 	u8 tx_phase;
124 	u8 rx_phase;
125 };
126 
127 struct sd_emmc_desc {
128 	u32 cmd_cfg;
129 	u32 cmd_arg;
130 	u32 cmd_data;
131 	u32 cmd_resp;
132 };
133 
134 struct meson_host {
135 	struct	device		*dev;
136 	struct	mmc_host	*mmc;
137 	struct	mmc_command	*cmd;
138 
139 	spinlock_t lock;
140 	void __iomem *regs;
141 	struct clk *core_clk;
142 	struct clk_mux mux;
143 	struct clk *mux_clk;
144 	unsigned long current_clock;
145 
146 	struct clk_divider cfg_div;
147 	struct clk *cfg_div_clk;
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 	struct meson_tuning_params tp;
156 	bool vqmmc_enabled;
157 };
158 
159 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
160 #define CMD_CFG_BLOCK_MODE BIT(9)
161 #define CMD_CFG_R1B BIT(10)
162 #define CMD_CFG_END_OF_CHAIN BIT(11)
163 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
164 #define CMD_CFG_NO_RESP BIT(16)
165 #define CMD_CFG_NO_CMD BIT(17)
166 #define CMD_CFG_DATA_IO BIT(18)
167 #define CMD_CFG_DATA_WR BIT(19)
168 #define CMD_CFG_RESP_NOCRC BIT(20)
169 #define CMD_CFG_RESP_128 BIT(21)
170 #define CMD_CFG_RESP_NUM BIT(22)
171 #define CMD_CFG_DATA_NUM BIT(23)
172 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
173 #define CMD_CFG_ERROR BIT(30)
174 #define CMD_CFG_OWNER BIT(31)
175 
176 #define CMD_DATA_MASK GENMASK(31, 2)
177 #define CMD_DATA_BIG_ENDIAN BIT(1)
178 #define CMD_DATA_SRAM BIT(0)
179 #define CMD_RESP_MASK GENMASK(31, 1)
180 #define CMD_RESP_SRAM BIT(0)
181 
182 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
183 {
184 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
185 
186 	if (!timeout)
187 		return SD_EMMC_CMD_TIMEOUT_DATA;
188 
189 	timeout = roundup_pow_of_two(timeout);
190 
191 	return min(timeout, 32768U); /* max. 2^15 ms */
192 }
193 
194 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
195 {
196 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
197 		return cmd->mrq->cmd;
198 	else if (mmc_op_multi(cmd->opcode) &&
199 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
200 		return cmd->mrq->stop;
201 	else
202 		return NULL;
203 }
204 
205 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
206 					struct mmc_request *mrq)
207 {
208 	struct mmc_data *data = mrq->data;
209 	struct scatterlist *sg;
210 	int i;
211 	bool use_desc_chain_mode = true;
212 
213 	for_each_sg(data->sg, sg, data->sg_len, i)
214 		/* check for 8 byte alignment */
215 		if (sg->offset & 7) {
216 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
217 			use_desc_chain_mode = false;
218 			break;
219 		}
220 
221 	if (use_desc_chain_mode)
222 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
223 }
224 
225 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
226 {
227 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
228 }
229 
230 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
231 {
232 	return data && data->flags & MMC_DATA_READ &&
233 	       !meson_mmc_desc_chain_mode(data);
234 }
235 
236 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
237 {
238 	struct mmc_data *data = mrq->data;
239 
240 	if (!data)
241 		return;
242 
243 	meson_mmc_get_transfer_mode(mmc, mrq);
244 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
245 
246 	if (!meson_mmc_desc_chain_mode(data))
247 		return;
248 
249 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
250                                    mmc_get_dma_dir(data));
251 	if (!data->sg_count)
252 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
