xref: /openbmc/u-boot/drivers/spi/cf_spi.c (revision e2a53458)
1 /*
2  *
3  * (C) Copyright 2000-2003
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  *
6  * Copyright (C) 2004-2009 Freescale Semiconductor, Inc.
7  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 #include <common.h>
29 #include <spi.h>
30 #include <malloc.h>
31 #include <asm/immap.h>
32 
33 struct cf_spi_slave {
34 	struct spi_slave slave;
35 	uint baudrate;
36 	int charbit;
37 };
38 
39 int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
40 	       void *din, ulong flags);
41 struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave, uint mode);
42 void cfspi_init(void);
43 void cfspi_tx(u32 ctrl, u16 data);
44 u16 cfspi_rx(void);
45 
46 extern void cfspi_port_conf(void);
47 extern int cfspi_claim_bus(uint bus, uint cs);
48 extern void cfspi_release_bus(uint bus, uint cs);
49 
50 DECLARE_GLOBAL_DATA_PTR;
51 
52 #ifndef CONFIG_SPI_IDLE_VAL
53 #if defined(CONFIG_SPI_MMC)
54 #define CONFIG_SPI_IDLE_VAL	0xFFFF
55 #else
56 #define CONFIG_SPI_IDLE_VAL	0x0
57 #endif
58 #endif
59 
60 #if defined(CONFIG_CF_DSPI)
61 /* DSPI specific mode */
62 #define SPI_MODE_MOD	0x00200000
63 #define SPI_DBLRATE	0x00100000
64 
65 void cfspi_init(void)
66 {
67 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
68 
69 	cfspi_port_conf();	/* port configuration */
70 
71 	dspi->mcr = DSPI_MCR_MSTR | DSPI_MCR_CSIS7 | DSPI_MCR_CSIS6 |
72 	    DSPI_MCR_CSIS5 | DSPI_MCR_CSIS4 | DSPI_MCR_CSIS3 |
73 	    DSPI_MCR_CSIS2 | DSPI_MCR_CSIS1 | DSPI_MCR_CSIS0 |
74 	    DSPI_MCR_CRXF | DSPI_MCR_CTXF;
75 
76 	/* Default setting in platform configuration */
77 #ifdef CONFIG_SYS_DSPI_CTAR0
78 	dspi->ctar[0] = CONFIG_SYS_DSPI_CTAR0;
79 #endif
80 #ifdef CONFIG_SYS_DSPI_CTAR1
81 	dspi->ctar[1] = CONFIG_SYS_DSPI_CTAR1;
82 #endif
83 #ifdef CONFIG_SYS_DSPI_CTAR2
84 	dspi->ctar[2] = CONFIG_SYS_DSPI_CTAR2;
85 #endif
86 #ifdef CONFIG_SYS_DSPI_CTAR3
87 	dspi->ctar[3] = CONFIG_SYS_DSPI_CTAR3;
88 #endif
89 #ifdef CONFIG_SYS_DSPI_CTAR4
90 	dspi->ctar[4] = CONFIG_SYS_DSPI_CTAR4;
91 #endif
92 #ifdef CONFIG_SYS_DSPI_CTAR5
93 	dspi->ctar[5] = CONFIG_SYS_DSPI_CTAR5;
94 #endif
95 #ifdef CONFIG_SYS_DSPI_CTAR6
96 	dspi->ctar[6] = CONFIG_SYS_DSPI_CTAR6;
97 #endif
98 #ifdef CONFIG_SYS_DSPI_CTAR7
99 	dspi->ctar[7] = CONFIG_SYS_DSPI_CTAR7;
100 #endif
101 }
102 
103 void cfspi_tx(u32 ctrl, u16 data)
104 {
105 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
106 
107 	while ((dspi->sr & 0x0000F000) >= 4) ;
108 
109 	dspi->tfr = (ctrl | data);
110 }
111 
112 u16 cfspi_rx(void)
113 {
114 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
115 
116 	while ((dspi->sr & 0x000000F0) == 0) ;
117 
118 	return (dspi->rfr & 0xFFFF);
119 }
120 
121 int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
122 	       void *din, ulong flags)
123 {
124 	struct cf_spi_slave *cfslave = (struct cf_spi_slave *)slave;
125 	u16 *spi_rd16 = NULL, *spi_wr16 = NULL;
126 	u8 *spi_rd = NULL, *spi_wr = NULL;
127 	static u32 ctrl = 0;
128 	uint len = bitlen >> 3;
129 
130 	if (cfslave->charbit == 16) {
131 		bitlen >>= 1;
132 		spi_wr16 = (u16 *) dout;
133 		spi_rd16 = (u16 *) din;
134 	} else {
