drivers/w1/slaves/w1_therm.c - maze/linux - Git at Google

 /*
  *	w1_therm.c
  *
  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
  *
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the therms 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/types.h>

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/sched.h>
 #include <linux/device.h>
 #include <linux/types.h>
 #include <linux/delay.h>

 #include "../w1.h"
 #include "../w1_int.h"
 #include "../w1_family.h"

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");

 /* Allow the strong pullup to be disabled, but default to enabled.
  * If it was disabled a parasite powered device might not get the require
  * current to do a temperature conversion.  If it is enabled parasite powered
  * devices have a better chance of getting the current required.
  */
 static int w1_strong_pullup = 1;
 module_param_named(strong_pullup, w1_strong_pullup, int, 0);

 static u8 bad_roms[][9] = {
 				{0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
 				{}
 			};

 static ssize_t w1_therm_read(struct device *device,
 	struct device_attribute *attr, char *buf);

 static struct device_attribute w1_therm_attr =
 	__ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL);

 static int w1_therm_add_slave(struct w1_slave *sl)
 {
 	return device_create_file(&sl->dev, &w1_therm_attr);
 }

 static void w1_therm_remove_slave(struct w1_slave *sl)
 {
 	device_remove_file(&sl->dev, &w1_therm_attr);
 }

 static struct w1_family_ops w1_therm_fops = {
 	.add_slave	= w1_therm_add_slave,
 	.remove_slave	= w1_therm_remove_slave,
 };

 static struct w1_family w1_therm_family_DS18S20 = {
 	.fid = W1_THERM_DS18S20,
 	.fops = &w1_therm_fops,
 };

 static struct w1_family w1_therm_family_DS18B20 = {
 	.fid = W1_THERM_DS18B20,
 	.fops = &w1_therm_fops,
 };

 static struct w1_family w1_therm_family_DS1822 = {
 	.fid = W1_THERM_DS1822,
 	.fops = &w1_therm_fops,
 };

 static struct w1_family w1_therm_family_DS28EA00 = {
 	.fid = W1_THERM_DS28EA00,
 	.fops = &w1_therm_fops,
 };

 static struct w1_family w1_therm_family_DS1825 = {
 	.fid = W1_THERM_DS1825,
 	.fops = &w1_therm_fops,
 };

 struct w1_therm_family_converter
 {
 	u8			broken;
 	u16			reserved;
 	struct w1_family	*f;
 	int			(*convert)(u8 rom[9]);
 };

 /* The return value is millidegrees Centigrade. */
 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
 static inline int w1_DS18S20_convert_temp(u8 rom[9]);

 static struct w1_therm_family_converter w1_therm_families[] = {
 	{
 		.f		= &w1_therm_family_DS18S20,
 		.convert 	= w1_DS18S20_convert_temp
 	},
 	{
 		.f		= &w1_therm_family_DS1822,
 		.convert 	= w1_DS18B20_convert_temp
 	},
 	{
 		.f		= &w1_therm_family_DS18B20,
 		.convert 	= w1_DS18B20_convert_temp
 	},
 	{
 		.f		= &w1_therm_family_DS28EA00,
 		.convert	= w1_DS18B20_convert_temp
 	},
 	{
 		.f		= &w1_therm_family_DS1825,
 		.convert	= w1_DS18B20_convert_temp
 	}
 };

 static inline int w1_DS18B20_convert_temp(u8 rom[9])
 {
 	s16 t = le16_to_cpup((__le16 *)rom);
 	return t*1000/16;
 }

 static inline int w1_DS18S20_convert_temp(u8 rom[9])
 {
 	int t, h;

 	if (!rom[7])
 		return 0;

 	if (rom[1] == 0)
 		t = ((s32)rom[0] >> 1)*1000;
 	else
 		t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);

 	t -= 250;
 	h = 1000*((s32)rom[7] - (s32)rom[6]);
 	h /= (s32)rom[7];
 	t += h;

 	return t;
 }

 static inline int w1_convert_temp(u8 rom[9], u8 fid)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
 		if (w1_therm_families[i].f->fid == fid)
 			return w1_therm_families[i].convert(rom);

 	return 0;
 }

 static int w1_therm_check_rom(u8 rom[9])
 {
 	int i;

 	for (i=0; i<sizeof(bad_roms)/9; ++i)
 		if (!memcmp(bad_roms[i], rom, 9))
 			return 1;

 	return 0;
 }

 static ssize_t w1_therm_read(struct device *device,
 	struct device_attribute *attr, char *buf)
 {
 	struct w1_slave *sl = dev_to_w1_slave(device);
 	struct w1_master *dev = sl->master;
 	u8 rom[9], crc, verdict, external_power;
 	int i, max_trying = 10;
 	ssize_t c = PAGE_SIZE;

 	i = mutex_lock_interruptible(&dev->bus_mutex);
 	if (i != 0)
 		return i;

 	memset(rom, 0, sizeof(rom));

 	verdict = 0;
 	crc = 0;

 	while (max_trying--) {
 		if (!w1_reset_select_slave(sl)) {
 			int count = 0;
 			unsigned int tm = 750;
 			unsigned long sleep_rem;

 			w1_write_8(dev, W1_READ_PSUPPLY);
 			external_power = w1_read_8(dev);

 			if (w1_reset_select_slave(sl))
 				continue;

