xref: /openbmc/u-boot/drivers/mmc/mxsmmc.c (revision c9aa831e)
1 /*
2  * Freescale i.MX28 SSP MMC driver
3  *
4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
5  * on behalf of DENX Software Engineering GmbH
6  *
7  * Based on code from LTIB:
8  * (C) Copyright 2008-2010 Freescale Semiconductor, Inc.
9  * Terry Lv
10  *
11  * Copyright 2007, Freescale Semiconductor, Inc
12  * Andy Fleming
13  *
14  * Based vaguely on the pxa mmc code:
15  * (C) Copyright 2003
16  * Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
17  *
18  * See file CREDITS for list of people who contributed to this
19  * project.
20  *
21  * This program is free software; you can redistribute it and/or
22  * modify it under the terms of the GNU General Public License as
23  * published by the Free Software Foundation; either version 2 of
24  * the License, or (at your option) any later version.
25  *
26  * This program is distributed in the hope that it will be useful,
27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
29  * GNU General Public License for more details.
30  *
31  * You should have received a copy of the GNU General Public License
32  * along with this program; if not, write to the Free Software
33  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
34  * MA 02111-1307 USA
35  */
36 #include <common.h>
37 #include <malloc.h>
38 #include <mmc.h>
39 #include <asm/errno.h>
40 #include <asm/io.h>
41 #include <asm/arch/clock.h>
42 #include <asm/arch/imx-regs.h>
43 #include <asm/arch/sys_proto.h>
44 #include <asm/arch/dma.h>
45 #include <bouncebuf.h>
46 
47 struct mxsmmc_priv {
48 	int			id;
49 	struct mxs_ssp_regs	*regs;
50 	uint32_t		buswidth;
51 	int			(*mmc_is_wp)(int);
52 	int			(*mmc_cd)(int);
53 	struct mxs_dma_desc	*desc;
54 };
55 
56 #if defined(CONFIG_MX23)
57 static const unsigned int mxsmmc_id_offset = 1;
58 #elif defined(CONFIG_MX28)
59 static const unsigned int mxsmmc_id_offset = 0;
60 #endif
61 
62 #define	MXSMMC_MAX_TIMEOUT	10000
63 #define MXSMMC_SMALL_TRANSFER	512
64 
65 static int mxsmmc_cd(struct mxsmmc_priv *priv)
66 {
67 	struct mxs_ssp_regs *ssp_regs = priv->regs;
68 
69 	if (priv->mmc_cd)
70 		return priv->mmc_cd(priv->id);
71 
72 	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
73 }
74 
75 static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data)
76 {
77 	struct mxs_ssp_regs *ssp_regs = priv->regs;
78 	uint32_t *data_ptr;
79 	int timeout = MXSMMC_MAX_TIMEOUT;
80 	uint32_t reg;
81 	uint32_t data_count = data->blocksize * data->blocks;
82 
83 	if (data->flags & MMC_DATA_READ) {
84 		data_ptr = (uint32_t *)data->dest;
85 		while (data_count && --timeout) {
86 			reg = readl(&ssp_regs->hw_ssp_status);
87 			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
88 				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
89 				data_count -= 4;
90 				timeout = MXSMMC_MAX_TIMEOUT;
91 			} else
92 				udelay(1000);
93 		}
94 	} else {
95 		data_ptr = (uint32_t *)data->src;
96 		timeout *= 100;
97 		while (data_count && --timeout) {
98 			reg = readl(&ssp_regs->hw_ssp_status);
99 			if (!(reg & SSP_STATUS_FIFO_FULL)) {
100 				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
101 				data_count -= 4;
102 				timeout = MXSMMC_MAX_TIMEOUT;
103 			} else
104 				udelay(1000);
105 		}
106 	}
107 
108 	return timeout ? 0 : COMM_ERR;
109 }
110 
111 static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data)
112 {
113 	uint32_t data_count = data->blocksize * data->blocks;
114 	int dmach;
115 	struct mxs_dma_desc *desc = priv->desc;
116 	void *addr;
117 	unsigned int flags;
118 	struct bounce_buffer bbstate;
119 
120 	memset(desc, 0, sizeof(struct mxs_dma_desc));
121 	desc->address = (dma_addr_t)desc;
122 
123 	if (data->flags & MMC_DATA_READ) {
124 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
125 		addr = data->dest;
126 		flags = GEN_BB_WRITE;
127 	} else {
128 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
129 		addr = (void *)data->src;
130 		flags = GEN_BB_READ;
131 	}
132 
133 	bounce_buffer_start(&bbstate, addr, data_count, flags);
134 
135 	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;
136 
137 	priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
138 				(data_count << MXS_DMA_DESC_BYTES_OFFSET);
139 
140 	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id + mxsmmc_id_offset;
141 	mxs_dma_desc_append(dmach, priv->desc);
142 	if (mxs_dma_go(dmach)) {
143 		bounce_buffer_stop(&bbstate);
144 		return COMM_ERR;
145 	}
146 
147 	bounce_buffer_stop(&bbstate);
148 
149 	return 0;
150 }
151 
152 /*
153  * Sends a command out on the bus.  Takes the mmc pointer,
154  * a command pointer, and an optional data pointer.
