xref: /openbmc/u-boot/drivers/mmc/pxa_mmc_gen.c (revision b24a8ec1)
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  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <asm/arch/hardware.h>
11 #include <asm/arch/regs-mmc.h>
12 #include <linux/errno.h>
13 #include <asm/io.h>
14 #include <malloc.h>
15 #include <mmc.h>
16 
17 /* PXAMMC Generic default config for various CPUs */
18 #if defined(CONFIG_CPU_PXA25X)
19 #define PXAMMC_FIFO_SIZE	1
20 #define PXAMMC_MIN_SPEED	312500
21 #define PXAMMC_MAX_SPEED	20000000
22 #define PXAMMC_HOST_CAPS	(0)
23 #elif defined(CONFIG_CPU_PXA27X)
24 #define PXAMMC_CRC_SKIP
25 #define PXAMMC_FIFO_SIZE	32
26 #define PXAMMC_MIN_SPEED	304000
27 #define PXAMMC_MAX_SPEED	19500000
28 #define PXAMMC_HOST_CAPS	(MMC_MODE_4BIT)
29 #elif defined(CONFIG_CPU_MONAHANS)
30 #define PXAMMC_FIFO_SIZE	32
31 #define PXAMMC_MIN_SPEED	304000
32 #define PXAMMC_MAX_SPEED	26000000
33 #define PXAMMC_HOST_CAPS	(MMC_MODE_4BIT | MMC_MODE_HS)
34 #else
35 #error "This CPU isn't supported by PXA MMC!"
36 #endif
37 
38 #define MMC_STAT_ERRORS							\
39 	(MMC_STAT_RES_CRC_ERROR | MMC_STAT_SPI_READ_ERROR_TOKEN |	\
40 	MMC_STAT_CRC_READ_ERROR | MMC_STAT_TIME_OUT_RESPONSE |		\
41 	MMC_STAT_READ_TIME_OUT | MMC_STAT_CRC_WRITE_ERROR)
42 
43 /* 1 millisecond (in wait cycles below it's 100 x 10uS waits) */
44 #define PXA_MMC_TIMEOUT	100
45 
46 struct pxa_mmc_priv {
47 	struct pxa_mmc_regs *regs;
48 };
49 
50 /* Wait for bit to be set */
51 static int pxa_mmc_wait(struct mmc *mmc, uint32_t mask)
52 {
53 	struct pxa_mmc_priv *priv = mmc->priv;
54 	struct pxa_mmc_regs *regs = priv->regs;
55 	unsigned int timeout = PXA_MMC_TIMEOUT;
56 
57 	/* Wait for bit to be set */
58 	while (--timeout) {
59 		if (readl(&regs->stat) & mask)
60 			break;
61 		udelay(10);
62 	}
63 
64 	if (!timeout)
65 		return -ETIMEDOUT;
66 
67 	return 0;
68 }
69 
70 static int pxa_mmc_stop_clock(struct mmc *mmc)
71 {
72 	struct pxa_mmc_priv *priv = mmc->priv;
73 	struct pxa_mmc_regs *regs = priv->regs;
74 	unsigned int timeout = PXA_MMC_TIMEOUT;
75 
76 	/* If the clock aren't running, exit */
77 	if (!(readl(&regs->stat) & MMC_STAT_CLK_EN))
78 		return 0;
79 
80 	/* Tell the controller to turn off the clock */
81 	writel(MMC_STRPCL_STOP_CLK, &regs->strpcl);
82 
83 	/* Wait until the clock are off */
84 	while (--timeout) {
85 		if (!(readl(&regs->stat) & MMC_STAT_CLK_EN))
86 			break;
87 		udelay(10);
88 	}
89 
90 	/* The clock refused to stop, scream and die a painful death */
91 	if (!timeout)
92 		return -ETIMEDOUT;
93 
94 	/* The clock stopped correctly */
95 	return 0;
96 }
97 
98 static int pxa_mmc_start_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
99 				uint32_t cmdat)
100 {
101 	struct pxa_mmc_priv *priv = mmc->priv;
102 	struct pxa_mmc_regs *regs = priv->regs;
103 	int ret;