135 		spi_wr = (u8 *) dout;
136 		spi_rd = (u8 *) din;
137 	}
138 
139 	if ((flags & SPI_XFER_BEGIN) == SPI_XFER_BEGIN)
140 		ctrl |= DSPI_TFR_CONT;
141 
142 	ctrl = (ctrl & 0xFF000000) | ((1 << slave->cs) << 16);
143 
144 	if (len > 1) {
145 		int tmp_len = len - 1;
146 		while (tmp_len--) {
147 			if (dout != NULL) {
148 				if (cfslave->charbit == 16)
149 					cfspi_tx(ctrl, *spi_wr16++);
150 				else
151 					cfspi_tx(ctrl, *spi_wr++);
152 				cfspi_rx();
153 			}
154 
155 			if (din != NULL) {
156 				cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
157 				if (cfslave->charbit == 16)
158 					*spi_rd16++ = cfspi_rx();
159 				else
160 					*spi_rd++ = cfspi_rx();
161 			}
162 		}
163 
164 		len = 1;	/* remaining byte */
165 	}
166 
167 	if ((flags & SPI_XFER_END) == SPI_XFER_END)
168 		ctrl &= ~DSPI_TFR_CONT;
169 
170 	if (len) {
171 		if (dout != NULL) {
172 			if (cfslave->charbit == 16)
173 				cfspi_tx(ctrl, *spi_wr16);
174 			else
175 				cfspi_tx(ctrl, *spi_wr);
176 			cfspi_rx();
177 		}
178 
179 		if (din != NULL) {
180 			cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
181 			if (cfslave->charbit == 16)
182 				*spi_rd16 = cfspi_rx();
183 			else
184 				*spi_rd = cfspi_rx();
185 		}
186 	} else {
187 		/* dummy read */
188 		cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
189 		cfspi_rx();
190 	}
191 
192 	return 0;
193 }
194 
195 struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave, uint mode)
196 {
197 	/*
198 	 * bit definition for mode:
199 	 * bit 31 - 28: Transfer size 3 to 16 bits
200 	 *     27 - 26: PCS to SCK delay prescaler
201 	 *     25 - 24: After SCK delay prescaler
202 	 *     23 - 22: Delay after transfer prescaler
203 	 *     21     : Allow overwrite for bit 31-22 and bit 20-8
204 	 *     20     : Double baud rate
205 	 *     19 - 16: PCS to SCK delay scaler
206 	 *     15 - 12: After SCK delay scaler
207 	 *     11 -  8: Delay after transfer scaler
208 	 *      7 -  0: SPI_CPHA, SPI_CPOL, SPI_LSB_FIRST
209 	 */
210 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
211 	int prescaler[] = { 2, 3, 5, 7 };
212 	int scaler[] = {
213 		2, 4, 6, 8,
214 		16, 32, 64, 128,
215 		256, 512, 1024, 2048,
216 		4096, 8192, 16384, 32768
217 	};
218 	int i, j, pbrcnt, brcnt, diff, tmp, dbr = 0;
219 	int best_i, best_j, bestmatch = 0x7FFFFFFF, baud_speed;
220 	u32 bus_setup = 0;
221 
222 	tmp = (prescaler[3] * scaler[15]);
223 	/* Maximum and minimum baudrate it can handle */
224 	if ((cfslave->baudrate > (gd->bus_clk >> 1)) ||
225 	    (cfslave->baudrate < (gd->bus_clk / tmp))) {
226 		printf("Exceed baudrate limitation: Max %d - Min %d\n",
227 		       (int)(gd->bus_clk >> 1), (int)(gd->bus_clk / tmp));
228 		return NULL;
229 	}
230 
231 	/* Activate Double Baud when it exceed 1/4 the bus clk */
232 	if ((CONFIG_SYS_DSPI_CTAR0 & DSPI_CTAR_DBR) ||
233 	    (cfslave->baudrate > (gd->bus_clk / (prescaler[0] * scaler[0])))) {
234 		bus_setup |= DSPI_CTAR_DBR;
235 		dbr = 1;
236 	}
237 
238 	if (mode & SPI_CPOL)
239 		bus_setup |= DSPI_CTAR_CPOL;
240 	if (mode & SPI_CPHA)
241 		bus_setup |= DSPI_CTAR_CPHA;
242 	if (mode & SPI_LSB_FIRST)
