xref: /openbmc/linux/drivers/mmc/host/meson-gx-mmc.c (revision fc28ab18)
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 
39 #define DRIVER_NAME "meson-gx-mmc"
40 
41 #define SD_EMMC_CLOCK 0x0
42 #define   CLK_DIV_SHIFT 0
43 #define   CLK_DIV_WIDTH 6
44 #define   CLK_DIV_MASK 0x3f
45 #define   CLK_DIV_MAX 63
46 #define   CLK_SRC_SHIFT 6
47 #define   CLK_SRC_WIDTH 2
48 #define   CLK_SRC_MASK 0x3
49 #define   CLK_SRC_XTAL 0   /* external crystal */
50 #define   CLK_SRC_XTAL_RATE 24000000
51 #define   CLK_SRC_PLL 1    /* FCLK_DIV2 */
52 #define   CLK_SRC_PLL_RATE 1000000000
53 #define   CLK_PHASE_SHIFT 8
54 #define   CLK_PHASE_MASK 0x3
55 #define   CLK_PHASE_0 0
56 #define   CLK_PHASE_90 1
57 #define   CLK_PHASE_180 2
58 #define   CLK_PHASE_270 3
59 #define   CLK_ALWAYS_ON BIT(24)
60 
61 #define SD_EMMC_DElAY 0x4
62 #define SD_EMMC_ADJUST 0x8
63 #define SD_EMMC_CALOUT 0x10
64 #define SD_EMMC_START 0x40
65 #define   START_DESC_INIT BIT(0)
66 #define   START_DESC_BUSY BIT(1)
67 #define   START_DESC_ADDR_SHIFT 2
68 #define   START_DESC_ADDR_MASK (~0x3)
69 
70 #define SD_EMMC_CFG 0x44
71 #define   CFG_BUS_WIDTH_SHIFT 0
72 #define   CFG_BUS_WIDTH_MASK 0x3
73 #define   CFG_BUS_WIDTH_1 0x0
74 #define   CFG_BUS_WIDTH_4 0x1
75 #define   CFG_BUS_WIDTH_8 0x2
76 #define   CFG_DDR BIT(2)
77 #define   CFG_BLK_LEN_SHIFT 4
78 #define   CFG_BLK_LEN_MASK 0xf
79 #define   CFG_RESP_TIMEOUT_SHIFT 8
80 #define   CFG_RESP_TIMEOUT_MASK 0xf
81 #define   CFG_RC_CC_SHIFT 12
82 #define   CFG_RC_CC_MASK 0xf
83 #define   CFG_STOP_CLOCK BIT(22)
84 #define   CFG_CLK_ALWAYS_ON BIT(18)
85 #define   CFG_AUTO_CLK BIT(23)
86 
87 #define SD_EMMC_STATUS 0x48
88 #define   STATUS_BUSY BIT(31)
89 
90 #define SD_EMMC_IRQ_EN 0x4c
91 #define   IRQ_EN_MASK 0x3fff
92 #define   IRQ_RXD_ERR_SHIFT 0
93 #define   IRQ_RXD_ERR_MASK 0xff
94 #define   IRQ_TXD_ERR BIT(8)
95 #define   IRQ_DESC_ERR BIT(9)
96 #define   IRQ_RESP_ERR BIT(10)
97 #define   IRQ_RESP_TIMEOUT BIT(11)
98 #define   IRQ_DESC_TIMEOUT BIT(12)
99 #define   IRQ_END_OF_CHAIN BIT(13)
100 #define   IRQ_RESP_STATUS BIT(14)
101 #define   IRQ_SDIO BIT(15)
102 
103 #define SD_EMMC_CMD_CFG 0x50
104 #define SD_EMMC_CMD_ARG 0x54
105 #define SD_EMMC_CMD_DAT 0x58
106 #define SD_EMMC_CMD_RSP 0x5c
107 #define SD_EMMC_CMD_RSP1 0x60
108 #define SD_EMMC_CMD_RSP2 0x64
109 #define SD_EMMC_CMD_RSP3 0x68
110 
111 #define SD_EMMC_RXD 0x94
112 #define SD_EMMC_TXD 0x94
113 #define SD_EMMC_LAST_REG SD_EMMC_TXD
114 
115 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
116 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
117 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
118 #define MUX_CLK_NUM_PARENTS 2
119 
120 struct meson_host {
121 	struct	device		*dev;
122 	struct	mmc_host	*mmc;
123 	struct	mmc_request	*mrq;
124 	struct	mmc_command	*cmd;
125 
126 	spinlock_t lock;
127 	void __iomem *regs;
128 	int irq;
129 	u32 ocr_mask;
130 	struct clk *core_clk;
131 	struct clk_mux mux;
