Initial import

1 files changed, 464 insertions, 0 deletions

diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
new file mode 100644
index 000000000..282092421
--- /dev/null
+++ b/drivers/w1/w1_io.c
@@ -0,0 +1,464 @@
+/*
+ *	w1_io.c
+ *
+ * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
+ *
+ *
+ * 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 <linux/module.h>
+
+#include "w1.h"
+#include "w1_log.h"
+
+static int w1_delay_parm = 1;
+module_param_named(delay_coef, w1_delay_parm, int, 0);
+
+static int w1_disable_irqs = 0;
+module_param_named(disable_irqs, w1_disable_irqs, 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
+};
+
+static void w1_delay(unsigned long tm)
+{
+	udelay(tm * w1_delay_parm);
+}
+
+static void w1_write_bit(struct w1_master *dev, int bit);
+static u8 w1_read_bit(struct w1_master *dev);
+
+/**
+ * w1_touch_bit() - Generates a write-0 or write-1 cycle and samples the level.
+ * @dev:	the master device
+ * @bit:	0 - write a 0, 1 - write a 0 read the level
+ */
+static 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 if (bit)
+		return w1_read_bit(dev);
+	else {
+		w1_write_bit(dev, 0);
+		return 0;
+	}
+}
+
+/**
+ * w1_write_bit() - Generates a write-0 or write-1 cycle.
+ * @dev:	the master device
+ * @bit:	bit to write
+ *
+ * Only call if dev->bus_master->touch_bit is NULL
+ */
+static void w1_write_bit(struct w1_master *dev, int bit)
+{
+	unsigned long flags = 0;
+
+	if(w1_disable_irqs) local_irq_save(flags);
+
+	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);
+	}
+
+	if(w1_disable_irqs) local_irq_restore(flags);
+}
+
+/**
+ * w1_pre_write() - pre-write operations
+ * @dev:	the master device
+ *
+ * Pre-write operation, currently only supporting strong pullups.
+ * Program the hardware for a strong pullup, if one has been requested and
+ * the hardware supports it.
+ */
+static void w1_pre_write(struct w1_master *dev)
+{
+	if (dev->pullup_duration &&
+		dev->enable_pullup && dev->bus_master->set_pullup) {
+		dev->bus_master->set_pullup(dev->bus_master->data,
+			dev->pullup_duration);
+	}
+}
+
+/**
+ * w1_post_write() - post-write options
+ * @dev:	the master device
+ *
+ * Post-write operation, currently only supporting strong pullups.
+ * If a strong pullup was requested, clear it if the hardware supports
+ * them, or execute the delay otherwise, in either case clear the request.
+ */
+static void w1_post_write(struct w1_master *dev)
+{
+	if (dev->pullup_duration) {
+		if (dev->enable_pullup && dev->bus_master->set_pullup)
+			dev->bus_master->set_pullup(dev->bus_master->data, 0);
+		else
+			msleep(dev->pullup_duration);
+		dev->pullup_duration = 0;
+	}
+}
+
+/**
+ * w1_write_8() - Writes 8 bits.
+ * @dev:	the master device
+ * @byte:	the byte to write
+ */
+void w1_write_8(struct w1_master *dev, u8 byte)
+{
+	int i;
+
+	if (dev->bus_master->write_byte) {
+		w1_pre_write(dev);
+		dev->bus_master->write_byte(dev->bus_master->data, byte);
+	}
+	else
+		for (i = 0; i < 8; ++i) {
+			if (i == 7)
+				w1_pre_write(dev);
+			w1_touch_bit(dev, (byte >> i) & 0x1);
+		}
+	w1_post_write(dev);
+}
+EXPORT_SYMBOL_GPL(w1_write_8);
+
+
+/**
+ * w1_read_bit() - Generates a write-1 cycle and samples the level.
