xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision f7c35abe)
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 
40 #define DRIVER_NAME "meson-gx-mmc"
41 
42 #define SD_EMMC_CLOCK 0x0
43 #define   CLK_DIV_SHIFT 0
44 #define   CLK_DIV_WIDTH 6
45 #define   CLK_DIV_MASK 0x3f
46 #define   CLK_DIV_MAX 63
47 #define   CLK_SRC_SHIFT 6
48 #define   CLK_SRC_WIDTH 2
49 #define   CLK_SRC_MASK 0x3
50 #define   CLK_SRC_XTAL 0   /* external crystal */
51 #define   CLK_SRC_XTAL_RATE 24000000
52 #define   CLK_SRC_PLL 1    /* FCLK_DIV2 */
53 #define   CLK_SRC_PLL_RATE 1000000000
54 #define   CLK_PHASE_SHIFT 8
55 #define   CLK_PHASE_MASK 0x3
56 #define   CLK_PHASE_0 0
57 #define   CLK_PHASE_90 1
58 #define   CLK_PHASE_180 2
59 #define   CLK_PHASE_270 3
60 #define   CLK_ALWAYS_ON BIT(24)
61 
62 #define SD_EMMC_DElAY 0x4
63 #define SD_EMMC_ADJUST 0x8
64 #define SD_EMMC_CALOUT 0x10
65 #define SD_EMMC_START 0x40
66 #define   START_DESC_INIT BIT(0)
67 #define   START_DESC_BUSY BIT(1)
68 #define   START_DESC_ADDR_SHIFT 2
69 #define   START_DESC_ADDR_MASK (~0x3)
70 
71 #define SD_EMMC_CFG 0x44
72 #define   CFG_BUS_WIDTH_SHIFT 0
73 #define   CFG_BUS_WIDTH_MASK 0x3
74 #define   CFG_BUS_WIDTH_1 0x0
75 #define   CFG_BUS_WIDTH_4 0x1
76 #define   CFG_BUS_WIDTH_8 0x2
77 #define   CFG_DDR BIT(2)
78 #define   CFG_BLK_LEN_SHIFT 4
79 #define   CFG_BLK_LEN_MASK 0xf
80 #define   CFG_RESP_TIMEOUT_SHIFT 8
81 #define   CFG_RESP_TIMEOUT_MASK 0xf
82 #define   CFG_RC_CC_SHIFT 12
83 #define   CFG_RC_CC_MASK 0xf
84 #define   CFG_STOP_CLOCK BIT(22)
85 #define   CFG_CLK_ALWAYS_ON BIT(18)
86 #define   CFG_CHK_DS BIT(20)
87 #define   CFG_AUTO_CLK BIT(23)
88 
89 #define SD_EMMC_STATUS 0x48
90 #define   STATUS_BUSY BIT(31)
91 
92 #define SD_EMMC_IRQ_EN 0x4c
93 #define   IRQ_EN_MASK 0x3fff
94 #define   IRQ_RXD_ERR_SHIFT 0
95 #define   IRQ_RXD_ERR_MASK 0xff
96 #define   IRQ_TXD_ERR BIT(8)
97 #define   IRQ_DESC_ERR BIT(9)
98 #define   IRQ_RESP_ERR BIT(10)
99 #define   IRQ_RESP_TIMEOUT BIT(11)
100 #define   IRQ_DESC_TIMEOUT BIT(12)
101 #define   IRQ_END_OF_CHAIN BIT(13)
102 #define   IRQ_RESP_STATUS BIT(14)
103 #define   IRQ_SDIO BIT(15)
104 
105 #define SD_EMMC_CMD_CFG 0x50
106 #define SD_EMMC_CMD_ARG 0x54
107 #define SD_EMMC_CMD_DAT 0x58
108 #define SD_EMMC_CMD_RSP 0x5c
109 #define SD_EMMC_CMD_RSP1 0x60
110 #define SD_EMMC_CMD_RSP2 0x64
111 #define SD_EMMC_CMD_RSP3 0x68
112 
113 #define SD_EMMC_RXD 0x94
114 #define SD_EMMC_TXD 0x94
115 #define SD_EMMC_LAST_REG SD_EMMC_TXD
116 
117 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
118 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
119 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
120 #define MUX_CLK_NUM_PARENTS 2
121 
122 struct meson_host {
123 	struct	device		*dev;
124 	struct	mmc_host	*mmc;
125 	struct	mmc_request	*mrq;
126 	struct	mmc_command	*cmd;
127 
128 	spinlock_t lock;
129 	void __iomem *regs;
130 	int irq;
131 	u32 ocr_mask;
132 	struct clk *core_clk;
