xref: /openbmc/u-boot/drivers/mmc/mmc_spi.c (revision 274bced8)
1 /*
2  * generic mmc spi driver
3  *
4  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
5  * Licensed under the GPL-2 or later.
6  */
7 #include <common.h>
8 #include <errno.h>
9 #include <malloc.h>
10 #include <part.h>
11 #include <mmc.h>
12 #include <spi.h>
13 #include <crc.h>
14 #include <linux/crc7.h>
15 #include <asm/byteorder.h>
16 
17 /* MMC/SD in SPI mode reports R1 status always */
18 #define R1_SPI_IDLE		(1 << 0)
19 #define R1_SPI_ERASE_RESET	(1 << 1)
20 #define R1_SPI_ILLEGAL_COMMAND	(1 << 2)
21 #define R1_SPI_COM_CRC		(1 << 3)
22 #define R1_SPI_ERASE_SEQ	(1 << 4)
23 #define R1_SPI_ADDRESS		(1 << 5)
24 #define R1_SPI_PARAMETER	(1 << 6)
25 /* R1 bit 7 is always zero, reuse this bit for error */
26 #define R1_SPI_ERROR		(1 << 7)
27 
28 /* Response tokens used to ack each block written: */
29 #define SPI_MMC_RESPONSE_CODE(x)	((x) & 0x1f)
30 #define SPI_RESPONSE_ACCEPTED		((2 << 1)|1)
31 #define SPI_RESPONSE_CRC_ERR		((5 << 1)|1)
32 #define SPI_RESPONSE_WRITE_ERR		((6 << 1)|1)
33 
34 /* Read and write blocks start with these tokens and end with crc;
35  * on error, read tokens act like a subset of R2_SPI_* values.
36  */
37 #define SPI_TOKEN_SINGLE	0xfe	/* single block r/w, multiblock read */
38 #define SPI_TOKEN_MULTI_WRITE	0xfc	/* multiblock write */
39 #define SPI_TOKEN_STOP_TRAN	0xfd	/* terminate multiblock write */
40 
41 /* MMC SPI commands start with a start bit "0" and a transmit bit "1" */
42 #define MMC_SPI_CMD(x) (0x40 | (x & 0x3f))
43 
44 /* bus capability */
45 #define MMC_SPI_VOLTAGE (MMC_VDD_32_33 | MMC_VDD_33_34)
46 #define MMC_SPI_MIN_CLOCK 400000 /* 400KHz to meet MMC spec */
47 
48 /* timeout value */
49 #define CTOUT 8
50 #define RTOUT 3000000 /* 1 sec */
51 #define WTOUT 3000000 /* 1 sec */
52 
53 static uint mmc_spi_sendcmd(struct mmc *mmc, ushort cmdidx, u32 cmdarg)
54 {
55 	struct spi_slave *spi = mmc->priv;
56 	u8 cmdo[7];
57 	u8 r1;
58 	int i;
59 	cmdo[0] = 0xff;
60 	cmdo[1] = MMC_SPI_CMD(cmdidx);
61 	cmdo[2] = cmdarg >> 24;
62 	cmdo[3] = cmdarg >> 16;
63 	cmdo[4] = cmdarg >> 8;
64 	cmdo[5] = cmdarg;
65 	cmdo[6] = (crc7(0, &cmdo[1], 5) << 1) | 0x01;
66 	spi_xfer(spi, sizeof(cmdo) * 8, cmdo, NULL, 0);
67 	for (i = 0; i < CTOUT; i++) {
68 		spi_xfer(spi, 1 * 8, NULL, &r1, 0);
69 		if (i && (r1 & 0x80) == 0) /* r1 response */
70 			break;
71 	}
72 	debug("%s:cmd%d resp%d %x\n", __func__, cmdidx, i, r1);
73 	return r1;
74 }
75 
76 static uint mmc_spi_readdata(struct mmc *mmc, void *xbuf,
77 				u32 bcnt, u32 bsize)
78 {
79 	struct spi_slave *spi = mmc->priv;
80 	u8 *buf = xbuf;
81 	u8 r1;
82 	u16 crc;
83 	int i;
84 	while (bcnt--) {
85 		for (i = 0; i < RTOUT; i++) {
86 			spi_xfer(spi, 1 * 8, NULL, &r1, 0);
87 			if (r1 != 0xff) /* data token */
88 				break;
89 		}
90 		debug("%s:tok%d %x\n", __func__, i, r1);
91 		if (r1 == SPI_TOKEN_SINGLE) {
92 			spi_xfer(spi, bsize * 8, NULL, buf, 0);
93 			spi_xfer(spi, 2 * 8, NULL, &crc, 0);
94 #ifdef CONFIG_MMC_SPI_CRC_ON
95 			if (be_to_cpu16(crc16_ccitt(0, buf, bsize)) != crc) {
96 				debug("%s: CRC error\n", mmc->cfg->name);
97 				r1 = R1_SPI_COM_CRC;
98 				break;
99 			}
100 #endif
101 			r1 = 0;
102 		} else {
103 			r1 = R1_SPI_ERROR;
104 			break;
105 		}
106 		buf += bsize;