132 	struct clk *mux_clk;
133 	struct clk *mux_parent[MUX_CLK_NUM_PARENTS];
134 	unsigned long mux_parent_rate[MUX_CLK_NUM_PARENTS];
135 
136 	struct clk_divider cfg_div;
137 	struct clk *cfg_div_clk;
138 
139 	unsigned int bounce_buf_size;
140 	void *bounce_buf;
141 	dma_addr_t bounce_dma_addr;
142 
143 	bool vqmmc_enabled;
144 };
145 
146 struct sd_emmc_desc {
147 	u32 cmd_cfg;
148 	u32 cmd_arg;
149 	u32 cmd_data;
150 	u32 cmd_resp;
151 };
152 #define CMD_CFG_LENGTH_SHIFT 0
153 #define CMD_CFG_LENGTH_MASK 0x1ff
154 #define CMD_CFG_BLOCK_MODE BIT(9)
155 #define CMD_CFG_R1B BIT(10)
156 #define CMD_CFG_END_OF_CHAIN BIT(11)
157 #define CMD_CFG_TIMEOUT_SHIFT 12
158 #define CMD_CFG_TIMEOUT_MASK 0xf
159 #define CMD_CFG_NO_RESP BIT(16)
160 #define CMD_CFG_NO_CMD BIT(17)
161 #define CMD_CFG_DATA_IO BIT(18)
162 #define CMD_CFG_DATA_WR BIT(19)
163 #define CMD_CFG_RESP_NOCRC BIT(20)
164 #define CMD_CFG_RESP_128 BIT(21)
165 #define CMD_CFG_RESP_NUM BIT(22)
166 #define CMD_CFG_DATA_NUM BIT(23)
167 #define CMD_CFG_CMD_INDEX_SHIFT 24
168 #define CMD_CFG_CMD_INDEX_MASK 0x3f
169 #define CMD_CFG_ERROR BIT(30)
170 #define CMD_CFG_OWNER BIT(31)
171 
172 #define CMD_DATA_MASK (~0x3)
173 #define CMD_DATA_BIG_ENDIAN BIT(1)
174 #define CMD_DATA_SRAM BIT(0)
175 #define CMD_RESP_MASK (~0x1)
176 #define CMD_RESP_SRAM BIT(0)
177 
178 static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate)
179 {
180 	struct mmc_host *mmc = host->mmc;
181 	int ret = 0;
182 	u32 cfg;
183 
184 	if (clk_rate) {
185 		if (WARN_ON(clk_rate > mmc->f_max))
186 			clk_rate = mmc->f_max;
187 		else if (WARN_ON(clk_rate < mmc->f_min))
188 			clk_rate = mmc->f_min;
189 	}
190 
191 	if (clk_rate == mmc->actual_clock)
192 		return 0;
193 
194 	/* stop clock */
195 	cfg = readl(host->regs + SD_EMMC_CFG);
196 	if (!(cfg & CFG_STOP_CLOCK)) {
197 		cfg |= CFG_STOP_CLOCK;
198 		writel(cfg, host->regs + SD_EMMC_CFG);
199 	}
200 
201 	dev_dbg(host->dev, "change clock rate %u -> %lu\n",
202 		mmc->actual_clock, clk_rate);
203 
204 	if (clk_rate == 0) {
205 		mmc->actual_clock = 0;
206 		return 0;
207 	}
208 
209 	ret = clk_set_rate(host->cfg_div_clk, clk_rate);
210 	if (ret)
211 		dev_warn(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
212 			 clk_rate, ret);
213 	else if (clk_rate && clk_rate != clk_get_rate(host->cfg_div_clk))
214 		dev_warn(host->dev, "divider requested rate %lu != actual rate %lu: ret=%d\n",
215 			 clk_rate, clk_get_rate(host->cfg_div_clk), ret);
216 	else
217 		mmc->actual_clock = clk_rate;
218 
219 	/* (re)start clock, if non-zero */
220 	if (!ret && clk_rate) {
221 		cfg = readl(host->regs + SD_EMMC_CFG);
222 		cfg &= ~CFG_STOP_CLOCK;
223 		writel(cfg, host->regs + SD_EMMC_CFG);
224 	}
225 
226 	return ret;
227 }
228 
229 /*
230  * The SD/eMMC IP block has an internal mux and divider used for
231  * generating the MMC clock.  Use the clock framework to create and
232  * manage these clocks.
