xref: /openbmc/u-boot/drivers/mmc/mxsmmc.c (revision b46694df)
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/imx-common/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 #define	MXSMMC_MAX_TIMEOUT	10000
57 #define MXSMMC_SMALL_TRANSFER	512
58 
59 static int mxsmmc_cd(struct mxsmmc_priv *priv)
60 {
61 	struct mxs_ssp_regs *ssp_regs = priv->regs;
62 
63 	if (priv->mmc_cd)
64 		return priv->mmc_cd(priv->id);
65 
66 	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
67 }
68 
69 static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data)
70 {
71 	struct mxs_ssp_regs *ssp_regs = priv->regs;
72 	uint32_t *data_ptr;
73 	int timeout = MXSMMC_MAX_TIMEOUT;
74 	uint32_t reg;
75 	uint32_t data_count = data->blocksize * data->blocks;
76 
77 	if (data->flags & MMC_DATA_READ) {
78 		data_ptr = (uint32_t *)data->dest;
79 		while (data_count && --timeout) {
80 			reg = readl(&ssp_regs->hw_ssp_status);
81 			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
82 				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
83 				data_count -= 4;
84 				timeout = MXSMMC_MAX_TIMEOUT;
85 			} else
86 				udelay(1000);
87 		}
88 	} else {
89 		data_ptr = (uint32_t *)data->src;
90 		timeout *= 100;
91 		while (data_count && --timeout) {
92 			reg = readl(&ssp_regs->hw_ssp_status);
93 			if (!(reg & SSP_STATUS_FIFO_FULL)) {
94 				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
95 				data_count -= 4;
96 				timeout = MXSMMC_MAX_TIMEOUT;
97 			} else
98 				udelay(1000);
99 		}
100 	}
101 
102 	return timeout ? 0 : COMM_ERR;
103 }
104 
105 static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data)
106 {
107 	uint32_t data_count = data->blocksize * data->blocks;
108 	int dmach;
109 	struct mxs_dma_desc *desc = priv->desc;
110 	void *addr;
111 	unsigned int flags;
112 	struct bounce_buffer bbstate;
113 
114 	memset(desc, 0, sizeof(struct mxs_dma_desc));
115 	desc->address = (dma_addr_t)desc;
116 
117 	if (data->flags & MMC_DATA_READ) {
118 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
119 		addr = data->dest;
120 		flags = GEN_BB_WRITE;
121 	} else {
122 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
123 		addr = (void *)data->src;
124 		flags = GEN_BB_READ;
125 	}
126 
127 	bounce_buffer_start(&bbstate, addr, data_count, flags);
128 
129 	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;
130 
131 	priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
132 				(data_count << MXS_DMA_DESC_BYTES_OFFSET);
133 
134 	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id;
135 	mxs_dma_desc_append(dmach, priv->desc);
136 	if (mxs_dma_go(dmach)) {
137 		bounce_buffer_stop(&bbstate);
138 		return COMM_ERR;
139 	}
140 
141 	bounce_buffer_stop(&bbstate);
142 
143 	return 0;
144 }
145 
146 /*
147  * Sends a command out on the bus.  Takes the mmc pointer,
148  * a command pointer, and an optional data pointer.
