/* * 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/slab.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."); MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); /* 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. * In case the parasite power-detection is not working (seems to be the case * for some DS18S20) the strong pullup can also be forced, regardless of the * power state of the devices. * * Summary of options: * - strong_pullup = 0 Disable strong pullup completely * - strong_pullup = 1 Enable automatic strong pullup detection * - strong_pullup = 2 Force strong pullup */ static int w1_strong_pullup = 1; module_param_named(strong_pullup, w1_strong_pullup, int, 0); struct w1_therm_family_data { uint8_t rom[9]; atomic_t refcnt; }; /* return the address of the refcnt in the family data */ #define THERM_REFCNT(family_data) \ (&((struct w1_therm_family_data *)family_data)->refcnt) static int w1_therm_add_slave(struct w1_slave *sl) { sl->family_data = kzalloc(sizeof(struct w1_therm_family_data), GFP_KERNEL); if (!sl->family_data) return -ENOMEM; atomic_set(THERM_REFCNT(sl->family_data), 1); return 0; } static void w1_therm_remove_slave(struct w1_slave *sl) { int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); while (refcnt) { msleep(1000); refcnt = atomic_read(THERM_REFCNT(sl->family_data)); } kfree(sl->family_data); sl->family_data = NULL; } static ssize_t w1_slave_show(struct device *device, struct device_attribute *attr, char *buf); static ssize_t w1_slave_store(struct device *device, struct device_attribute *attr, const char *buf, size_t size); static ssize_t w1_seq_show(struct device *device, struct device_attribute *attr, char *buf); static DEVICE_ATTR_RW(w1_slave); static DEVICE_ATTR_RO(w1_seq); static struct attribute *w1_therm_attrs[] = { &dev_attr_w1_slave.attr, NULL, }; static struct attribute *w1_ds28ea00_attrs[] = { &dev_attr_w1_slave.attr, &dev_attr_w1_seq.attr, NULL, }; ATTRIBUTE_GROUPS(w1_therm); ATTRIBUTE_GROUPS(w1_ds28ea00); static struct w1_family_ops w1_therm_fops = { .add_slave = w1_therm_add_slave, .remove_slave = w1_therm_remove_slave, .groups = w1_therm_groups, }; static struct w1_family_ops w1_ds28ea00_fops = { .add_slave = w1_therm_add_slave, .remove_slave = w1_therm_remove_slave, .groups = w1_ds28ea00_groups, }; 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_ds28ea00_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]); int (*precision)(struct device *device, int val); int (*eeprom)(struct device *device); }; /* write configuration to eeprom */ static inline int w1_therm_eeprom(struct device *device); /* Set precision for conversion */ static inline int w1_DS18B20_precision(struct device *device, int val); static inline int w1_DS18S20_precision(struct device *device, int val); /* 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, .precision = w1_DS18S20_precision, .eeprom = w1_therm_eeprom }, { .f = &w1_therm_family_DS1822, .convert = w1_DS18B20_convert_temp, .precision = w1_DS18S20_precision, .eeprom = w1_therm_eeprom }, { .f = &w1_therm_family_DS18B20, .convert = w1_DS18B20_convert_temp, .precision = w1_DS18B20_precision, .eeprom = w1_therm_eeprom }, { .f = &w1_therm_family_DS28EA00, .convert = w1_DS18B20_convert_temp, .precision = w1_DS18S20_precision, .eeprom = w1_therm_eeprom }, { .f = &w1_therm_family_DS1825, .convert = w1_DS18B20_convert_temp, .precision = w1_DS18S20_precision, .eeprom = w1_therm_eeprom } }; static inline int w1_therm_eeprom(struct device *device) { struct w1_slave *sl = dev_to_w1_slave(device); struct w1_master *dev = sl->master; u8 