xref: /linux/drivers/mmc/host/litex_mmc.c (revision 889600e21e3be388a6817c2a0dac0411df860751)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * LiteX LiteSDCard driver
4  *
5  * Copyright (C) 2019-2020 Antmicro <contact@antmicro.com>
6  * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@antmicro.com>
7  * Copyright (C) 2019-2020 Maciej Dudek <mdudek@internships.antmicro.com>
8  * Copyright (C) 2020 Paul Mackerras <paulus@ozlabs.org>
9  * Copyright (C) 2020-2022 Gabriel Somlo <gsomlo@gmail.com>
10  */
11 
12 #include <linux/bits.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/interrupt.h>
17 #include <linux/iopoll.h>
18 #include <linux/litex.h>
19 #include <linux/math.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 
23 #include <linux/mmc/host.h>
24 #include <linux/mmc/mmc.h>
25 #include <linux/mmc/sd.h>
26 
27 #define LITEX_PHY_CARDDETECT  0x00
28 #define LITEX_PHY_CLOCKERDIV  0x04
29 #define LITEX_PHY_INITIALIZE  0x08
30 #define LITEX_PHY_WRITESTATUS 0x0C
31 #define LITEX_PHY_SETTINGS    0x18
32 #define LITEX_CORE_CMDARG     0x00
33 #define LITEX_CORE_CMDCMD     0x04
34 #define LITEX_CORE_CMDSND     0x08
35 #define LITEX_CORE_CMDRSP     0x0C
36 #define LITEX_CORE_CMDEVT     0x1C
37 #define LITEX_CORE_DATEVT     0x20
38 #define LITEX_CORE_BLKLEN     0x24
39 #define LITEX_CORE_BLKCNT     0x28
40 #define LITEX_BLK2MEM_BASE    0x00
41 #define LITEX_BLK2MEM_LEN     0x08
42 #define LITEX_BLK2MEM_ENA     0x0C
43 #define LITEX_BLK2MEM_DONE    0x10
44 #define LITEX_BLK2MEM_LOOP    0x14
45 #define LITEX_MEM2BLK_BASE    0x00
46 #define LITEX_MEM2BLK_LEN     0x08
47 #define LITEX_MEM2BLK_ENA     0x0C
48 #define LITEX_MEM2BLK_DONE    0x10
49 #define LITEX_MEM2BLK_LOOP    0x14
50 #define LITEX_MEM2BLK         0x18
51 #define LITEX_IRQ_STATUS      0x00
52 #define LITEX_IRQ_PENDING     0x04
53 #define LITEX_IRQ_ENABLE      0x08
54 
55 #define SD_CTL_DATA_XFER_NONE  0
56 #define SD_CTL_DATA_XFER_READ  1
57 #define SD_CTL_DATA_XFER_WRITE 2
58 
59 #define SD_CTL_RESP_NONE       0
60 #define SD_CTL_RESP_SHORT      1
61 #define SD_CTL_RESP_LONG       2
62 #define SD_CTL_RESP_SHORT_BUSY 3
63 
64 #define SD_BIT_DONE    BIT(0)
65 #define SD_BIT_WR_ERR  BIT(1)
66 #define SD_BIT_TIMEOUT BIT(2)
67 #define SD_BIT_CRC_ERR BIT(3)
68 
69 #define SD_SLEEP_US       5
70 #define SD_TIMEOUT_US 20000
71 
72 #define SD_INIT_DELAY_US  1000
73 #define SD_INIT_CLK_HZ    400000
74 
75 #define SD_PHY_SPEED_1X 0
76 #define SD_PHY_SPEED_4X 1
77 #define SD_PHY_SPEED_8X 2
78 
79 #define SDIRQ_CARD_DETECT    1
80 #define SDIRQ_SD_TO_MEM_DONE 2
81 #define SDIRQ_MEM_TO_SD_DONE 4
82 #define SDIRQ_CMD_DONE       8
83 
84 struct litex_mmc_host {
85 	struct mmc_host *mmc;
86 
87 	void __iomem *sdphy;
88 	void __iomem *sdcore;
89 	void __iomem *sdreader;
90 	void __iomem *sdwriter;
