xref: /openbmc/u-boot/drivers/mmc/mxsmmc.c (revision 4d764244)
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  * SPDX-License-Identifier:	GPL-2.0+
19  */
20 #include <common.h>
21 #include <malloc.h>
22 #include <mmc.h>
23 #include <asm/errno.h>
24 #include <asm/io.h>
25 #include <asm/arch/clock.h>
26 #include <asm/arch/imx-regs.h>
27 #include <asm/arch/sys_proto.h>
28 #include <asm/imx-common/dma.h>
29 #include <bouncebuf.h>
30 
31 struct mxsmmc_priv {
32 	int			id;
33 	struct mxs_ssp_regs	*regs;
34 	uint32_t		buswidth;
35 	int			(*mmc_is_wp)(int);
36 	int			(*mmc_cd)(int);
37 	struct mxs_dma_desc	*desc;
38 };
39 
40 #define	MXSMMC_MAX_TIMEOUT	10000
41 #define MXSMMC_SMALL_TRANSFER	512
42 
43 static int mxsmmc_cd(struct mxsmmc_priv *priv)
44 {
45 	struct mxs_ssp_regs *ssp_regs = priv->regs;
46 
47 	if (priv->mmc_cd)
48 		return priv->mmc_cd(priv->id);
49 
50 	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
51 }
52 
53 static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data)
54 {
55 	struct mxs_ssp_regs *ssp_regs = priv->regs;
56 	uint32_t *data_ptr;
57 	int timeout = MXSMMC_MAX_TIMEOUT;
58 	uint32_t reg;
59 	uint32_t data_count = data->blocksize * data->blocks;
60 
61 	if (data->flags & MMC_DATA_READ) {
62 		data_ptr = (uint32_t *)data->dest;
63 		while (data_count && --timeout) {
64 			reg = readl(&ssp_regs->hw_ssp_status);
65 			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
66 				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
67 				data_count -= 4;
68 				timeout = MXSMMC_MAX_TIMEOUT;
69 			} else
70 				udelay(1000);
71 		}
72 	} else {
73 		data_ptr = (uint32_t *)data->src;
74 		timeout *= 100;
75 		while (data_count && --timeout) {
76 			reg = readl(&ssp_regs->hw_ssp_status);
77 			if (!(reg & SSP_STATUS_FIFO_FULL)) {
78 				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
79 				data_count -= 4;
80 				timeout = MXSMMC_MAX_TIMEOUT;
81 			} else
82 				udelay(1000);
83 		}
84 	}
85 
86 	return timeout ? 0 : COMM_ERR;
87 }
88 
89 static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data)
90 {
91 	uint32_t data_count = data->blocksize * data->blocks;
92 	int dmach;
93 	struct mxs_dma_desc *desc = priv->desc;
94 	void *addr;
95 	unsigned int flags;
96 	struct bounce_buffer bbstate;
97 
98 	memset(desc, 0, sizeof(struct mxs_dma_desc));
99 	desc->address = (dma_addr_t)desc;
100 
101 	if (data->flags & MMC_DATA_READ) {
102 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
103 		addr = data->dest;
104 		flags = GEN_BB_WRITE;
105 	} else {
106 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
107 		addr = (void *)data->src;
108 		flags = GEN_BB_READ;
109 	}
110 
111 	bounce_buffer_start(&bbstate, addr, data_count, flags);
112 
113 	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;
114 
115 	priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
116 				(data_count << MXS_DMA_DESC_BYTES_OFFSET);
117 
118 	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id;
119 	mxs_dma_desc_append(dmach, priv->desc);
120 	if (mxs_dma_go(dmach)) {
121 		bounce_buffer_stop(&bbstate);
122 		return COMM_ERR;
123 	}
124 
125 	bounce_buffer_stop(&bbstate);
126 
127 	return 0;
128 }
129 
130 /*
131  * Sends a command out on the bus.  Takes the mmc pointer,
132  * a command pointer, and an optional data pointer.
