ALSA: hda - Add static_hdmi_pcm option to HDMI codec parser
[linux-2.6/next.git] / drivers / spi / spi_butterfly.c
blob0d4ceba3b5900258c071c86ebd1ff02ad50a2cdf
1 /*
2 * spi_butterfly.c - parport-to-butterfly adapter
4 * Copyright (C) 2005 David Brownell
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/parport.h>
26 #include <linux/sched.h>
27 #include <linux/spi/spi.h>
28 #include <linux/spi/spi_bitbang.h>
29 #include <linux/spi/flash.h>
31 #include <linux/mtd/partitions.h>
35 * This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
36 * with a battery powered AVR microcontroller and lots of goodies. You
37 * can use GCC to develop firmware for this.
39 * See Documentation/spi/butterfly for information about how to build
40 * and use this custom parallel port cable.
44 /* DATA output bits (pins 2..9 == D0..D7) */
45 #define butterfly_nreset (1 << 1) /* pin 3 */
47 #define spi_sck_bit (1 << 0) /* pin 2 */
48 #define spi_mosi_bit (1 << 7) /* pin 9 */
50 #define vcc_bits ((1 << 6) | (1 << 5)) /* pins 7, 8 */
52 /* STATUS input bits */
53 #define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */
55 /* CONTROL output bits */
56 #define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */
60 static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
62 return spi->controller_data;
66 struct butterfly {
67 /* REVISIT ... for now, this must be first */
68 struct spi_bitbang bitbang;
70 struct parport *port;
71 struct pardevice *pd;
73 u8 lastbyte;
75 struct spi_device *dataflash;
76 struct spi_device *butterfly;
77 struct spi_board_info info[2];
81 /*----------------------------------------------------------------------*/
83 static inline void
84 setsck(struct spi_device *spi, int is_on)
86 struct butterfly *pp = spidev_to_pp(spi);
87 u8 bit, byte = pp->lastbyte;
89 bit = spi_sck_bit;
91 if (is_on)
92 byte |= bit;
93 else
94 byte &= ~bit;
95 parport_write_data(pp->port, byte);
96 pp->lastbyte = byte;
99 static inline void
100 setmosi(struct spi_device *spi, int is_on)
102 struct butterfly *pp = spidev_to_pp(spi);
103 u8 bit, byte = pp->lastbyte;
105 bit = spi_mosi_bit;
107 if (is_on)
108 byte |= bit;
109 else
110 byte &= ~bit;
111 parport_write_data(pp->port, byte);
112 pp->lastbyte = byte;
115 static inline int getmiso(struct spi_device *spi)
117 struct butterfly *pp = spidev_to_pp(spi);
118 int value;
119 u8 bit;
121 bit = spi_miso_bit;
123 /* only STATUS_BUSY is NOT negated */
124 value = !(parport_read_status(pp->port) & bit);
125 return (bit == PARPORT_STATUS_BUSY) ? value : !value;
128 static void butterfly_chipselect(struct spi_device *spi, int value)
130 struct butterfly *pp = spidev_to_pp(spi);
132 /* set default clock polarity */
133 if (value != BITBANG_CS_INACTIVE)
134 setsck(spi, spi->mode & SPI_CPOL);
136 /* here, value == "activate or not";
137 * most PARPORT_CONTROL_* bits are negated, so we must
138 * morph it to value == "bit value to write in control register"
140 if (spi_cs_bit == PARPORT_CONTROL_INIT)
141 value = !value;
143 parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
147 /* we only needed to implement one mode here, and choose SPI_MODE_0 */
149 #define spidelay(X) do{}while(0)
150 //#define spidelay ndelay
152 #include "spi_bitbang_txrx.h"
154 static u32
155 butterfly_txrx_word_mode0(struct spi_device *spi,
156 unsigned nsecs,
157 u32 word, u8 bits)
159 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
162 /*----------------------------------------------------------------------*/
164 /* override default partitioning with cmdlinepart */
165 static struct mtd_partition partitions[] = { {
166 /* JFFS2 wants partitions of 4*N blocks for this device,
167 * so sectors 0 and 1 can't be partitions by themselves.