233  */
234 static int meson_mmc_clk_init(struct meson_host *host)
235 {
236 	struct clk_init_data init;
237 	char clk_name[32];
238 	int i, ret = 0;
239 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
240 	unsigned int mux_parent_count = 0;
241 	const char *clk_div_parents[1];
242 	unsigned int f_min = UINT_MAX;
243 	u32 clk_reg, cfg;
244 
245 	/* get the mux parents */
246 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
247 		char name[16];
248 
249 		snprintf(name, sizeof(name), "clkin%d", i);
250 		host->mux_parent[i] = devm_clk_get(host->dev, name);
251 		if (IS_ERR(host->mux_parent[i])) {
252 			ret = PTR_ERR(host->mux_parent[i]);
253 			if (PTR_ERR(host->mux_parent[i]) != -EPROBE_DEFER)
254 				dev_err(host->dev, "Missing clock %s\n", name);
255 			host->mux_parent[i] = NULL;
256 			return ret;
257 		}
258 
259 		host->mux_parent_rate[i] = clk_get_rate(host->mux_parent[i]);
260 		mux_parent_names[i] = __clk_get_name(host->mux_parent[i]);
261 		mux_parent_count++;
262 		if (host->mux_parent_rate[i] < f_min)
263 			f_min = host->mux_parent_rate[i];
264 	}
265 
266 	/* cacluate f_min based on input clocks, and max divider value */
267 	if (f_min != UINT_MAX)
268 		f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX);
269 	else
270 		f_min = 4000000;  /* default min: 400 MHz */
271 	host->mmc->f_min = f_min;
272 
273 	/* create the mux */
274 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
275 	init.name = clk_name;
276 	init.ops = &clk_mux_ops;
277 	init.flags = 0;
278 	init.parent_names = mux_parent_names;
279 	init.num_parents = mux_parent_count;
280 
281 	host->mux.reg = host->regs + SD_EMMC_CLOCK;
282 	host->mux.shift = CLK_SRC_SHIFT;
283 	host->mux.mask = CLK_SRC_MASK;
284 	host->mux.flags = 0;
285 	host->mux.table = NULL;
286 	host->mux.hw.init = &init;
287 
288 	host->mux_clk = devm_clk_register(host->dev, &host->mux.hw);
289 	if (WARN_ON(IS_ERR(host->mux_clk)))
290 		return PTR_ERR(host->mux_clk);
291 
292 	/* create the divider */
293 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
294 	init.name = devm_kstrdup(host->dev, clk_name, GFP_KERNEL);
295 	init.ops = &clk_divider_ops;
296 	init.flags = CLK_SET_RATE_PARENT;
297 	clk_div_parents[0] = __clk_get_name(host->mux_clk);
298 	init.parent_names = clk_div_parents;
299 	init.num_parents = ARRAY_SIZE(clk_div_parents);
300 
301 	host->cfg_div.reg = host->regs + SD_EMMC_CLOCK;
302 	host->cfg_div.shift = CLK_DIV_SHIFT;
303 	host->cfg_div.width = CLK_DIV_WIDTH;
304 	host->cfg_div.hw.init = &init;
305 	host->cfg_div.flags = CLK_DIVIDER_ONE_BASED |
306 		CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ALLOW_ZERO;
307 
308 	host->cfg_div_clk = devm_clk_register(host->dev, &host->cfg_div.hw);
309 	if (WARN_ON(PTR_ERR_OR_ZERO(host->cfg_div_clk)))
310 		return PTR_ERR(host->cfg_div_clk);
311 
312 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
313 	clk_reg = 0;
314 	clk_reg |= CLK_PHASE_180 << CLK_PHASE_SHIFT;
315 	clk_reg |= CLK_SRC_XTAL << CLK_SRC_SHIFT;
316 	clk_reg |= CLK_DIV_MAX << CLK_DIV_SHIFT;
317 	clk_reg &= ~CLK_ALWAYS_ON;
318 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
319 
320 	/* Ensure clock starts in "auto" mode, not "always on" */
321 	cfg = readl(host->regs + SD_EMMC_CFG);