253 }
254 
255 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
256 			       int err)
257 {
258 	struct mmc_data *data = mrq->data;
259 
260 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
261 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
262 			     mmc_get_dma_dir(data));
263 }
264 
265 static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate)
266 {
267 	struct mmc_host *mmc = host->mmc;
268 	int ret;
269 	u32 cfg;
270 
271 	if (clk_rate) {
272 		if (WARN_ON(clk_rate > mmc->f_max))
273 			clk_rate = mmc->f_max;
274 		else if (WARN_ON(clk_rate < mmc->f_min))
275 			clk_rate = mmc->f_min;
276 	}
277 
278 	if (clk_rate == host->current_clock)
279 		return 0;
280 
281 	/* stop clock */
282 	cfg = readl(host->regs + SD_EMMC_CFG);
283 	if (!(cfg & CFG_STOP_CLOCK)) {
284 		cfg |= CFG_STOP_CLOCK;
285 		writel(cfg, host->regs + SD_EMMC_CFG);
286 	}
287 
288 	dev_dbg(host->dev, "change clock rate %u -> %lu\n",
289 		mmc->actual_clock, clk_rate);
290 
291 	if (!clk_rate) {
292 		mmc->actual_clock = 0;
293 		host->current_clock = 0;
294 		/* return with clock being stopped */
295 		return 0;
296 	}
297 
298 	ret = clk_set_rate(host->cfg_div_clk, clk_rate);
299 	if (ret) {
300 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
301 			clk_rate, ret);
302 		return ret;
303 	}
304 
305 	mmc->actual_clock = clk_get_rate(host->cfg_div_clk);
306 	host->current_clock = clk_rate;
307 
308 	if (clk_rate != mmc->actual_clock)
309 		dev_dbg(host->dev,
310 			"divider requested rate %lu != actual rate %u\n",
311 			clk_rate, mmc->actual_clock);
312 
313 	/* (re)start clock */
314 	cfg = readl(host->regs + SD_EMMC_CFG);
315 	cfg &= ~CFG_STOP_CLOCK;
316 	writel(cfg, host->regs + SD_EMMC_CFG);
317 
318 	return 0;
319 }
320 
321 /*
322  * The SD/eMMC IP block has an internal mux and divider used for
323  * generating the MMC clock.  Use the clock framework to create and
324  * manage these clocks.
325  */
326 static int meson_mmc_clk_init(struct meson_host *host)
327 {
328 	struct clk_init_data init;
329 	char clk_name[32];
330 	int i, ret = 0;
331 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
332 	const char *clk_div_parents[1];
333 	u32 clk_reg, cfg;
334 
335 	/* get the mux parents */
336 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
337 		struct clk *clk;
338 		char name[16];
339 
340 		snprintf(name, sizeof(name), "clkin%d", i);
341 		clk = devm_clk_get(host->dev, name);
342 		if (IS_ERR(clk)) {
343 			if (clk != ERR_PTR(-EPROBE_DEFER))
344 				dev_err(host->dev, "Missing clock %s\n", name);
345 			return PTR_ERR(clk);
346 		}
347 
348 		mux_parent_names[i] = __clk_get_name(clk);
349 	}
350 
351 	/* create the mux */
352 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
353 	init.name = clk_name;
354 	init.ops = &clk_mux_ops;
355 	init.flags = 0;
356 	init.parent_names = mux_parent_names;
357 	init.num_parents = MUX_CLK_NUM_PARENTS;
358 	host->mux.reg = host->regs + SD_EMMC_CLOCK;
359 	host->mux.shift = __bf_shf(CLK_SRC_MASK);
360 	host->mux.mask = CLK_SRC_MASK;
361 	host->mux.flags = 0;
362 	host->mux.table = NULL;
363 	host->mux.hw.init = &init;
364 
365 	host->mux_clk = devm_clk_register(host->dev, &host->mux.hw);
366 	if (WARN_ON(IS_ERR(host->mux_clk)))
367 		return PTR_ERR(host->mux_clk);
368 
369 	/* create the divider */
370 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
371 	init.name = clk_name;
372 	init.ops = &clk_divider_ops;
