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![Evgeniy Polyakov](/assets/img/avatar_default.png)
Patch is based on work from Ben Gardner <bgardner@wabtec.com> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
268 lines
5.8 KiB
C
268 lines
5.8 KiB
C
/*
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* w1_therm.c
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*
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* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the therms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <asm/types.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/device.h>
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#include <linux/types.h>
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#include <linux/delay.h>
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#include "w1.h"
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#include "w1_io.h"
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#include "w1_int.h"
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#include "w1_family.h"
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
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MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
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static u8 bad_roms[][9] = {
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{0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
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{}
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};
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static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
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static struct bin_attribute w1_therm_bin_attr = {
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.attr = {
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.name = "w1_slave",
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.mode = S_IRUGO,
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.owner = THIS_MODULE,
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},
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.size = W1_SLAVE_DATA_SIZE,
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.read = w1_therm_read_bin,
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};
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static int w1_therm_add_slave(struct w1_slave *sl)
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{
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return sysfs_create_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
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}
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static void w1_therm_remove_slave(struct w1_slave *sl)
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{
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sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
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}
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static struct w1_family_ops w1_therm_fops = {
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.add_slave = w1_therm_add_slave,
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.remove_slave = w1_therm_remove_slave,
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};
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static struct w1_family w1_therm_family_DS18S20 = {
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.fid = W1_THERM_DS18S20,
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.fops = &w1_therm_fops,
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};
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static struct w1_family w1_therm_family_DS18B20 = {
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.fid = W1_THERM_DS18B20,
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.fops = &w1_therm_fops,
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};
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static struct w1_family w1_therm_family_DS1822 = {
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.fid = W1_THERM_DS1822,
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.fops = &w1_therm_fops,
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};
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struct w1_therm_family_converter
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{
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u8 broken;
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u16 reserved;
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struct w1_family *f;
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int (*convert)(u8 rom[9]);
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};
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static inline int w1_DS18B20_convert_temp(u8 rom[9]);
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static inline int w1_DS18S20_convert_temp(u8 rom[9]);
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static struct w1_therm_family_converter w1_therm_families[] = {
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{
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.f = &w1_therm_family_DS18S20,
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.convert = w1_DS18S20_convert_temp
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},
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{
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.f = &w1_therm_family_DS1822,
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.convert = w1_DS18B20_convert_temp
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},
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{
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.f = &w1_therm_family_DS18B20,
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.convert = w1_DS18B20_convert_temp
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},
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};
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static inline int w1_DS18B20_convert_temp(u8 rom[9])
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{
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int t = (rom[1] << 8) | rom[0];
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t /= 16;
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return t;
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}
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static inline int w1_DS18S20_convert_temp(u8 rom[9])
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{
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int t, h;
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if (!rom[7])
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return 0;
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if (rom[1] == 0)
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t = ((s32)rom[0] >> 1)*1000;
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else
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t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
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t -= 250;
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h = 1000*((s32)rom[7] - (s32)rom[6]);
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h /= (s32)rom[7];
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t += h;
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return t;
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}
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static inline int w1_convert_temp(u8 rom[9], u8 fid)
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{
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int i;
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for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
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if (w1_therm_families[i].f->fid == fid)
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return w1_therm_families[i].convert(rom);
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return 0;
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}
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static int w1_therm_check_rom(u8 rom[9])
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{
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int i;
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for (i=0; i<sizeof(bad_roms)/9; ++i)
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if (!memcmp(bad_roms[i], rom, 9))
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return 1;
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return 0;
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}
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static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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struct w1_master *dev = sl->master;
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u8 rom[9], crc, verdict;
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int i, max_trying = 10;
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atomic_inc(&sl->refcnt);
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smp_mb__after_atomic_inc();
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if (down_interruptible(&sl->master->mutex)) {
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count = 0;
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goto out_dec;
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}
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if (off > W1_SLAVE_DATA_SIZE) {
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count = 0;
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goto out;
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}
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if (off + count > W1_SLAVE_DATA_SIZE) {
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count = 0;
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goto out;
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}
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memset(buf, 0, count);
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memset(rom, 0, sizeof(rom));
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count = 0;
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verdict = 0;
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crc = 0;
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while (max_trying--) {
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if (!w1_reset_select_slave(sl)) {
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int count = 0;
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unsigned int tm = 750;
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w1_write_8(dev, W1_CONVERT_TEMP);
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while (tm) {
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tm = msleep_interruptible(tm);
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if (signal_pending(current))
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flush_signals(current);
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}
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if (!w1_reset_select_slave(sl)) {
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w1_write_8(dev, W1_READ_SCRATCHPAD);
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if ((count = w1_read_block(dev, rom, 9)) != 9) {
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dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
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}
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crc = w1_calc_crc8(rom, 8);
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if (rom[8] == crc && rom[0])
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verdict = 1;
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}
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}
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if (!w1_therm_check_rom(rom))
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break;
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}
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for (i = 0; i < 9; ++i)
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count += sprintf(buf + count, "%02x ", rom[i]);
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count += sprintf(buf + count, ": crc=%02x %s\n",
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crc, (verdict) ? "YES" : "NO");
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if (verdict)
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memcpy(sl->rom, rom, sizeof(sl->rom));
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else
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dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
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for (i = 0; i < 9; ++i)
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count += sprintf(buf + count, "%02x ", sl->rom[i]);
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count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
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out:
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up(&dev->mutex);
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out_dec:
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smp_mb__before_atomic_inc();
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atomic_dec(&sl->refcnt);
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return count;
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}
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static int __init w1_therm_init(void)
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{
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int err, i;
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for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
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err = w1_register_family(w1_therm_families[i].f);
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if (err)
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w1_therm_families[i].broken = 1;
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}
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return 0;
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}
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static void __exit w1_therm_fini(void)
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{
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int i;
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for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
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if (!w1_therm_families[i].broken)
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w1_unregister_family(w1_therm_families[i].f);
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}
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module_init(w1_therm_init);
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module_exit(w1_therm_fini);
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