107 	}
108 	return r1;
109 }
110 
111 static uint mmc_spi_writedata(struct mmc *mmc, const void *xbuf,
112 			      u32 bcnt, u32 bsize, int multi)
113 {
114 	struct spi_slave *spi = mmc->priv;
115 	const u8 *buf = xbuf;
116 	u8 r1;
117 	u16 crc;
118 	u8 tok[2];
119 	int i;
120 	tok[0] = 0xff;
121 	tok[1] = multi ? SPI_TOKEN_MULTI_WRITE : SPI_TOKEN_SINGLE;
122 	while (bcnt--) {
123 #ifdef CONFIG_MMC_SPI_CRC_ON
124 		crc = cpu_to_be16(crc16_ccitt(0, (u8 *)buf, bsize));
125 #endif
126 		spi_xfer(spi, 2 * 8, tok, NULL, 0);
127 		spi_xfer(spi, bsize * 8, buf, NULL, 0);
128 		spi_xfer(spi, 2 * 8, &crc, NULL, 0);
129 		for (i = 0; i < CTOUT; i++) {
130 			spi_xfer(spi, 1 * 8, NULL, &r1, 0);
131 			if ((r1 & 0x10) == 0) /* response token */
132 				break;
133 		}
134 		debug("%s:tok%d %x\n", __func__, i, r1);
135 		if (SPI_MMC_RESPONSE_CODE(r1) == SPI_RESPONSE_ACCEPTED) {
136 			for (i = 0; i < WTOUT; i++) { /* wait busy */
137 				spi_xfer(spi, 1 * 8, NULL, &r1, 0);
138 				if (i && r1 == 0xff) {
139 					r1 = 0;
140 					break;
141 				}
142 			}
143 			if (i == WTOUT) {
144 				debug("%s:wtout %x\n", __func__, r1);
145 				r1 = R1_SPI_ERROR;
146 				break;
147 			}
148 		} else {
149 			debug("%s: err %x\n", __func__, r1);
150 			r1 = R1_SPI_COM_CRC;
151 			break;
152 		}
153 		buf += bsize;
154 	}
155 	if (multi && bcnt == -1) { /* stop multi write */
156 		tok[1] = SPI_TOKEN_STOP_TRAN;
157 		spi_xfer(spi, 2 * 8, tok, NULL, 0);
158 		for (i = 0; i < WTOUT; i++) { /* wait busy */
159 			spi_xfer(spi, 1 * 8, NULL, &r1, 0);
160 			if (i && r1 == 0xff) {
161 				r1 = 0;
162 				break;
163 			}
164 		}
165 		if (i == WTOUT) {
166 			debug("%s:wstop %x\n", __func__, r1);
167 			r1 = R1_SPI_ERROR;
168 		}
169 	}
170 	return r1;
171 }
172 
173 static int mmc_spi_request(struct mmc *mmc, struct mmc_cmd *cmd,
174 		struct mmc_data *data)
175 {
176 	struct spi_slave *spi = mmc->priv;
177 	u8 r1;
178 	int i;
179 	int ret = 0;
180 	debug("%s:cmd%d %x %x\n", __func__,
181 	      cmd->cmdidx, cmd->resp_type, cmd->cmdarg);
182 	spi_claim_bus(spi);
183 	spi_cs_activate(spi);
184 	r1 = mmc_spi_sendcmd(mmc, cmd->cmdidx, cmd->cmdarg);
185 	if (r1 == 0xff) { /* no response */
186 		ret = -ENOMEDIUM;
187 		goto done;
188 	} else if (r1 & R1_SPI_COM_CRC) {
189 		ret = -ECOMM;
190 		goto done;
191 	} else if (r1 & ~R1_SPI_IDLE) { /* other errors */
192 		ret = -ETIMEDOUT;
193 		goto done;
194 	} else if (cmd->resp_type == MMC_RSP_R2) {
195 		r1 = mmc_spi_readdata(mmc, cmd->response, 1, 16);
196 		for (i = 0; i < 4; i++)
197 			cmd->response[i] = be32_to_cpu(cmd->response[i]);
198 		debug("r128 %x %x %x %x\n", cmd->response[0], cmd->response[1],
199 		      cmd->response[2], cmd->response[3]);
200 	} else if (!data) {
201 		switch (cmd->cmdidx) {
202 		case SD_CMD_APP_SEND_OP_COND:
203 		case MMC_CMD_SEND_OP_COND:
204 			cmd->response[0] = (r1 & R1_SPI_IDLE) ? 0 : OCR_BUSY;
205 			break;
206 		case SD_CMD_SEND_IF_COND:
207 		case MMC_CMD_SPI_READ_OCR:
208 			spi_xfer(spi, 4 * 8, NULL, cmd->response, 0);
209 			cmd->response[0] = be32_to_cpu(cmd->response[0]);
210 			debug("r32 %x\n", cmd->response[0]);
211 			break;
212 		case MMC_CMD_SEND_STATUS:
213 			spi_xfer(spi, 1 * 8, NULL, cmd->response, 0);
214 			cmd->response[0] = (cmd->response[0] & 0xff) ?