155  */
156 static int
157 mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
158 {
159 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
160 	struct mxs_ssp_regs *ssp_regs = priv->regs;
161 	uint32_t reg;
162 	int timeout;
163 	uint32_t ctrl0;
164 	int ret;
165 
166 	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);
167 
168 	/* Check bus busy */
169 	timeout = MXSMMC_MAX_TIMEOUT;
170 	while (--timeout) {
171 		udelay(1000);
172 		reg = readl(&ssp_regs->hw_ssp_status);
173 		if (!(reg &
174 			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
175 			SSP_STATUS_CMD_BUSY))) {
176 			break;
177 		}
178 	}
179 
180 	if (!timeout) {
181 		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
182 		return TIMEOUT;
183 	}
184 
185 	/* See if card is present */
186 	if (!mxsmmc_cd(priv)) {
187 		printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
188 		return NO_CARD_ERR;
189 	}
190 
191 	/* Start building CTRL0 contents */
192 	ctrl0 = priv->buswidth;
193 
194 	/* Set up command */
195 	if (!(cmd->resp_type & MMC_RSP_CRC))
196 		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
197 	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
198 		ctrl0 |= SSP_CTRL0_GET_RESP;
199 	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
200 		ctrl0 |= SSP_CTRL0_LONG_RESP;
201 
202 	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
203 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
204 	else
205 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
206 
207 	/* Command index */
208 	reg = readl(&ssp_regs->hw_ssp_cmd0);
209 	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
210 	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
211 	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
212 		reg |= SSP_CMD0_APPEND_8CYC;
213 	writel(reg, &ssp_regs->hw_ssp_cmd0);
214 
215 	/* Command argument */
216 	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);
217 
218 	/* Set up data */
219 	if (data) {
220 		/* READ or WRITE */
221 		if (data->flags & MMC_DATA_READ) {
222 			ctrl0 |= SSP_CTRL0_READ;
223 		} else if (priv->mmc_is_wp &&
224 			priv->mmc_is_wp(mmc->block_dev.dev)) {
225 			printf("MMC%d: Can not write a locked card!\n",
226 				mmc->block_dev.dev);
227 			return UNUSABLE_ERR;
228 		}
229 
230 		ctrl0 |= SSP_CTRL0_DATA_XFER;
231 
232 		reg = data->blocksize * data->blocks;
233 #if defined(CONFIG_MX23)
234 		ctrl0 |= reg & SSP_CTRL0_XFER_COUNT_MASK;
235 
236 		clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
237 			SSP_CMD0_BLOCK_SIZE_MASK | SSP_CMD0_BLOCK_COUNT_MASK,
238 			((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) |
239 			((ffs(data->blocksize) - 1) <<
240 				SSP_CMD0_BLOCK_SIZE_OFFSET));
241 #elif defined(CONFIG_MX28)
242 		writel(reg, &ssp_regs->hw_ssp_xfer_size);
243 
244 		reg = ((data->blocks - 1) <<
245 			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
246 			((ffs(data->blocksize) - 1) <<
247 			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
248 		writel(reg, &ssp_regs->hw_ssp_block_size);
249 #endif
250 	}
251 
252 	/* Kick off the command */
253 	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
254 	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);
255 
256 	/* Wait for the command to complete */
257 	timeout = MXSMMC_MAX_TIMEOUT;
258 	while (--timeout) {
259 		udelay(1000);
260 		reg = readl(&ssp_regs->hw_ssp_status);
261 		if (!(reg & SSP_STATUS_CMD_BUSY))
262 			break;
263 	}
264 
265 	if (!timeout) {
266 		printf("MMC%d: Command %d busy\n",
267 			mmc->block_dev.dev, cmd->cmdidx);
268 		return TIMEOUT;
269 	}
270 
271 	/* Check command timeout */
272 	if (reg & SSP_STATUS_RESP_TIMEOUT) {
273 		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
274 			mmc->block_dev.dev, cmd->cmdidx, reg);
275 		return TIMEOUT;
276 	}
277 
278 	/* Check command errors */
279 	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
280 		printf("MMC%d: Command %d error (status 0x%08x)!\n",
281 			mmc->block_dev.dev, cmd->cmdidx, reg);
282 		return COMM_ERR;
283 	}
284 
285 	/* Copy response to response buffer */
286 	if (cmd->resp_type & MMC_RSP_136) {
287 		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
288 		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
289 		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
290 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
291 	} else
292 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);
293 
294 	/* Return if no data to process */
295 	if (!data)
296 		return 0;
297 