104 
105 	/* The card can send a "busy" response */
106 	if (cmd->resp_type & MMC_RSP_BUSY)
107 		cmdat |= MMC_CMDAT_BUSY;
108 
109 	/* Inform the controller about response type */
110 	switch (cmd->resp_type) {
111 	case MMC_RSP_R1:
112 	case MMC_RSP_R1b:
113 		cmdat |= MMC_CMDAT_R1;
114 		break;
115 	case MMC_RSP_R2:
116 		cmdat |= MMC_CMDAT_R2;
117 		break;
118 	case MMC_RSP_R3:
119 		cmdat |= MMC_CMDAT_R3;
120 		break;
121 	default:
122 		break;
123 	}
124 
125 	/* Load command and it's arguments into the controller */
126 	writel(cmd->cmdidx, &regs->cmd);
127 	writel(cmd->cmdarg >> 16, &regs->argh);
128 	writel(cmd->cmdarg & 0xffff, &regs->argl);
129 	writel(cmdat, &regs->cmdat);
130 
131 	/* Start the controller clock and wait until they are started */
132 	writel(MMC_STRPCL_START_CLK, &regs->strpcl);
133 
134 	ret = pxa_mmc_wait(mmc, MMC_STAT_CLK_EN);
135 	if (ret)
136 		return ret;
137 
138 	/* Correct and happy end */
139 	return 0;
140 }
141 
142 static int pxa_mmc_cmd_done(struct mmc *mmc, struct mmc_cmd *cmd)
143 {
144 	struct pxa_mmc_priv *priv = mmc->priv;
145 	struct pxa_mmc_regs *regs = priv->regs;
146 	uint32_t a, b, c;
147 	int i;
148 	int stat;
149 
150 	/* Read the controller status */
151 	stat = readl(&regs->stat);
152 
153 	/*
154 	 * Linux says:
155 	 * Did I mention this is Sick.  We always need to
156 	 * discard the upper 8 bits of the first 16-bit word.
157 	 */
158 	a = readl(&regs->res) & 0xffff;
159 	for (i = 0; i < 4; i++) {
160 		b = readl(&regs->res) & 0xffff;
161 		c = readl(&regs->res) & 0xffff;
162 		cmd->response[i] = (a << 24) | (b << 8) | (c >> 8);
163 		a = c;
164 	}
165 
166 	/* The command response didn't arrive */
167 	if (stat & MMC_STAT_TIME_OUT_RESPONSE)
168 		return -ETIMEDOUT;
169 	else if (stat & MMC_STAT_RES_CRC_ERROR
170 			&& cmd->resp_type & MMC_RSP_CRC) {
171 #ifdef	PXAMMC_CRC_SKIP
172 		if (cmd->resp_type & MMC_RSP_136
173 				&& cmd->response[0] & (1 << 31))
174 			printf("Ignoring CRC, this may be dangerous!\n");
175 		else
176 #endif
177 		return -EILSEQ;
178 	}
179 
180 	/* The command response was successfully read */
181 	return 0;
182 }
183 
184 static int pxa_mmc_do_read_xfer(struct mmc *mmc, struct mmc_data *data)
185 {
186 	struct pxa_mmc_priv *priv = mmc->priv;
187 	struct pxa_mmc_regs *regs = priv->regs;
188 	uint32_t len;
189 	uint32_t *buf = (uint32_t *)data->dest;
190 	int size;
191 	int ret;
192 
193 	len = data->blocks * data->blocksize;
194 
195 	while (len) {
196 		/* The controller has data ready */
197 		if (readl(&regs->i_reg) & MMC_I_REG_RXFIFO_RD_REQ) {
198 			size = min(len, (uint32_t)PXAMMC_FIFO_SIZE);
199 			len -= size;
200 			size /= 4;
201 
202 			/* Read data into the buffer */
203 			while (size--)
204 				*buf++ = readl(&regs->rxfifo);
205 
206 		}
207 