91 	void __iomem *sdirq;
92 
93 	void *buffer;
94 	size_t buf_size;
95 	dma_addr_t dma;
96 
97 	struct completion cmd_done;
98 	int irq;
99 
100 	unsigned int ref_clk;
101 	unsigned int sd_clk;
102 
103 	u8 width;
104 
105 	u32 resp[4];
106 };
107 
litex_mmc_sdcard_wait_done(void __iomem * reg,struct device * dev)108 static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device *dev)
109 {
110 	u8 evt;
111 	int ret;
112 
113 	ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE,
114 				 SD_SLEEP_US, SD_TIMEOUT_US);
115 	if (ret)
116 		return ret;
117 	if (evt == SD_BIT_DONE)
118 		return 0;
119 	if (evt & SD_BIT_WR_ERR)
120 		return -EIO;
121 	if (evt & SD_BIT_TIMEOUT)
122 		return -ETIMEDOUT;
123 	if (evt & SD_BIT_CRC_ERR)
124 		return -EILSEQ;
125 	dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt);
126 	return -EINVAL;
127 }
128 
litex_mmc_send_cmd(struct litex_mmc_host * host,u8 cmd,u32 arg,u8 response_len,u8 transfer)129 static int litex_mmc_send_cmd(struct litex_mmc_host *host,
130 			      u8 cmd, u32 arg, u8 response_len, u8 transfer)
131 {
132 	struct device *dev = mmc_dev(host->mmc);
133 	void __iomem *reg;
134 	int ret;
135 	u8 evt;
136 
137 	litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg);
138 	litex_write32(host->sdcore + LITEX_CORE_CMDCMD,
139 		      cmd << 8 | transfer << 5 | response_len);
140 	litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1);
141 
142 	/*
143 	 * Wait for an interrupt if we have an interrupt and either there is
144 	 * data to be transferred, or if the card can report busy via DAT0.
145 	 */
146 	if (host->irq > 0 &&
147 	    (transfer != SD_CTL_DATA_XFER_NONE ||
148 	     response_len == SD_CTL_RESP_SHORT_BUSY)) {
149 		reinit_completion(&host->cmd_done);
150 		litex_write32(host->sdirq + LITEX_IRQ_ENABLE,
151 			      SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT);
152 		wait_for_completion(&host->cmd_done);
153 	}
154 
155 	ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, dev);
156 	if (ret) {
157 		dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, ret);
158 		return ret;
159 	}
160 
161 	if (response_len != SD_CTL_RESP_NONE) {
162 		/*
163 		 * NOTE: this matches the semantics of litex_read32()
164 		 * regardless of underlying arch endianness!
165 		 */
166 		memcpy_fromio(host->resp,
167 			      host->sdcore + LITEX_CORE_CMDRSP, 0x10);
168 	}
169 
170 	if (transfer == SD_CTL_DATA_XFER_NONE)
171 		return ret; /* OK from prior litex_mmc_sdcard_wait_done() */
172 
173 	ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, dev);
174 	if (ret) {
175 		dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, ret);
176 		return ret;
177 	}
178 
179 	/* Wait for completion of (read or write) DMA transfer */
180 	reg = (transfer == SD_CTL_DATA_XFER_READ) ?