243 		bus_setup |= DSPI_CTAR_LSBFE;
244 
245 	/* Overwrite default value set in platform configuration file */
246 	if (mode & SPI_MODE_MOD) {
247 
248 		if ((mode & 0xF0000000) == 0)
249 			bus_setup |=
250 			    dspi->ctar[cfslave->slave.bus] & 0x78000000;
251 		else
252 			bus_setup |= ((mode & 0xF0000000) >> 1);
253 
254 		/*
255 		 * Check to see if it is enabled by default in platform
256 		 * config, or manual setting passed by mode parameter
257 		 */
258 		if (mode & SPI_DBLRATE) {
259 			bus_setup |= DSPI_CTAR_DBR;
260 			dbr = 1;
261 		}
262 		bus_setup |= (mode & 0x0FC00000) >> 4;	/* PSCSCK, PASC, PDT */
263 		bus_setup |= (mode & 0x000FFF00) >> 4;	/* CSSCK, ASC, DT */
264 	} else
265 		bus_setup |= (dspi->ctar[cfslave->slave.bus] & 0x78FCFFF0);
266 
267 	cfslave->charbit =
268 	    ((dspi->ctar[cfslave->slave.bus] & 0x78000000) ==
269 	     0x78000000) ? 16 : 8;
270 
271 	pbrcnt = sizeof(prescaler) / sizeof(int);
272 	brcnt = sizeof(scaler) / sizeof(int);
273 
274 	/* baudrate calculation - to closer value, may not be exact match */
275 	for (best_i = 0, best_j = 0, i = 0; i < pbrcnt; i++) {
276 		baud_speed = gd->bus_clk / prescaler[i];
277 		for (j = 0; j < brcnt; j++) {
278 			tmp = (baud_speed / scaler[j]) * (1 + dbr);
279 
280 			if (tmp > cfslave->baudrate)
281 				diff = tmp - cfslave->baudrate;
282 			else
283 				diff = cfslave->baudrate - tmp;
284 
285 			if (diff < bestmatch) {
286 				bestmatch = diff;
287 				best_i = i;
288 				best_j = j;
289 			}
290 		}
291 	}
292 	bus_setup |= (DSPI_CTAR_PBR(best_i) | DSPI_CTAR_BR(best_j));
293 	dspi->ctar[cfslave->slave.bus] = bus_setup;
294 
295 	return &cfslave->slave;
296 }
297 #endif				/* CONFIG_CF_DSPI */
298 
299 #ifdef CONFIG_CF_QSPI
300 /* 52xx, 53xx */
301 #endif				/* CONFIG_CF_QSPI */
302 
303 #ifdef CONFIG_CMD_SPI
304 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
305 {
306 	if (((cs >= 0) && (cs < 8)) && ((bus >= 0) && (bus < 8)))
307 		return 1;
308 	else
309 		return 0;
310 }
311 
312 void spi_init_f(void)
313 {
314 }
315 
316 void spi_init_r(void)
317 {
318 }
319 
320 void spi_init(void)
321 {
322 	cfspi_init();
323 }
324 
325 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
326 				  unsigned int max_hz, unsigned int mode)
327 {
328 	struct cf_spi_slave *cfslave;
329 
330 	if (!spi_cs_is_valid(bus, cs))
331 		return NULL;
332 
333 	cfslave = malloc(sizeof(struct cf_spi_slave));
334 	if (!cfslave)
335 		return NULL;
336 
337 	cfslave->slave.bus = bus;
338 	cfslave->slave.cs = cs;
339 	cfslave->baudrate = max_hz;
340 
341 	/* specific setup */
342 	return cfspi_setup_slave(cfslave, mode);
343 }
344 
345 void spi_free_slave(struct spi_slave *slave)
346 {
347 	free(slave);
348 }
349 
350 int spi_claim_bus(struct spi_slave *slave)
351 {
352 	return cfspi_claim_bus(slave->bus, slave->cs);
353 }
354 
355 void spi_release_bus(struct spi_slave *slave)
356 {
357 	cfspi_release_bus(slave->bus, slave->cs);
358 }
359 
360 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
361 	     void *din, unsigned long flags)
362 {
363 	return cfspi_xfer(slave, bitlen, dout, din, flags);
364 }
365 #endif				/* CONFIG_CMD_SPI */
366