208 		if (readl(&regs->stat) & MMC_STAT_ERRORS)
209 			return -EIO;
210 	}
211 
212 	/* Wait for the transmission-done interrupt */
213 	ret = pxa_mmc_wait(mmc, MMC_STAT_DATA_TRAN_DONE);
214 	if (ret)
215 		return ret;
216 
217 	return 0;
218 }
219 
220 static int pxa_mmc_do_write_xfer(struct mmc *mmc, struct mmc_data *data)
221 {
222 	struct pxa_mmc_priv *priv = mmc->priv;
223 	struct pxa_mmc_regs *regs = priv->regs;
224 	uint32_t len;
225 	uint32_t *buf = (uint32_t *)data->src;
226 	int size;
227 	int ret;
228 
229 	len = data->blocks * data->blocksize;
230 
231 	while (len) {
232 		/* The controller is ready to receive data */
233 		if (readl(&regs->i_reg) & MMC_I_REG_TXFIFO_WR_REQ) {
234 			size = min(len, (uint32_t)PXAMMC_FIFO_SIZE);
235 			len -= size;
236 			size /= 4;
237 
238 			while (size--)
239 				writel(*buf++, &regs->txfifo);
240 
241 			if (min(len, (uint32_t)PXAMMC_FIFO_SIZE) < 32)
242 				writel(MMC_PRTBUF_BUF_PART_FULL, &regs->prtbuf);
243 		}
244 
245 		if (readl(&regs->stat) & MMC_STAT_ERRORS)
246 			return -EIO;
247 	}
248 
249 	/* Wait for the transmission-done interrupt */
250 	ret = pxa_mmc_wait(mmc, MMC_STAT_DATA_TRAN_DONE);
251 	if (ret)
252 		return ret;
253 
254 	/* Wait until the data are really written to the card */
255 	ret = pxa_mmc_wait(mmc, MMC_STAT_PRG_DONE);
256 	if (ret)
257 		return ret;
258 
259 	return 0;
260 }
261 
262 static int pxa_mmc_request(struct mmc *mmc, struct mmc_cmd *cmd,
263 				struct mmc_data *data)
264 {
265 	struct pxa_mmc_priv *priv = mmc->priv;
266 	struct pxa_mmc_regs *regs = priv->regs;
267 	uint32_t cmdat = 0;
268 	int ret;
269 
270 	/* Stop the controller */
271 	ret = pxa_mmc_stop_clock(mmc);
272 	if (ret)
273 		return ret;
274 
275 	/* If we're doing data transfer, configure the controller accordingly */
276 	if (data) {
277 		writel(data->blocks, &regs->nob);
278 		writel(data->blocksize, &regs->blklen);
279 		/* This delay can be optimized, but stick with max value */
280 		writel(0xffff, &regs->rdto);
281 		cmdat |= MMC_CMDAT_DATA_EN;
282 		if (data->flags & MMC_DATA_WRITE)
283 			cmdat |= MMC_CMDAT_WRITE;
284 	}
285 
286 	/* Run in 4bit mode if the card can do it */
287 	if (mmc->bus_width == 4)
288 		cmdat |= MMC_CMDAT_SD_4DAT;
289 
290 	/* Execute the command */
291 	ret = pxa_mmc_start_cmd(mmc, cmd, cmdat);
292 	if (ret)
293 		return ret;
294 
295 	/* Wait until the command completes */
296 	ret = pxa_mmc_wait(mmc, MMC_STAT_END_CMD_RES);
297 	if (ret)
298 		return ret;
299 
300 	/* Read back the result */
301 	ret = pxa_mmc_cmd_done(mmc, cmd);
302 	if (ret)
303 		return ret;
304 
305 	/* In case there was a data transfer scheduled, do it */
306 	if (data) {
307 		if (data->flags & MMC_DATA_WRITE)
308 			pxa_mmc_do_write_xfer(mmc, data);
309 		else
310 			pxa_mmc_do_read_xfer(mmc, data);