181 		host->sdreader + LITEX_BLK2MEM_DONE :
182 		host->sdwriter + LITEX_MEM2BLK_DONE;
183 	ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE,
184 				 SD_SLEEP_US, SD_TIMEOUT_US);
185 	if (ret)
186 		dev_err(dev, "DMA timeout (cmd %d)\n", cmd);
187 
188 	return ret;
189 }
190 
litex_mmc_get_cd(struct mmc_host * mmc)191 static int litex_mmc_get_cd(struct mmc_host *mmc)
192 {
193 	struct litex_mmc_host *host = mmc_priv(mmc);
194 	int ret;
195 
196 	if (!mmc_card_is_removable(mmc))
197 		return 1;
198 
199 	ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT);
200 	if (ret)
201 		return ret;
202 
203 	return 0;
204 }
205 
litex_mmc_interrupt(int irq,void * arg)206 static irqreturn_t litex_mmc_interrupt(int irq, void *arg)
207 {
208 	struct mmc_host *mmc = arg;
209 	struct litex_mmc_host *host = mmc_priv(mmc);
210 	u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING);
211 	irqreturn_t ret = IRQ_NONE;
212 
213 	/* Check for card change interrupt */
214 	if (pending & SDIRQ_CARD_DETECT) {
215 		litex_write32(host->sdirq + LITEX_IRQ_PENDING,
216 			      SDIRQ_CARD_DETECT);
217 		mmc_detect_change(mmc, msecs_to_jiffies(10));
218 		ret = IRQ_HANDLED;
219 	}
220 
221 	/* Check for command completed */
222 	if (pending & SDIRQ_CMD_DONE) {
223 		/* Disable it so it doesn't keep interrupting */
224 		litex_write32(host->sdirq + LITEX_IRQ_ENABLE,
225 			      SDIRQ_CARD_DETECT);
226 		complete(&host->cmd_done);
227 		ret = IRQ_HANDLED;
228 	}
229 
230 	return ret;
231 }
232 
litex_mmc_response_len(struct mmc_command * cmd)233 static u32 litex_mmc_response_len(struct mmc_command *cmd)
234 {
235 	if (cmd->flags & MMC_RSP_136)
236 		return SD_CTL_RESP_LONG;
237 	if (!(cmd->flags & MMC_RSP_PRESENT))
238 		return SD_CTL_RESP_NONE;
239 	if (cmd->flags & MMC_RSP_BUSY)
240 		return SD_CTL_RESP_SHORT_BUSY;
241 	return SD_CTL_RESP_SHORT;
242 }
243 
litex_mmc_do_dma(struct litex_mmc_host * host,struct mmc_data * data,unsigned int * len,bool * direct,u8 * transfer)244 static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data *data,
245 			     unsigned int *len, bool *direct, u8 *transfer)
246 {
247 	struct device *dev = mmc_dev(host->mmc);
248 	dma_addr_t dma;
249 	int sg_count;
250 
251 	/*
252 	 * Try to DMA directly to/from the data buffer.
253 	 * We can do that if the buffer can be mapped for DMA
254 	 * in one contiguous chunk.
255 	 */
256 	dma = host->dma;
257 	*len = data->blksz * data->blocks;
258 	sg_count = dma_map_sg(dev, data->sg, data->sg_len,
259 			      mmc_get_dma_dir(data));
260 	if (sg_count == 1) {
261 		dma = sg_dma_address(data->sg);
262 		*len = sg_dma_len(data->sg);
263 		*direct = true;
264 	} else if (*len > host->buf_size)
265 		*len = host->buf_size;
266 
267 	if (data->flags & MMC_DATA_READ) {
268 		litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
269 		litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma);
270 		litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len);
271 		litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1);
272 		*transfer = SD_CTL_DATA_XFER_READ;
273 	} else if (data->flags & MMC_DATA_WRITE) {
274 		if (!*direct)
275 			sg_copy_to_buffer(data->sg, data->sg_len,
276 					  host->buffer, *len);
277 		litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
278 		litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma);
279 		litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len);
280 		litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1);
281 		*transfer = SD_CTL_DATA_XFER_WRITE;
282 	} else {
283 		dev_warn(dev, "Data present w/o read or write flag.\n");
284 		/* Continue: set cmd status, mark req done */
285 	}
286 
287 	litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz);