322 	cfg &= ~CFG_CLK_ALWAYS_ON;
323 	cfg |= CFG_AUTO_CLK;
324 	writel(cfg, host->regs + SD_EMMC_CFG);
325 
326 	ret = clk_prepare_enable(host->cfg_div_clk);
327 	if (!ret)
328 		ret = meson_mmc_clk_set(host, f_min);
329 
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 	val = readl(host->regs + SD_EMMC_CFG);
382 	switch (ios->bus_width) {
383 	case MMC_BUS_WIDTH_1:
384 		bus_width = CFG_BUS_WIDTH_1;
385 		break;
386 	case MMC_BUS_WIDTH_4:
387 		bus_width = CFG_BUS_WIDTH_4;
388 		break;
389 	case MMC_BUS_WIDTH_8:
390 		bus_width = CFG_BUS_WIDTH_8;
391 		break;
392 	default:
393 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
394 			ios->bus_width);
395 		bus_width = CFG_BUS_WIDTH_4;
396 		return;
397 	}
398 
399 	val = readl(host->regs + SD_EMMC_CFG);
400 	orig = val;
401 
402 	val &= ~(CFG_BUS_WIDTH_MASK << CFG_BUS_WIDTH_SHIFT);
403 	val |= bus_width << CFG_BUS_WIDTH_SHIFT;
404 
405 	val &= ~(CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
406 	val |= ilog2(SD_EMMC_CFG_BLK_SIZE) << CFG_BLK_LEN_SHIFT;
407 
408 	val &= ~(CFG_RESP_TIMEOUT_MASK << CFG_RESP_TIMEOUT_SHIFT);
409 	val |= ilog2(SD_EMMC_CFG_RESP_TIMEOUT) << CFG_RESP_TIMEOUT_SHIFT;
410 
411 	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
412 	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
413 
414 	writel(val, host->regs + SD_EMMC_CFG);
415 
416 	if (val != orig)
417 		dev_dbg(host->dev, "%s: SD_EMMC_CFG: 0x%08x -> 0x%08x\n",
418 			__func__, orig, val);
419 }
420 
421 static int meson_mmc_request_done(struct mmc_host *mmc, struct mmc_request *mrq)
422 {
423 	struct meson_host *host = mmc_priv(mmc);
424 
425 	WARN_ON(host->mrq != mrq);
426 
427 	host->mrq = NULL;
428 	host->cmd = NULL;
429 	mmc_request_done(host->mmc, mrq);
430 
431 	return 0;
432 }
433 
434 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
435 {
436 	struct meson_host *host = mmc_priv(mmc);
437 	struct sd_emmc_desc *desc, desc_tmp;
438 	u32 cfg;
439 	u8 blk_len, cmd_cfg_timeout;
440 	unsigned int xfer_bytes = 0;
441 
442 	/* Setup descriptors */
443 	dma_rmb();
444 	desc = &desc_tmp;
445 	memset(desc, 0, sizeof(struct sd_emmc_desc));
446 
447 	desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK)	<<
448 		CMD_CFG_CMD_INDEX_SHIFT;
449 	desc->cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
450 	desc->cmd_arg = cmd->arg;
451 
452 	/* Response */
453 	if (cmd->flags & MMC_RSP_PRESENT) {
454 		desc->cmd_cfg &= ~CMD_CFG_NO_RESP;
455 		if (cmd->flags & MMC_RSP_136)
456 			desc->cmd_cfg |= CMD_CFG_RESP_128;
457 		desc->cmd_cfg |= CMD_CFG_RESP_NUM;
458 		desc->cmd_resp = 0;
459 
460 		if (!(cmd->flags & MMC_RSP_CRC))
461 			desc->cmd_cfg |= CMD_CFG_RESP_NOCRC;
462 
463 		if (cmd->flags & MMC_RSP_BUSY)
464 			desc->cmd_cfg |= CMD_CFG_R1B;
465 	} else {
466 		desc->cmd_cfg |= CMD_CFG_NO_RESP;
467 	}
468 
469 	/* data? */
470 	if (cmd->data) {
471 		desc->cmd_cfg |= CMD_CFG_DATA_IO;
472 		if (cmd->data->blocks > 1) {
473 			desc->cmd_cfg |= CMD_CFG_BLOCK_MODE;
474 			desc->cmd_cfg |=
475 				(cmd->data->blocks & CMD_CFG_LENGTH_MASK) <<
476 				CMD_CFG_LENGTH_SHIFT;
477 
478 			/* check if block-size matches, if not update */
479 			cfg = readl(host->regs + SD_EMMC_CFG);