133 	struct clk_mux mux;
134 	struct clk *mux_clk;
135 	struct clk *mux_parent[MUX_CLK_NUM_PARENTS];
136 	unsigned long current_clock;
137 
138 	struct clk_divider cfg_div;
139 	struct clk *cfg_div_clk;
140 
141 	unsigned int bounce_buf_size;
142 	void *bounce_buf;
143 	dma_addr_t bounce_dma_addr;
144 
145 	bool vqmmc_enabled;
146 };
147 
148 struct sd_emmc_desc {
149 	u32 cmd_cfg;
150 	u32 cmd_arg;
151 	u32 cmd_data;
152 	u32 cmd_resp;
153 };
154 #define CMD_CFG_LENGTH_SHIFT 0
155 #define CMD_CFG_LENGTH_MASK 0x1ff
156 #define CMD_CFG_BLOCK_MODE BIT(9)
157 #define CMD_CFG_R1B BIT(10)
158 #define CMD_CFG_END_OF_CHAIN BIT(11)
159 #define CMD_CFG_TIMEOUT_SHIFT 12
160 #define CMD_CFG_TIMEOUT_MASK 0xf
161 #define CMD_CFG_NO_RESP BIT(16)
162 #define CMD_CFG_NO_CMD BIT(17)
163 #define CMD_CFG_DATA_IO BIT(18)
164 #define CMD_CFG_DATA_WR BIT(19)
165 #define CMD_CFG_RESP_NOCRC BIT(20)
166 #define CMD_CFG_RESP_128 BIT(21)
167 #define CMD_CFG_RESP_NUM BIT(22)
168 #define CMD_CFG_DATA_NUM BIT(23)
169 #define CMD_CFG_CMD_INDEX_SHIFT 24
170 #define CMD_CFG_CMD_INDEX_MASK 0x3f
171 #define CMD_CFG_ERROR BIT(30)
172 #define CMD_CFG_OWNER BIT(31)
173 
174 #define CMD_DATA_MASK (~0x3)
175 #define CMD_DATA_BIG_ENDIAN BIT(1)
176 #define CMD_DATA_SRAM BIT(0)
177 #define CMD_RESP_MASK (~0x1)
178 #define CMD_RESP_SRAM BIT(0)
179 
180 static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate)
181 {
182 	struct mmc_host *mmc = host->mmc;
183 	int ret;
184 	u32 cfg;
185 
186 	if (clk_rate) {
187 		if (WARN_ON(clk_rate > mmc->f_max))
188 			clk_rate = mmc->f_max;
189 		else if (WARN_ON(clk_rate < mmc->f_min))
190 			clk_rate = mmc->f_min;
191 	}
192 
193 	if (clk_rate == host->current_clock)
194 		return 0;
195 
196 	/* stop clock */
197 	cfg = readl(host->regs + SD_EMMC_CFG);
198 	if (!(cfg & CFG_STOP_CLOCK)) {
199 		cfg |= CFG_STOP_CLOCK;
200 		writel(cfg, host->regs + SD_EMMC_CFG);
201 	}
202 
203 	dev_dbg(host->dev, "change clock rate %u -> %lu\n",
204 		mmc->actual_clock, clk_rate);
205 
206 	if (!clk_rate) {
207 		mmc->actual_clock = 0;
208 		host->current_clock = 0;
209 		/* return with clock being stopped */
210 		return 0;
211 	}
212 
213 	ret = clk_set_rate(host->cfg_div_clk, clk_rate);
214 	if (ret) {
215 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
216 			clk_rate, ret);
217 		return ret;
218 	}
219 
220 	mmc->actual_clock = clk_get_rate(host->cfg_div_clk);
221 	host->current_clock = clk_rate;
222 
223 	if (clk_rate != mmc->actual_clock)
224 		dev_dbg(host->dev,
225 			"divider requested rate %lu != actual rate %u\n",
226 			clk_rate, mmc->actual_clock);
227 
228 	/* (re)start clock */
229 	cfg = readl(host->regs + SD_EMMC_CFG);
230 	cfg &= ~CFG_STOP_CLOCK;
231 	writel(cfg, host->regs + SD_EMMC_CFG);
232 
233 	return 0;
234 }
235 
236 /*
237  * The SD/eMMC IP block has an internal mux and divider used for
238  * generating the MMC clock.  Use the clock framework to create and
239  * manage these clocks.
