diff options
author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-31 17:08:53 -0300 |
---|---|---|
committer | Jonathan Corbet <corbet@lwn.net> | 2019-07-31 14:16:17 -0600 |
commit | e9bb627561535dd584b43a8c0afe93a67bc6a2c5 (patch) | |
tree | ca91d46418c232f56b7f36010d6fe4317eb9d2ad /Documentation/w1 | |
parent | f139291c713069b5fa826ff509190efb5df83860 (diff) |
docs: w1: convert to ReST and add to the kAPI group of docs
The 1wire documentation was written with w1 developers in
mind, so, it makes sense to add it together with the driver-api
set.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/w1')
-rw-r--r-- | Documentation/w1/index.rst | 21 | ||||
-rw-r--r-- | Documentation/w1/masters/ds2482.rst (renamed from Documentation/w1/masters/ds2482) | 16 | ||||
-rw-r--r-- | Documentation/w1/masters/ds2490.rst (renamed from Documentation/w1/masters/ds2490) | 6 | ||||
-rw-r--r-- | Documentation/w1/masters/index.rst | 14 | ||||
-rw-r--r-- | Documentation/w1/masters/mxc-w1 | 12 | ||||
-rw-r--r-- | Documentation/w1/masters/mxc-w1.rst | 17 | ||||
-rw-r--r-- | Documentation/w1/masters/omap-hdq.rst (renamed from Documentation/w1/masters/omap-hdq) | 12 | ||||
-rw-r--r-- | Documentation/w1/masters/w1-gpio.rst (renamed from Documentation/w1/masters/w1-gpio) | 21 | ||||
-rw-r--r-- | Documentation/w1/slaves/index.rst | 16 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds2406.rst (renamed from Documentation/w1/slaves/w1_ds2406) | 4 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds2413.rst (renamed from Documentation/w1/slaves/w1_ds2413) | 9 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds2423 | 47 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds2423.rst | 54 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds2438.rst (renamed from Documentation/w1/slaves/w1_ds2438) | 10 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds28e04.rst (renamed from Documentation/w1/slaves/w1_ds28e04) | 5 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_ds28e17.rst (renamed from Documentation/w1/slaves/w1_ds28e17) | 16 | ||||
-rw-r--r-- | Documentation/w1/slaves/w1_therm.rst (renamed from Documentation/w1/slaves/w1_therm) | 11 | ||||
-rw-r--r-- | Documentation/w1/w1-generic.rst (renamed from Documentation/w1/w1.generic) | 88 | ||||
-rw-r--r-- | Documentation/w1/w1-netlink.rst (renamed from Documentation/w1/w1.netlink) | 89 |
19 files changed, 303 insertions, 165 deletions
diff --git a/Documentation/w1/index.rst b/Documentation/w1/index.rst new file mode 100644 index 000000000000..57cba81865e2 --- /dev/null +++ b/Documentation/w1/index.rst @@ -0,0 +1,21 @@ +. SPDX-License-Identifier: GPL-2.0 + +================ +1-Wire Subsystem +================ + +.. toctree:: + :maxdepth: 1 + + + w1-generic.rst + w1-netlink.rst + masters/index + slaves/index + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/w1/masters/ds2482 b/Documentation/w1/masters/ds2482.rst index 56f8edace6ac..17ebe8f660cd 100644 --- a/Documentation/w1/masters/ds2482 +++ b/Documentation/w1/masters/ds2482.rst @@ -1,13 +1,19 @@ +==================== Kernel driver ds2482 ==================== Supported chips: + * Maxim DS2482-100, Maxim DS2482-800 + Prefix: 'ds2482' + Addresses scanned: None + Datasheets: - http://datasheets.maxim-ic.com/en/ds/DS2482-100.pdf - http://datasheets.maxim-ic.com/en/ds/DS2482-800.pdf + + - http://datasheets.maxim-ic.com/en/ds/DS2482-100.pdf + - http://datasheets.maxim-ic.com/en/ds/DS2482-800.pdf Author: Ben Gardner <bgardner@wabtec.com> @@ -23,9 +29,11 @@ General Remarks --------------- Valid addresses are 0x18, 0x19, 0x1a, and 0x1b. + However, the device cannot be detected without writing to the i2c bus, so no detection is done. You should instantiate the device explicitly. -$ modprobe ds2482 -$ echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-0/new_device +:: + $ modprobe ds2482 + $ echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-0/new_device diff --git a/Documentation/w1/masters/ds2490 b/Documentation/w1/masters/ds2490.rst index 3e091151dd80..7e5b50f9c0f5 100644 --- a/Documentation/w1/masters/ds2490 +++ b/Documentation/w1/masters/ds2490.rst @@ -1,7 +1,9 @@ +==================== Kernel driver ds2490 ==================== Supported chips: + * Maxim