149  */
150 static int
151 mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
152 {
153 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
154 	struct mxs_ssp_regs *ssp_regs = priv->regs;
155 	uint32_t reg;
156 	int timeout;
157 	uint32_t ctrl0;
158 	int ret;
159 
160 	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);
161 
162 	/* Check bus busy */
163 	timeout = MXSMMC_MAX_TIMEOUT;
164 	while (--timeout) {
165 		udelay(1000);
166 		reg = readl(&ssp_regs->hw_ssp_status);
167 		if (!(reg &
168 			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
169 			SSP_STATUS_CMD_BUSY))) {
170 			break;
171 		}
172 	}
173 
174 	if (!timeout) {
175 		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
176 		return TIMEOUT;
177 	}
178 
179 	/* See if card is present */
180 	if (!mxsmmc_cd(priv)) {
181 		printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
182 		return NO_CARD_ERR;
183 	}
184 
185 	/* Start building CTRL0 contents */
186 	ctrl0 = priv->buswidth;
187 
188 	/* Set up command */
189 	if (!(cmd->resp_type & MMC_RSP_CRC))
190 		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
191 	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
192 		ctrl0 |= SSP_CTRL0_GET_RESP;
193 	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
194 		ctrl0 |= SSP_CTRL0_LONG_RESP;
195 
196 	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
197 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
198 	else
199 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
200 
201 	/* Command index */
202 	reg = readl(&ssp_regs->hw_ssp_cmd0);
203 	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
204 	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
205 	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
206 		reg |= SSP_CMD0_APPEND_8CYC;
207 	writel(reg, &ssp_regs->hw_ssp_cmd0);
208 
209 	/* Command argument */
210 	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);
211 
212 	/* Set up data */
213 	if (data) {
214 		/* READ or WRITE */
215 		if (data->flags & MMC_DATA_READ) {
216 			ctrl0 |= SSP_CTRL0_READ;
217 		} else if (priv->mmc_is_wp &&
218 			priv->mmc_is_wp(mmc->block_dev.dev)) {
219 			printf("MMC%d: Can not write a locked card!\n",
220 				mmc->block_dev.dev);
221 			return UNUSABLE_ERR;
222 		}
223 
224 		ctrl0 |= SSP_CTRL0_DATA_XFER;
225 
226 		reg = data->blocksize * data->blocks;
227 #if defined(CONFIG_MX23)
228 		ctrl0 |= reg & SSP_CTRL0_XFER_COUNT_MASK;
229 
230 		clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
231 			SSP_CMD0_BLOCK_SIZE_MASK | SSP_CMD0_BLOCK_COUNT_MASK,
232 			((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) |
233 			((ffs(data->blocksize) - 1) <<
234 				SSP_CMD0_BLOCK_SIZE_OFFSET));
235 #elif defined(CONFIG_MX28)
236 		writel(reg, &ssp_regs->hw_ssp_xfer_size);
237 
238 		reg = ((data->blocks - 1) <<
239 			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
240 			((ffs(data->blocksize) - 1) <<
241 			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
242 		writel(reg, &ssp_regs->hw_ssp_block_size);
243 #endif
244 	}
245 
246 	/* Kick off the command */
247 	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
248 	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);
249 
250 	/* Wait for the command to complete */
251 	timeout = MXSMMC_MAX_TIMEOUT;
252 	while (--timeout) {
253 		udelay(1000);
254 		reg = readl(&ssp_regs->hw_ssp_status);
255 		if (!(reg & SSP_STATUS_CMD_BUSY))
256 			break;
257 	}
258 
259 	if (!timeout) {
260 		printf("MMC%d: Command %d busy\n",
261 			mmc->block_dev.dev, cmd->cmdidx);
262 		return TIMEOUT;
263 	}
264 
265 	/* Check command timeout */
266 	if (reg & SSP_STATUS_RESP_TIMEOUT) {
267 		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
268 			mmc->block_dev.dev, cmd->cmdidx, reg);
269 		return TIMEOUT;
270 	}
271 
272 	/* Check command errors */
273 	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
274 		printf("MMC%d: Command %d error (status 0x%08x)!\n",
275 			mmc->block_dev.dev, cmd->cmdidx, reg);
276 		return COMM_ERR;
277 	}
278 
279 	/* Copy response to response buffer */
280 	if (cmd->resp_type & MMC_RSP_136) {
281 		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
282 		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
283 		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
284 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
285 	} else
286 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);
287 