311 	}
312 
313 	return 0;
314 }
315 
316 static int pxa_mmc_set_ios(struct mmc *mmc)
317 {
318 	struct pxa_mmc_priv *priv = mmc->priv;
319 	struct pxa_mmc_regs *regs = priv->regs;
320 	uint32_t tmp;
321 	uint32_t pxa_mmc_clock;
322 
323 	if (!mmc->clock) {
324 		pxa_mmc_stop_clock(mmc);
325 		return 0;
326 	}
327 
328 	/* PXA3xx can do 26MHz with special settings. */
329 	if (mmc->clock == 26000000) {
330 		writel(0x7, &regs->clkrt);
331 		return 0;
332 	}
333 
334 	/* Set clock to the card the usual way. */
335 	pxa_mmc_clock = 0;
336 	tmp = mmc->cfg->f_max / mmc->clock;
337 	tmp += tmp % 2;
338 
339 	while (tmp > 1) {
340 		pxa_mmc_clock++;
341 		tmp >>= 1;
342 	}
343 
344 	writel(pxa_mmc_clock, &regs->clkrt);
345 
346 	return 0;
347 }
348 
349 static int pxa_mmc_init(struct mmc *mmc)
350 {
351 	struct pxa_mmc_priv *priv = mmc->priv;
352 	struct pxa_mmc_regs *regs = priv->regs;
353 
354 	/* Make sure the clock are stopped */
355 	pxa_mmc_stop_clock(mmc);
356 
357 	/* Turn off SPI mode */
358 	writel(0, &regs->spi);
359 
360 	/* Set up maximum timeout to wait for command response */
361 	writel(MMC_RES_TO_MAX_MASK, &regs->resto);
362 
363 	/* Mask all interrupts */
364 	writel(~(MMC_I_MASK_TXFIFO_WR_REQ | MMC_I_MASK_RXFIFO_RD_REQ),
365 		&regs->i_mask);
366 	return 0;
367 }
368 
369 static const struct mmc_ops pxa_mmc_ops = {
370 	.send_cmd	= pxa_mmc_request,
371 	.set_ios	= pxa_mmc_set_ios,
372 	.init		= pxa_mmc_init,
373 };
374 
375 static struct mmc_config pxa_mmc_cfg = {
376 	.name		= "PXA MMC",
377 	.ops		= &pxa_mmc_ops,
378 	.voltages	= MMC_VDD_32_33 | MMC_VDD_33_34,
379 	.f_max		= PXAMMC_MAX_SPEED,
380 	.f_min		= PXAMMC_MIN_SPEED,
381 	.host_caps	= PXAMMC_HOST_CAPS,
382 	.b_max		= CONFIG_SYS_MMC_MAX_BLK_COUNT,
383 };
384 
385 int pxa_mmc_register(int card_index)
386 {
387 	struct mmc *mmc;
388 	struct pxa_mmc_priv *priv;
389 	uint32_t reg;
390 	int ret = -ENOMEM;
391 
392 	priv = malloc(sizeof(struct pxa_mmc_priv));
393 	if (!priv)
394 		goto err0;
395 
396 	memset(priv, 0, sizeof(*priv));
397 
398 	switch (card_index) {
399 	case 0:
400 		priv->regs = (struct pxa_mmc_regs *)MMC0_BASE;
401 		break;
402 	case 1:
403 		priv->regs = (struct pxa_mmc_regs *)MMC1_BASE;
404 		break;
405 	default:
406 		ret = -EINVAL;
407 		printf("PXA MMC: Invalid MMC controller ID (card_index = %d)\n",
408 			card_index);
409 		goto err1;
410 	}
411 
412 #ifndef	CONFIG_CPU_MONAHANS	/* PXA2xx */
413 	reg = readl(CKEN);
414 	reg |= CKEN12_MMC;
415 	writel(reg, CKEN);
416 #else				/* PXA3xx */
417 	reg = readl(CKENA);
418 	reg |= CKENA_12_MMC0 | CKENA_13_MMC1;
419 	writel(reg, CKENA);
420 #endif
421 
422 	mmc = mmc_create(&pxa_mmc_cfg, priv);
423 	if (mmc == NULL)
424 		goto err1;
425 
426 	return 0;
427 
428 err1:
429 	free(priv);
430 err0:
431 	return ret;
432 }
433