xref: /openbmc/u-boot/drivers/mmc/pxa_mmc_gen.c (revision e712e545)
1 /*
2  * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
3  *
4  * Loosely based on the old code and Linux's PXA MMC driver
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU 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, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19  * MA 02111-1307 USA
20  */
21 
22 #include <config.h>
23 #include <common.h>
24 #include <malloc.h>
25 
26 #include <mmc.h>
27 #include <asm/errno.h>
28 #include <asm/arch/hardware.h>
29 #include <asm/arch/regs-mmc.h>
30 #include <asm/io.h>
31 
32 /* PXAMMC Generic default config for various CPUs */
33 #if defined(CONFIG_CPU_PXA25X)
34 #define PXAMMC_FIFO_SIZE	1
35 #define PXAMMC_MIN_SPEED	312500
36 #define PXAMMC_MAX_SPEED	20000000
37 #define PXAMMC_HOST_CAPS	(0)
38 #elif defined(CONFIG_CPU_PXA27X)
39 #define PXAMMC_CRC_SKIP
40 #define PXAMMC_FIFO_SIZE	32
41 #define PXAMMC_MIN_SPEED	304000
42 #define PXAMMC_MAX_SPEED	19500000
43 #define PXAMMC_HOST_CAPS	(MMC_MODE_4BIT)
44 #elif defined(CONFIG_CPU_MONAHANS)
45 #define PXAMMC_FIFO_SIZE	32
46 #define PXAMMC_MIN_SPEED	304000
47 #define PXAMMC_MAX_SPEED	26000000
48 #define PXAMMC_HOST_CAPS	(MMC_MODE_4BIT | MMC_MODE_HS)
49 #else
50 #error "This CPU isn't supported by PXA MMC!"
51 #endif
52 
53 #define MMC_STAT_ERRORS							\
54 	(MMC_STAT_RES_CRC_ERROR | MMC_STAT_SPI_READ_ERROR_TOKEN |	\
55 	MMC_STAT_CRC_READ_ERROR | MMC_STAT_TIME_OUT_RESPONSE |		\
56 	MMC_STAT_READ_TIME_OUT | MMC_STAT_CRC_WRITE_ERROR)
57 
58 /* 1 millisecond (in wait cycles below it's 100 x 10uS waits) */
59 #define PXA_MMC_TIMEOUT	100
60 
61 struct pxa_mmc_priv {
62 	struct pxa_mmc_regs *regs;
63 };
64 
65 /* Wait for bit to be set */
66 static int pxa_mmc_wait(struct mmc *mmc, uint32_t mask)
67 {
68 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
69 	struct pxa_mmc_regs *regs = priv->regs;
70 	unsigned int timeout = PXA_MMC_TIMEOUT;
71 
72 	/* Wait for bit to be set */
73 	while (--timeout) {
74 		if (readl(&regs->stat) & mask)
75 			break;
76 		udelay(10);
77 	}
78 
79 	if (!timeout)
80 		return -ETIMEDOUT;
81 
82 	return 0;
83 }
84 
85 static int pxa_mmc_stop_clock(struct mmc *mmc)
86 {
87 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
88 	struct pxa_mmc_regs *regs = priv->regs;
89 	unsigned int timeout = PXA_MMC_TIMEOUT;
90 
91 	/* If the clock aren't running, exit */
92 	if (!(readl(&regs->stat) & MMC_STAT_CLK_EN))
93 		return 0;
94 
95 	/* Tell the controller to turn off the clock */
96 	writel(MMC_STRPCL_STOP_CLK, &regs->strpcl);
97 
98 	/* Wait until the clock are off */
99 	while (--timeout) {
100 		if (!(readl(&regs->stat) & MMC_STAT_CLK_EN))
101 			break;
102 		udelay(10);
103 	}
104 
105 	/* The clock refused to stop, scream and die a painful death */
106 	if (!timeout)
107 		return -ETIMEDOUT;
108 
109 	/* The clock stopped correctly */