288 	litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks);
289 }
290 
litex_mmc_request(struct mmc_host * mmc,struct mmc_request * mrq)291 static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
292 {
293 	struct litex_mmc_host *host = mmc_priv(mmc);
294 	struct device *dev = mmc_dev(mmc);
295 	struct mmc_command *cmd = mrq->cmd;
296 	struct mmc_command *sbc = mrq->sbc;
297 	struct mmc_data *data = mrq->data;
298 	struct mmc_command *stop = mrq->stop;
299 	unsigned int retries = cmd->retries;
300 	unsigned int len = 0;
301 	bool direct = false;
302 	u32 response_len = litex_mmc_response_len(cmd);
303 	u8 transfer = SD_CTL_DATA_XFER_NONE;
304 
305 	/* First check that the card is still there */
306 	if (!litex_mmc_get_cd(mmc)) {
307 		cmd->error = -ENOMEDIUM;
308 		mmc_request_done(mmc, mrq);
309 		return;
310 	}
311 
312 	/* Send set-block-count command if needed */
313 	if (sbc) {
314 		sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc->arg,
315 						litex_mmc_response_len(sbc),
316 						SD_CTL_DATA_XFER_NONE);
317 		if (sbc->error) {
318 			mmc_request_done(mmc, mrq);
319 			return;
320 		}
321 	}
322 
323 	if (data)
324 		litex_mmc_do_dma(host, data, &len, &direct, &transfer);
325 
326 	do {
327 		cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd->arg,
328 						response_len, transfer);
329 	} while (cmd->error && retries-- > 0);
330 
331 	if (response_len == SD_CTL_RESP_SHORT) {
332 		/* Pull short response fields from appropriate host registers */
333 		cmd->resp[0] = host->resp[3];
334 		cmd->resp[1] = host->resp[2] & 0xFF;
335 	} else if (response_len == SD_CTL_RESP_LONG) {
336 		cmd->resp[0] = host->resp[0];
337 		cmd->resp[1] = host->resp[1];
338 		cmd->resp[2] = host->resp[2];
339 		cmd->resp[3] = host->resp[3];
340 	}
341 
342 	/* Send stop-transmission command if required */
343 	if (stop && (cmd->error || !sbc))
344 		stop->error = litex_mmc_send_cmd(host, stop->opcode, stop->arg,
345 						 litex_mmc_response_len(stop),
346 						 SD_CTL_DATA_XFER_NONE);
347 
348 	if (data) {
349 		dma_unmap_sg(dev, data->sg, data->sg_len,
350 			     mmc_get_dma_dir(data));
351 	}
352 
353 	if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) {
354 		data->bytes_xfered = min(len, mmc->max_req_size);
355 		if (transfer == SD_CTL_DATA_XFER_READ && !direct) {
356 			sg_copy_from_buffer(data->sg, sg_nents(data->sg),
357 					    host->buffer, data->bytes_xfered);
358 		}
359 	}
360 
361 	mmc_request_done(mmc, mrq);
362 }
363 
litex_mmc_setclk(struct litex_mmc_host * host,unsigned int freq)364 static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq)
365 {
366 	struct device *dev = mmc_dev(host->mmc);
367 	u32 div;
368 
369 	div = freq ? DIV_ROUND_UP(host->ref_clk, freq) : 256U;
370 	div = clamp(div, 2U, 256U);
371 	dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n",
372 		freq, host->ref_clk / ((div + 1) & ~1U), div);
373 	litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div);
374 	host->sd_clk = freq;
375 }
376 
litex_mmc_set_ios(struct mmc_host * mmc,struct mmc_ios * ios)377 static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
378 {
379 	struct litex_mmc_host *host = mmc_priv(mmc);
380 	unsigned int bus_width = SD_PHY_SPEED_1X;
381 
382 	switch (ios->bus_width) {
383 	case MMC_BUS_WIDTH_1:
384 		bus_width = SD_PHY_SPEED_1X;
385 		break;
386 	case MMC_BUS_WIDTH_4:
387 		bus_width = SD_PHY_SPEED_4X;
388 		break;
389 	case MMC_BUS_WIDTH_8:
390 		bus_width = SD_PHY_SPEED_8X;
391 		break;
392 	}
393 
394 	if (host->width != ios->bus_width) {
395 		litex_write8(host->sdphy + LITEX_PHY_SETTINGS, bus_width);
396 		host->width = ios->bus_width;
397 	}
398 
399 	/*
400 	 * The SD specification requires at least 74 idle clocks before CMD0.