rom[9], external_power; int ret, max_trying = 10; u8 *family_data = sl->family_data; ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) goto post_unlock; if (!sl->family_data) { ret = -ENODEV; goto pre_unlock; } /* prevent the slave from going away in sleep */ atomic_inc(THERM_REFCNT(family_data)); memset(rom, 0, sizeof(rom)); while (max_trying--) { if (!w1_reset_select_slave(sl)) { unsigned int tm = 10; unsigned long sleep_rem; /* check if in parasite mode */ w1_write_8(dev, W1_READ_PSUPPLY); external_power = w1_read_8(dev); if (w1_reset_select_slave(sl)) continue; /* 10ms strong pullup/delay after the copy command */ if (w1_strong_pullup == 2 || (!external_power && w1_strong_pullup)) w1_next_pullup(dev, tm); w1_write_8(dev, W1_COPY_SCRATCHPAD); if (external_power) { mutex_unlock(&dev->bus_mutex); sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { ret = -EINTR; goto post_unlock; } ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) goto post_unlock; } else if (!w1_strong_pullup) { sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { ret = -EINTR; goto pre_unlock; } } break; } } pre_unlock: mutex_unlock(&dev->bus_mutex); post_unlock: atomic_dec(THERM_REFCNT(family_data)); return ret; } /* DS18S20 does not feature configuration register */ static inline int w1_DS18S20_precision(struct device *device, int val) { return 0; } static inline int w1_DS18B20_precision(struct device *device, int val) { struct w1_slave *sl = dev_to_w1_slave(device); struct w1_master *dev = sl->master; u8 rom[9], crc; int ret, max_trying = 10; u8 *family_data = sl->family_data; uint8_t precision_bits; uint8_t mask = 0x60; if (val > 12 || val < 9) { pr_warn("Unsupported precision\n"); return -1; } ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) goto post_unlock; if (!sl->family_data) { ret = -ENODEV; goto pre_unlock; } /* prevent the slave from going away in sleep */ atomic_inc(THERM_REFCNT(family_data)); memset(rom, 0, sizeof(rom)); /* translate precision to bitmask (see datasheet page 9) */ switch (val) { case 9: precision_bits = 0x00; break; case 10: precision_bits = 0x20; break; case 11: precision_bits = 0x40; break; case 12: default: precision_bits = 0x60; break; } while (max_trying--) { crc = 0; if (!w1_reset_select_slave(sl)) { int count = 0; /* read values to only alter precision bits */ w1_write_8(dev, W1_READ_SCRATCHPAD); count = w1_read_block(dev, rom, 9); if (count != 9) dev_warn(device, "w1_read_block() returned %u instead of 9.\n", count); crc = w1_calc_crc8(rom, 8); if (rom[8] == crc) { rom[4] = (rom[4] & ~mask) | (precision_bits & mask); if (!w1_reset_select_slave(sl)) { w1_write_8(dev, W1_WRITE_SCRATCHPAD); w1_write_8(dev, rom[2]); w1_write_8(dev, rom[3]); w1_write_8(dev, rom[4]); break; } } } } pre_unlock: mutex_unlock(&dev->bus_mutex); post_unlock: atomic_dec(THERM_REFCNT(family_data)); return ret; } 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 ssize_t w1_slave_store(struct device *device, struct device_attribute *attr, const char *buf, size_t size) { int val, ret; struct w1_slave *sl = dev_to_w1_slave(device); int i; ret = kstrtoint(buf, 0, &val); if (ret) return ret; for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { if (w1_therm_families[i].f->fid == sl->family->fid) { /* zero value indicates to write current configuration to eeprom */ if (val == 0) ret = w1_therm_families[i].eeprom(device); else ret = w1_therm_families[i].precision(device, val); break; } } return ret ? : size; } static ssize_t w1_slave_show(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, ret, max_trying = 10; ssize_t c = PAGE_SIZE; u8 *family_data = sl->family_data; ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) goto post_unlock; if (!sl->family_data) { ret = -ENODEV; goto pre_unlock; } /* prevent the slave from going away in sleep */ atomic_inc(THERM_REFCNT(family_data)); memset(rom, 0, sizeof(rom)); while (max_trying--) { verdict = 0; crc = 0; 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 (w1_strong_pullup == 2 || (!