xref: /openbmc/u-boot/drivers/spi/fsl_espi.c (revision b46694df)
1 /*
2  * eSPI controller driver.
3  *
4  * Copyright 2010-2011 Freescale Semiconductor, Inc.
5  * Author: Mingkai Hu (Mingkai.hu@freescale.com)
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20  * MA 02111-1307 USA
21  */
22 
23 #include <common.h>
24 
25 #include <malloc.h>
26 #include <spi.h>
27 #include <asm/immap_85xx.h>
28 
29 struct fsl_spi_slave {
30 	struct spi_slave slave;
31 	unsigned int	div16;
32 	unsigned int	pm;
33 	unsigned int	mode;
34 	size_t		cmd_len;
35 	u8		cmd_buf[16];
36 	size_t		data_len;
37 	unsigned int    max_transfer_length;
38 };
39 
40 #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
41 
42 #define ESPI_MAX_CS_NUM		4
43 
44 #define ESPI_EV_RNE		(1 << 9)
45 #define ESPI_EV_TNF		(1 << 8)
46 
47 #define ESPI_MODE_EN		(1 << 31)	/* Enable interface */
48 #define ESPI_MODE_TXTHR(x)	((x) << 8)	/* Tx FIFO threshold */
49 #define ESPI_MODE_RXTHR(x)	((x) << 0)	/* Rx FIFO threshold */
50 
51 #define ESPI_COM_CS(x)		((x) << 30)
52 #define ESPI_COM_TRANLEN(x)	((x) << 0)
53 
54 #define ESPI_CSMODE_CI_INACTIVEHIGH	(1 << 31)
55 #define ESPI_CSMODE_CP_BEGIN_EDGCLK	(1 << 30)
56 #define ESPI_CSMODE_REV_MSB_FIRST	(1 << 29)
57 #define ESPI_CSMODE_DIV16		(1 << 28)
58 #define ESPI_CSMODE_PM(x)		((x) << 24)
59 #define ESPI_CSMODE_POL_ASSERTED_LOW	(1 << 20)
60 #define ESPI_CSMODE_LEN(x)		((x) << 16)
61 #define ESPI_CSMODE_CSBEF(x)		((x) << 12)
62 #define ESPI_CSMODE_CSAFT(x)		((x) << 8)
63 #define ESPI_CSMODE_CSCG(x)		((x) << 3)
64 
65 #define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
66 		ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
67 		ESPI_CSMODE_CSCG(1))
68 
69 #define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
70 
71 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
72 		unsigned int max_hz, unsigned int mode)
73 {
74 	struct fsl_spi_slave *fsl;
75 	sys_info_t sysinfo;
76 	unsigned long spibrg = 0;
77 	unsigned char pm = 0;
78 
79 	if (!spi_cs_is_valid(bus, cs))
80 		return NULL;
81 
82 	fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
83 	if (!fsl)
84 		return NULL;
85 
86 	fsl->mode = mode;
87 	fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
88 
89 	/* Set eSPI BRG clock source */
90 	get_sys_info(&sysinfo);
91 	spibrg = sysinfo.freqSystemBus / 2;
92 	fsl->div16 = 0;
93 	if ((spibrg / max_hz) > 32) {
94 		fsl->div16 = ESPI_CSMODE_DIV16;
95 		pm = spibrg / (max_hz * 16 * 2);
96 		if (pm > 16) {
97 			pm = 16;
98 			debug("Requested speed is too low: %d Hz, %ld Hz "
99 				"is used.\n", max_hz, spibrg / (32 * 16));
100 		}
101 	} else
102 		pm = spibrg / (max_hz * 2);
103 	if (pm)
104 		pm--;
105 	fsl->pm = pm;
106 
107 	return &fsl->slave;
108 }
109 
110 void spi_free_slave(struct spi_slave *slave)
111 {
112 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
113 	free(fsl);
114 }
115 
116 void spi_init(void)
117 {
118 
119 }
120 
121 int spi_claim_bus(struct spi_slave *slave)
122 {
123 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
124 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
125 	unsigned char pm = fsl->pm;
126 	unsigned int cs = slave->cs;
127 	unsigned int mode =  fsl->mode;
128 	unsigned int div16 = fsl->div16;
129 	int i;
130 
131 	debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
132 
133 	/* Enable eSPI interface */
134 	out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
135 			| ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
136 
137 	out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
138 	out_be32(&espi->mask, 0x00000000); /* Mask  all eSPI interrupts */
139 
140 	/* Init CS mode interface */
141 	for (i = 0; i < ESPI_MAX_CS_NUM; i++)
142 		out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
143 
144 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
145 		~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
146 		| ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
147 		| ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
148 
149 	/* Set eSPI BRG clock source */
150 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
151 		| ESPI_CSMODE_PM(pm) | div16);
152 
153 	/* Set eSPI mode */
154 	if (mode & SPI_CPHA)
155 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
156 			| ESPI_CSMODE_CP_BEGIN_EDGCLK);
157 	if (mode & SPI_CPOL)
158 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
159 			| ESPI_CSMODE_CI_INACTIVEHIGH);
160 
161 	/* Character bit order: msb first */
162 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
163 		| ESPI_CSMODE_REV_MSB_FIRST);
164 
165 	/* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
166 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