240  */
241 static int meson_mmc_clk_init(struct meson_host *host)
242 {
243 	struct clk_init_data init;
244 	char clk_name[32];
245 	int i, ret = 0;
246 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
247 	unsigned int mux_parent_count = 0;
248 	const char *clk_div_parents[1];
249 	u32 clk_reg, cfg;
250 
251 	/* get the mux parents */
252 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
253 		char name[16];
254 
255 		snprintf(name, sizeof(name), "clkin%d", i);
256 		host->mux_parent[i] = devm_clk_get(host->dev, name);
257 		if (IS_ERR(host->mux_parent[i])) {
258 			ret = PTR_ERR(host->mux_parent[i]);
259 			if (PTR_ERR(host->mux_parent[i]) != -EPROBE_DEFER)
260 				dev_err(host->dev, "Missing clock %s\n", name);
261 			host->mux_parent[i] = NULL;
262 			return ret;
263 		}
264 
265 		mux_parent_names[i] = __clk_get_name(host->mux_parent[i]);
266 		mux_parent_count++;
267 	}
268 
269 	/* create the mux */
270 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
271 	init.name = clk_name;
272 	init.ops = &clk_mux_ops;
273 	init.flags = 0;
274 	init.parent_names = mux_parent_names;
275 	init.num_parents = mux_parent_count;
276 
277 	host->mux.reg = host->regs + SD_EMMC_CLOCK;
278 	host->mux.shift = CLK_SRC_SHIFT;
279 	host->mux.mask = CLK_SRC_MASK;
280 	host->mux.flags = 0;
281 	host->mux.table = NULL;
282 	host->mux.hw.init = &init;
283 
284 	host->mux_clk = devm_clk_register(host->dev, &host->mux.hw);
285 	if (WARN_ON(IS_ERR(host->mux_clk)))
286 		return PTR_ERR(host->mux_clk);
287 
288 	/* create the divider */
289 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
290 	init.name = devm_kstrdup(host->dev, clk_name, GFP_KERNEL);
291 	init.ops = &clk_divider_ops;
292 	init.flags = CLK_SET_RATE_PARENT;
293 	clk_div_parents[0] = __clk_get_name(host->mux_clk);
294 	init.parent_names = clk_div_parents;
295 	init.num_parents = ARRAY_SIZE(clk_div_parents);
296 
297 	host->cfg_div.reg = host->regs + SD_EMMC_CLOCK;
298 	host->cfg_div.shift = CLK_DIV_SHIFT;
299 	host->cfg_div.width = CLK_DIV_WIDTH;
300 	host->cfg_div.hw.init = &init;
301 	host->cfg_div.flags = CLK_DIVIDER_ONE_BASED |
302 		CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ALLOW_ZERO;
303 
304 	host->cfg_div_clk = devm_clk_register(host->dev, &host->cfg_div.hw);
305 	if (WARN_ON(PTR_ERR_OR_ZERO(host->cfg_div_clk)))
306 		return PTR_ERR(host->cfg_div_clk);
307 
308 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
309 	clk_reg = 0;
310 	clk_reg |= CLK_PHASE_180 << CLK_PHASE_SHIFT;
311 	clk_reg |= CLK_SRC_XTAL << CLK_SRC_SHIFT;
312 	clk_reg |= CLK_DIV_MAX << CLK_DIV_SHIFT;
313 	clk_reg &= ~CLK_ALWAYS_ON;
314 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
315 
316 	/* Ensure clock starts in "auto" mode, not "always on" */
317 	cfg = readl(host->regs + SD_EMMC_CFG);
318 	cfg &= ~CFG_CLK_ALWAYS_ON;
319 	cfg |= CFG_AUTO_CLK;
