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authorDavid Brownell <david-b@pacbell.net>2006-01-21 16:21:43 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2006-02-06 15:17:17 -0500
commit9c1da3cb46316e40bac766ce45556dc4fd8df3ca (patch)
treed2ab578f2601383f39d316dfca0f00d12da21dba
parent022f7b07bf2b384ece7fbd7edb90e54cd78db252 (diff)
[PATCH] SPI: spi_butterfly, restore lost deltas
This resolves some minor version skew glitches that accumulated for the AVR Butterfly adapter driver, which caused among other things the existence of a duplicate Kconfig entry. Most of it boils down to comment updates, but in one case it removes some now-superfluous code that would be better if not copied into other controller-level drivers. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
-rw-r--r--Documentation/spi/butterfly23
-rw-r--r--drivers/spi/Kconfig10
-rw-r--r--drivers/spi/spi_butterfly.c36
3 files changed, 34 insertions, 35 deletions
diff --git a/Documentation/spi/butterfly b/Documentation/spi/butterfly
index a2e8c8d90e35..9927af7a629c 100644
--- a/Documentation/spi/butterfly
+++ b/Documentation/spi/butterfly
@@ -12,13 +12,20 @@ You can make this adapter from an old printer cable and solder things
12directly to the Butterfly. Or (if you have the parts and skills) you 12directly to the Butterfly. Or (if you have the parts and skills) you
13can come up with something fancier, providing ciruit protection to the 13can come up with something fancier, providing ciruit protection to the
14Butterfly and the printer port, or with a better power supply than two 14Butterfly and the printer port, or with a better power supply than two
15signal pins from the printer port. 15signal pins from the printer port. Or for that matter, you can use
16similar cables to talk to many AVR boards, even a breadboard.
17
18This is more powerful than "ISP programming" cables since it lets kernel
19SPI protocol drivers interact with the AVR, and could even let the AVR
20issue interrupts to them. Later, your protocol driver should work
21easily with a "real SPI controller", instead of this bitbanger.
16 22
17 23
18The first cable connections will hook Linux up to one SPI bus, with the 24The first cable connections will hook Linux up to one SPI bus, with the
19AVR and a DataFlash chip; and to the AVR reset line. This is all you 25AVR and a DataFlash chip; and to the AVR reset line. This is all you
20need to reflash the firmware, and the pins are the standard Atmel "ISP" 26need to reflash the firmware, and the pins are the standard Atmel "ISP"
21connector pins (used also on non-Butterfly AVR boards). 27connector pins (used also on non-Butterfly AVR boards). On the parport
28side this is like "sp12" programming cables.
22 29
23 Signal Butterfly Parport (DB-25) 30 Signal Butterfly Parport (DB-25)
24 ------ --------- --------------- 31 ------ --------- ---------------
@@ -40,10 +47,14 @@ by clearing PORTB.[0-3]); (b) configure the mtd_dataflash driver; and
40 SELECT = J400.PB0/nSS = pin 17/C3,nSELECT 47 SELECT = J400.PB0/nSS = pin 17/C3,nSELECT
41 GND = J400.GND = pin 24/GND 48 GND = J400.GND = pin 24/GND
42 49
43The "USI" controller, using J405, can be used for a second SPI bus. That 50Or you could flash firmware making the AVR into an SPI slave (keeping the
44would let you talk to the AVR over SPI, running firmware that makes it act 51DataFlash in reset) and tweak the spi_butterfly driver to make it bind to
45as an SPI slave, while letting either Linux or the AVR use the DataFlash. 52the driver for your custom SPI-based protocol.
46There are plenty of spare parport pins to wire this one up, such as: 53
54The "USI" controller, using J405, can also be used for a second SPI bus.
55That would let you talk to the AVR using custom SPI-with-USI firmware,
56while letting either Linux or the AVR use the DataFlash. There are plenty
57of spare parport pins to wire this one up, such as:
47 58
48 Signal Butterfly Parport (DB-25) 59 Signal Butterfly Parport (DB-25)
49 ------ --------- --------------- 60 ------ --------- ---------------
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index b77dbd63e596..7a75faeb0526 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -75,16 +75,6 @@ config SPI_BUTTERFLY
75 inexpensive battery powered microcontroller evaluation board. 75 inexpensive battery powered microcontroller evaluation board.
76 This same cable can be used to flash new firmware. 76 This same cable can be used to flash new firmware.
77 77
78config SPI_BUTTERFLY
79 tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
80 depends on SPI_MASTER && PARPORT && EXPERIMENTAL
81 select SPI_BITBANG
82 help
83 This uses a custom parallel port cable to connect to an AVR
84 Butterfly <http://www.atmel.com/products/avr/butterfly>, an
85 inexpensive battery powered microcontroller evaluation board.