480 			blk_len = cfg & (CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
481 			blk_len >>= CFG_BLK_LEN_SHIFT;
482 			if (blk_len != ilog2(cmd->data->blksz)) {
483 				dev_warn(host->dev, "%s: update blk_len %d -> %d\n",
484 					__func__, blk_len,
485 					 ilog2(cmd->data->blksz));
486 				blk_len = ilog2(cmd->data->blksz);
487 				cfg &= ~(CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
488 				cfg |= blk_len << CFG_BLK_LEN_SHIFT;
489 				writel(cfg, host->regs + SD_EMMC_CFG);
490 			}
491 		} else {
492 			desc->cmd_cfg &= ~CMD_CFG_BLOCK_MODE;
493 			desc->cmd_cfg |=
494 				(cmd->data->blksz & CMD_CFG_LENGTH_MASK) <<
495 				CMD_CFG_LENGTH_SHIFT;
496 		}
497 
498 		cmd->data->bytes_xfered = 0;
499 		xfer_bytes = cmd->data->blksz * cmd->data->blocks;
500 		if (cmd->data->flags & MMC_DATA_WRITE) {
501 			desc->cmd_cfg |= CMD_CFG_DATA_WR;
502 			WARN_ON(xfer_bytes > host->bounce_buf_size);
503 			sg_copy_to_buffer(cmd->data->sg, cmd->data->sg_len,
504 					  host->bounce_buf, xfer_bytes);
505 			cmd->data->bytes_xfered = xfer_bytes;
506 			dma_wmb();
507 		} else {
508 			desc->cmd_cfg &= ~CMD_CFG_DATA_WR;
509 		}
510 
511 		if (xfer_bytes > 0) {
512 			desc->cmd_cfg &= ~CMD_CFG_DATA_NUM;
513 			desc->cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
514 		} else {
515 			/* write data to data_addr */
516 			desc->cmd_cfg |= CMD_CFG_DATA_NUM;
517 			desc->cmd_data = 0;
518 		}
519 
520 		cmd_cfg_timeout = 12;
521 	} else {
522 		desc->cmd_cfg &= ~CMD_CFG_DATA_IO;
523 		cmd_cfg_timeout = 10;
524 	}
525 	desc->cmd_cfg |= (cmd_cfg_timeout & CMD_CFG_TIMEOUT_MASK) <<
526 		CMD_CFG_TIMEOUT_SHIFT;
527 
528 	host->cmd = cmd;
529 
530 	/* Last descriptor */
531 	desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN;
532 	writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
533 	writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT);
534 	writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP);
535 	wmb(); /* ensure descriptor is written before kicked */
536 	writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG);
537 }
538 
539 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
540 {
541 	struct meson_host *host = mmc_priv(mmc);
542 
543 	WARN_ON(host->mrq != NULL);
544 
545 	/* Stop execution */
546 	writel(0, host->regs + SD_EMMC_START);
547 
548 	/* clear, ack, enable all interrupts */
549 	writel(0, host->regs + SD_EMMC_IRQ_EN);
550 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
551 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_IRQ_EN);
552 
553 	host->mrq = mrq;
554 
555 	if (mrq->sbc)
556 		meson_mmc_start_cmd(mmc, mrq->sbc);
557 	else
558 		meson_mmc_start_cmd(mmc, mrq->cmd);
559 }
560 
561 static int meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
562 {
563 	struct meson_host *host = mmc_priv(mmc);
564 
565 	if (cmd->flags & MMC_RSP_136) {
566 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
567 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
568 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
569 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
570 	} else if (cmd->flags & MMC_RSP_PRESENT) {
571 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
572 	}
573 
574 	return 0;
575 }
576 