320 	writel(cfg, host->regs + SD_EMMC_CFG);
321 
322 	ret = clk_prepare_enable(host->cfg_div_clk);
323 	if (ret)
324 		return ret;
325 
326 	/* Get the nearest minimum clock to 400KHz */
327 	host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 400000);
328 
329 	ret = meson_mmc_clk_set(host, host->mmc->f_min);
330 	if (!ret)
331 		clk_disable_unprepare(host->cfg_div_clk);
332 
333 	return ret;
334 }
335 
336 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
337 {
338 	struct meson_host *host = mmc_priv(mmc);
339 	u32 bus_width;
340 	u32 val, orig;
341 
342 	/*
343 	 * GPIO regulator, only controls switching between 1v8 and
344 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
345 	 */
346 	switch (ios->power_mode) {
347 	case MMC_POWER_OFF:
348 		if (!IS_ERR(mmc->supply.vmmc))
349 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
350 
351 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
352 			regulator_disable(mmc->supply.vqmmc);
353 			host->vqmmc_enabled = false;
354 		}
355 
356 		break;
357 
358 	case MMC_POWER_UP:
359 		if (!IS_ERR(mmc->supply.vmmc))
360 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
361 		break;
362 
363 	case MMC_POWER_ON:
364 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
365 			int ret = regulator_enable(mmc->supply.vqmmc);
366 
367 			if (ret < 0)
368 				dev_err(mmc_dev(mmc),
369 					"failed to enable vqmmc regulator\n");
370 			else
371 				host->vqmmc_enabled = true;
372 		}
373 
374 		break;
375 	}
376 
377 
378 	meson_mmc_clk_set(host, ios->clock);
379 
380 	/* Bus width */
381 	switch (ios->bus_width) {
382 	case MMC_BUS_WIDTH_1:
383 		bus_width = CFG_BUS_WIDTH_1;
384 		break;
385 	case MMC_BUS_WIDTH_4:
386 		bus_width = CFG_BUS_WIDTH_4;
387 		break;
388 	case MMC_BUS_WIDTH_8:
389 		bus_width = CFG_BUS_WIDTH_8;
390 		break;
391 	default:
392 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
393 			ios->bus_width);
394 		bus_width = CFG_BUS_WIDTH_4;
395 	}
396 
397 	val = readl(host->regs + SD_EMMC_CFG);
398 	orig = val;
399 
400 	val &= ~(CFG_BUS_WIDTH_MASK << CFG_BUS_WIDTH_SHIFT);
401 	val |= bus_width << CFG_BUS_WIDTH_SHIFT;
402 
403 	val &= ~(CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
404 	val |= ilog2(SD_EMMC_CFG_BLK_SIZE) << CFG_BLK_LEN_SHIFT;
405 
406 	val &= ~(CFG_RESP_TIMEOUT_MASK << CFG_RESP_TIMEOUT_SHIFT);
407 	val |= ilog2(SD_EMMC_CFG_RESP_TIMEOUT) << CFG_RESP_TIMEOUT_SHIFT;
408 
409 	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
410 	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
411 
412 	val &= ~CFG_DDR;
413 	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
414 	    ios->timing == MMC_TIMING_MMC_DDR52 ||
415 	    ios->timing == MMC_TIMING_MMC_HS400)
416 		val |= CFG_DDR;
417 
418 	val &= ~CFG_CHK_DS;
419 	if (ios->timing == MMC_TIMING_MMC_HS400)
420 		val |= CFG_CHK_DS;
