lwn.git/drivers/w1, branch docs-5.13

w1: w1_therm: Fix conversion result for negative temperatures

2021-01-27T13:59:16+00:00

DS18B20 device driver returns an incorrect value for negative temperatures due to a missing sign-extension in w1_DS18B20_convert_temp(). Fix by using s16 temperature value when converting to int. Fixes: 9ace0b4dab1c (w1: w1_therm: Add support for GXCAS GX20MH01 device.) Cc: stable Reported-by: Paweł Marciniak Signed-off-by: Ivan Zaentsev Link: https://lore.kernel.org/r/20210121093021.224764-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman

w1/masters/ds2490: queue up found IDs during scan

2021-01-20T17:50:21+00:00

Queue up found IDs in a buffer and run the callback once for each found ID at the end. This is necessary because we hold the bus_mutex during the whole scan, and some of the "add-device" callbacks deadlock as they themselves want to mutex_lock(bus_mutex). Acked-by: Evgeniy Polyakov Signed-off-by: Christian Vogel Link: https://lore.kernel.org/r/20210113195018.7498-3-vogelchr@vogel.cx Signed-off-by: Greg Kroah-Hartman

w1/w1.c: w1 address crc quick for DS28E04 eeproms

2021-01-20T17:50:21+00:00

Onewire addresses are 64bit family(8bit), unique_id(48bit), crc(8bit) (LSBt to MSB) and self-consistent: crc = crc8(family, unique). DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO have strap pins to set 7 LSB of the address, unfortunately without updating the crc part of the address. It is only consistent if all strap pins float high. [see datasheet 19-6134; Rev 12/11 page 6: 64-bit device id number] We therefore introduce a special handling of family 0x1c (DS28E04) to check address consistency with 7 LSBs of the unique_id set to 1. Acked-by: Evgeniy Polyakov Signed-off-by: Christian Vogel Link: https://lore.kernel.org/r/20210113195018.7498-2-vogelchr@vogel.cx Signed-off-by: Greg Kroah-Hartman

w1: w1_therm: Rename conflicting sysfs attribute 'eeprom' to 'eeprom_cmd'

2020-11-12T07:50:13+00:00

Duplicate attribute 'eeprom' is defined in: 1) Documentation/ABI/testing/sysfs-driver-w1_therm 2) Documentation/ABI/stable/sysfs-driver-w1_ds28e04 Both drivers define an attribute: /sys/bus/w1/devices/.../eeprom with conflicting behavior. Fix by renaming the newer one in w1_therm.c to 'eeprom_cmd'. Reported-by: Mauro Carvalho Chehab Suggested-by: Greg Kroah-Hartman Link: https://lore.kernel.org/lkml/20201029152845.6bbb39ce@coco.lan/ Signed-off-by: Ivan Zaentsev Link: https://lore.kernel.org/r/20201112064931.8471-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman

w1: w1_therm: make w1_poll_completion static

2020-10-05T12:49:24+00:00

kernel test robot rightly points out that w1_poll_completion() should be static, so mark it as such. Cc: Ivan Zaentsev Reported-by: kernel test robot Link: https://lore.kernel.org/r/20201005123703.GA800532@kroah.com Signed-off-by: Greg Kroah-Hartman

w1: Constify static w1_family_ops structs

2020-10-05T11:21:49+00:00

The only usage of these structs is to assign their address to the fops field in the w1_family struct, which is a const pointer. Make them const to allow the compiler to put them in read-only memory. This was done with the following Coccinelle semantic patch (http://coccinelle.lip6.fr/): // @r1 disable optional_qualifier @ identifier i; position p; @@ static struct w1_family_ops i@p = {...}; @ok1@ identifier r1.i; position p; identifier s; @@ static struct w1_family s = { .fops=&i@p, }; @bad1@ position p!={r1.p,ok1.p}; identifier r1.i; @@ i@p @depends on !bad1 disable optional_qualifier@ identifier r1.i; @@ static +const struct w1_family_ops i={}; // Signed-off-by: Rikard Falkeborn Link: https://lore.kernel.org/r/20201004193202.4044-3-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman

w1: Constify struct w1_family_ops

2020-10-05T11:21:49+00:00

The fops field in the w1_family struct is never modified. Make it const to indicate that. Constifying the pointer makes it possible for drivers to declare static w1_family_ops structs const, which in turn will allow the compiler to put it in read-only memory. Reviewed-by: Sebastian Reichel Signed-off-by: Rikard Falkeborn Link: https://lore.kernel.org/r/20201004193202.4044-2-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman

w1: mxc_w1: Fix timeout resolution problem leading to bus error

2020-10-02T13:53:25+00:00

On my platform (i.MX53) bus access sometimes fails with w1_search: max_slave_count 64 reached, will continue next search. The reason is the use of jiffies to implement a 200us timeout in mxc_w1_ds2_touch_bit(). On some platforms the jiffies timer resolution is insufficient for this. Fix by replacing jiffies by ktime_get(). For consistency apply the same change to the other use of jiffies in mxc_w1_ds2_reset_bus(). Fixes: f80b2581a706 ("w1: mxc_w1: Optimize mxc_w1_ds2_touch_bit()") Cc: stable Signed-off-by: Martin Fuzzey Link: https://lore.kernel.org/r/1601455030-6607-1-git-send-email-martin.fuzzey@flowbird.group Signed-off-by: Greg Kroah-Hartman

w1: w1_therm: Add support for GXCAS GX20MH01 device.

2020-10-02T09:49:54+00:00

GX20MH01 device shares family number 0x28 with DS18B20. The device is generally compatible with DS18B20. Added are the lowest 2^-5, 2^-6 temperature bits in Config register; R2 bit in Config register enabling 13 and 14 bit resolutions. It is powered up in 14 bit mode. Signed-off-by: Ivan Zaentsev Link: https://lore.kernel.org/r/20200904160004.87710-2-ivan.zaentsev@wirenboard.ru Acked-by: Evgeniy Polyakov Signed-off-by: Greg Kroah-Hartman

w1: w1_therm: Add sysfs entries to control conversion time and driver features

2020-10-02T09:49:50+00:00

The conversion time of common DS18B20 clones deviates from datasheet specs. Allow adjustment and automatic measure of the conversion time. Add 'conv_time' sysfs attribute: *read*: Current conversion time in milliseconds. *write*: '0': Set default conversion time. '1': Measure and set the conversion time. Make a single temperature conversion, poll and measure an actual value. Measured value is increased by 20% for temperature drift. A new conversion time is returned by reading the same attribute. other positive value: Set the conversion time in milliseconds. The setting is active until a resolution change. Then it is reset to default conversion time for a new resolution. Add 'features' sysfs attribute to control optional driver settings per device. Bit masks to read/write (logical OR): 1: Enable check for conversion success. If byte 6 of scratchpad memory is 0xC after conversion, and temperature reads 85.00 (powerup value) or 127.94 (insufficient power) - return a conversion error. 2: Enable poll for conversion completion. Generate read cycles after the conversion start and wait for 1's. In parasite power mode this feature is not available. There are some clones of DS18B20 with fixed 12 bit resolution. Make the driver verify the resolution by reading back the device after resolution change. Signed-off-by: Ivan Zaentsev Acked-by: Evgeniy Polyakov Link: https://lore.kernel.org/r/20200904160004.87710-1-ivan.zaentsev@wirenboard.ru Signed-off-by: Greg Kroah-Hartman