xref: /openbmc/u-boot/drivers/spi/fsl_espi.c (revision bf48fcb6)
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 = malloc(sizeof(struct fsl_spi_slave));
83 	if (!fsl)
84 		return NULL;
85 
86 	fsl->slave.bus = bus;
87 	fsl->slave.cs = cs;
88 	fsl->mode = mode;
89 	fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
90 
91 	/* Set eSPI BRG clock source */
92 	get_sys_info(&sysinfo);
93 	spibrg = sysinfo.freqSystemBus / 2;
94 	fsl->div16 = 0;
95 	if ((spibrg / max_hz) > 32) {
96 		fsl->div16 = ESPI_CSMODE_DIV16;
97 		pm = spibrg / (max_hz * 16 * 2);
98 		if (pm > 16) {
99 			pm = 16;
100 			debug("Requested speed is too low: %d Hz, %ld Hz "
101 				"is used.\n", max_hz, spibrg / (32 * 16));
102 		}
103 	} else
104 		pm = spibrg / (max_hz * 2);
105 	if (pm)
106 		pm--;
107 	fsl->pm = pm;
108 
109 	return &fsl->slave;
110 }
111 
112 void spi_free_slave(struct spi_slave *slave)
113 {
114 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
115 	free(fsl);
116 }
117 
118 void spi_init(void)
119 {
120 
121 }
122 
123 int spi_claim_bus(struct spi_slave *slave)
124 {
125 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
126 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
127 	unsigned char pm = fsl->pm;
128 	unsigned int cs = slave->cs;
129 	unsigned int mode =  fsl->mode;
130 	unsigned int div16 = fsl->div16;
131 	int i;
132 
133 	debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
134 
135 	/* Enable eSPI interface */
136 	out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
137 			| ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
138 
139 	out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
140 	out_be32(&espi->mask, 0x00000000); /* Mask  all eSPI interrupts */
141 
142 	/* Init CS mode interface */
143 	for (i = 0; i < ESPI_MAX_CS_NUM; i++)
144 		out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
145 
146 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
147 		~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
148 		| ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
149 		| ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
150 
151 	/* Set eSPI BRG clock source */
152 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
153 		| ESPI_CSMODE_PM(pm) | div16);
154 
155 	/* Set eSPI mode */
156 	if (mode & SPI_CPHA)
157 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
158 			| ESPI_CSMODE_CP_BEGIN_EDGCLK);
159 	if (mode & SPI_CPOL)
160 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
161 			| ESPI_CSMODE_CI_INACTIVEHIGH);
162 
163 	/* Character bit order: msb first */
164 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
165 		| ESPI_CSMODE_REV_MSB_FIRST);
166 
167 	/* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
168 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
169 		| ESPI_CSMODE_LEN(7));
170 
171 	return 0;
172 }
173 
174 void spi_release_bus(struct spi_slave *slave)
175 {
176 
177 }
178 
179 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
180 		void *data_in, unsigned long flags)
181 {
182 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
183 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
184 	unsigned int tmpdout, tmpdin, event;
185 	const void *dout = NULL;
186 	void *din = NULL;
187 	int len = 0;
188 	int num_blks, num_chunks, max_tran_len, tran_len;
189 	int num_bytes;
190 	unsigned char *ch;
191 	unsigned char *buffer = NULL;
192 	size_t buf_len;
193 	u8 *cmd_buf = fsl->cmd_buf;
194 	size_t cmd_len = fsl->cmd_len;
195 	size_t data_len = bitlen / 8;
196 	size_t rx_offset = 0;
197 
198 	max_tran_len = fsl->max_transfer_length;
199 	switch (flags) {
200 	case SPI_XFER_BEGIN:
201 		cmd_len = fsl->cmd_len = data_len;
202 		memcpy(cmd_buf, data_out, cmd_len);
