/* * w1_therm.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 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/device.h> #include <linux/types.h> #include <linux/delay.h> #include "w1.h" #include "w1_io.h" #include "w1_int.h" #include "w1_family.h" MODULE_LICENSE("GPL"); MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>"); MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); static u8 bad_roms[][9] = { {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87}, {} }; static ssize_t w1_therm_read_name(struct device *, struct device_attribute *attr, char *); static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t); static struct w1_family_ops w1_therm_fops = { .rname = &w1_therm_read_name, .rbin = &w1_therm_read_bin, }; 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, }; struct w1_therm_family_converter { u8 broken; u16 reserved; struct w1_family *f; int (*convert)(u8 rom[9]); }; 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 }, }; static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf) { struct w1_slave *sl = container_of(dev, struct w1_slave, dev); return sprintf(buf, "%s\n", sl->name); } static inline int w1_DS18B20_convert_temp(u8 rom[9]) { int t = (rom[1] << 8) | rom[0]; t /= 16; return t; } 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<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++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_bin(struct kobject *kobj, char *buf, loff_t off, size_t count) { struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj), struct w1_slave, dev); struct w1_master *dev = sl->master; u8 rom[9], crc, verdict; int i, max_trying = 10; atomic_inc(&sl->refcnt); smp_mb__after_atomic_inc(); if (down_interruptible(&sl->master->mutex)) { count = 0; goto out_dec; } if (off > W1_SLAVE_DATA_SIZE) { count = 0; goto out; } if (off + count > W1_SLAVE_DATA_SIZE) { count = 0; goto out; } memset(buf, 0, count); memset(rom, 0, sizeof(rom)); count = 0; verdict = 0; crc = 0; while (max_trying--) { if (!w1_reset_bus (dev)) { int count = 0; u8 match[9] = {W1_MATCH_ROM, }; unsigned int tm = 750; memcpy(&match[1], (u64 *) & sl->reg_num, 8); w1_write_block(dev, match, 9); w1_write_8(dev, W1_CONVERT_TEMP); while (tm) { tm = msleep_interruptible(tm); if (signal_pending(current)) flush_signals(current); } if (!w1_reset_bus (dev)) { w1_write_block(dev, match, 9); w1_write_8(dev, W1_READ_SCRATCHPAD); if ((count = w1_read_block(dev, rom, 9)) != 9) { dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count); } crc = w1_calc_crc8(rom, 8); if (rom[8] == crc && rom[0]) verdict = 1; } } if (!w1_therm_check_rom(rom)) break; } for (i = 0; i < 9; ++i) count += sprintf(buf + count, "%02x ", rom[i]); count += sprintf(buf + count, ": crc=%02x %s\n", crc, (verdict) ? "YES" : "NO"); if (verdict) memcpy(sl->rom, rom, sizeof(sl->rom)); else dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n"); for (i = 0; i < 9; ++i) count += sprintf(buf + count, "%02x ", sl->rom[i]); count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid)); out: up(&dev->mutex); out_dec: smp_mb__before_atomic_inc(); atomic_dec(&sl->refcnt); return count; } static int __init w1_therm_init(void) { int err, i; for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++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<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++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);