/* * w1_therm.c * * Copyright (c) 2004 Evgeniy Polyakov * * * 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 #include #include #include #include #include #include #include #include "../w1.h" #include "../w1_int.h" #include "../w1_family.h" MODULE_LICENSE("GPL"); MODULE_AUTHOR("Evgeniy Polyakov "); 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_bin(struct kobject *, struct bin_attribute *, char *, loff_t, size_t); static struct bin_attribute w1_therm_bin_attr = { .attr = { .name = "w1_slave", .mode = S_IRUGO, }, .size = W1_SLAVE_DATA_SIZE, .read = w1_therm_read_bin, }; static int w1_therm_add_slave(struct w1_slave *sl) { return sysfs_create_bin_file(&sl->dev.kobj, &w1_therm_bin_attr); } static void w1_therm_remove_slave(struct w1_slave *sl) { sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_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, }; 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 }, }; static inline int w1_DS18B20_convert_temp(u8 rom[9]) { s16 t = (rom[1] << 8) | rom[0]; t = t*1000/16; 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 < 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; imaster; u8 rom[9], crc, verdict; int i, max_trying = 10; mutex_lock(&sl->master->mutex); 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_select_slave(sl)) { int count = 0; unsigned int tm = 750; /* 750ms strong pullup (or delay) after the convert */ if (w1_strong_pullup) w1_next_pullup(dev, tm); w1_write_8(dev, W1_CONVERT_TEMP); if (!w1_strong_pullup) msleep(tm); if (!w1_reset_select_slave(sl)) { 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) 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: mutex_unlock(&dev->mutex); return count; } 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);