203 		return 0;
204 	case 0:
205 	case SPI_XFER_END:
206 		if (bitlen == 0) {
207 			spi_cs_deactivate(slave);
208 			return 0;
209 		}
210 		buf_len = 2 * cmd_len + min(data_len, max_tran_len);
211 		len = cmd_len + data_len;
212 		rx_offset = cmd_len;
213 		buffer = (unsigned char *)malloc(buf_len);
214 		if (!buffer) {
215 			debug("SF: Failed to malloc memory.\n");
216 			return 1;
217 		}
218 		memcpy(buffer, cmd_buf, cmd_len);
219 		if (data_in == NULL)
220 			memcpy(buffer + cmd_len, data_out, data_len);
221 		break;
222 	case SPI_XFER_BEGIN | SPI_XFER_END:
223 		len = data_len;
224 		buffer = (unsigned char *)malloc(len * 2);
225 		if (!buffer) {
226 			debug("SF: Failed to malloc memory.\n");
227 			return 1;
228 		}
229 		memcpy(buffer, data_out, len);
230 		rx_offset = len;
231 		cmd_len = 0;
232 		break;
233 	}
234 
235 	debug("spi_xfer: slave %u:%u dout %08X(%p) din %08X(%p) len %u\n",
236 	      slave->bus, slave->cs, *(uint *) dout,
237 	      dout, *(uint *) din, din, len);
238 
239 	num_chunks = data_len / max_tran_len +
240 		(data_len % max_tran_len ? 1 : 0);
241 	while (num_chunks--) {
242 		if (data_in)
243 			din = buffer + rx_offset;
244 		dout = buffer;
245 		tran_len = min(data_len , max_tran_len);
246 		num_blks = (tran_len + cmd_len) / 4 +
247 			((tran_len + cmd_len) % 4 ? 1 : 0);
248 		num_bytes = (tran_len + cmd_len) % 4;
249 		fsl->data_len = tran_len + cmd_len;
250 		spi_cs_activate(slave);
251 
252 		/* Clear all eSPI events */
253 		out_be32(&espi->event , 0xffffffff);
254 		/* handle data in 32-bit chunks */
255 		while (num_blks--) {
256 
257 			event = in_be32(&espi->event);
258 			if (event & ESPI_EV_TNF) {
259 				tmpdout = *(u32 *)dout;
260 
261 				/* Set up the next iteration */
262 				if (len > 4) {
263 					len -= 4;
264 					dout += 4;
265 				}
266 
267 				out_be32(&espi->tx, tmpdout);
268 				out_be32(&espi->event, ESPI_EV_TNF);
269 				debug("***spi_xfer:...%08x written\n", tmpdout);
270 			}
271 
272 			/* Wait for eSPI transmit to get out */
273 			udelay(80);
274 
275 			event = in_be32(&espi->event);
276 			if (event & ESPI_EV_RNE) {
277 				tmpdin = in_be32(&espi->rx);
278 				if (num_blks == 0 && num_bytes != 0) {
279 					ch = (unsigned char *)&tmpdin;
280 					while (num_bytes--)
281 						*(unsigned char *)din++ = *ch++;
282 				} else {
283 					*(u32 *) din = tmpdin;
284 					din += 4;
285 				}
286 
287 				out_be32(&espi->event, in_be32(&espi->event)
288 						| ESPI_EV_RNE);
289 				debug("***spi_xfer:...%08x readed\n", tmpdin);
290 			}
291 		}
292 		if (data_in) {
293 			memcpy(data_in, buffer + 2 * cmd_len, tran_len);
294 			if (*buffer == 0x0b) {
295 				data_in += tran_len;
296 				data_len -= tran_len;
297 				*(int *)buffer += tran_len;
298 			}
299 		}
300 		spi_cs_deactivate(slave);
301 	}
302 
303 	free(buffer);
304 	return 0;
305 }
306 
307 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
308 {
309 	return bus == 0 && cs < ESPI_MAX_CS_NUM;
310 }
311 
312 void spi_cs_activate(struct spi_slave *slave)
313 {
314 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
315 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
316 	unsigned int com = 0;
317 	size_t data_len = fsl->data_len;
318 
319 	com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
320 	com |= ESPI_COM_CS(slave->cs);
321 	com |= ESPI_COM_TRANLEN(data_len - 1);
322 	out_be32(&espi->com, com);
323 }
324 
325 void spi_cs_deactivate(struct spi_slave *slave)
326 {
327 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
328 
329 	/* clear the RXCNT and TXCNT */
330 	out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
331 	out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
332 }
333