133  */
134 static int
135 mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
136 {
137 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
138 	struct mxs_ssp_regs *ssp_regs = priv->regs;
139 	uint32_t reg;
140 	int timeout;
141 	uint32_t ctrl0;
142 	int ret;
143 
144 	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);
145 
146 	/* Check bus busy */
147 	timeout = MXSMMC_MAX_TIMEOUT;
148 	while (--timeout) {
149 		udelay(1000);
150 		reg = readl(&ssp_regs->hw_ssp_status);
151 		if (!(reg &
152 			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
153 			SSP_STATUS_CMD_BUSY))) {
154 			break;
155 		}
156 	}
157 
158 	if (!timeout) {
159 		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
160 		return TIMEOUT;
161 	}
162 
163 	/* See if card is present */
164 	if (!mxsmmc_cd(priv)) {
165 		printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
166 		return NO_CARD_ERR;
167 	}
168 
169 	/* Start building CTRL0 contents */
170 	ctrl0 = priv->buswidth;
171 
172 	/* Set up command */
173 	if (!(cmd->resp_type & MMC_RSP_CRC))
174 		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
175 	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
176 		ctrl0 |= SSP_CTRL0_GET_RESP;
177 	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
178 		ctrl0 |= SSP_CTRL0_LONG_RESP;
179 
180 	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
181 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
182 	else
183 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
184 
185 	/* Command index */
186 	reg = readl(&ssp_regs->hw_ssp_cmd0);
187 	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
188 	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
189 	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
190 		reg |= SSP_CMD0_APPEND_8CYC;
191 	writel(reg, &ssp_regs->hw_ssp_cmd0);
192 
193 	/* Command argument */
194 	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);
195 
196 	/* Set up data */
197 	if (data) {
198 		/* READ or WRITE */
199 		if (data->flags & MMC_DATA_READ) {
200 			ctrl0 |= SSP_CTRL0_READ;
201 		} else if (priv->mmc_is_wp &&
202 			priv->mmc_is_wp(mmc->block_dev.dev)) {
203 			printf("MMC%d: Can not write a locked card!\n",
204 				mmc->block_dev.dev);
205 			return UNUSABLE_ERR;
206 		}
207 
208 		ctrl0 |= SSP_CTRL0_DATA_XFER;
209 
210 		reg = data->blocksize * data->blocks;
211 #if defined(CONFIG_MX23)
212 		ctrl0 |= reg & SSP_CTRL0_XFER_COUNT_MASK;
213 
214 		clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
215 			SSP_CMD0_BLOCK_SIZE_MASK | SSP_CMD0_BLOCK_COUNT_MASK,
216 			((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) |
217 			((ffs(data->blocksize) - 1) <<
218 				SSP_CMD0_BLOCK_SIZE_OFFSET));
219 #elif defined(CONFIG_MX28)
220 		writel(reg, &ssp_regs->hw_ssp_xfer_size);
221 
222 		reg = ((data->blocks - 1) <<
223 			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
224 			((ffs(data->blocksize) - 1) <<
225 			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
226 		writel(reg, &ssp_regs->hw_ssp_block_size);
227 #endif
228 	}
229 
230 	/* Kick off the command */
231 	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
232 	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);
233 
234 	/* Wait for the command to complete */
235 	timeout = MXSMMC_MAX_TIMEOUT;
236 	while (--timeout) {
237 		udelay(1000);
238 		reg = readl(&ssp_regs->hw_ssp_status);
239 		if (!(reg & SSP_STATUS_CMD_BUSY))
240 			break;
241 	}
242 
243 	if (!timeout) {
244 		printf("MMC%d: Command %d busy\n",
245 			mmc->block_dev.dev, cmd->cmdidx);
246 		return TIMEOUT;
247 	}
248 
249 	/* Check command timeout */
250 	if (reg & SSP_STATUS_RESP_TIMEOUT) {
251 		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
252 			mmc->block_dev.dev, cmd->cmdidx, reg);
253 		return TIMEOUT;
254 	}
255 
256 	/* Check command errors */
257 	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
258 		printf("MMC%d: Command %d error (status 0x%08x)!\n",
259 			mmc->block_dev.dev, cmd->cmdidx, reg);
260 		return COMM_ERR;
261 	}
262 
263 	/* Copy response to response buffer */
264 	if (cmd->resp_type & MMC_RSP_136) {
265 		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
266 		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
267 		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
268 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
269 	} else
270 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);
271 
272 	/* Return if no data to process */