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) { ret = -EINTR; goto post_unlock; } ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) goto post_unlock; } else if (!w1_strong_pullup) { sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { ret = -EINTR; goto pre_unlock; } } if (!w1_reset_select_slave(sl)) { w1_write_8(dev, W1_READ_SCRATCHPAD); count = w1_read_block(dev, rom, 9); if (count != 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 (verdict) 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(family_data, rom, sizeof(rom)); else dev_warn(device, "Read failed CRC check\n"); for (i = 0; i < 9; ++i) c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", ((u8 *)family_data)[i]); c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", w1_convert_temp(rom, sl->family->fid)); ret = PAGE_SIZE - c; pre_unlock: mutex_unlock(&dev->bus_mutex); post_unlock: atomic_dec(THERM_REFCNT(family_data)); return ret; } #define W1_42_CHAIN 0x99 #define W1_42_CHAIN_OFF 0x3C #define W1_42_CHAIN_OFF_INV 0xC3 #define W1_42_CHAIN_ON 0x5A #define W1_42_CHAIN_ON_INV 0xA5 #define W1_42_CHAIN_DONE 0x96 #define W1_42_CHAIN_DONE_INV 0x69 #define W1_42_COND_READ 0x0F #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA #define W1_42_FINISHED_BYTE 0xFF static ssize_t w1_seq_show(struct device *device, struct device_attribute *attr, char *buf) { struct w1_slave *sl = dev_to_w1_slave(device); ssize_t c = PAGE_SIZE; int rv; int i; u8 ack; u64 rn; struct w1_reg_num *reg_num; int seq = 0; mutex_lock(&sl->master->bus_mutex); /* Place all devices in CHAIN state */ if (w1_reset_bus(sl->master)) goto error; w1_write_8(sl->master, W1_SKIP_ROM); w1_write_8(sl->master, W1_42_CHAIN); w1_write_8(sl->master, W1_42_CHAIN_ON); w1_write_8(sl->master, W1_42_CHAIN_ON_INV); msleep(sl->master->pullup_duration); /* check for acknowledgment */ ack = w1_read_8(sl->master); if (ack != W1_42_SUCCESS_CONFIRM_BYTE) goto error; /* In case the bus fails to send 0xFF, limit*/ for (i = 0; i <= 64; i++) { if (w1_reset_bus(sl->master)) goto error; w1_write_8(sl->master, W1_42_COND_READ); rv = w1_read_block(sl->master, (u8 *)&rn, 8); reg_num = (struct w1_reg_num *) &rn; if (reg_num->family == W1_42_FINISHED_BYTE) break; if (sl->reg_num.id == reg_num->id) seq = i; w1_write_8(sl->master, W1_42_CHAIN); w1_write_8(sl->master, W1_42_CHAIN_DONE); w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); w1_read_block(sl->master, &ack, sizeof(ack)); /* check for acknowledgment */ ack = w1_read_8(sl->master); if (ack != W1_42_SUCCESS_CONFIRM_BYTE) goto error; } /* Exit from CHAIN state */ if (w1_reset_bus(sl->master)) goto error; w1_write_8(sl->master, W1_SKIP_ROM); w1_write_8(sl->master, W1_42_CHAIN); w1_write_8(sl->master, W1_42_CHAIN_OFF); w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); /* check for acknowledgment */ ack = w1_read_8(sl->master); if (ack != W1_42_SUCCESS_CONFIRM_BYTE) goto error; mutex_unlock(&sl->master->bus_mutex); c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); return PAGE_SIZE - c; error: mutex_unlock(&sl->master->bus_mutex); return -EIO; } 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);