373 	init.flags = CLK_SET_RATE_PARENT;
374 	clk_div_parents[0] = __clk_get_name(host->mux_clk);
375 	init.parent_names = clk_div_parents;
376 	init.num_parents = ARRAY_SIZE(clk_div_parents);
377 
378 	host->cfg_div.reg = host->regs + SD_EMMC_CLOCK;
379 	host->cfg_div.shift = __bf_shf(CLK_DIV_MASK);
380 	host->cfg_div.width = __builtin_popcountl(CLK_DIV_MASK);
381 	host->cfg_div.hw.init = &init;
382 	host->cfg_div.flags = CLK_DIVIDER_ONE_BASED |
383 		CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ALLOW_ZERO;
384 
385 	host->cfg_div_clk = devm_clk_register(host->dev, &host->cfg_div.hw);
386 	if (WARN_ON(PTR_ERR_OR_ZERO(host->cfg_div_clk)))
387 		return PTR_ERR(host->cfg_div_clk);
388 
389 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
390 	clk_reg = 0;
391 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, host->tp.core_phase);
392 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, host->tp.tx_phase);
393 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, host->tp.rx_phase);
394 	clk_reg |= FIELD_PREP(CLK_SRC_MASK, CLK_SRC_XTAL);
395 	clk_reg |= FIELD_PREP(CLK_DIV_MASK, CLK_DIV_MAX);
396 	clk_reg &= ~CLK_ALWAYS_ON;
397 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
398 
399 	/* Ensure clock starts in "auto" mode, not "always on" */
400 	cfg = readl(host->regs + SD_EMMC_CFG);
401 	cfg &= ~CFG_CLK_ALWAYS_ON;
402 	cfg |= CFG_AUTO_CLK;
403 	writel(cfg, host->regs + SD_EMMC_CFG);
404 
405 	ret = clk_prepare_enable(host->cfg_div_clk);
406 	if (ret)
407 		return ret;
408 
409 	/* Get the nearest minimum clock to 400KHz */
410 	host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 400000);
411 
412 	ret = meson_mmc_clk_set(host, host->mmc->f_min);
413 	if (ret)
414 		clk_disable_unprepare(host->cfg_div_clk);
415 
416 	return ret;
417 }
418 
419 static void meson_mmc_set_tuning_params(struct mmc_host *mmc)
420 {
421 	struct meson_host *host = mmc_priv(mmc);
422 	u32 regval;
423 
424 	/* stop clock */
425 	regval = readl(host->regs + SD_EMMC_CFG);
426 	regval |= CFG_STOP_CLOCK;
427 	writel(regval, host->regs + SD_EMMC_CFG);
428 
429 	regval = readl(host->regs + SD_EMMC_CLOCK);
430 	regval &= ~CLK_CORE_PHASE_MASK;
431 	regval |= FIELD_PREP(CLK_CORE_PHASE_MASK, host->tp.core_phase);
432 	regval &= ~CLK_TX_PHASE_MASK;
433 	regval |= FIELD_PREP(CLK_TX_PHASE_MASK, host->tp.tx_phase);
434 	regval &= ~CLK_RX_PHASE_MASK;
435 	regval |= FIELD_PREP(CLK_RX_PHASE_MASK, host->tp.rx_phase);
436 	writel(regval, host->regs + SD_EMMC_CLOCK);
437 
438 	/* start clock */
439 	regval = readl(host->regs + SD_EMMC_CFG);
440 	regval &= ~CFG_STOP_CLOCK;
441 	writel(regval, host->regs + SD_EMMC_CFG);
442 }
443 
444 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
445 {
446 	struct meson_host *host = mmc_priv(mmc);
447 	u32 bus_width;
448 	u32 val, orig;
449 
450 	/*
451 	 * GPIO regulator, only controls switching between 1v8 and
452 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
453 	 */
454 	switch (ios->power_mode) {
455 	case MMC_POWER_OFF:
456 		if (!IS_ERR(mmc->supply.vmmc))
457 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
458 
459 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
460 			regulator_disable(mmc->supply.vqmmc);
461 			host->vqmmc_enabled = false;
462 		}
463 
464 		break;
465 
466 	case MMC_POWER_UP:
467 		if (!IS_ERR(mmc->supply.vmmc))
468 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
469 		break;
470 
471 	case MMC_POWER_ON:
