xref: /openbmc/u-boot/drivers/spi/cf_spi.c (revision 15855700)
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 #if defined(CONFIG_CF_DSPI)
53 /* DSPI specific mode */
54 #define SPI_MODE_MOD	0x00200000
55 #define SPI_DBLRATE	0x00100000
56 
57 void cfspi_init(void)
58 {
59 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
60 
61 	cfspi_port_conf();	/* port configuration */
62 
63 	dspi->mcr = DSPI_MCR_MSTR | DSPI_MCR_CSIS7 | DSPI_MCR_CSIS6 |
64 	    DSPI_MCR_CSIS5 | DSPI_MCR_CSIS4 | DSPI_MCR_CSIS3 |
65 	    DSPI_MCR_CSIS2 | DSPI_MCR_CSIS1 | DSPI_MCR_CSIS0 |
66 	    DSPI_MCR_CRXF | DSPI_MCR_CTXF;
67 
68 	/* Default setting in platform configuration */
69 #ifdef CONFIG_SYS_DSPI_CTAR0
70 	dspi->ctar[0] = CONFIG_SYS_DSPI_CTAR0;
71 #endif
72 #ifdef CONFIG_SYS_DSPI_CTAR1
73 	dspi->ctar[1] = CONFIG_SYS_DSPI_CTAR1;
74 #endif
75 #ifdef CONFIG_SYS_DSPI_CTAR2
76 	dspi->ctar[2] = CONFIG_SYS_DSPI_CTAR2;
77 #endif
78 #ifdef CONFIG_SYS_DSPI_CTAR3
79 	dspi->ctar[3] = CONFIG_SYS_DSPI_CTAR3;
80 #endif
81 #ifdef CONFIG_SYS_DSPI_CTAR4
82 	dspi->ctar[4] = CONFIG_SYS_DSPI_CTAR4;
83 #endif
84 #ifdef CONFIG_SYS_DSPI_CTAR5
85 	dspi->ctar[5] = CONFIG_SYS_DSPI_CTAR5;
86 #endif
87 #ifdef CONFIG_SYS_DSPI_CTAR6
88 	dspi->ctar[6] = CONFIG_SYS_DSPI_CTAR6;
89 #endif
90 #ifdef CONFIG_SYS_DSPI_CTAR7
91 	dspi->ctar[7] = CONFIG_SYS_DSPI_CTAR7;
92 #endif
93 }
94 
95 void cfspi_tx(u32 ctrl, u16 data)
96 {
97 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
98 
99 	while ((dspi->sr & 0x0000F000) >= 4) ;
100 
101 	dspi->tfr = (ctrl | data);
102 }
103 
104 u16 cfspi_rx(void)
105 {
106 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
107 
108 	while ((dspi->sr & 0x000000F0) == 0) ;
109 
110 	return (dspi->rfr & 0xFFFF);
111 }
112 
113 int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
114 	       void *din, ulong flags)
115 {
116 	struct cf_spi_slave *cfslave = (struct cf_spi_slave *)slave;
117 	u16 *spi_rd16 = NULL, *spi_wr16 = NULL;
118 	u8 *spi_rd = NULL, *spi_wr = NULL;
119 	static u32 ctrl = 0;
120 	uint len = bitlen >> 3;
121 
122 	if (cfslave->charbit == 16) {
123 		bitlen >>= 1;
124 		spi_wr16 = (u16 *) dout;
125 		spi_rd16 = (u16 *) din;
126 	} else {
127 		spi_wr = (u8 *) dout;
128 		spi_rd = (u8 *) din;
129 	}
130 
131 	if ((flags & SPI_XFER_BEGIN) == SPI_XFER_BEGIN)
132 		ctrl |= DSPI_TFR_CONT;
133 
134 	ctrl = (ctrl & 0xFF000000) | ((1 << slave->cs) << 16);
135 
136 	if (len > 1) {
137 		int tmp_len = len - 1;
138 		while (tmp_len--) {
139 			if (dout != NULL) {
140 				if (cfslave->charbit == 16)
141 					cfspi_tx(ctrl, *spi_wr16++);
142 				else
143 					cfspi_tx(ctrl, *spi_wr++);
144 				cfspi_rx();
145 			}
146 
147 			if (din != NULL) {
148 				cfspi_tx(ctrl, 0);
149 				if (cfslave->charbit == 16)
150 					*spi_rd16++ = cfspi_rx();
151 				else