273 	if (!data)
274 		return 0;
275 
276 	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
277 		ret = mxsmmc_send_cmd_pio(priv, data);
278 		if (ret) {
279 			printf("MMC%d: Data timeout with command %d "
280 				"(status 0x%08x)!\n",
281 				mmc->block_dev.dev, cmd->cmdidx, reg);
282 			return ret;
283 		}
284 	} else {
285 		ret = mxsmmc_send_cmd_dma(priv, data);
286 		if (ret) {
287 			printf("MMC%d: DMA transfer failed\n",
288 				mmc->block_dev.dev);
289 			return ret;
290 		}
291 	}
292 
293 	/* Check data errors */
294 	reg = readl(&ssp_regs->hw_ssp_status);
295 	if (reg &
296 		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
297 		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
298 		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
299 			mmc->block_dev.dev, cmd->cmdidx, reg);
300 		return COMM_ERR;
301 	}
302 
303 	return 0;
304 }
305 
306 static void mxsmmc_set_ios(struct mmc *mmc)
307 {
308 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
309 	struct mxs_ssp_regs *ssp_regs = priv->regs;
310 
311 	/* Set the clock speed */
312 	if (mmc->clock)
313 		mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);
314 
315 	switch (mmc->bus_width) {
316 	case 1:
317 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
318 		break;
319 	case 4:
320 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
321 		break;
322 	case 8:
323 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
324 		break;
325 	}
326 
327 	/* Set the bus width */
328 	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
329 			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);
330 
331 	debug("MMC%d: Set %d bits bus width\n",
332 		mmc->block_dev.dev, mmc->bus_width);
333 }
334 
335 static int mxsmmc_init(struct mmc *mmc)
336 {
337 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
338 	struct mxs_ssp_regs *ssp_regs = priv->regs;
339 
340 	/* Reset SSP */
341 	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
342 
343 	/* Reconfigure the SSP block for MMC operation */
344 	writel(SSP_CTRL1_SSP_MODE_SD_MMC |
345 		SSP_CTRL1_WORD_LENGTH_EIGHT_BITS |
346 		SSP_CTRL1_DMA_ENABLE |
347 		SSP_CTRL1_POLARITY |
348 		SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
349 		SSP_CTRL1_DATA_CRC_IRQ_EN |
350 		SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
351 		SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
352 		SSP_CTRL1_RESP_ERR_IRQ_EN,
353 		&ssp_regs->hw_ssp_ctrl1_set);
354 
355 	/* Set initial bit clock 400 KHz */
356 	mxs_set_ssp_busclock(priv->id, 400);
357 
358 	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
359 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
360 	udelay(200);
361 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);
362 
363 	return 0;
364 }
365 
366 int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), int (*cd)(int))
367 {
368 	struct mmc *mmc = NULL;
369 	struct mxsmmc_priv *priv = NULL;
370 	int ret;
371 	const unsigned int mxsmmc_clk_id = mxs_ssp_clock_by_bus(id);
372 
373 	if (!mxs_ssp_bus_id_valid(id))
374 		return -ENODEV;
375 
376 	mmc = malloc(sizeof(struct mmc));
377 	if (!mmc)
378 		return -ENOMEM;
379 
380 	priv = malloc(sizeof(struct mxsmmc_priv));
381 	if (!priv) {
382 		free(mmc);
383 		return -ENOMEM;
384 	}
385 
386 	priv->desc = mxs_dma_desc_alloc();
387 	if (!priv->desc) {
388 		free(priv);
389 		free(mmc);
390 		return -ENOMEM;
391 	}
392 
393 	ret = mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + id);
394 	if (ret)
395 		return ret;
396 
397 	priv->mmc_is_wp = wp;
398 	priv->mmc_cd = cd;
399 	priv->id = id;
400 	priv->regs = mxs_ssp_regs_by_bus(id);
401 
402 	sprintf(mmc->name, "MXS MMC");
403 	mmc->send_cmd = mxsmmc_send_cmd;
404 	mmc->set_ios = mxsmmc_set_ios;
405 	mmc->init = mxsmmc_init;
406 	mmc->getcd = NULL;
407 	mmc->getwp = NULL;
408 	mmc->priv = priv;
409 
410 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
411 
412 	mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
413 			 MMC_MODE_HS_52MHz | MMC_MODE_HS |
414 			 MMC_MODE_HC;
415 
416 	/*
417 	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
418 	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
419 	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
420 	 * CLOCK_RATE could be any integer from 0 to 255.
421 	 */
422 	mmc->f_min = 400000;
423 	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
424 	mmc->b_max = 0x20;
425 
426 	mmc_register(mmc);
427 	return 0;
428 }
429