421 
422 	writel(val, host->regs + SD_EMMC_CFG);
423 
424 	if (val != orig)
425 		dev_dbg(host->dev, "%s: SD_EMMC_CFG: 0x%08x -> 0x%08x\n",
426 			__func__, orig, val);
427 }
428 
429 static int meson_mmc_request_done(struct mmc_host *mmc, struct mmc_request *mrq)
430 {
431 	struct meson_host *host = mmc_priv(mmc);
432 
433 	WARN_ON(host->mrq != mrq);
434 
435 	host->mrq = NULL;
436 	host->cmd = NULL;
437 	mmc_request_done(host->mmc, mrq);
438 
439 	return 0;
440 }
441 
442 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
443 {
444 	struct meson_host *host = mmc_priv(mmc);
445 	struct sd_emmc_desc *desc, desc_tmp;
446 	u32 cfg;
447 	u8 blk_len, cmd_cfg_timeout;
448 	unsigned int xfer_bytes = 0;
449 
450 	/* Setup descriptors */
451 	dma_rmb();
452 	desc = &desc_tmp;
453 	memset(desc, 0, sizeof(struct sd_emmc_desc));
454 
455 	desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK)	<<
456 		CMD_CFG_CMD_INDEX_SHIFT;
457 	desc->cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
458 	desc->cmd_arg = cmd->arg;
459 
460 	/* Response */
461 	if (cmd->flags & MMC_RSP_PRESENT) {
462 		desc->cmd_cfg &= ~CMD_CFG_NO_RESP;
463 		if (cmd->flags & MMC_RSP_136)
464 			desc->cmd_cfg |= CMD_CFG_RESP_128;
465 		desc->cmd_cfg |= CMD_CFG_RESP_NUM;
466 		desc->cmd_resp = 0;
467 
468 		if (!(cmd->flags & MMC_RSP_CRC))
469 			desc->cmd_cfg |= CMD_CFG_RESP_NOCRC;
470 
471 		if (cmd->flags & MMC_RSP_BUSY)
472 			desc->cmd_cfg |= CMD_CFG_R1B;
473 	} else {
474 		desc->cmd_cfg |= CMD_CFG_NO_RESP;
475 	}
476 
477 	/* data? */
478 	if (cmd->data) {
479 		desc->cmd_cfg |= CMD_CFG_DATA_IO;
480 		if (cmd->data->blocks > 1) {
481 			desc->cmd_cfg |= CMD_CFG_BLOCK_MODE;
482 			desc->cmd_cfg |=
483 				(cmd->data->blocks & CMD_CFG_LENGTH_MASK) <<
484 				CMD_CFG_LENGTH_SHIFT;
485 
486 			/* check if block-size matches, if not update */
487 			cfg = readl(host->regs + SD_EMMC_CFG);
488 			blk_len = cfg & (CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
489 			blk_len >>= CFG_BLK_LEN_SHIFT;
490 			if (blk_len != ilog2(cmd->data->blksz)) {
491 				dev_dbg(host->dev, "%s: update blk_len %d -> %d\n",
492 					__func__, blk_len,
493 					ilog2(cmd->data->blksz));
494 				blk_len = ilog2(cmd->data->blksz);
495 				cfg &= ~(CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
496 				cfg |= blk_len << CFG_BLK_LEN_SHIFT;
497 				writel(cfg, host->regs + SD_EMMC_CFG);
498 			}
499 		} else {
500 			desc->cmd_cfg &= ~CMD_CFG_BLOCK_MODE;
501 			desc->cmd_cfg |=
502 				(cmd->data->blksz & CMD_CFG_LENGTH_MASK) <<
503 				CMD_CFG_LENGTH_SHIFT;
504 		}
505 
506 		cmd->data->bytes_xfered = 0;
507 		xfer_bytes = cmd->data->blksz * cmd->data->blocks;
508 		if (cmd->data->flags & MMC_DATA_WRITE) {
509 			desc->cmd_cfg |= CMD_CFG_DATA_WR;
510 			WARN_ON(xfer_bytes > host->bounce_buf_size);
511 			sg_copy_to_buffer(cmd->data->sg, cmd->data->sg_len,
