b02f8bede2
The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
135 lines
3.8 KiB
C
135 lines
3.8 KiB
C
/*
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* 1-Wire implementation for the ds2780 chip
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*
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* Author: Renata Sayakhova <renata@oktetlabs.ru>
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*
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* Based on w1-ds2760 driver
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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 terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#ifndef _W1_DS2781_H
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#define _W1_DS2781_H
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/* Function commands */
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#define W1_DS2781_READ_DATA 0x69
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#define W1_DS2781_WRITE_DATA 0x6C
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#define W1_DS2781_COPY_DATA 0x48
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#define W1_DS2781_RECALL_DATA 0xB8
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#define W1_DS2781_LOCK 0x6A
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/* Register map */
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/* Register 0x00 Reserved */
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#define DS2781_STATUS 0x01
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#define DS2781_RAAC_MSB 0x02
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#define DS2781_RAAC_LSB 0x03
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#define DS2781_RSAC_MSB 0x04
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#define DS2781_RSAC_LSB 0x05
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#define DS2781_RARC 0x06
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#define DS2781_RSRC 0x07
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#define DS2781_IAVG_MSB 0x08
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#define DS2781_IAVG_LSB 0x09
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#define DS2781_TEMP_MSB 0x0A
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#define DS2781_TEMP_LSB 0x0B
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#define DS2781_VOLT_MSB 0x0C
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#define DS2781_VOLT_LSB 0x0D
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#define DS2781_CURRENT_MSB 0x0E
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#define DS2781_CURRENT_LSB 0x0F
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#define DS2781_ACR_MSB 0x10
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#define DS2781_ACR_LSB 0x11
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#define DS2781_ACRL_MSB 0x12
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#define DS2781_ACRL_LSB 0x13
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#define DS2781_AS 0x14
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#define DS2781_SFR 0x15
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#define DS2781_FULL_MSB 0x16
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#define DS2781_FULL_LSB 0x17
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#define DS2781_AE_MSB 0x18
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#define DS2781_AE_LSB 0x19
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#define DS2781_SE_MSB 0x1A
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#define DS2781_SE_LSB 0x1B
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/* Register 0x1C - 0x1E Reserved */
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#define DS2781_EEPROM 0x1F
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#define DS2781_EEPROM_BLOCK0_START 0x20
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/* Register 0x20 - 0x2F User EEPROM */
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#define DS2781_EEPROM_BLOCK0_END 0x2F
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/* Register 0x30 - 0x5F Reserved */
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#define DS2781_EEPROM_BLOCK1_START 0x60
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#define DS2781_CONTROL 0x60
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#define DS2781_AB 0x61
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#define DS2781_AC_MSB 0x62
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#define DS2781_AC_LSB 0x63
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#define DS2781_VCHG 0x64
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#define DS2781_IMIN 0x65
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#define DS2781_VAE 0x66
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#define DS2781_IAE 0x67
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#define DS2781_AE_40 0x68
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#define DS2781_RSNSP 0x69
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#define DS2781_FULL_40_MSB 0x6A
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#define DS2781_FULL_40_LSB 0x6B
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#define DS2781_FULL_4_SLOPE 0x6C
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#define DS2781_FULL_3_SLOPE 0x6D
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#define DS2781_FULL_2_SLOPE 0x6E
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#define DS2781_FULL_1_SLOPE 0x6F
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#define DS2781_AE_4_SLOPE 0x70
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#define DS2781_AE_3_SLOPE 0x71
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#define DS2781_AE_2_SLOPE 0x72
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#define DS2781_AE_1_SLOPE 0x73
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#define DS2781_SE_4_SLOPE 0x74
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#define DS2781_SE_3_SLOPE 0x75
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#define DS2781_SE_2_SLOPE 0x76
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#define DS2781_SE_1_SLOPE 0x77
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#define DS2781_RSGAIN_MSB 0x78
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#define DS2781_RSGAIN_LSB 0x79
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#define DS2781_RSTC 0x7A
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#define DS2781_COB 0x7B
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#define DS2781_TBP34 0x7C
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#define DS2781_TBP23 0x7D
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#define DS2781_TBP12 0x7E
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#define DS2781_EEPROM_BLOCK1_END 0x7F
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/* Register 0x7D - 0xFF Reserved */
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#define DS2781_FSGAIN_MSB 0xB0
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#define DS2781_FSGAIN_LSB 0xB1
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/* Number of valid register addresses */
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#define DS2781_DATA_SIZE 0xB2
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/* Status register bits */
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#define DS2781_STATUS_CHGTF (1 << 7)
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#define DS2781_STATUS_AEF (1 << 6)
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#define DS2781_STATUS_SEF (1 << 5)
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#define DS2781_STATUS_LEARNF (1 << 4)
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/* Bit 3 Reserved */
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#define DS2781_STATUS_UVF (1 << 2)
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#define DS2781_STATUS_PORF (1 << 1)
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/* Bit 0 Reserved */
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/* Control register bits */
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/* Bit 7 Reserved */
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#define DS2781_CONTROL_NBEN (1 << 7)
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#define DS2781_CONTROL_UVEN (1 << 6)
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#define DS2781_CONTROL_PMOD (1 << 5)
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#define DS2781_CONTROL_RNAOP (1 << 4)
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#define DS1781_CONTROL_UVTH (1 << 3)
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/* Bit 0 - 2 Reserved */
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/* Special feature register bits */
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/* Bit 1 - 7 Reserved */
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#define DS2781_SFR_PIOSC (1 << 0)
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/* EEPROM register bits */
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#define DS2781_EEPROM_EEC (1 << 7)
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#define DS2781_EEPROM_LOCK (1 << 6)
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/* Bit 2 - 6 Reserved */
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#define DS2781_EEPROM_BL1 (1 << 1)
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#define DS2781_EEPROM_BL0 (1 << 0)
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extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
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int io);
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extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd);
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#endif /* !_W1_DS2781_H */
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