401 	 * These dummy cycles is generated by writing LITEX_PHY_INITIALIZE.
402 	 */
403 	if (ios->chip_select == MMC_CS_HIGH) {
404 		litex_mmc_setclk(host, SD_INIT_CLK_HZ);
405 		litex_write8(host->sdphy + LITEX_PHY_INITIALIZE, 1);
406 		fsleep(SD_INIT_DELAY_US);
407 		return;
408 	}
409 
410 	/* Update sd_clk */
411 	if (ios->clock != host->sd_clk)
412 		litex_mmc_setclk(host, ios->clock);
413 }
414 
415 static const struct mmc_host_ops litex_mmc_ops = {
416 	.get_cd = litex_mmc_get_cd,
417 	.request = litex_mmc_request,
418 	.set_ios = litex_mmc_set_ios,
419 };
420 
litex_mmc_irq_init(struct platform_device * pdev,struct litex_mmc_host * host)421 static int litex_mmc_irq_init(struct platform_device *pdev,
422 			      struct litex_mmc_host *host)
423 {
424 	struct device *dev = mmc_dev(host->mmc);
425 	int ret;
426 
427 	ret = platform_get_irq_optional(pdev, 0);
428 	if (ret < 0 && ret != -ENXIO)
429 		return ret;
430 	if (ret > 0)
431 		host->irq = ret;
432 	else {
433 		dev_warn(dev, "Failed to get IRQ, using polling\n");
434 		goto use_polling;
435 	}
436 
437 	host->sdirq = devm_platform_ioremap_resource_byname(pdev, "irq");
438 	if (IS_ERR(host->sdirq))
439 		return PTR_ERR(host->sdirq);
440 
441 	ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0,
442 			       "litex-mmc", host->mmc);
443 	if (ret < 0) {
444 		dev_warn(dev, "IRQ request error %d, using polling\n", ret);
445 		goto use_polling;
446 	}
447 
448 	/* Clear & enable card-change interrupts */
449 	litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT);
450 	litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT);
451 
452 	return 0;
453 
454 use_polling:
455 	host->mmc->caps |= MMC_CAP_NEEDS_POLL;
456 	host->irq = 0;
457 	return 0;
458 }
459 
litex_mmc_probe(struct platform_device * pdev)460 static int litex_mmc_probe(struct platform_device *pdev)
461 {
462 	struct device *dev = &pdev->dev;
463 	struct litex_mmc_host *host;
464 	struct mmc_host *mmc;
465 	struct clk *clk;
466 	int ret;
467 
468 	/*
469 	 * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512,
470 	 * and max_blk_count accordingly set to 8;
471 	 * If for some reason we need to modify max_blk_count, we must also
472 	 * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;`
473 	 */
474 	mmc = devm_mmc_alloc_host(dev, sizeof(*host));
475 	if (!mmc)
476 		return -ENOMEM;
477 
478 	host = mmc_priv(mmc);
479 	host->mmc = mmc;
480 
481 	/* Initialize clock source */
482 	clk = devm_clk_get(dev, NULL);
483 	if (IS_ERR(clk))
484 		return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
485 	host->ref_clk = clk_get_rate(clk);
486 	host->sd_clk = 0;
487 	host->width = MMC_BUS_WIDTH_1;
488 
489 	/* LiteSDCard can support 64-bit DMA addressing */
490 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
491 	if (ret)
492 		return ret;
493 
494 	host->buf_size = mmc->max_req_size * 2;
495 	host->buffer = dmam_alloc_coherent(dev, host->buf_size,
496 					   &host->dma, GFP_KERNEL);
497 	if (host->buffer == NULL)
498 		return -ENOMEM;
499 
500 	host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy");
