xref: /openbmc/u-boot/drivers/mmc/mxsmmc.c (revision b24a8ec1)
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 <linux/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 	struct mmc_config	cfg;	/* mmc configuration */
39 };
40 
41 #define	MXSMMC_MAX_TIMEOUT	10000
42 #define MXSMMC_SMALL_TRANSFER	512
43 
44 static int mxsmmc_cd(struct mxsmmc_priv *priv)
45 {
46 	struct mxs_ssp_regs *ssp_regs = priv->regs;
47 
48 	if (priv->mmc_cd)
49 		return priv->mmc_cd(priv->id);
50 
51 	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
52 }
53 
54 static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data)
55 {
56 	struct mxs_ssp_regs *ssp_regs = priv->regs;
57 	uint32_t *data_ptr;
58 	int timeout = MXSMMC_MAX_TIMEOUT;
59 	uint32_t reg;
60 	uint32_t data_count = data->blocksize * data->blocks;
61 
62 	if (data->flags & MMC_DATA_READ) {
63 		data_ptr = (uint32_t *)data->dest;
64 		while (data_count && --timeout) {
65 			reg = readl(&ssp_regs->hw_ssp_status);
66 			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
67 				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
68 				data_count -= 4;
69 				timeout = MXSMMC_MAX_TIMEOUT;
70 			} else
71 				udelay(1000);
72 		}
73 	} else {
74 		data_ptr = (uint32_t *)data->src;
75 		timeout *= 100;
76 		while (data_count && --timeout) {
77 			reg = readl(&ssp_regs->hw_ssp_status);
78 			if (!(reg & SSP_STATUS_FIFO_FULL)) {
79 				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
80 				data_count -= 4;
81 				timeout = MXSMMC_MAX_TIMEOUT;
82 			} else
83 				udelay(1000);
84 		}
85 	}
86 
87 	return timeout ? 0 : -ECOMM;
88 }
89 
90 static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data)
91 {
92 	uint32_t data_count = data->blocksize * data->blocks;
93 	int dmach;
94 	struct mxs_dma_desc *desc = priv->desc;
95 	void *addr;
96 	unsigned int flags;
97 	struct bounce_buffer bbstate;
98 
99 	memset(desc, 0, sizeof(struct mxs_dma_desc));
100 	desc->address = (dma_addr_t)desc;
101 
102 	if (data->flags & MMC_DATA_READ) {
103 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
104 		addr = data->dest;
105 		flags = GEN_BB_WRITE;
106 	} else {
107 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
108 		addr = (void *)data->src;
109 		flags = GEN_BB_READ;
110 	}
111 
112 	bounce_buffer_start(&bbstate, addr, data_count, flags);
113 
114 	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;
115 
116 	priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
117 				(data_count << MXS_DMA_DESC_BYTES_OFFSET);
118 
119 	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id;
120 	mxs_dma_desc_append(dmach, priv->desc);
121 	if (mxs_dma_go(dmach)) {
122 		bounce_buffer_stop(&bbstate);
123 		return -ECOMM;
124 	}
125 
126 	bounce_buffer_stop(&bbstate);
127 
128 	return 0;
129 }
130 
131 /*
132  * Sends a command out on the bus.  Takes the mmc pointer,
133  * a command pointer, and an optional data pointer.