152 					*spi_rd++ = cfspi_rx();
153 			}
154 		}
155 
156 		len = 1;	/* remaining byte */
157 	}
158 
159 	if ((flags & SPI_XFER_END) == SPI_XFER_END)
160 		ctrl &= ~DSPI_TFR_CONT;
161 
162 	if (len) {
163 		if (dout != NULL) {
164 			if (cfslave->charbit == 16)
165 				cfspi_tx(ctrl, *spi_wr16);
166 			else
167 				cfspi_tx(ctrl, *spi_wr);
168 			cfspi_rx();
169 		}
170 
171 		if (din != NULL) {
172 			cfspi_tx(ctrl, 0);
173 			if (cfslave->charbit == 16)
174 				*spi_rd16 = cfspi_rx();
175 			else
176 				*spi_rd = cfspi_rx();
177 		}
178 	} else {
179 		/* dummy read */
180 		cfspi_tx(ctrl, 0);
181 		cfspi_rx();
182 	}
183 
184 	return 0;
185 }
186 
187 struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave, uint mode)
188 {
189 	/*
190 	 * bit definition for mode:
191 	 * bit 31 - 28: Transfer size 3 to 16 bits
192 	 *     27 - 26: PCS to SCK delay prescaler
193 	 *     25 - 24: After SCK delay prescaler
194 	 *     23 - 22: Delay after transfer prescaler
195 	 *     21     : Allow overwrite for bit 31-22 and bit 20-8
196 	 *     20     : Double baud rate
197 	 *     19 - 16: PCS to SCK delay scaler
198 	 *     15 - 12: After SCK delay scaler
199 	 *     11 -  8: Delay after transfer scaler
200 	 *      7 -  0: SPI_CPHA, SPI_CPOL, SPI_LSB_FIRST
201 	 */
202 	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
203 	int prescaler[] = { 2, 3, 5, 7 };
204 	int scaler[] = {
205 		2, 4, 6, 8,
206 		16, 32, 64, 128,
207 		256, 512, 1024, 2048,
208 		4096, 8192, 16384, 32768
209 	};
210 	int i, j, pbrcnt, brcnt, diff, tmp, dbr = 0;
211 	int best_i, best_j, bestmatch = 0x7FFFFFFF, baud_speed;
212 	u32 bus_setup = 0;
213 
214 	tmp = (prescaler[3] * scaler[15]);
215 	/* Maximum and minimum baudrate it can handle */
216 	if ((cfslave->baudrate > (gd->bus_clk >> 1)) ||
217 	    (cfslave->baudrate < (gd->bus_clk / tmp))) {
218 		printf("Exceed baudrate limitation: Max %d - Min %d\n",
219 		       (int)(gd->bus_clk >> 1), (int)(gd->bus_clk / tmp));
220 		return NULL;
221 	}
222 
223 	/* Activate Double Baud when it exceed 1/4 the bus clk */
224 	if ((CONFIG_SYS_DSPI_CTAR0 & DSPI_CTAR_DBR) ||
225 	    (cfslave->baudrate > (gd->bus_clk / (prescaler[0] * scaler[0])))) {
226 		bus_setup |= DSPI_CTAR_DBR;
227 		dbr = 1;
228 	}
229 
230 	if (mode & SPI_CPOL)
231 		bus_setup |= DSPI_CTAR_CPOL;
232 	if (mode & SPI_CPHA)
233 		bus_setup |= DSPI_CTAR_CPHA;
234 	if (mode & SPI_LSB_FIRST)
235 		bus_setup |= DSPI_CTAR_LSBFE;
236 
237 	/* Overwrite default value set in platform configuration file */
238 	if (mode & SPI_MODE_MOD) {
239 
240 		if ((mode & 0xF0000000) == 0)
241 			bus_setup |=
242 			    dspi->ctar[cfslave->slave.bus] & 0x78000000;
243 		else
244 			bus_setup |= ((mode & 0xF0000000) >> 1);
245 
246 		/*
247 		 * Check to see if it is enabled by default in platform