512 					  host->bounce_buf, xfer_bytes);
513 			cmd->data->bytes_xfered = xfer_bytes;
514 			dma_wmb();
515 		} else {
516 			desc->cmd_cfg &= ~CMD_CFG_DATA_WR;
517 		}
518 
519 		if (xfer_bytes > 0) {
520 			desc->cmd_cfg &= ~CMD_CFG_DATA_NUM;
521 			desc->cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
522 		} else {
523 			/* write data to data_addr */
524 			desc->cmd_cfg |= CMD_CFG_DATA_NUM;
525 			desc->cmd_data = 0;
526 		}
527 
528 		cmd_cfg_timeout = 12;
529 	} else {
530 		desc->cmd_cfg &= ~CMD_CFG_DATA_IO;
531 		cmd_cfg_timeout = 10;
532 	}
533 	desc->cmd_cfg |= (cmd_cfg_timeout & CMD_CFG_TIMEOUT_MASK) <<
534 		CMD_CFG_TIMEOUT_SHIFT;
535 
536 	host->cmd = cmd;
537 
538 	/* Last descriptor */
539 	desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN;
540 	writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
541 	writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT);
542 	writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP);
543 	wmb(); /* ensure descriptor is written before kicked */
544 	writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG);
545 }
546 
547 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
548 {
549 	struct meson_host *host = mmc_priv(mmc);
550 
551 	WARN_ON(host->mrq != NULL);
552 
553 	/* Stop execution */
554 	writel(0, host->regs + SD_EMMC_START);
555 
556 	host->mrq = mrq;
557 
558 	if (mrq->sbc)
559 		meson_mmc_start_cmd(mmc, mrq->sbc);
560 	else
561 		meson_mmc_start_cmd(mmc, mrq->cmd);
562 }
563 
564 static int meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
565 {
566 	struct meson_host *host = mmc_priv(mmc);
567 
568 	if (cmd->flags & MMC_RSP_136) {
569 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
570 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
571 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
572 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
573 	} else if (cmd->flags & MMC_RSP_PRESENT) {
574 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
575 	}
576 
577 	return 0;
578 }
579 
580 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
581 {
582 	struct meson_host *host = dev_id;
583 	struct mmc_request *mrq;
584 	struct mmc_command *cmd;
585 	u32 irq_en, status, raw_status;
586 	irqreturn_t ret = IRQ_HANDLED;
587 
588 	if (WARN_ON(!host))
589 		return IRQ_NONE;
590 
591 	cmd = host->cmd;
592 
593 	mrq = host->mrq;
594 
595 	if (WARN_ON(!mrq))
596 		return IRQ_NONE;
597 
598 	if (WARN_ON(!cmd))
599 		return IRQ_NONE;
600 
601 	spin_lock(&host->lock);
602 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
603 	raw_status = readl(host->regs + SD_EMMC_STATUS);
604 	status = raw_status & irq_en;
605 
606 	if (!status) {
607 		dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
608 			 raw_status, irq_en);
609 		ret = IRQ_NONE;
610 		goto out;