134  */
135 static int
136 mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
137 {
138 	struct mxsmmc_priv *priv = mmc->priv;
139 	struct mxs_ssp_regs *ssp_regs = priv->regs;
140 	uint32_t reg;
141 	int timeout;
142 	uint32_t ctrl0;
143 	int ret;
144 
145 	debug("MMC%d: CMD%d\n", mmc->block_dev.devnum, cmd->cmdidx);
146 
147 	/* Check bus busy */
148 	timeout = MXSMMC_MAX_TIMEOUT;
149 	while (--timeout) {
150 		udelay(1000);
151 		reg = readl(&ssp_regs->hw_ssp_status);
152 		if (!(reg &
153 			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
154 			SSP_STATUS_CMD_BUSY))) {
155 			break;
156 		}
157 	}
158 
159 	if (!timeout) {
160 		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.devnum);
161 		return -ETIMEDOUT;
162 	}
163 
164 	/* See if card is present */
165 	if (!mxsmmc_cd(priv)) {
166 		printf("MMC%d: No card detected!\n", mmc->block_dev.devnum);
167 		return -ENOMEDIUM;
168 	}
169 
170 	/* Start building CTRL0 contents */
171 	ctrl0 = priv->buswidth;
172 
173 	/* Set up command */
174 	if (!(cmd->resp_type & MMC_RSP_CRC))
175 		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
176 	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
177 		ctrl0 |= SSP_CTRL0_GET_RESP;
178 	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
179 		ctrl0 |= SSP_CTRL0_LONG_RESP;
180 
181 	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
182 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
183 	else
184 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
185 
186 	/* Command index */
187 	reg = readl(&ssp_regs->hw_ssp_cmd0);
188 	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
189 	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
190 	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
191 		reg |= SSP_CMD0_APPEND_8CYC;
192 	writel(reg, &ssp_regs->hw_ssp_cmd0);
193 
194 	/* Command argument */
195 	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);
196 
197 	/* Set up data */
198 	if (data) {
199 		/* READ or WRITE */
200 		if (data->flags & MMC_DATA_READ) {
201 			ctrl0 |= SSP_CTRL0_READ;
202 		} else if (priv->mmc_is_wp &&
203 			priv->mmc_is_wp(mmc->block_dev.devnum)) {
204 			printf("MMC%d: Can not write a locked card!\n",
205 				mmc->block_dev.devnum);
206 			return -EOPNOTSUPP;
207 		}
208 
209 		ctrl0 |= SSP_CTRL0_DATA_XFER;
210 
211 		reg = data->blocksize * data->blocks;
212 #if defined(CONFIG_MX23)
213 		ctrl0 |= reg & SSP_CTRL0_XFER_COUNT_MASK;
214 
215 		clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
216 			SSP_CMD0_BLOCK_SIZE_MASK | SSP_CMD0_BLOCK_COUNT_MASK,
217 			((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) |
218 			((ffs(data->blocksize) - 1) <<
219 				SSP_CMD0_BLOCK_SIZE_OFFSET));
220 #elif defined(CONFIG_MX28)
221 		writel(reg, &ssp_regs->hw_ssp_xfer_size);
222 
223 		reg = ((data->blocks - 1) <<
224 			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
225 			((ffs(data->blocksize) - 1) <<
226 			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
227 		writel(reg, &ssp_regs->hw_ssp_block_size);
228 #endif
229 	}
230 
231 	/* Kick off the command */
232 	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
233 	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);
234 
235 	/* Wait for the command to complete */
236 	timeout = MXSMMC_MAX_TIMEOUT;
237 	while (--timeout) {
238 		udelay(1000);
239 		reg = readl(&ssp_regs->hw_ssp_status);
240 		if (!(reg & SSP_STATUS_CMD_BUSY))
241 			break;
242 	}
243 
244 	if (!timeout) {
245 		printf("MMC%d: Command %d busy\n",
246 			mmc->block_dev.devnum, cmd->cmdidx);
247 		return -ETIMEDOUT;
248 	}
249 
250 	/* Check command timeout */
251 	if (reg & SSP_STATUS_RESP_TIMEOUT) {
252 		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
253 			mmc->block_dev.devnum, cmd->cmdidx, reg);
254 		return -ETIMEDOUT;
255 	}
256 
257 	/* Check command errors */
258 	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
259 		printf("MMC%d: Command %d error (status 0x%08x)!\n",
260 			mmc->block_dev.devnum, cmd->cmdidx, reg);
261 		return -ECOMM;
262 	}
263 
264 	/* Copy response to response buffer */
265 	if (cmd->resp_type & MMC_RSP_136) {
266 		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
267 		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
268 		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
269 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
270 	} else
271 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);
272 
273 	/* Return if no data to process */