110 	return 0;
111 }
112 
113 static int pxa_mmc_start_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
114 				uint32_t cmdat)
115 {
116 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
117 	struct pxa_mmc_regs *regs = priv->regs;
118 	int ret;
119 
120 	/* The card can send a "busy" response */
121 	if (cmd->flags & MMC_RSP_BUSY)
122 		cmdat |= MMC_CMDAT_BUSY;
123 
124 	/* Inform the controller about response type */
125 	switch (cmd->resp_type) {
126 	case MMC_RSP_R1:
127 	case MMC_RSP_R1b:
128 		cmdat |= MMC_CMDAT_R1;
129 		break;
130 	case MMC_RSP_R2:
131 		cmdat |= MMC_CMDAT_R2;
132 		break;
133 	case MMC_RSP_R3:
134 		cmdat |= MMC_CMDAT_R3;
135 		break;
136 	default:
137 		break;
138 	}
139 
140 	/* Load command and it's arguments into the controller */
141 	writel(cmd->cmdidx, &regs->cmd);
142 	writel(cmd->cmdarg >> 16, &regs->argh);
143 	writel(cmd->cmdarg & 0xffff, &regs->argl);
144 	writel(cmdat, &regs->cmdat);
145 
146 	/* Start the controller clock and wait until they are started */
147 	writel(MMC_STRPCL_START_CLK, &regs->strpcl);
148 
149 	ret = pxa_mmc_wait(mmc, MMC_STAT_CLK_EN);
150 	if (ret)
151 		return ret;
152 
153 	/* Correct and happy end */
154 	return 0;
155 }
156 
157 static int pxa_mmc_cmd_done(struct mmc *mmc, struct mmc_cmd *cmd)
158 {
159 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
160 	struct pxa_mmc_regs *regs = priv->regs;
161 	uint32_t a, b, c;
162 	int i;
163 	int stat;
164 
165 	/* Read the controller status */
166 	stat = readl(&regs->stat);
167 
168 	/*
169 	 * Linux says:
170 	 * Did I mention this is Sick.  We always need to
171 	 * discard the upper 8 bits of the first 16-bit word.
172 	 */
173 	a = readl(&regs->res) & 0xffff;
174 	for (i = 0; i < 4; i++) {
175 		b = readl(&regs->res) & 0xffff;
176 		c = readl(&regs->res) & 0xffff;
177 		cmd->response[i] = (a << 24) | (b << 8) | (c >> 8);
178 		a = c;
179 	}
180 
181 	/* The command response didn't arrive */
182 	if (stat & MMC_STAT_TIME_OUT_RESPONSE)
183 		return -ETIMEDOUT;
184 	else if (stat & MMC_STAT_RES_CRC_ERROR && cmd->flags & MMC_RSP_CRC) {
185 #ifdef	PXAMMC_CRC_SKIP
186 		if (cmd->flags & MMC_RSP_136 && cmd->response[0] & (1 << 31))
187 			printf("Ignoring CRC, this may be dangerous!\n");
188 		else
189 #endif
190 		return -EILSEQ;
191 	}
192 
193 	/* The command response was successfully read */
194 	return 0;
195 }
196 
197 static int pxa_mmc_do_read_xfer(struct mmc *mmc, struct mmc_data *data)
198 {
199 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
200 	struct pxa_mmc_regs *regs = priv->regs;
201 	uint32_t len;
202 	uint32_t *buf = (uint32_t *)data->dest;
203 	int size;
204 	int ret;
205 
206 	len = data->blocks * data->blocksize;
207 
208 	while (len) {
209 		/* The controller has data ready */
210 		if (readl(&regs->i_reg) & MMC_I_REG_RXFIFO_RD_REQ) {