170 /* sector 0 = 8 pages * 264 bytes/page (1 block)
171 * sector 1 = 248 pages * 264 bytes/page
173 .name = "bookkeeping", // 66 KB
174 .offset = 0,
175 .size = (8 + 248) * 264,
176 // .mask_flags = MTD_WRITEABLE,
177 }, {
178 /* sector 2 = 256 pages * 264 bytes/page
179 * sectors 3-5 = 512 pages * 264 bytes/page
181 .name = "filesystem", // 462 KB
182 .offset = MTDPART_OFS_APPEND,
183 .size = MTDPART_SIZ_FULL,
184 } };
186 static struct flash_platform_data flash = {
187 .name = "butterflash",
188 .parts = partitions,
189 .nr_parts = ARRAY_SIZE(partitions),
193 /* REVISIT remove this ugly global and its "only one" limitation */
194 static struct butterfly *butterfly;
196 static void butterfly_attach(struct parport *p)
198 struct pardevice *pd;
199 int status;
200 struct butterfly *pp;
201 struct spi_master *master;
202 struct device *dev = p->physport->dev;
204 if (butterfly || !dev)
205 return;
207 /* REVISIT: this just _assumes_ a butterfly is there ... no probe,
208 * and no way to be selective about what it binds to.
211 master = spi_alloc_master(dev, sizeof *pp);
212 if (!master) {
213 status = -ENOMEM;
214 goto done;
216 pp = spi_master_get_devdata(master);
219 * SPI and bitbang hookup
221 * use default setup(), cleanup(), and transfer() methods; and
222 * only bother implementing mode 0. Start it later.
224 master->bus_num = 42;
225 master->num_chipselect = 2;
227 pp->bitbang.master = spi_master_get(master);
228 pp->bitbang.chipselect = butterfly_chipselect;
229 pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
232 * parport hookup
234 pp->port = p;
235 pd = parport_register_device(p, "spi_butterfly",
236 NULL, NULL, NULL,
237 0 /* FLAGS */, pp);
238 if (!pd) {
239 status = -ENOMEM;
240 goto clean0;
242 pp->pd = pd;
244 status = parport_claim(pd);
245 if (status < 0)
246 goto clean1;
249 * Butterfly reset, powerup, run firmware
251 pr_debug("%s: powerup/reset Butterfly\n", p->name);
253 /* nCS for dataflash (this bit is inverted on output) */
254 parport_frob_control(pp->port, spi_cs_bit, 0);
256 /* stabilize power with chip in reset (nRESET), and
257 * spi_sck_bit clear (CPOL=0)
259 pp->lastbyte |= vcc_bits;
260 parport_write_data(pp->port, pp->lastbyte);
261 msleep(5);
263 /* take it out of reset; assume long reset delay */
264 pp->lastbyte |= butterfly_nreset;
265 parport_write_data(pp->port, pp->lastbyte);
266 msleep(100);
270 * Start SPI ... for now, hide that we're two physical busses.
272 status = spi_bitbang_start(&pp->bitbang);
273 if (status < 0)
274 goto clean2;
276 /* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
277 * (firmware resets at45, acts as spi slave) or neither (we ignore
278 * both, AVR uses AT45). Here we expect firmware for the first option.
281 pp->info[0].max_speed_hz = 15 * 1000 * 1000;
282 strcpy(pp->info[0].modalias, "mtd_dataflash");
283 pp->info[0].platform_data = &flash;
284 pp->info[0].chip_select = 1;
285 pp->info[0].controller_data = pp;
286 pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
287 if (pp->dataflash)
288 pr_debug("%s: dataflash at %s\n", p->name,
289 dev_name(&pp->dataflash->dev));
291 // dev_info(_what?_, ...)
292 pr_info("%s: AVR Butterfly\n", p->name);
293 butterfly = pp;
294 return;
296 clean2:
297 /* turn off VCC */
298 parport_write_data(pp->port, 0);
300 parport_release(pp->pd);
301 clean1:
302 parport_unregister_device(pd);
303 clean0:
304 (void) spi_master_put(pp->bitbang.master);
305 done:
306 pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
309 static void butterfly_detach(struct parport *p)
311 struct butterfly *pp;
312 int status;
314 /* FIXME this global is ugly ... but, how to quickly get from
315 * the parport to the "struct butterfly" associated with it?
316 * "old school" driver-internal device lists?
318 if (!butterfly || butterfly->port != p)
319 return;
320 pp = butterfly;
321 butterfly = NULL;
323 /* stop() unregisters child devices too */
324 status = spi_bitbang_stop(&pp->bitbang);
326 /* turn off VCC */
327 parport_write_data(pp->port, 0);
328 msleep(10);
330 parport_release(pp->pd);
331 parport_unregister_device(pp->pd);
333 (void) spi_master_put(pp->bitbang.master);
336 static struct parport_driver butterfly_driver = {
337 .name = "spi_butterfly",
338 .attach = butterfly_attach,
339 .detach = butterfly_detach,
343 static int __init butterfly_init(void)
345 return parport_register_driver(&butterfly_driver);
347 device_initcall(butterfly_init);
349 static void __exit butterfly_exit(void)
351 parport_unregister_driver(&butterfly_driver);
353 module_exit(butterfly_exit);
355 MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly");
356 MODULE_LICENSE("GPL");