215 				MMC_STATUS_ERROR : MMC_STATUS_RDY_FOR_DATA;
216 			break;
217 		}
218 	} else {
219 		debug("%s:data %x %x %x\n", __func__,
220 		      data->flags, data->blocks, data->blocksize);
221 		if (data->flags == MMC_DATA_READ)
222 			r1 = mmc_spi_readdata(mmc, data->dest,
223 				data->blocks, data->blocksize);
224 		else if  (data->flags == MMC_DATA_WRITE)
225 			r1 = mmc_spi_writedata(mmc, data->src,
226 				data->blocks, data->blocksize,
227 				(cmd->cmdidx == MMC_CMD_WRITE_MULTIPLE_BLOCK));
228 		if (r1 & R1_SPI_COM_CRC)
229 			ret = -ECOMM;
230 		else if (r1) /* other errors */
231 			ret = -ETIMEDOUT;
232 	}
233 done:
234 	spi_cs_deactivate(spi);
235 	spi_release_bus(spi);
236 	return ret;
237 }
238 
239 static int mmc_spi_set_ios(struct mmc *mmc)
240 {
241 	struct spi_slave *spi = mmc->priv;
242 
243 	debug("%s: clock %u\n", __func__, mmc->clock);
244 	if (mmc->clock)
245 		spi_set_speed(spi, mmc->clock);
246 	return 0;
247 }
248 
249 static int mmc_spi_init_p(struct mmc *mmc)
250 {
251 	struct spi_slave *spi = mmc->priv;
252 	spi_set_speed(spi, MMC_SPI_MIN_CLOCK);
253 	spi_claim_bus(spi);
254 	/* cs deactivated for 100+ clock */
255 	spi_xfer(spi, 18 * 8, NULL, NULL, 0);
256 	spi_release_bus(spi);
257 	return 0;
258 }
259 
260 static const struct mmc_ops mmc_spi_ops = {
261 	.send_cmd	= mmc_spi_request,
262 	.set_ios	= mmc_spi_set_ios,
263 	.init		= mmc_spi_init_p,
264 };
265 
266 static struct mmc_config mmc_spi_cfg = {
267 	.name		= "MMC_SPI",
268 	.ops		= &mmc_spi_ops,
269 	.host_caps	= MMC_MODE_SPI,
270 	.voltages	= MMC_SPI_VOLTAGE,
271 	.f_min		= MMC_SPI_MIN_CLOCK,
272 	.part_type	= PART_TYPE_DOS,
273 	.b_max		= CONFIG_SYS_MMC_MAX_BLK_COUNT,
274 };
275 
276 struct mmc *mmc_spi_init(uint bus, uint cs, uint speed, uint mode)
277 {
278 	struct mmc *mmc;
279 	struct spi_slave *spi;
280 
281 	spi = spi_setup_slave(bus, cs, speed, mode);
282 	if (spi == NULL)
283 		return NULL;
284 
285 	mmc_spi_cfg.f_max = speed;
286 
287 	mmc = mmc_create(&mmc_spi_cfg, spi);
288 	if (mmc == NULL) {
289 		spi_free_slave(spi);
290 		return NULL;
291 	}
292 	return mmc;
293 }
294