211 			size = min(len, PXAMMC_FIFO_SIZE);
212 			len -= size;
213 			size /= 4;
214 
215 			/* Read data into the buffer */
216 			while (size--)
217 				*buf++ = readl(&regs->rxfifo);
218 
219 		}
220 
221 		if (readl(&regs->stat) & MMC_STAT_ERRORS)
222 			return -EIO;
223 	}
224 
225 	/* Wait for the transmission-done interrupt */
226 	ret = pxa_mmc_wait(mmc, MMC_STAT_DATA_TRAN_DONE);
227 	if (ret)
228 		return ret;
229 
230 	return 0;
231 }
232 
233 static int pxa_mmc_do_write_xfer(struct mmc *mmc, struct mmc_data *data)
234 {
235 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
236 	struct pxa_mmc_regs *regs = priv->regs;
237 	uint32_t len;
238 	uint32_t *buf = (uint32_t *)data->src;
239 	int size;
240 	int ret;
241 
242 	len = data->blocks * data->blocksize;
243 
244 	while (len) {
245 		/* The controller is ready to receive data */
246 		if (readl(&regs->i_reg) & MMC_I_REG_TXFIFO_WR_REQ) {
247 			size = min(len, PXAMMC_FIFO_SIZE);
248 			len -= size;
249 			size /= 4;
250 
251 			while (size--)
252 				writel(*buf++, &regs->txfifo);
253 
254 			if (min(len, PXAMMC_FIFO_SIZE) < 32)
255 				writel(MMC_PRTBUF_BUF_PART_FULL, &regs->prtbuf);
256 		}
257 
258 		if (readl(&regs->stat) & MMC_STAT_ERRORS)
259 			return -EIO;
260 	}
261 
262 	/* Wait for the transmission-done interrupt */
263 	ret = pxa_mmc_wait(mmc, MMC_STAT_DATA_TRAN_DONE);
264 	if (ret)
265 		return ret;
266 
267 	/* Wait until the data are really written to the card */
268 	ret = pxa_mmc_wait(mmc, MMC_STAT_PRG_DONE);
269 	if (ret)
270 		return ret;
271 
272 	return 0;
273 }
274 
275 static int pxa_mmc_request(struct mmc *mmc, struct mmc_cmd *cmd,
276 				struct mmc_data *data)
277 {
278 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
279 	struct pxa_mmc_regs *regs = priv->regs;
280 	uint32_t cmdat = 0;
281 	int ret;
282 
283 	/* Stop the controller */
284 	ret = pxa_mmc_stop_clock(mmc);
285 	if (ret)
286 		return ret;
287 
288 	/* If we're doing data transfer, configure the controller accordingly */
289 	if (data) {
290 		writel(data->blocks, &regs->nob);
291 		writel(data->blocksize, &regs->blklen);
292 		/* This delay can be optimized, but stick with max value */
293 		writel(0xffff, &regs->rdto);
294 		cmdat |= MMC_CMDAT_DATA_EN;
295 		if (data->flags & MMC_DATA_WRITE)
296 			cmdat |= MMC_CMDAT_WRITE;
297 	}
298 
299 	/* Run in 4bit mode if the card can do it */
300 	if (mmc->bus_width == 4)
301 		cmdat |= MMC_CMDAT_SD_4DAT;
302 
303 	/* Execute the command */
304 	ret = pxa_mmc_start_cmd(mmc, cmd, cmdat);
305 	if (ret)
306 		return ret;
307 
308 	/* Wait until the command completes */
309 	ret = pxa_mmc_wait(mmc, MMC_STAT_END_CMD_RES);
310 	if (ret)
311 		return ret;
312 
313 	/* Read back the result */
314 	ret = pxa_mmc_cmd_done(mmc, cmd);
315 	if (ret)
316 		return ret;
317 
318 	/* In case there was a data transfer scheduled, do it */