86 This same cable can be used to flash new firmware.
87
88# 78#
89# Add new SPI master controllers in alphabetical order above this line 79# Add new SPI master controllers in alphabetical order above this line
90# 80#
diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c
index 79a3c59615ab..ff9e5faa4dc9 100644
--- a/drivers/spi/spi_butterfly.c
+++ b/drivers/spi/spi_butterfly.c
@@ -163,21 +163,20 @@ static void butterfly_chipselect(struct spi_device *spi, int value)
163 struct butterfly *pp = spidev_to_pp(spi); 163 struct butterfly *pp = spidev_to_pp(spi);
164 164
165 /* set default clock polarity */ 165 /* set default clock polarity */
166 if (value) 166 if (value != BITBANG_CS_INACTIVE)
167 setsck(spi, spi->mode & SPI_CPOL); 167 setsck(spi, spi->mode & SPI_CPOL);
168 168
169 /* no chipselect on this USI link config */ 169 /* no chipselect on this USI link config */
170 if (is_usidev(spi)) 170 if (is_usidev(spi))
171 return; 171 return;
172 172
173 /* here, value == "activate or not" */ 173 /* here, value == "activate or not";
174 174 * most PARPORT_CONTROL_* bits are negated, so we must
175 /* most PARPORT_CONTROL_* bits are negated */ 175 * morph it to value == "bit value to write in control register"
176 */
176 if (spi_cs_bit == PARPORT_CONTROL_INIT) 177 if (spi_cs_bit == PARPORT_CONTROL_INIT)
177 value = !value; 178 value = !value;
178 179
179 /* here, value == "bit value to write in control register" */
180
181 parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0); 180 parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
182} 181}
183 182
@@ -202,7 +201,9 @@ butterfly_txrx_word_mode0(struct spi_device *spi,
202 201
203/* override default partitioning with cmdlinepart */ 202/* override default partitioning with cmdlinepart */
204static struct mtd_partition partitions[] = { { 203static struct mtd_partition partitions[] = { {
205 /* JFFS2 wants partitions of 4*N blocks for this device ... */ 204 /* JFFS2 wants partitions of 4*N blocks for this device,
205 * so sectors 0 and 1 can't be partitions by themselves.
206 */
206 207
207 /* sector 0 = 8 pages * 264 bytes/page (1 block) 208 /* sector 0 = 8 pages * 264 bytes/page (1 block)
208 * sector 1 = 248 pages * 264 bytes/page 209 * sector 1 = 248 pages * 264 bytes/page
@@ -316,8 +317,9 @@ static void butterfly_attach(struct parport *p)
316 if (status < 0) 317 if (status < 0)
317 goto clean2; 318 goto clean2;
318 319
319 /* Bus 1 lets us talk to at45db041b (firmware disables AVR) 320 /* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR
320 * or AVR (firmware resets at45, acts as spi slave) 321 * (firmware resets at45, acts as spi slave) or neither (we ignore
322 * both, AVR uses AT45). Here we expect firmware for the first option.
321 */ 323 */
322 pp->info[0].max_speed_hz = 15 * 1000 * 1000; 324 pp->info[0].max_speed_hz = 15 * 1000 * 1000;
323 strcpy(pp->info[0].modalias, "mtd_dataflash"); 325 strcpy(pp->info[0].modalias, "mtd_dataflash");
@@ -330,7 +332,9 @@ static void butterfly_attach(struct parport *p)
330 pp->dataflash->dev.bus_id); 332 pp->dataflash->dev.bus_id);
331 333
332#ifdef HAVE_USI 334#ifdef HAVE_USI
333 /* even more custom AVR firmware */ 335 /* Bus 2 is only for talking to the AVR, and it can work no
336 * matter who masters bus 1; needs appropriate AVR firmware.
337 */
334 pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000; 338 pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000;
335 strcpy(pp->info[1].modalias, "butterfly"); 339 strcpy(pp->info[1].modalias, "butterfly");
336 // pp->info[1].platform_data = ... TBD ... ; 340 // pp->info[1].platform_data = ... TBD ... ;
@@ -378,13 +382,8 @@ static void butterfly_detach(struct parport *p)
378 pp = butterfly; 382 pp = butterfly;
379 butterfly = NULL; 383 butterfly = NULL;
380 384
381#ifdef HAVE_USI 385 /* stop() unregisters child devices too */
382 spi_unregister_device(pp->butterfly); 386 pdev = to_platform_device(pp->bitbang.master->cdev.dev);
383 pp->butterfly = NULL;
384#endif
385 spi_unregister_device(pp->dataflash);
386 pp->dataflash = NULL;
387
388 status = spi_bitbang_stop(&pp->bitbang); 387 status = spi_bitbang_stop(&pp->bitbang);
389 388
390 /* turn off VCC */ 389 /* turn off VCC */
@@ -394,8 +393,6 @@ static void butterfly_detach(struct parport *p)
394 parport_release(pp->pd); 393 parport_release(pp->pd);
395 parport_unregister_device(pp->pd); 394 parport_unregister_device(pp->pd);
396 395
397 pdev = to_platform_device(pp->bitbang.master->cdev.dev);
398
399 (void) spi_master_put(pp->bitbang.master); 396 (void) spi_master_put(pp->bitbang.master);
400 397
401 platform_device_unregister(pdev); 398 platform_device_unregister(pdev);
@@ -420,4 +417,5 @@ static void __exit butterfly_exit(void)
420} 417}
421module_exit(butterfly_exit); 418module_exit(butterfly_exit);
422 419
420MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly");
423MODULE_LICENSE("GPL"); 421MODULE_LICENSE("GPL");