472 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
473 			int ret = regulator_enable(mmc->supply.vqmmc);
474 
475 			if (ret < 0)
476 				dev_err(mmc_dev(mmc),
477 					"failed to enable vqmmc regulator\n");
478 			else
479 				host->vqmmc_enabled = true;
480 		}
481 
482 		break;
483 	}
484 
485 
486 	meson_mmc_clk_set(host, ios->clock);
487 
488 	/* Bus width */
489 	switch (ios->bus_width) {
490 	case MMC_BUS_WIDTH_1:
491 		bus_width = CFG_BUS_WIDTH_1;
492 		break;
493 	case MMC_BUS_WIDTH_4:
494 		bus_width = CFG_BUS_WIDTH_4;
495 		break;
496 	case MMC_BUS_WIDTH_8:
497 		bus_width = CFG_BUS_WIDTH_8;
498 		break;
499 	default:
500 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
501 			ios->bus_width);
502 		bus_width = CFG_BUS_WIDTH_4;
503 	}
504 
505 	val = readl(host->regs + SD_EMMC_CFG);
506 	orig = val;
507 
508 	val &= ~CFG_BUS_WIDTH_MASK;
509 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
510 
511 	val &= ~CFG_DDR;
512 	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
513 	    ios->timing == MMC_TIMING_MMC_DDR52 ||
514 	    ios->timing == MMC_TIMING_MMC_HS400)
515 		val |= CFG_DDR;
516 
517 	val &= ~CFG_CHK_DS;
518 	if (ios->timing == MMC_TIMING_MMC_HS400)
519 		val |= CFG_CHK_DS;
520 
521 	if (val != orig) {
522 		writel(val, host->regs + SD_EMMC_CFG);
523 		dev_dbg(host->dev, "%s: SD_EMMC_CFG: 0x%08x -> 0x%08x\n",
524 			__func__, orig, val);
525 	}
526 }
527 
528 static void meson_mmc_request_done(struct mmc_host *mmc,
529 				   struct mmc_request *mrq)
530 {
531 	struct meson_host *host = mmc_priv(mmc);
532 
533 	host->cmd = NULL;
534 	mmc_request_done(host->mmc, mrq);
535 }
536 
537 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
538 {
539 	struct meson_host *host = mmc_priv(mmc);
540 	u32 cfg, blksz_old;
541 
542 	cfg = readl(host->regs + SD_EMMC_CFG);
543 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
544 
545 	if (!is_power_of_2(blksz))
546 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
547 
548 	blksz = ilog2(blksz);
549 
550 	/* check if block-size matches, if not update */
551 	if (blksz == blksz_old)
552 		return;
553 
554 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
555 		blksz_old, blksz);
556 
557 	cfg &= ~CFG_BLK_LEN_MASK;
558 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
559 	writel(cfg, host->regs + SD_EMMC_CFG);
560 }
561 
562 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
563 {
564 	if (cmd->flags & MMC_RSP_PRESENT) {
565 		if (cmd->flags & MMC_RSP_136)
566 			*cmd_cfg |= CMD_CFG_RESP_128;
567 		*cmd_cfg |= CMD_CFG_RESP_NUM;
568 
569 		if (!(cmd->flags & MMC_RSP_CRC))
570 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
571 
572 		if (cmd->flags & MMC_RSP_BUSY)
573 			*cmd_cfg |= CMD_CFG_R1B;
574 	} else {
575 		*cmd_cfg |= CMD_CFG_NO_RESP;
576 	}
577 }
578 
579 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
580 {
581 	struct meson_host *host = mmc_priv(mmc);
582 	struct sd_emmc_desc *desc = host->descs;
583 	struct mmc_data *data = host->cmd->data;
584 	struct scatterlist *sg;
585 	u32 start;
586 	int i;
587 
588 	if (data->flags & MMC_DATA_WRITE)
589 		cmd_cfg |= CMD_CFG_DATA_WR;
590 
591 	if (data->blocks > 1) {
592 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
593 		meson_mmc_set_blksz(mmc, data->blksz);
594 	}
595 
596 	for_each_sg(data->sg, sg, data->sg_count, i) {
597 		unsigned int len = sg_dma_len(sg);
598 
599 		if (data->blocks > 1)
600 			len /= data->blksz;