319 	if (data) {
320 		if (data->flags & MMC_DATA_WRITE)
321 			pxa_mmc_do_write_xfer(mmc, data);
322 		else
323 			pxa_mmc_do_read_xfer(mmc, data);
324 	}
325 
326 	return 0;
327 }
328 
329 static void pxa_mmc_set_ios(struct mmc *mmc)
330 {
331 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
332 	struct pxa_mmc_regs *regs = priv->regs;
333 	uint32_t tmp;
334 	uint32_t pxa_mmc_clock;
335 
336 	if (!mmc->clock) {
337 		pxa_mmc_stop_clock(mmc);
338 		return;
339 	}
340 
341 	/* PXA3xx can do 26MHz with special settings. */
342 	if (mmc->clock == 26000000) {
343 		writel(0x7, &regs->clkrt);
344 		return;
345 	}
346 
347 	/* Set clock to the card the usual way. */
348 	pxa_mmc_clock = 0;
349 	tmp = mmc->f_max / mmc->clock;
350 	tmp += tmp % 2;
351 
352 	while (tmp > 1) {
353 		pxa_mmc_clock++;
354 		tmp >>= 1;
355 	}
356 
357 	writel(pxa_mmc_clock, &regs->clkrt);
358 }
359 
360 static int pxa_mmc_init(struct mmc *mmc)
361 {
362 	struct pxa_mmc_priv *priv = (struct pxa_mmc_priv *)mmc->priv;
363 	struct pxa_mmc_regs *regs = priv->regs;
364 
365 	/* Make sure the clock are stopped */
366 	pxa_mmc_stop_clock(mmc);
367 
368 	/* Turn off SPI mode */
369 	writel(0, &regs->spi);
370 
371 	/* Set up maximum timeout to wait for command response */
372 	writel(MMC_RES_TO_MAX_MASK, &regs->resto);
373 
374 	/* Mask all interrupts */
375 	writel(~(MMC_I_MASK_TXFIFO_WR_REQ | MMC_I_MASK_RXFIFO_RD_REQ),
376 		&regs->i_mask);
377 	return 0;
378 }
379 
380 int pxa_mmc_register(int card_index)
381 {
382 	struct mmc *mmc;
383 	struct pxa_mmc_priv *priv;
384 	uint32_t reg;
385 	int ret = -ENOMEM;
386 
387 	mmc = malloc(sizeof(struct mmc));
388 	if (!mmc)
389 		goto err0;
390 
391 	priv = malloc(sizeof(struct pxa_mmc_priv));
392 	if (!priv)
393 		goto err1;
394 
395 	switch (card_index) {
396 	case 0:
397 		priv->regs = (struct pxa_mmc_regs *)MMC0_BASE;
398 		break;
399 	case 1:
400 		priv->regs = (struct pxa_mmc_regs *)MMC1_BASE;
401 		break;
402 	default:
403 		printf("PXA MMC: Invalid MMC controller ID (card_index = %d)\n",
404 			card_index);
405 		goto err2;
406 	}
407 
408 	mmc->priv = priv;
409 
410 	sprintf(mmc->name, "PXA MMC");
411 	mmc->send_cmd	= pxa_mmc_request;
412 	mmc->set_ios	= pxa_mmc_set_ios;
413 	mmc->init	= pxa_mmc_init;
414 	mmc->getcd	= NULL;
415 
416 	mmc->voltages	= MMC_VDD_32_33 | MMC_VDD_33_34;
417 	mmc->f_max	= PXAMMC_MAX_SPEED;
418 	mmc->f_min	= PXAMMC_MIN_SPEED;
419 	mmc->host_caps	= PXAMMC_HOST_CAPS;
420 
421 	mmc->b_max = 0;
422 
423 #ifndef	CONFIG_CPU_MONAHANS	/* PXA2xx */
424 	reg = readl(CKEN);
425 	reg |= CKEN12_MMC;
426 	writel(reg, CKEN);
427 #else				/* PXA3xx */
428 	reg = readl(CKENA);
429 	reg |= CKENA_12_MMC0 | CKENA_13_MMC1;
430 	writel(reg, CKENA);
431 #endif
432 
433 	mmc_register(mmc);
434 
435 	return 0;
436 
437 err2:
438 	free(priv);
439 err1:
440 	free(mmc);
441 err0:
442 	return ret;
443 }
444