577 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
578 {
579 	struct meson_host *host = dev_id;
580 	struct mmc_request *mrq;
581 	struct mmc_command *cmd;
582 	u32 irq_en, status, raw_status;
583 	irqreturn_t ret = IRQ_HANDLED;
584 
585 	if (WARN_ON(!host))
586 		return IRQ_NONE;
587 
588 	cmd = host->cmd;
589 
590 	mrq = host->mrq;
591 
592 	if (WARN_ON(!mrq))
593 		return IRQ_NONE;
594 
595 	if (WARN_ON(!cmd))
596 		return IRQ_NONE;
597 
598 	spin_lock(&host->lock);
599 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
600 	raw_status = readl(host->regs + SD_EMMC_STATUS);
601 	status = raw_status & irq_en;
602 
603 	if (!status) {
604 		dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
605 			 raw_status, irq_en);
606 		ret = IRQ_NONE;
607 		goto out;
608 	}
609 
610 	cmd->error = 0;
611 	if (status & IRQ_RXD_ERR_MASK) {
612 		dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
613 		cmd->error = -EILSEQ;
614 	}
615 	if (status & IRQ_TXD_ERR) {
616 		dev_dbg(host->dev, "Unhandled IRQ: TXD error\n");
617 		cmd->error = -EILSEQ;
618 	}
619 	if (status & IRQ_DESC_ERR)
620 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor error\n");
621 	if (status & IRQ_RESP_ERR) {
622 		dev_dbg(host->dev, "Unhandled IRQ: Response error\n");
623 		cmd->error = -EILSEQ;
624 	}
625 	if (status & IRQ_RESP_TIMEOUT) {
626 		dev_dbg(host->dev, "Unhandled IRQ: Response timeout\n");
627 		cmd->error = -ETIMEDOUT;
628 	}
629 	if (status & IRQ_DESC_TIMEOUT) {
630 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor timeout\n");
631 		cmd->error = -ETIMEDOUT;
632 	}
633 	if (status & IRQ_SDIO)
634 		dev_dbg(host->dev, "Unhandled IRQ: SDIO.\n");
635 
636 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS))
637 		ret = IRQ_WAKE_THREAD;
638 	else  {
639 		dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC CMD%u arg=0x%08x flags=0x%08x stop=%d\n",
640 			 status, cmd->opcode, cmd->arg,
641 			 cmd->flags, mrq->stop ? 1 : 0);
642 		if (cmd->data) {
643 			struct mmc_data *data = cmd->data;
644 
645 			dev_warn(host->dev, "\tblksz %u blocks %u flags 0x%08x (%s%s)",
646 				 data->blksz, data->blocks, data->flags,
647 				 data->flags & MMC_DATA_WRITE ? "write" : "",
648 				 data->flags & MMC_DATA_READ ? "read" : "");
649 		}
650 	}
651 
652 out:
653 	/* ack all (enabled) interrupts */
654 	writel(status, host->regs + SD_EMMC_STATUS);
655 
656 	if (ret == IRQ_HANDLED) {
657 		meson_mmc_read_resp(host->mmc, cmd);
658 		meson_mmc_request_done(host->mmc, cmd->mrq);
659 	}
660 
661 	spin_unlock(&host->lock);
662 	return ret;
663 }
664 
665 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
666 {
667 	struct meson_host *host = dev_id;
668 	struct mmc_request *mrq = host->mrq;
669 	struct mmc_command *cmd = host->cmd;
670 	struct mmc_data *data;
671 	unsigned int xfer_bytes;
672 	int ret = IRQ_HANDLED;
673 
674 	if (WARN_ON(!mrq))
675 		return IRQ_NONE;
676 
677 	if (WARN_ON(!cmd))
678 		return IRQ_NONE;
679 
680 	data = cmd->data;
681 	if (data) {
682 		xfer_bytes = data->blksz * data->blocks;
683 		if (data->flags & MMC_DATA_READ) {
684 			WARN_ON(xfer_bytes > host->bounce_buf_size);
685 			sg_copy_from_buffer(data->sg, data->sg_len,
686 					    host->bounce_buf, xfer_bytes);