601 
602 		desc[i].cmd_cfg = cmd_cfg;
603 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
604 		if (i > 0)
605 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
606 		desc[i].cmd_arg = host->cmd->arg;
607 		desc[i].cmd_resp = 0;
608 		desc[i].cmd_data = sg_dma_address(sg);
609 	}
610 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
611 
612 	dma_wmb(); /* ensure descriptor is written before kicked */
613 	start = host->descs_dma_addr | START_DESC_BUSY;
614 	writel(start, host->regs + SD_EMMC_START);
615 }
616 
617 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
618 {
619 	struct meson_host *host = mmc_priv(mmc);
620 	struct mmc_data *data = cmd->data;
621 	u32 cmd_cfg = 0, cmd_data = 0;
622 	unsigned int xfer_bytes = 0;
623 
624 	/* Setup descriptors */
625 	dma_rmb();
626 
627 	host->cmd = cmd;
628 
629 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
630 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
631 
632 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
633 
634 	/* data? */
635 	if (data) {
636 		data->bytes_xfered = 0;
637 		cmd_cfg |= CMD_CFG_DATA_IO;
638 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
639 				      ilog2(meson_mmc_get_timeout_msecs(data)));
640 
641 		if (meson_mmc_desc_chain_mode(data)) {
642 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
643 			return;
644 		}
645 
646 		if (data->blocks > 1) {
647 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
648 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
649 					      data->blocks);
650 			meson_mmc_set_blksz(mmc, data->blksz);
651 		} else {
652 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
653 		}
654 
655 		xfer_bytes = data->blksz * data->blocks;
656 		if (data->flags & MMC_DATA_WRITE) {
657 			cmd_cfg |= CMD_CFG_DATA_WR;
658 			WARN_ON(xfer_bytes > host->bounce_buf_size);
659 			sg_copy_to_buffer(data->sg, data->sg_len,
660 					  host->bounce_buf, xfer_bytes);
661 			dma_wmb();
662 		}
663 
664 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
665 	} else {
666 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
667 				      ilog2(SD_EMMC_CMD_TIMEOUT));
668 	}
669 
670 	/* Last descriptor */
671 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
672 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
673 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
674 	writel(0, host->regs + SD_EMMC_CMD_RSP);
675 	wmb(); /* ensure descriptor is written before kicked */
676 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
677 }
678 
679 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
680 {
681 	struct meson_host *host = mmc_priv(mmc);
682 	bool needs_pre_post_req = mrq->data &&
683 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
684 
685 	if (needs_pre_post_req) {
686 		meson_mmc_get_transfer_mode(mmc, mrq);
687 		if (!meson_mmc_desc_chain_mode(mrq->data))
688 			needs_pre_post_req = false;
689 	}
690 
691 	if (needs_pre_post_req)
692 		meson_mmc_pre_req(mmc, mrq);
693 
694 	/* Stop execution */
695 	writel(0, host->regs + SD_EMMC_START);
696 
697 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
698 
699 	if (needs_pre_post_req)
700 		meson_mmc_post_req(mmc, mrq, 0);
701 }
702 
703 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
704 {
705 	struct meson_host *host = mmc_priv(mmc);
706 
707 	if (cmd->flags & MMC_RSP_136) {
708 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