501 	if (IS_ERR(host->sdphy))
502 		return PTR_ERR(host->sdphy);
503 
504 	host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core");
505 	if (IS_ERR(host->sdcore))
506 		return PTR_ERR(host->sdcore);
507 
508 	host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader");
509 	if (IS_ERR(host->sdreader))
510 		return PTR_ERR(host->sdreader);
511 
512 	host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer");
513 	if (IS_ERR(host->sdwriter))
514 		return PTR_ERR(host->sdwriter);
515 
516 	/* Ensure DMA bus masters are disabled */
517 	litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
518 	litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
519 
520 	/* Ensure the litex is at bus width x1 */
521 	litex_write8(host->sdphy + LITEX_PHY_SETTINGS, SD_PHY_SPEED_1X);
522 
523 	init_completion(&host->cmd_done);
524 	ret = litex_mmc_irq_init(pdev, host);
525 	if (ret)
526 		return ret;
527 
528 	mmc->ops = &litex_mmc_ops;
529 
530 	ret = mmc_regulator_get_supply(mmc);
531 	if (ret || mmc->ocr_avail == 0) {
532 		dev_warn(dev, "can't get voltage, defaulting to 3.3V\n");
533 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
534 	}
535 
536 	/*
537 	 * Set default sd_clk frequency range based on empirical observations
538 	 * of LiteSDCard gateware behavior on typical SDCard media
539 	 */
540 	mmc->f_min = 12.5e6;
541 	mmc->f_max = 50e6;
542 
543 	ret = mmc_of_parse(mmc);
544 	if (ret)
545 		return ret;
546 
547 	/* Only drop 8-bit bus_width support */
548 	mmc->caps &= ~MMC_CAP_8_BIT_DATA;
549 
550 	/* Set default capabilities */
551 	mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
552 		     MMC_CAP_DRIVER_TYPE_D |
553 		     MMC_CAP_CMD23;
554 	mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT |
555 		      MMC_CAP2_NO_SDIO |
556 		      MMC_CAP2_NO_MMC;
557 
558 	platform_set_drvdata(pdev, host);
559 
560 	ret = mmc_add_host(mmc);
561 	if (ret)
562 		return ret;
563 
564 	dev_info(dev, "LiteX MMC controller initialized.\n");
565 	return 0;
566 }
567 
litex_mmc_remove(struct platform_device * pdev)568 static void litex_mmc_remove(struct platform_device *pdev)
569 {
570 	struct litex_mmc_host *host = platform_get_drvdata(pdev);
571 
572 	mmc_remove_host(host->mmc);
573 }
574 
575 static const struct of_device_id litex_match[] = {
576 	{ .compatible = "litex,mmc" },
577 	{ }
578 };
579 MODULE_DEVICE_TABLE(of, litex_match);
580 
581 static struct platform_driver litex_mmc_driver = {
582 	.probe = litex_mmc_probe,
583 	.remove = litex_mmc_remove,
584 	.driver = {
585 		.name = "litex-mmc",
586 		.of_match_table = litex_match,
587 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
588 	},
589 };
590 module_platform_driver(litex_mmc_driver);
591 
592 MODULE_DESCRIPTION("LiteX SDCard driver");
593 MODULE_AUTHOR("Antmicro <contact@antmicro.com>");
594 MODULE_AUTHOR("Kamil Rakoczy <krakoczy@antmicro.com>");
595 MODULE_AUTHOR("Maciej Dudek <mdudek@internships.antmicro.com>");
596 MODULE_AUTHOR("Paul Mackerras <paulus@ozlabs.org>");
597 MODULE_AUTHOR("Gabriel Somlo <gsomlo@gmail.com>");
598 MODULE_LICENSE("GPL v2");
599