167 		| ESPI_CSMODE_LEN(7));
168 
169 	return 0;
170 }
171 
172 void spi_release_bus(struct spi_slave *slave)
173 {
174 
175 }
176 
177 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
178 		void *data_in, unsigned long flags)
179 {
180 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
181 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
182 	unsigned int tmpdout, tmpdin, event;
183 	const void *dout = NULL;
184 	void *din = NULL;
185 	int len = 0;
186 	int num_blks, num_chunks, max_tran_len, tran_len;
187 	int num_bytes;
188 	unsigned char *ch;
189 	unsigned char *buffer = NULL;
190 	size_t buf_len;
191 	u8 *cmd_buf = fsl->cmd_buf;
192 	size_t cmd_len = fsl->cmd_len;
193 	size_t data_len = bitlen / 8;
194 	size_t rx_offset = 0;
195 
196 	max_tran_len = fsl->max_transfer_length;
197 	switch (flags) {
198 	case SPI_XFER_BEGIN:
199 		cmd_len = fsl->cmd_len = data_len;
200 		memcpy(cmd_buf, data_out, cmd_len);
201 		return 0;
202 	case 0:
203 	case SPI_XFER_END:
204 		if (bitlen == 0) {
205 			spi_cs_deactivate(slave);
206 			return 0;
207 		}
208 		buf_len = 2 * cmd_len + min(data_len, max_tran_len);
209 		len = cmd_len + data_len;
210 		rx_offset = cmd_len;
211 		buffer = (unsigned char *)malloc(buf_len);
212 		if (!buffer) {
213 			debug("SF: Failed to malloc memory.\n");
214 			return 1;
215 		}
216 		memcpy(buffer, cmd_buf, cmd_len);
217 		if (data_in == NULL)
218 			memcpy(buffer + cmd_len, data_out, data_len);
219 		break;
220 	case SPI_XFER_BEGIN | SPI_XFER_END:
221 		len = data_len;
222 		buffer = (unsigned char *)malloc(len * 2);
223 		if (!buffer) {
224 			debug("SF: Failed to malloc memory.\n");
225 			return 1;
226 		}
227 		memcpy(buffer, data_out, len);
228 		rx_offset = len;
229 		cmd_len = 0;
230 		break;
231 	}
232 
233 	debug("spi_xfer: slave %u:%u dout %08X(%p) din %08X(%p) len %u\n",
234 	      slave->bus, slave->cs, *(uint *) dout,
235 	      dout, *(uint *) din, din, len);
236 
237 	num_chunks = data_len / max_tran_len +
238 		(data_len % max_tran_len ? 1 : 0);
239 	while (num_chunks--) {
240 		if (data_in)
241 			din = buffer + rx_offset;
242 		dout = buffer;
243 		tran_len = min(data_len , max_tran_len);
244 		num_blks = (tran_len + cmd_len) / 4 +
245 			((tran_len + cmd_len) % 4 ? 1 : 0);
246 		num_bytes = (tran_len + cmd_len) % 4;
247 		fsl->data_len = tran_len + cmd_len;
248 		spi_cs_activate(slave);
249 
250 		/* Clear all eSPI events */
251 		out_be32(&espi->event , 0xffffffff);
252 		/* handle data in 32-bit chunks */
253 		while (num_blks--) {
254 
255 			event = in_be32(&espi->event);
256 			if (event & ESPI_EV_TNF) {
257 				tmpdout = *(u32 *)dout;
258 
259 				/* Set up the next iteration */
260 				if (len > 4) {
261 					len -= 4;
262 					dout += 4;
263 				}
264 
265 				out_be32(&espi->tx, tmpdout);
266 				out_be32(&espi->event, ESPI_EV_TNF);
267 				debug("***spi_xfer:...%08x written\n", tmpdout);
268 			}
269 
270 			/* Wait for eSPI transmit to get out */
271 			udelay(80);
272 
273 			event = in_be32(&espi->event);
274 			if (event & ESPI_EV_RNE) {
275 				tmpdin = in_be32(&espi->rx);
276 				if (num_blks == 0 && num_bytes != 0) {
277 					ch = (unsigned char *)&tmpdin;
278 					while (num_bytes--)
279 						*(unsigned char *)din++ = *ch++;
280 				} else {
281 					*(u32 *) din = tmpdin;
282 					din += 4;
283 				}
284 
285 				out_be32(&espi->event, in_be32(&espi->event)
286 						| ESPI_EV_RNE);
287 				debug("***spi_xfer:...%08x readed\n", tmpdin);
288 			}
289 		}
290 		if (data_in) {
291 			memcpy(data_in, buffer + 2 * cmd_len, tran_len);
292 			if (*buffer == 0x0b) {
293 				data_in += tran_len;
294 				data_len -= tran_len;
295 				*(int *)buffer += tran_len;
296 			}
297 		}
298 		spi_cs_deactivate(slave);
299 	}
300 
301 	free(buffer);
302 	return 0;
303 }
304 
305 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
306 {
307 	return bus == 0 && cs < ESPI_MAX_CS_NUM;
308 }
309 
310 void spi_cs_activate(struct spi_slave *slave)
311 {
312 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
313 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
314 	unsigned int com = 0;
315 	size_t data_len = fsl->data_len;
316 
317 	com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
318 	com |= ESPI_COM_CS(slave->cs);
319 	com |= ESPI_COM_TRANLEN(data_len - 1);
320 	out_be32(&espi->com, com);
321 }
322 
323 void spi_cs_deactivate(struct spi_slave *slave)
324 {
325 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
326 
327 	/* clear the RXCNT and TXCNT */
328 	out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
329 	out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
330 }
331