611 	}
612 
613 	cmd->error = 0;
614 	if (status & IRQ_RXD_ERR_MASK) {
615 		dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
616 		cmd->error = -EILSEQ;
617 	}
618 	if (status & IRQ_TXD_ERR) {
619 		dev_dbg(host->dev, "Unhandled IRQ: TXD error\n");
620 		cmd->error = -EILSEQ;
621 	}
622 	if (status & IRQ_DESC_ERR)
623 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor error\n");
624 	if (status & IRQ_RESP_ERR) {
625 		dev_dbg(host->dev, "Unhandled IRQ: Response error\n");
626 		cmd->error = -EILSEQ;
627 	}
628 	if (status & IRQ_RESP_TIMEOUT) {
629 		dev_dbg(host->dev, "Unhandled IRQ: Response timeout\n");
630 		cmd->error = -ETIMEDOUT;
631 	}
632 	if (status & IRQ_DESC_TIMEOUT) {
633 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor timeout\n");
634 		cmd->error = -ETIMEDOUT;
635 	}
636 	if (status & IRQ_SDIO)
637 		dev_dbg(host->dev, "Unhandled IRQ: SDIO.\n");
638 
639 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS))
640 		ret = IRQ_WAKE_THREAD;
641 	else  {
642 		dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC CMD%u arg=0x%08x flags=0x%08x stop=%d\n",
643 			 status, cmd->opcode, cmd->arg,
644 			 cmd->flags, mrq->stop ? 1 : 0);
645 		if (cmd->data) {
646 			struct mmc_data *data = cmd->data;
647 
648 			dev_warn(host->dev, "\tblksz %u blocks %u flags 0x%08x (%s%s)",
649 				 data->blksz, data->blocks, data->flags,
650 				 data->flags & MMC_DATA_WRITE ? "write" : "",
651 				 data->flags & MMC_DATA_READ ? "read" : "");
652 		}
653 	}
654 
655 out:
656 	/* ack all (enabled) interrupts */
657 	writel(status, host->regs + SD_EMMC_STATUS);
658 
659 	if (ret == IRQ_HANDLED) {
660 		meson_mmc_read_resp(host->mmc, cmd);
661 		meson_mmc_request_done(host->mmc, cmd->mrq);
662 	}
663 
664 	spin_unlock(&host->lock);
665 	return ret;
666 }
667 
668 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
669 {
670 	struct meson_host *host = dev_id;
671 	struct mmc_request *mrq = host->mrq;
672 	struct mmc_command *cmd = host->cmd;
673 	struct mmc_data *data;
674 	unsigned int xfer_bytes;
675 
676 	if (WARN_ON(!mrq))
677 		return IRQ_NONE;
678 
679 	if (WARN_ON(!cmd))
680 		return IRQ_NONE;
681 
682 	data = cmd->data;
683 	if (data && data->flags & MMC_DATA_READ) {
684 		xfer_bytes = data->blksz * data->blocks;
685 		WARN_ON(xfer_bytes > host->bounce_buf_size);
686 		sg_copy_from_buffer(data->sg, data->sg_len,
687 				    host->bounce_buf, xfer_bytes);
688 		data->bytes_xfered = xfer_bytes;
689 	}
690 
691 	meson_mmc_read_resp(host->mmc, cmd);
692 	if (!data || !data->stop || mrq->sbc)
693 		meson_mmc_request_done(host->mmc, mrq);
694 	else
695 		meson_mmc_start_cmd(host->mmc, data->stop);
696 
697 	return IRQ_HANDLED;
698 }
699 
700 /*
701  * NOTE: we only need this until the GPIO/pinctrl driver can handle
702  * interrupts.  For now, the MMC core will use this for polling.