 			/* 750ms strong pullup (or delay) after the convert */
 			if (!external_power && w1_strong_pullup)
 				w1_next_pullup(dev, tm);

 			w1_write_8(dev, W1_CONVERT_TEMP);

 			if (external_power) {
 				mutex_unlock(&dev->bus_mutex);

 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0)
 					return -EINTR;

 				i = mutex_lock_interruptible(&dev->bus_mutex);
 				if (i != 0)
 					return i;
 			} else if (!w1_strong_pullup) {
 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0) {
 					mutex_unlock(&dev->bus_mutex);
 					return -EINTR;
 				}
 			}

 			if (!w1_reset_select_slave(sl)) {

 				w1_write_8(dev, W1_READ_SCRATCHPAD);
 				if ((count = w1_read_block(dev, rom, 9)) != 9) {
 					dev_warn(device, "w1_read_block() "
 						"returned %u instead of 9.\n",
 						count);
 				}

 				crc = w1_calc_crc8(rom, 8);

 				if (rom[8] == crc)
 					verdict = 1;
 			}
 		}

 		if (!w1_therm_check_rom(rom))
 			break;
 	}

 	for (i = 0; i < 9; ++i)
 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]);
 	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
 			   crc, (verdict) ? "YES" : "NO");
 	if (verdict)
 		memcpy(sl->rom, rom, sizeof(sl->rom));
 	else
 		dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n");

 	for (i = 0; i < 9; ++i)
 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);

 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
 		w1_convert_temp(rom, sl->family->fid));
 	mutex_unlock(&dev->bus_mutex);

 	return PAGE_SIZE - c;
 }

 static int __init w1_therm_init(void)
 {
 	int err, i;

 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
 		err = w1_register_family(w1_therm_families[i].f);
 		if (err)
 			w1_therm_families[i].broken = 1;
 	}

 	return 0;
 }

 static void __exit w1_therm_fini(void)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
 		if (!w1_therm_families[i].broken)
 			w1_unregister_family(w1_therm_families[i].f);
 }

 module_init(w1_therm_init);
 module_exit(w1_therm_fini);
	/*
	* w1_therm.c
	*
	* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
	*
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the therms 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/types.h>

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/sched.h>
	#include <linux/device.h>
	#include <linux/types.h>
	#include <linux/delay.h>

	#include "../w1.h"
	#include "../w1_int.h"
	#include "../w1_family.h"

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
	MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");

	/* Allow the strong pullup to be disabled, but default to enabled.
	* If it was disabled a parasite powered device might not get the require
	* current to do a temperature conversion. If it is enabled parasite powered
	* devices have a better chance of getting the current required.
	*/
	static int w1_strong_pullup = 1;
	module_param_named(strong_pullup, w1_strong_pullup, int, 0);

	static u8 bad_roms[][9] = {
	{0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
	{}
	};

	static ssize_t w1_therm_read(struct device *device,
	struct device_attribute attr, char buf);

	static struct device_attribute w1_therm_attr =
	__ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL);

	static int w1_therm_add_slave(struct w1_slave *sl)
	{
	return device_create_file(&sl->dev, &w1_therm_attr);
	}

	static void w1_therm_remove_slave(struct w1_slave *sl)
	{
	device_remove_file(&sl->dev, &w1_therm_attr);
	}

	static struct w1_family_ops w1_therm_fops = {
	.add_slave = w1_therm_add_slave,
	.remove_slave = w1_therm_remove_slave,
	};

	static struct w1_family w1_therm_family_DS18S20 = {
	.fid = W1_THERM_DS18S20,
	.fops = &w1_therm_fops,
	};

	static struct w1_family w1_therm_family_DS18B20 = {
	.fid = W1_THERM_DS18B20,
	.fops = &w1_therm_fops,
	};

	static struct w1_family w1_therm_family_DS1822 = {
	.fid = W1_THERM_DS1822,
	.fops = &w1_therm_fops,
	};

	static struct w1_family w1_therm_family_DS28EA00 = {
	.fid = W1_THERM_DS28EA00,
	.fops = &w1_therm_fops,
	};

	static struct w1_family w1_therm_family_DS1825 = {
	.fid = W1_THERM_DS1825,
	.fops = &w1_therm_fops,
	};

	struct w1_therm_family_converter
	{
	u8 broken;
	u16 reserved;
	struct w1_family *f;
	int (*convert)(u8 rom[9]);
	};