248 		 * config, or manual setting passed by mode parameter
249 		 */
250 		if (mode & SPI_DBLRATE) {
251 			bus_setup |= DSPI_CTAR_DBR;
252 			dbr = 1;
253 		}
254 		bus_setup |= (mode & 0x0FC00000) >> 4;	/* PSCSCK, PASC, PDT */
255 		bus_setup |= (mode & 0x000FFF00) >> 4;	/* CSSCK, ASC, DT */
256 	} else
257 		bus_setup |= (dspi->ctar[cfslave->slave.bus] & 0x78FCFFF0);
258 
259 	cfslave->charbit =
260 	    ((dspi->ctar[cfslave->slave.bus] & 0x78000000) ==
261 	     0x78000000) ? 16 : 8;
262 
263 	pbrcnt = sizeof(prescaler) / sizeof(int);
264 	brcnt = sizeof(scaler) / sizeof(int);
265 
266 	/* baudrate calculation - to closer value, may not be exact match */
267 	for (best_i = 0, best_j = 0, i = 0; i < pbrcnt; i++) {
268 		baud_speed = gd->bus_clk / prescaler[i];
269 		for (j = 0; j < brcnt; j++) {
270 			tmp = (baud_speed / scaler[j]) * (1 + dbr);
271 
272 			if (tmp > cfslave->baudrate)
273 				diff = tmp - cfslave->baudrate;
274 			else
275 				diff = cfslave->baudrate - tmp;
276 
277 			if (diff < bestmatch) {
278 				bestmatch = diff;
279 				best_i = i;
280 				best_j = j;
281 			}
282 		}
283 	}
284 	bus_setup |= (DSPI_CTAR_PBR(best_i) | DSPI_CTAR_BR(best_j));
285 	dspi->ctar[cfslave->slave.bus] = bus_setup;
286 
287 	return &cfslave->slave;
288 }
289 #endif				/* CONFIG_CF_DSPI */
290 
291 #ifdef CONFIG_CF_QSPI
292 /* 52xx, 53xx */
293 #endif				/* CONFIG_CF_QSPI */
294 
295 #ifdef CONFIG_CMD_SPI
296 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
297 {
298 	if (((cs >= 0) && (cs < 8)) && ((bus >= 0) && (bus < 8)))
299 		return 1;
300 	else
301 		return 0;
302 }
303 
304 void spi_init_f(void)
305 {
306 }
307 
308 void spi_init_r(void)
309 {
310 }
311 
312 void spi_init(void)
313 {
314 	cfspi_init();
315 }
316 
317 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
318 				  unsigned int max_hz, unsigned int mode)
319 {
320 	struct cf_spi_slave *cfslave;
321 
322 	if (!spi_cs_is_valid(bus, cs))
323 		return NULL;
324 
325 	cfslave = malloc(sizeof(struct cf_spi_slave));
326 	if (!cfslave)
327 		return NULL;
328 
329 	cfslave->slave.bus = bus;
330 	cfslave->slave.cs = cs;
331 	cfslave->baudrate = max_hz;
332 
333 	/* specific setup */
334 	return cfspi_setup_slave(cfslave, mode);
335 }
336 
337 void spi_free_slave(struct spi_slave *slave)
338 {
339 	free(slave);
340 }
341 
342 int spi_claim_bus(struct spi_slave *slave)
343 {
344 	return cfspi_claim_bus(slave->bus, slave->cs);
345 }
346 
347 void spi_release_bus(struct spi_slave *slave)
348 {
349 	cfspi_release_bus(slave->bus, slave->cs);
350 }
351 
352 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
353 	     void *din, unsigned long flags)
354 {
355 	return cfspi_xfer(slave, bitlen, dout, din, flags);
356 }
357 #endif				/* CONFIG_CMD_SPI */
358