709 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
710 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
711 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
712 	} else if (cmd->flags & MMC_RSP_PRESENT) {
713 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
714 	}
715 }
716 
717 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
718 {
719 	struct meson_host *host = dev_id;
720 	struct mmc_command *cmd;
721 	struct mmc_data *data;
722 	u32 irq_en, status, raw_status;
723 	irqreturn_t ret = IRQ_HANDLED;
724 
725 	if (WARN_ON(!host))
726 		return IRQ_NONE;
727 
728 	cmd = host->cmd;
729 
730 	if (WARN_ON(!cmd))
731 		return IRQ_NONE;
732 
733 	data = cmd->data;
734 
735 	spin_lock(&host->lock);
736 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
737 	raw_status = readl(host->regs + SD_EMMC_STATUS);
738 	status = raw_status & irq_en;
739 
740 	if (!status) {
741 		dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
742 			 raw_status, irq_en);
743 		ret = IRQ_NONE;
744 		goto out;
745 	}
746 
747 	meson_mmc_read_resp(host->mmc, cmd);
748 
749 	cmd->error = 0;
750 	if (status & IRQ_RXD_ERR_MASK) {
751 		dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
752 		cmd->error = -EILSEQ;
753 	}
754 	if (status & IRQ_TXD_ERR) {
755 		dev_dbg(host->dev, "Unhandled IRQ: TXD error\n");
756 		cmd->error = -EILSEQ;
757 	}
758 	if (status & IRQ_DESC_ERR)
759 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor error\n");
760 	if (status & IRQ_RESP_ERR) {
761 		dev_dbg(host->dev, "Unhandled IRQ: Response error\n");
762 		cmd->error = -EILSEQ;
763 	}
764 	if (status & IRQ_RESP_TIMEOUT) {
765 		dev_dbg(host->dev, "Unhandled IRQ: Response timeout\n");
766 		cmd->error = -ETIMEDOUT;
767 	}
768 	if (status & IRQ_DESC_TIMEOUT) {
769 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor timeout\n");
770 		cmd->error = -ETIMEDOUT;
771 	}
772 	if (status & IRQ_SDIO)
773 		dev_dbg(host->dev, "Unhandled IRQ: SDIO.\n");
774 
775 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
776 		if (data && !cmd->error)
777 			data->bytes_xfered = data->blksz * data->blocks;
778 		if (meson_mmc_bounce_buf_read(data) ||
779 		    meson_mmc_get_next_command(cmd))
780 			ret = IRQ_WAKE_THREAD;
781 	} else {
782 		dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC CMD%u arg=0x%08x flags=0x%08x stop=%d\n",
783 			 status, cmd->opcode, cmd->arg,
784 			 cmd->flags, cmd->mrq->stop ? 1 : 0);
785 		if (cmd->data) {
786 			struct mmc_data *data = cmd->data;
787 
788 			dev_warn(host->dev, "\tblksz %u blocks %u flags 0x%08x (%s%s)",
789 				 data->blksz, data->blocks, data->flags,
790 				 data->flags & MMC_DATA_WRITE ? "write" : "",
791 				 data->flags & MMC_DATA_READ ? "read" : "");
792 		}
793 	}
794 
795 out:
796 	/* ack all (enabled) interrupts */
797 	writel(status, host->regs + SD_EMMC_STATUS);
798 
799 	if (ret == IRQ_HANDLED)
800 		meson_mmc_request_done(host->mmc, cmd->mrq);
801 
802 	spin_unlock(&host->lock);
803 	return ret;
804 }
805 
806 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
807 {
808 	struct meson_host *host = dev_id;
809 	struct mmc_command *next_cmd, *cmd = host->cmd;
810 	struct mmc_data *data;
811 	unsigned int xfer_bytes;
812 
813 	if (WARN_ON(!cmd))
814 		return IRQ_NONE;
815 
816 	data = cmd->data;
817 	if (meson_mmc_bounce_buf_read(data)) {
818 		xfer_bytes = data->blksz * data->blocks;
819 		WARN_ON(xfer_bytes > host->bounce_buf_size);
820 		sg_copy_from_buffer(data->sg, data->sg_len,