687 			data->bytes_xfered = xfer_bytes;
688 		}
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 ret;
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 		dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
746 		goto free_host;
747 	}
748 
749 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
750 	host->regs = devm_ioremap_resource(&pdev->dev, res);
751 	if (IS_ERR(host->regs)) {
752 		ret = PTR_ERR(host->regs);
753 		goto free_host;
754 	}
755 
756 	host->irq = platform_get_irq(pdev, 0);
757 	if (host->irq == 0) {
758 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
759 		ret = -EINVAL;
760 		goto free_host;
761 	}
762 
763 	host->core_clk = devm_clk_get(&pdev->dev, "core");
764 	if (IS_ERR(host->core_clk)) {
765 		ret = PTR_ERR(host->core_clk);
766 		goto free_host;
767 	}
768 
769 	ret = clk_prepare_enable(host->core_clk);
770 	if (ret)
771 		goto free_host;
772 
773 	ret = meson_mmc_clk_init(host);
774 	if (ret)
775 		goto free_host;
776 
777 	/* Stop execution */
778 	writel(0, host->regs + SD_EMMC_START);
779 
780 	/* clear, ack, enable all interrupts */
781 	writel(0, host->regs + SD_EMMC_IRQ_EN);
782 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
783 
784 	ret = devm_request_threaded_irq(&pdev->dev, host->irq,
785 					meson_mmc_irq, meson_mmc_irq_thread,
786 					IRQF_SHARED, DRIVER_NAME, host);
787 	if (ret)
788 		goto free_host;
789 
790 	/* data bounce buffer */
791 	host->bounce_buf_size = SZ_512K;
792 	host->bounce_buf =
793 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
794 				   &host->bounce_dma_addr, GFP_KERNEL);
795 	if (host->bounce_buf == NULL) {
796 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
797 		ret = -ENOMEM;
798 		goto free_host;
799 	}
800 
801 	mmc->ops = &meson_mmc_ops;
802 	mmc_add_host(mmc);
803 
804 	return 0;
805 
806 free_host:
807 	clk_disable_unprepare(host->cfg_div_clk);
808 	clk_disable_unprepare(host->core_clk);
809 	mmc_free_host(mmc);
810 	return ret;
811 }
812 
813 static int meson_mmc_remove(struct platform_device *pdev)
814 {
815 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
816 
817 	if (WARN_ON(!host))
818 		return 0;
819 
820 	if (host->bounce_buf)
821 		dma_free_coherent(host->dev, host->bounce_buf_size,
822 				  host->bounce_buf, host->bounce_dma_addr);
823 
824 	clk_disable_unprepare(host->cfg_div_clk);
825 	clk_disable_unprepare(host->core_clk);
826 
827 	mmc_free_host(host->mmc);
828 	return 0;
829 }
830 
831 static const struct of_device_id meson_mmc_of_match[] = {
832 	{ .compatible = "amlogic,meson-gx-mmc", },
833 	{ .compatible = "amlogic,meson-gxbb-mmc", },
834 	{ .compatible = "amlogic,meson-gxl-mmc", },
835 	{ .compatible = "amlogic,meson-gxm-mmc", },
836 	{}
837 };
838 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
839 
840 static struct platform_driver meson_mmc_driver = {
841 	.probe		= meson_mmc_probe,
842 	.remove		= meson_mmc_remove,
843 	.driver		= {
844 		.name = DRIVER_NAME,
845 		.of_match_table = of_match_ptr(meson_mmc_of_match),
846 	},
847 };
848 
849 module_platform_driver(meson_mmc_driver);
850 
851 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
852 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
853 MODULE_LICENSE("GPL v2");
854