274 	if (!data)
275 		return 0;
276 
277 	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
278 		ret = mxsmmc_send_cmd_pio(priv, data);
279 		if (ret) {
280 			printf("MMC%d: Data timeout with command %d "
281 				"(status 0x%08x)!\n",
282 				mmc->block_dev.devnum, cmd->cmdidx, reg);
283 			return ret;
284 		}
285 	} else {
286 		ret = mxsmmc_send_cmd_dma(priv, data);
287 		if (ret) {
288 			printf("MMC%d: DMA transfer failed\n",
289 				mmc->block_dev.devnum);
290 			return ret;
291 		}
292 	}
293 
294 	/* Check data errors */
295 	reg = readl(&ssp_regs->hw_ssp_status);
296 	if (reg &
297 		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
298 		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
299 		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
300 			mmc->block_dev.devnum, cmd->cmdidx, reg);
301 		return -ECOMM;
302 	}
303 
304 	return 0;
305 }
306 
307 static int mxsmmc_set_ios(struct mmc *mmc)
308 {
309 	struct mxsmmc_priv *priv = mmc->priv;
310 	struct mxs_ssp_regs *ssp_regs = priv->regs;
311 
312 	/* Set the clock speed */
313 	if (mmc->clock)
314 		mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);
315 
316 	switch (mmc->bus_width) {
317 	case 1:
318 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
319 		break;
320 	case 4:
321 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
322 		break;
323 	case 8:
324 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
325 		break;
326 	}
327 
328 	/* Set the bus width */
329 	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
330 			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);
331 
332 	debug("MMC%d: Set %d bits bus width\n",
333 		mmc->block_dev.devnum, mmc->bus_width);
334 
335 	return 0;
336 }
337 
338 static int mxsmmc_init(struct mmc *mmc)
339 {
340 	struct mxsmmc_priv *priv = mmc->priv;
341 	struct mxs_ssp_regs *ssp_regs = priv->regs;
342 
343 	/* Reset SSP */
344 	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
345 
346 	/* Reconfigure the SSP block for MMC operation */
347 	writel(SSP_CTRL1_SSP_MODE_SD_MMC |
348 		SSP_CTRL1_WORD_LENGTH_EIGHT_BITS |
349 		SSP_CTRL1_DMA_ENABLE |
350 		SSP_CTRL1_POLARITY |
351 		SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
352 		SSP_CTRL1_DATA_CRC_IRQ_EN |
353 		SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
354 		SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
355 		SSP_CTRL1_RESP_ERR_IRQ_EN,
356 		&ssp_regs->hw_ssp_ctrl1_set);
357 
358 	/* Set initial bit clock 400 KHz */
359 	mxs_set_ssp_busclock(priv->id, 400);
360 
361 	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
362 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
363 	udelay(200);
364 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);
365 
366 	return 0;
367 }
368 
369 static const struct mmc_ops mxsmmc_ops = {
370 	.send_cmd	= mxsmmc_send_cmd,
371 	.set_ios	= mxsmmc_set_ios,
372 	.init		= mxsmmc_init,
373 };
374 
375 int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), int (*cd)(int))
376 {
377 	struct mmc *mmc = NULL;
378 	struct mxsmmc_priv *priv = NULL;
379 	int ret;
380 	const unsigned int mxsmmc_clk_id = mxs_ssp_clock_by_bus(id);
381 
382 	if (!mxs_ssp_bus_id_valid(id))
383 		return -ENODEV;
384 
385 	priv = malloc(sizeof(struct mxsmmc_priv));
386 	if (!priv)
387 		return -ENOMEM;
388 
389 	priv->desc = mxs_dma_desc_alloc();
390 	if (!priv->desc) {
391 		free(priv);
392 		return -ENOMEM;
393 	}
394 
395 	ret = mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + id);
396 	if (ret)
397 		return ret;
398 
399 	priv->mmc_is_wp = wp;
400 	priv->mmc_cd = cd;
401 	priv->id = id;
402 	priv->regs = mxs_ssp_regs_by_bus(id);
403 
404 	priv->cfg.name = "MXS MMC";
405 	priv->cfg.ops = &mxsmmc_ops;
406 
407 	priv->cfg.voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
408 
409 	priv->cfg.host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
410 			 MMC_MODE_HS_52MHz | MMC_MODE_HS;
411 
412 	/*
413 	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
414 	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
415 	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
416 	 * CLOCK_RATE could be any integer from 0 to 255.
417 	 */
418 	priv->cfg.f_min = 400000;
419 	priv->cfg.f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
420 	priv->cfg.b_max = 0x20;
421 
422 	mmc = mmc_create(&priv->cfg, priv);
423 	if (mmc == NULL) {
424 		mxs_dma_desc_free(priv->desc);
425 		free(priv);
426 		return -ENOMEM;
427 	}
428 	return 0;
429 }
430