298 	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
299 		ret = mxsmmc_send_cmd_pio(priv, data);
300 		if (ret) {
301 			printf("MMC%d: Data timeout with command %d "
302 				"(status 0x%08x)!\n",
303 				mmc->block_dev.dev, cmd->cmdidx, reg);
304 			return ret;
305 		}
306 	} else {
307 		ret = mxsmmc_send_cmd_dma(priv, data);
308 		if (ret) {
309 			printf("MMC%d: DMA transfer failed\n",
310 				mmc->block_dev.dev);
311 			return ret;
312 		}
313 	}
314 
315 	/* Check data errors */
316 	reg = readl(&ssp_regs->hw_ssp_status);
317 	if (reg &
318 		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
319 		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
320 		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
321 			mmc->block_dev.dev, cmd->cmdidx, reg);
322 		return COMM_ERR;
323 	}
324 
325 	return 0;
326 }
327 
328 static void mxsmmc_set_ios(struct mmc *mmc)
329 {
330 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
331 	struct mxs_ssp_regs *ssp_regs = priv->regs;
332 
333 	/* Set the clock speed */
334 	if (mmc->clock)
335 		mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);
336 
337 	switch (mmc->bus_width) {
338 	case 1:
339 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
340 		break;
341 	case 4:
342 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
343 		break;
344 	case 8:
345 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
346 		break;
347 	}
348 
349 	/* Set the bus width */
350 	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
351 			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);
352 
353 	debug("MMC%d: Set %d bits bus width\n",
354 		mmc->block_dev.dev, mmc->bus_width);
355 }
356 
357 static int mxsmmc_init(struct mmc *mmc)
358 {
359 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
360 	struct mxs_ssp_regs *ssp_regs = priv->regs;
361 
362 	/* Reset SSP */
363 	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
364 
365 	/* Reconfigure the SSP block for MMC operation */
366 	writel(SSP_CTRL1_SSP_MODE_SD_MMC |
367 		SSP_CTRL1_WORD_LENGTH_EIGHT_BITS |
368 		SSP_CTRL1_DMA_ENABLE |
369 		SSP_CTRL1_POLARITY |
370 		SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
371 		SSP_CTRL1_DATA_CRC_IRQ_EN |
372 		SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
373 		SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
374 		SSP_CTRL1_RESP_ERR_IRQ_EN,
375 		&ssp_regs->hw_ssp_ctrl1_set);
376 
377 	/* Set initial bit clock 400 KHz */
378 	mxs_set_ssp_busclock(priv->id, 400);
379 
380 	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
381 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
382 	udelay(200);
383 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);
384 
385 	return 0;
386 }
387 
388 int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), int (*cd)(int))
389 {
390 	struct mmc *mmc = NULL;
391 	struct mxsmmc_priv *priv = NULL;
392 	int ret;
393 #if defined(CONFIG_MX23)
394 	const unsigned int mxsmmc_max_id = 2;
395 	const unsigned int mxsmmc_clk_id = 0;
396 #elif defined(CONFIG_MX28)
397 	const unsigned int mxsmmc_max_id = 4;
398 	const unsigned int mxsmmc_clk_id = id;
399 #endif
400 
401 	if (id >= mxsmmc_max_id)
402 		return -ENODEV;
403 
404 	mmc = malloc(sizeof(struct mmc));
405 	if (!mmc)
406 		return -ENOMEM;
407 
408 	priv = malloc(sizeof(struct mxsmmc_priv));
409 	if (!priv) {
410 		free(mmc);
411 		return -ENOMEM;
412 	}
413 
414 	priv->desc = mxs_dma_desc_alloc();
415 	if (!priv->desc) {
416 		free(priv);
417 		free(mmc);
418 		return -ENOMEM;
419 	}
420 
421 	ret = mxs_dma_init_channel(id + mxsmmc_id_offset);
422 	if (ret)
423 		return ret;
424 
425 	priv->mmc_is_wp = wp;
426 	priv->mmc_cd = cd;
427 	priv->id = id;
428 	priv->regs = mxs_ssp_regs_by_bus(id);
429 
430 	sprintf(mmc->name, "MXS MMC");
431 	mmc->send_cmd = mxsmmc_send_cmd;
432 	mmc->set_ios = mxsmmc_set_ios;
433 	mmc->init = mxsmmc_init;
434 	mmc->getcd = NULL;
435 	mmc->getwp = NULL;
436 	mmc->priv = priv;
437 
438 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
439 
440 	mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
441 			 MMC_MODE_HS_52MHz | MMC_MODE_HS;
442 
443 	/*
444 	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
445 	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
446 	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
447 	 * CLOCK_RATE could be any integer from 0 to 255.
448 	 */
449 	mmc->f_min = 400000;
450 	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
451 	mmc->b_max = 0x20;
452 
453 	mmc_register(mmc);
454 	return 0;
455 }
456