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| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
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| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/w1/w1_io.c | |
| download | olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip  | |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/w1/w1_io.c')
| -rw-r--r-- | drivers/w1/w1_io.c | 195 | 
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c new file mode 100644 index 00000000000..02796b5a39f --- /dev/null +++ b/drivers/w1/w1_io.c @@ -0,0 +1,195 @@ +/* + * 	w1_io.c + * + * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> + *  + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <asm/io.h> + +#include <linux/delay.h> +#include <linux/moduleparam.h> + +#include "w1.h" +#include "w1_log.h" +#include "w1_io.h" + +int w1_delay_parm = 1; +module_param_named(delay_coef, w1_delay_parm, int, 0); + +static u8 w1_crc8_table[] = { +	0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, +	157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, +	35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, +	190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, +	70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, +	219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, +	101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, +	248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, +	140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205, +	17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80, +	175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238, +	50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, +	202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, +	87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, +	233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, +	116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 +}; + +void w1_delay(unsigned long tm) +{ +	udelay(tm * w1_delay_parm); +} + +u8 w1_touch_bit(struct w1_master *dev, int bit) +{ +	if (dev->bus_master->touch_bit) +		return dev->bus_master->touch_bit(dev->bus_master->data, bit); +	else +		return w1_read_bit(dev); +} + +void w1_write_bit(struct w1_master *dev, int bit) +{ +	if (bit) { +		dev->bus_master->write_bit(dev->bus_master->data, 0); +		w1_delay(6); +		dev->bus_master->write_bit(dev->bus_master->data, 1); +		w1_delay(64); +	} else { +		dev->bus_master->write_bit(dev->bus_master->data, 0); +		w1_delay(60); +		dev->bus_master->write_bit(dev->bus_master->data, 1); +		w1_delay(10); +	} +} + +void w1_write_8(struct w1_master *dev, u8 byte) +{ +	int i; + +	if (dev->bus_master->write_byte) +		dev->bus_master->write_byte(dev->bus_master->data, byte); +	else +		for (i = 0; i < 8; ++i) +			w1_write_bit(dev, (byte >> i) & 0x1); +} + +u8 w1_read_bit(struct w1_master *dev) +{ +	int result; + +	dev->bus_master->write_bit(dev->bus_master->data, 0); +	w1_delay(6); +	dev->bus_master->write_bit(dev->bus_master->data, 1); +	w1_delay(9); + +	result = dev->bus_master->read_bit(dev->bus_master->data); +	w1_delay(55); + +	return result & 0x1; +} + +u8 w1_read_8(struct w1_master * dev) +{ +	int i; +	u8 res = 0; + +	if (dev->bus_master->read_byte) +		res = dev->bus_master->read_byte(dev->bus_master->data); +	else +		for (i = 0; i < 8; ++i) +			res |= (w1_read_bit(dev) << i); + +	return res; +} + +void w1_write_block(struct w1_master *dev, u8 *buf, int len) +{ +	int i; + +	if (dev->bus_master->write_block) +		dev->bus_master->write_block(dev->bus_master->data, buf, len); +	else +		for (i = 0; i < len; ++i) +			w1_write_8(dev, buf[i]); +} + +u8 w1_read_block(struct w1_master *dev, u8 *buf, int len) +{ +	int i; +	u8 ret; + +	if (dev->bus_master->read_block) +		ret = dev->bus_master->read_block(dev->bus_master->data, buf, len); +	else { +		for (i = 0; i < len; ++i) +			buf[i] = w1_read_8(dev); +		ret = len; +	} + +	return ret; +} + +int w1_reset_bus(struct w1_master *dev) +{ +	int result = 0; + +	if (dev->bus_master->reset_bus) +		result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1; +	else { +		dev->bus_master->write_bit(dev->bus_master->data, 0); +		w1_delay(480); +		dev->bus_master->write_bit(dev->bus_master->data, 1); +		w1_delay(70); + +		result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1; +		w1_delay(410); +	} + +	return result; +} + +u8 w1_calc_crc8(u8 * data, int len) +{ +	u8 crc = 0; + +	while (len--) +		crc = w1_crc8_table[crc ^ *data++]; + +	return crc; +} + +void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb) +{ +	dev->attempts++; +	if (dev->bus_master->search) +		dev->bus_master->search(dev->bus_master->data, cb); +	else +		w1_search(dev); +} + +EXPORT_SYMBOL(w1_write_bit); +EXPORT_SYMBOL(w1_write_8); +EXPORT_SYMBOL(w1_read_bit); +EXPORT_SYMBOL(w1_read_8); +EXPORT_SYMBOL(w1_reset_bus); +EXPORT_SYMBOL(w1_calc_crc8); +EXPORT_SYMBOL(w1_delay); +EXPORT_SYMBOL(w1_read_block); +EXPORT_SYMBOL(w1_write_block); +EXPORT_SYMBOL(w1_search_devices);  |