+ * @dev:	the master device
+ *
+ * Only call if dev->bus_master->touch_bit is NULL
+ */
+static u8 w1_read_bit(struct w1_master *dev)
+{
+	int result;
+	unsigned long flags = 0;
+
+	/* sample timing is critical here */
+	local_irq_save(flags);
+	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);
+	local_irq_restore(flags);
+
+	w1_delay(55);
+
+	return result & 0x1;
+}
+
+/**
+ * w1_triplet() - * Does a triplet - used for searching ROM addresses.
+ * @dev:	the master device
+ * @bdir:	the bit to write if both id_bit and comp_bit are 0
+ *
+ * Return bits:
+ *  bit 0 = id_bit
+ *  bit 1 = comp_bit
+ *  bit 2 = dir_taken
+ * If both bits 0 & 1 are set, the search should be restarted.
+ *
+ * Return:        bit fields - see above
+ */
+u8 w1_triplet(struct w1_master *dev, int bdir)
+{
+	if (dev->bus_master->triplet)
+		return dev->bus_master->triplet(dev->bus_master->data, bdir);
+	else {
+		u8 id_bit   = w1_touch_bit(dev, 1);
+		u8 comp_bit = w1_touch_bit(dev, 1);
+		u8 retval;
+
+		if (id_bit && comp_bit)
+			return 0x03;  /* error */
+
+		if (!id_bit && !comp_bit) {
+			/* Both bits are valid, take the direction given */
+			retval = bdir ? 0x04 : 0;
+		} else {
+			/* Only one bit is valid, take that direction */
+			bdir = id_bit;
+			retval = id_bit ? 0x05 : 0x02;
+		}
+
+		if (dev->bus_master->touch_bit)
+			w1_touch_bit(dev, bdir);
+		else
+			w1_write_bit(dev, bdir);
+		return retval;
+	}
+}
+
+/**
+ * w1_read_8() - Reads 8 bits.
+ * @dev:	the master device
+ *
+ * Return:        the byte read
+ */
+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_touch_bit(dev,1) << i);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(w1_read_8);
+
+/**
+ * w1_write_block() - Writes a series of bytes.
+ * @dev:	the master device
+ * @buf:	pointer to the data to write
+ * @len:	the number of bytes to write
+ */
+void w1_write_block(struct w1_master *dev, const u8 *buf, int len)
+{
+	int i;
+
+	if (dev->bus_master->write_block) {
+		w1_pre_write(dev);
+		dev->bus_master->write_block(dev->bus_master->data, buf, len);
+	}
+	else
+		for (i = 0; i < len; ++i)
+			w1_write_8(dev, buf[i]); /* calls w1_pre_write */
+	w1_post_write(dev);
+}
+EXPORT_SYMBOL_GPL(w1_write_block);
+
+/**
+ * w1_touch_block() - Touches a series of bytes.
+ * @dev:	the master device
+ * @buf:	pointer to the data to write
+ * @len:	the number of bytes to write
+ */
+void w1_touch_block(struct w1_master *dev, u8 *buf, int len)
+{
+	int i, j;
+	u8 tmp;
+
+	for (i = 0; i < len; ++i) {
+		tmp = 0;
+		for (j = 0; j < 8; ++j) {
+			if (j == 7)
+				w1_pre_write(dev);
+			tmp |= w1_touch_bit(dev, (buf[i] >> j) & 0x1) << j;
+		}
+
+		buf[i] = tmp;
+	}
+}
+EXPORT_SYMBOL_GPL(w1_touch_block);
+
+/**
+ * w1_read_block() - Reads a series of bytes.
+ * @dev:	the master device
+ * @buf:	pointer to the buffer to fill
+ * @len:	the number of bytes to read
+ * Return:	the number of bytes read
+ */
+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;
+}
+EXPORT_SYMBOL_GPL(w1_read_block);
+
+/**
+ * w1_reset_bus() - Issues a reset bus sequence.
+ * @dev:	the master device
+ * Return:	0=Device present, 1=No device present or error
+ */
+int w1_reset_bus(struct w1_master *dev)
+{
+	int result;
+	unsigned long flags = 0;
+
+	if(w1_disable_irqs) local_irq_save(flags);
+
+	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);
+		/* minimum 480, max ? us
+		 * be nice and sleep, except 18b20 spec lists 960us maximum,
+		 * so until we can sleep with microsecond accuracy, spin.