288 	/* Return if no data to process */
289 	if (!data)
290 		return 0;
291 
292 	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
293 		ret = mxsmmc_send_cmd_pio(priv, data);
294 		if (ret) {
295 			printf("MMC%d: Data timeout with command %d "
296 				"(status 0x%08x)!\n",
297 				mmc->block_dev.dev, cmd->cmdidx, reg);
298 			return ret;
299 		}
300 	} else {
301 		ret = mxsmmc_send_cmd_dma(priv, data);
302 		if (ret) {
303 			printf("MMC%d: DMA transfer failed\n",
304 				mmc->block_dev.dev);
305 			return ret;
306 		}
307 	}
308 
309 	/* Check data errors */
310 	reg = readl(&ssp_regs->hw_ssp_status);
311 	if (reg &
312 		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
313 		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
314 		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
315 			mmc->block_dev.dev, cmd->cmdidx, reg);
316 		return COMM_ERR;
317 	}
318 
319 	return 0;
320 }
321 
322 static void mxsmmc_set_ios(struct mmc *mmc)
323 {
324 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
325 	struct mxs_ssp_regs *ssp_regs = priv->regs;
326 
327 	/* Set the clock speed */
328 	if (mmc->clock)
329 		mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);
330 
331 	switch (mmc->bus_width) {
332 	case 1:
333 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
334 		break;
335 	case 4:
336 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
337 		break;
338 	case 8:
339 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
340 		break;
341 	}
342 
343 	/* Set the bus width */
344 	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
345 			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);
346 
347 	debug("MMC%d: Set %d bits bus width\n",
348 		mmc->block_dev.dev, mmc->bus_width);
349 }
350 
351 static int mxsmmc_init(struct mmc *mmc)
352 {
353 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
354 	struct mxs_ssp_regs *ssp_regs = priv->regs;
355 
356 	/* Reset SSP */
357 	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
358 
359 	/* Reconfigure the SSP block for MMC operation */
360 	writel(SSP_CTRL1_SSP_MODE_SD_MMC |
361 		SSP_CTRL1_WORD_LENGTH_EIGHT_BITS |
362 		SSP_CTRL1_DMA_ENABLE |
363 		SSP_CTRL1_POLARITY |
364 		SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
365 		SSP_CTRL1_DATA_CRC_IRQ_EN |
366 		SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
367 		SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
368 		SSP_CTRL1_RESP_ERR_IRQ_EN,
369 		&ssp_regs->hw_ssp_ctrl1_set);
370 
371 	/* Set initial bit clock 400 KHz */
372 	mxs_set_ssp_busclock(priv->id, 400);
373 
374 	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
375 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
376 	udelay(200);
377 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);
378 
379 	return 0;
380 }
381 
382 int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), int (*cd)(int))
383 {
384 	struct mmc *mmc = NULL;
385 	struct mxsmmc_priv *priv = NULL;
386 	int ret;
387 	const unsigned int mxsmmc_clk_id = mxs_ssp_clock_by_bus(id);
388 
389 	if (!mxs_ssp_bus_id_valid(id))
390 		return -ENODEV;
391 
392 	mmc = malloc(sizeof(struct mmc));
393 	if (!mmc)
394 		return -ENOMEM;
395 
396 	priv = malloc(sizeof(struct mxsmmc_priv));
397 	if (!priv) {
398 		free(mmc);
399 		return -ENOMEM;
400 	}
401 
402 	priv->desc = mxs_dma_desc_alloc();
403 	if (!priv->desc) {
404 		free(priv);
405 		free(mmc);
406 		return -ENOMEM;
407 	}
408 
409 	ret = mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + id);
410 	if (ret)
411 		return ret;
412 
413 	priv->mmc_is_wp = wp;
414 	priv->mmc_cd = cd;
415 	priv->id = id;
416 	priv->regs = mxs_ssp_regs_by_bus(id);
417 
418 	sprintf(mmc->name, "MXS MMC");
419 	mmc->send_cmd = mxsmmc_send_cmd;
420 	mmc->set_ios = mxsmmc_set_ios;
421 	mmc->init = mxsmmc_init;
422 	mmc->getcd = NULL;
423 	mmc->getwp = NULL;
424 	mmc->priv = priv;
425 
426 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
427 
428 	mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
429 			 MMC_MODE_HS_52MHz | MMC_MODE_HS;
430 
431 	/*
432 	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
433 	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
434 	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
435 	 * CLOCK_RATE could be any integer from 0 to 255.
436 	 */
437 	mmc->f_min = 400000;
438 	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
439 	mmc->b_max = 0x20;
440 
441 	mmc_register(mmc);
442 	return 0;
443 }
444