703  */
704 static int meson_mmc_get_cd(struct mmc_host *mmc)
705 {
706 	int status = mmc_gpio_get_cd(mmc);
707 
708 	if (status == -ENOSYS)
709 		return 1; /* assume present */
710 
711 	return status;
712 }
713 
714 static const struct mmc_host_ops meson_mmc_ops = {
715 	.request	= meson_mmc_request,
716 	.set_ios	= meson_mmc_set_ios,
717 	.get_cd         = meson_mmc_get_cd,
718 };
719 
720 static int meson_mmc_probe(struct platform_device *pdev)
721 {
722 	struct resource *res;
723 	struct meson_host *host;
724 	struct mmc_host *mmc;
725 	int ret;
726 
727 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
728 	if (!mmc)
729 		return -ENOMEM;
730 	host = mmc_priv(mmc);
731 	host->mmc = mmc;
732 	host->dev = &pdev->dev;
733 	dev_set_drvdata(&pdev->dev, host);
734 
735 	spin_lock_init(&host->lock);
736 
737 	/* Get regulators and the supported OCR mask */
738 	host->vqmmc_enabled = false;
739 	ret = mmc_regulator_get_supply(mmc);
740 	if (ret == -EPROBE_DEFER)
741 		goto free_host;
742 
743 	ret = mmc_of_parse(mmc);
744 	if (ret) {
745 		if (ret != -EPROBE_DEFER)
746 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
747 		goto free_host;
748 	}
749 
750 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
751 	host->regs = devm_ioremap_resource(&pdev->dev, res);
752 	if (IS_ERR(host->regs)) {
753 		ret = PTR_ERR(host->regs);
754 		goto free_host;
755 	}
756 
757 	host->irq = platform_get_irq(pdev, 0);
758 	if (host->irq == 0) {
759 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
760 		ret = -EINVAL;
761 		goto free_host;
762 	}
763 
764 	host->core_clk = devm_clk_get(&pdev->dev, "core");
765 	if (IS_ERR(host->core_clk)) {
766 		ret = PTR_ERR(host->core_clk);
767 		goto free_host;
768 	}
769 
770 	ret = clk_prepare_enable(host->core_clk);
771 	if (ret)
772 		goto free_host;
773 
774 	ret = meson_mmc_clk_init(host);
775 	if (ret)
776 		goto free_host;
777 
778 	/* Stop execution */
779 	writel(0, host->regs + SD_EMMC_START);
780 
781 	/* clear, ack, enable all interrupts */
782 	writel(0, host->regs + SD_EMMC_IRQ_EN);
783 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
784 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_IRQ_EN);
785 
786 	ret = devm_request_threaded_irq(&pdev->dev, host->irq,
787 					meson_mmc_irq, meson_mmc_irq_thread,
788 					IRQF_SHARED, DRIVER_NAME, host);
789 	if (ret)
790 		goto free_host;
791 
792 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
793 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
794 
795 	/* data bounce buffer */
796 	host->bounce_buf_size = mmc->max_req_size;
797 	host->bounce_buf =
798 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
799 				   &host->bounce_dma_addr, GFP_KERNEL);
800 	if (host->bounce_buf == NULL) {
801 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
802 		ret = -ENOMEM;
803 		goto free_host;
804 	}
805 
806 	mmc->ops = &meson_mmc_ops;
807 	mmc_add_host(mmc);
808 
809 	return 0;
810 
811 free_host:
812 	clk_disable_unprepare(host->cfg_div_clk);
813 	clk_disable_unprepare(host->core_clk);
814 	mmc_free_host(mmc);
815 	return ret;
816 }
817 
818 static int meson_mmc_remove(struct platform_device *pdev)
819 {
820 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
821 
822 	/* disable interrupts */
823 	writel(0, host->regs + SD_EMMC_IRQ_EN);
824 
825 	dma_free_coherent(host->dev, host->bounce_buf_size,
826 			  host->bounce_buf, host->bounce_dma_addr);
827 
828 	clk_disable_unprepare(host->cfg_div_clk);
829 	clk_disable_unprepare(host->core_clk);
830 
831 	mmc_free_host(host->mmc);
832 	return 0;
833 }
834 
835 static const struct of_device_id meson_mmc_of_match[] = {
836 	{ .compatible = "amlogic,meson-gx-mmc", },
837 	{ .compatible = "amlogic,meson-gxbb-mmc", },
838 	{ .compatible = "amlogic,meson-gxl-mmc", },
839 	{ .compatible = "amlogic,meson-gxm-mmc", },
840 	{}
841 };
842 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
843 
844 static struct platform_driver meson_mmc_driver = {
845 	.probe		= meson_mmc_probe,
846 	.remove		= meson_mmc_remove,
847 	.driver		= {
848 		.name = DRIVER_NAME,
849 		.of_match_table = of_match_ptr(meson_mmc_of_match),
850 	},
851 };
852 
853 module_platform_driver(meson_mmc_driver);
854 
855 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
856 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
857 MODULE_LICENSE("GPL v2");
858