+		 * Feel free to come up with some other way to give up the
+		 * cpu for such a short amount of time AND get it back in
+		 * the maximum amount of time.
+		 */
+		w1_delay(500);
+		dev->bus_master->write_bit(dev->bus_master->data, 1);
+		w1_delay(70);
+
+		result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
+		/* minmum 70 (above) + 430 = 500 us
+		 * There aren't any timing requirements between a reset and
+		 * the following transactions.  Sleeping is safe here.
+		 */
+		/* w1_delay(430); min required time */
+		msleep(1);
+	}
+
+	if(w1_disable_irqs) local_irq_restore(flags);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(w1_reset_bus);
+
+u8 w1_calc_crc8(u8 * data, int len)
+{
+	u8 crc = 0;
+
+	while (len--)
+		crc = w1_crc8_table[crc ^ *data++];
+
+	return crc;
+}
+EXPORT_SYMBOL_GPL(w1_calc_crc8);
+
+void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
+{
+	dev->attempts++;
+	if (dev->bus_master->search)
+		dev->bus_master->search(dev->bus_master->data, dev,
+			search_type, cb);
+	else
+		w1_search(dev, search_type, cb);
+}
+
+/**
+ * w1_reset_select_slave() - reset and select a slave
+ * @sl:		the slave to select
+ *
+ * Resets the bus and then selects the slave by sending either a skip rom
+ * or a rom match.  A skip rom is issued if there is only one device
+ * registered on the bus.
+ * The w1 master lock must be held.
+ *
+ * Return:	0=success, anything else=error
+ */
+int w1_reset_select_slave(struct w1_slave *sl)
+{
+	if (w1_reset_bus(sl->master))
+		return -1;
+
+	if (sl->master->slave_count == 1)
+		w1_write_8(sl->master, W1_SKIP_ROM);
+	else {
+		u8 match[9] = {W1_MATCH_ROM, };
+		u64 rn = le64_to_cpu(*((u64*)&sl->reg_num));
+
+		memcpy(&match[1], &rn, 8);
+		w1_write_block(sl->master, match, 9);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(w1_reset_select_slave);
+
+/**
+ * w1_reset_resume_command() - resume instead of another match ROM
+ * @dev:	the master device
+ *
+ * When the workflow with a slave amongst many requires several
+ * successive commands a reset between each, this function is similar
+ * to doing a reset then a match ROM for the last matched ROM. The
+ * advantage being that the matched ROM step is skipped in favor of the
+ * resume command. The slave must support the command of course.
+ *
+ * If the bus has only one slave, traditionnaly the match ROM is skipped
+ * and a "SKIP ROM" is done for efficiency. On multi-slave busses, this
+ * doesn't work of course, but the resume command is the next best thing.
+ *
+ * The w1 master lock must be held.
+ */
+int w1_reset_resume_command(struct w1_master *dev)
+{
+	if (w1_reset_bus(dev))
+		return -1;
+
+	/* This will make only the last matched slave perform a skip ROM. */
+	w1_write_8(dev, W1_RESUME_CMD);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(w1_reset_resume_command);
+
+/**
+ * w1_next_pullup() - register for a strong pullup
+ * @dev:	the master device
+ * @delay:	time in milliseconds
+ *
+ * Put out a strong pull-up of the specified duration after the next write
+ * operation.  Not all hardware supports strong pullups.  Hardware that
+ * doesn't support strong pullups will sleep for the given time after the
+ * write operation without a strong pullup.  This is a one shot request for
+ * the next write, specifying zero will clear a previous request.
+ * The w1 master lock must be held.
+ *
+ * Return:	0=success, anything else=error
+ */
+void w1_next_pullup(struct w1_master *dev, int delay)
+{
+	dev->pullup_duration = delay;
+}
+EXPORT_SYMBOL_GPL(w1_next_pullup);