821 				    host->bounce_buf, xfer_bytes);
822 	}
823 
824 	next_cmd = meson_mmc_get_next_command(cmd);
825 	if (next_cmd)
826 		meson_mmc_start_cmd(host->mmc, next_cmd);
827 	else
828 		meson_mmc_request_done(host->mmc, cmd->mrq);
829 
830 	return IRQ_HANDLED;
831 }
832 
833 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
834 {
835 	struct meson_host *host = mmc_priv(mmc);
836 	struct meson_tuning_params tp_old = host->tp;
837 	int ret = -EINVAL, i, cmd_error;
838 
839 	dev_info(mmc_dev(mmc), "(re)tuning...\n");
840 
841 	for (i = CLK_PHASE_0; i <= CLK_PHASE_270; i++) {
842 		host->tp.rx_phase = i;
843 		/* exclude the active parameter set if retuning */
844 		if (!memcmp(&tp_old, &host->tp, sizeof(tp_old)) &&
845 		    mmc->doing_retune)
846 			continue;
847 		meson_mmc_set_tuning_params(mmc);
848 		ret = mmc_send_tuning(mmc, opcode, &cmd_error);
849 		if (!ret)
850 			break;
851 	}
852 
853 	return ret;
854 }
855 
856 /*
857  * NOTE: we only need this until the GPIO/pinctrl driver can handle
858  * interrupts.  For now, the MMC core will use this for polling.
859  */
860 static int meson_mmc_get_cd(struct mmc_host *mmc)
861 {
862 	int status = mmc_gpio_get_cd(mmc);
863 
864 	if (status == -ENOSYS)
865 		return 1; /* assume present */
866 
867 	return status;
868 }
869 
870 static void meson_mmc_cfg_init(struct meson_host *host)
871 {
872 	u32 cfg = 0;
873 
874 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
875 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
876 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
877 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
878 
879 	writel(cfg, host->regs + SD_EMMC_CFG);
880 }
881 
882 static const struct mmc_host_ops meson_mmc_ops = {
883 	.request	= meson_mmc_request,
884 	.set_ios	= meson_mmc_set_ios,
885 	.get_cd         = meson_mmc_get_cd,
886 	.pre_req	= meson_mmc_pre_req,
887 	.post_req	= meson_mmc_post_req,
888 	.execute_tuning = meson_mmc_execute_tuning,
889 };
890 
891 static int meson_mmc_probe(struct platform_device *pdev)
892 {
893 	struct resource *res;
894 	struct meson_host *host;
895 	struct mmc_host *mmc;
896 	int ret, irq;
897 
898 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
899 	if (!mmc)
900 		return -ENOMEM;
901 	host = mmc_priv(mmc);
902 	host->mmc = mmc;
903 	host->dev = &pdev->dev;
904 	dev_set_drvdata(&pdev->dev, host);
905 
906 	spin_lock_init(&host->lock);
907 
908 	/* Get regulators and the supported OCR mask */
909 	host->vqmmc_enabled = false;
910 	ret = mmc_regulator_get_supply(mmc);
911 	if (ret == -EPROBE_DEFER)
912 		goto free_host;
913 
914 	ret = mmc_of_parse(mmc);
915 	if (ret) {
916 		if (ret != -EPROBE_DEFER)
917 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
918 		goto free_host;
919 	}
920 
921 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
922 	host->regs = devm_ioremap_resource(&pdev->dev, res);
923 	if (IS_ERR(host->regs)) {
924 		ret = PTR_ERR(host->regs);
925 		goto free_host;
926 	}
927 
928 	irq = platform_get_irq(pdev, 0);
929 	if (!irq) {
930 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
931 		ret = -EINVAL;
932 		goto free_host;
933 	}
934 
935 	host->core_clk = devm_clk_get(&pdev->dev, "core");
936 	if (IS_ERR(host->core_clk)) {
937 		ret = PTR_ERR(host->core_clk);
938 		goto free_host;
939 	}
940 
941 	ret = clk_prepare_enable(host->core_clk);
942 	if (ret)
943 		goto free_host;
944 
945 	host->tp.core_phase = CLK_PHASE_180;