	/* The return value is millidegrees Centigrade. */
	static inline int w1_DS18B20_convert_temp(u8 rom[9]);
	static inline int w1_DS18S20_convert_temp(u8 rom[9]);

	static struct w1_therm_family_converter w1_therm_families[] = {
	{
	.f = &w1_therm_family_DS18S20,
	.convert = w1_DS18S20_convert_temp
	},
	{
	.f = &w1_therm_family_DS1822,
	.convert = w1_DS18B20_convert_temp
	},
	{
	.f = &w1_therm_family_DS18B20,
	.convert = w1_DS18B20_convert_temp
	},
	{
	.f = &w1_therm_family_DS28EA00,
	.convert = w1_DS18B20_convert_temp
	},
	{
	.f = &w1_therm_family_DS1825,
	.convert = w1_DS18B20_convert_temp
	}
	};

	static inline int w1_DS18B20_convert_temp(u8 rom[9])
	{
	s16 t = le16_to_cpup((__le16 *)rom);
	return t*1000/16;
	}

	static inline int w1_DS18S20_convert_temp(u8 rom[9])
	{
	int t, h;

	if (!rom[7])
	return 0;

	if (rom[1] == 0)
	t = ((s32)rom[0] >> 1)*1000;
	else
	t = 1000(-1(s32)(0x100-rom[0]) >> 1);

	t -= 250;
	h = 1000*((s32)rom[7] - (s32)rom[6]);
	h /= (s32)rom[7];
	t += h;

	return t;
	}

	static inline int w1_convert_temp(u8 rom[9], u8 fid)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
	if (w1_therm_families[i].f->fid == fid)
	return w1_therm_families[i].convert(rom);

	return 0;
	}

	static int w1_therm_check_rom(u8 rom[9])
	{
	int i;

	for (i=0; i<sizeof(bad_roms)/9; ++i)
	if (!memcmp(bad_roms[i], rom, 9))
	return 1;

	return 0;
	}

	static ssize_t w1_therm_read(struct device *device,
	struct device_attribute attr, char buf)
	{
	struct w1_slave *sl = dev_to_w1_slave(device);
	struct w1_master *dev = sl->master;
	u8 rom[9], crc, verdict, external_power;
	int i, max_trying = 10;
	ssize_t c = PAGE_SIZE;

	i = mutex_lock_interruptible(&dev->bus_mutex);
	if (i != 0)
	return i;

	memset(rom, 0, sizeof(rom));

	verdict = 0;
	crc = 0;

	while (max_trying--) {
	if (!w1_reset_select_slave(sl)) {
	int count = 0;
	unsigned int tm = 750;
	unsigned long sleep_rem;

	w1_write_8(dev, W1_READ_PSUPPLY);
	external_power = w1_read_8(dev);

	if (w1_reset_select_slave(sl))
	continue;

	/* 750ms strong pullup (or delay) after the convert */
	if (!external_power && w1_strong_pullup)
	w1_next_pullup(dev, tm);

	w1_write_8(dev, W1_CONVERT_TEMP);

	if (external_power) {
	mutex_unlock(&dev->bus_mutex);

	sleep_rem = msleep_interruptible(tm);
	if (sleep_rem != 0)
	return -EINTR;

	i = mutex_lock_interruptible(&dev->bus_mutex);
	if (i != 0)
	return i;
	} else if (!w1_strong_pullup) {
	sleep_rem = msleep_interruptible(tm);
	if (sleep_rem != 0) {
	mutex_unlock(&dev->bus_mutex);
	return -EINTR;
	}
	}

	if (!w1_reset_select_slave(sl)) {

	w1_write_8(dev, W1_READ_SCRATCHPAD);
	if ((count = w1_read_block(dev, rom, 9)) != 9) {
	dev_warn(device, "w1_read_block() "
	"returned %u instead of 9.\n",
	count);
	}

	crc = w1_calc_crc8(rom, 8);

	if (rom[8] == crc)
	verdict = 1;
	}
	}

	if (!w1_therm_check_rom(rom))
	break;
	}

	for (i = 0; i < 9; ++i)
	c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]);
	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
	crc, (verdict) ? "YES" : "NO");
	if (verdict)
	memcpy(sl->rom, rom, sizeof(sl->rom));
	else
	dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n");

	for (i = 0; i < 9; ++i)
	c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);

	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
	w1_convert_temp(rom, sl->family->fid));
	mutex_unlock(&dev->bus_mutex);

	return PAGE_SIZE - c;
	}

	static int __init w1_therm_init(void)
	{
	int err, i;

	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
	err = w1_register_family(w1_therm_families[i].f);
	if (err)
	w1_therm_families[i].broken = 1;
	}

	return 0;
	}

	static void __exit w1_therm_fini(void)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
	if (!w1_therm_families[i].broken)
	w1_unregister_family(w1_therm_families[i].f);
	}

	module_init(w1_therm_init);
	module_exit(w1_therm_fini);