946 	host->tp.tx_phase = CLK_PHASE_0;
947 	host->tp.rx_phase = CLK_PHASE_0;
948 
949 	ret = meson_mmc_clk_init(host);
950 	if (ret)
951 		goto err_core_clk;
952 
953 	/* Stop execution */
954 	writel(0, host->regs + SD_EMMC_START);
955 
956 	/* clear, ack, enable all interrupts */
957 	writel(0, host->regs + SD_EMMC_IRQ_EN);
958 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
959 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_IRQ_EN);
960 
961 	/* set config to sane default */
962 	meson_mmc_cfg_init(host);
963 
964 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
965 					meson_mmc_irq_thread, IRQF_SHARED,
966 					NULL, host);
967 	if (ret)
968 		goto err_div_clk;
969 
970 	mmc->caps |= MMC_CAP_CMD23;
971 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
972 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
973 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
974 	mmc->max_seg_size = mmc->max_req_size;
975 
976 	/* data bounce buffer */
977 	host->bounce_buf_size = mmc->max_req_size;
978 	host->bounce_buf =
979 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
980 				   &host->bounce_dma_addr, GFP_KERNEL);
981 	if (host->bounce_buf == NULL) {
982 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
983 		ret = -ENOMEM;
984 		goto err_div_clk;
985 	}
986 
987 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
988 		      &host->descs_dma_addr, GFP_KERNEL);
989 	if (!host->descs) {
990 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
991 		ret = -ENOMEM;
992 		goto err_bounce_buf;
993 	}
994 
995 	mmc->ops = &meson_mmc_ops;
996 	mmc_add_host(mmc);
997 
998 	return 0;
999 
1000 err_bounce_buf:
1001 	dma_free_coherent(host->dev, host->bounce_buf_size,
1002 			  host->bounce_buf, host->bounce_dma_addr);
1003 err_div_clk:
1004 	clk_disable_unprepare(host->cfg_div_clk);
1005 err_core_clk:
1006 	clk_disable_unprepare(host->core_clk);
1007 free_host:
1008 	mmc_free_host(mmc);
1009 	return ret;
1010 }
1011 
1012 static int meson_mmc_remove(struct platform_device *pdev)
1013 {
1014 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1015 
1016 	mmc_remove_host(host->mmc);
1017 
1018 	/* disable interrupts */
1019 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1020 
1021 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1022 			  host->descs, host->descs_dma_addr);
1023 	dma_free_coherent(host->dev, host->bounce_buf_size,
1024 			  host->bounce_buf, host->bounce_dma_addr);
1025 
1026 	clk_disable_unprepare(host->cfg_div_clk);
1027 	clk_disable_unprepare(host->core_clk);
1028 
1029 	mmc_free_host(host->mmc);
1030 	return 0;
1031 }
1032 
1033 static const struct of_device_id meson_mmc_of_match[] = {
1034 	{ .compatible = "amlogic,meson-gx-mmc", },
1035 	{ .compatible = "amlogic,meson-gxbb-mmc", },
1036 	{ .compatible = "amlogic,meson-gxl-mmc", },
1037 	{ .compatible = "amlogic,meson-gxm-mmc", },
1038 	{}
1039 };
1040 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1041 
1042 static struct platform_driver meson_mmc_driver = {
1043 	.probe		= meson_mmc_probe,
1044 	.remove		= meson_mmc_remove,
1045 	.driver		= {
1046 		.name = DRIVER_NAME,
1047 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1048 	},
1049 };
1050 
1051 module_platform_driver(meson_mmc_driver);
1052 
1053 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
1054 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1055 MODULE_LICENSE("GPL v2");
1056