DS2490 based Author: Evgeniy Polyakov <johnpol@2ka.mipt.ru> @@ -18,6 +20,7 @@ which has 0x81 family ID integrated chip and DS2490 low-level operational chip. Notes and limitations. + - The weak pullup current is a minimum of 0.9mA and maximum of 6.0mA. - The 5V strong pullup is supported with a minimum of 5.9mA and a maximum of 30.4 mA. (From DS2490.pdf) @@ -65,4 +68,5 @@ Notes and limitations. reattaching would clear the problem. usbmon output in the guest and host did not explain the problem. My guess is a bug in either qemu or the host OS and more likely the host OS. --- 03-06-2008 David Fries <David@Fries.net> + +03-06-2008 David Fries <David@Fries.net> diff --git a/Documentation/w1/masters/index.rst b/Documentation/w1/masters/index.rst new file mode 100644 index 000000000000..4442a98850ad --- /dev/null +++ b/Documentation/w1/masters/index.rst @@ -0,0 +1,14 @@ +. SPDX-License-Identifier: GPL-2.0 + +===================== +1-wire Master Drivers +===================== + +.. toctree:: + :maxdepth: 1 + + ds2482 + ds2490 + mxc-w1 + omap-hdq + w1-gpio diff --git a/Documentation/w1/masters/mxc-w1 b/Documentation/w1/masters/mxc-w1 deleted file mode 100644 index 38be1ad65532..000000000000 --- a/Documentation/w1/masters/mxc-w1 +++ /dev/null @@ -1,12 +0,0 @@ -Kernel driver mxc_w1 -==================== - -Supported chips: - * Freescale MX27, MX31 and probably other i.MX SoCs - Datasheets: - http://www.freescale.com/files/32bit/doc/data_sheet/MCIMX31.pdf?fpsp=1 - http://cache.freescale.com/files/dsp/doc/archive/MCIMX27.pdf?fsrch=1&WT_TYPE= - Data%20Sheets&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation - -Author: Originally based on Freescale code, prepared for mainline by - Sascha Hauer <s.hauer@pengutronix.de> diff --git a/Documentation/w1/masters/mxc-w1.rst b/Documentation/w1/masters/mxc-w1.rst new file mode 100644 index 000000000000..334f9893103f --- /dev/null +++ b/Documentation/w1/masters/mxc-w1.rst @@ -0,0 +1,17 @@ +==================== +Kernel driver mxc_w1 +==================== + +Supported chips: + + * Freescale MX27, MX31 and probably other i.MX SoCs + + Datasheets: + + - http://www.freescale.com/files/32bit/doc/data_sheet/MCIMX31.pdf?fpsp=1 + - http://cache.freescale.com/files/dsp/doc/archive/MCIMX27.pdf?fsrch=1&WT_TYPE=Data%20Sheets&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation + +Author: + + Originally based on Freescale code, prepared for mainline by + Sascha Hauer <s.hauer@pengutronix.de> diff --git a/Documentation/w1/masters/omap-hdq b/Documentation/w1/masters/omap-hdq.rst index 234522709a5f..345298a59e50 100644 --- a/Documentation/w1/masters/omap-hdq +++ b/Documentation/w1/masters/omap-hdq.rst @@ -1,9 +1,10 @@ -Kernel driver for omap HDQ/1-wire module. +======================================== +Kernel driver for omap HDQ/1-wire module ======================================== Supported chips: ================ - HDQ/1-wire controller on the TI OMAP 2430/3430 platforms. +HDQ/1-wire controller on the TI OMAP 2430/3430 platforms. A useful link about HDQ basics: =============================== @@ -40,9 +41,10 @@ driver(drivers/w1/slaves/w1_bq27000.c) sets the ID to 1. Please note to load both the modules with a different ID if required, but note that the ID used should be same for both master and slave driver loading. -e.g: -insmod omap_hdq.ko W1_ID=2 -inamod w1_bq27000.ko F_ID=2 +e.g:: + + insmod omap_hdq.ko W1_ID=2 + inamod w1_bq27000.ko F_ID=2 The driver also supports 1-wire mode. In this mode, there is no need to pass slave ID as parameter. The driver will auto-detect slaves connected diff --git a/Documentation/w1/masters/w1-gpio b/Documentation/w1/masters/w1-gpio.rst index 623961d9e83f..18fdb7366372 100644 --- a/Documentation/w1/masters/w1-gpio +++ b/Documentation/w1/masters/w1-gpio.rst @@ -1,3 +1,4 @@ +===================== Kernel driver w1-gpio ===================== @@ -16,28 +17,30 @@ Documentation/devicetree/bindings/w1/w1-gpio.txt Example (mach-at91) ------------------- -#include <linux/gpio/machine.h> -#include <linux/w1-gpio.h> +:: + + #include <linux/gpio/machine.h> + #include <linux/w1-gpio.h> -static struct gpiod_lookup_table foo_w1_gpiod_table = { + static struct gpiod_lookup_table foo_w1_gpiod_table = { .dev_id = "w1-gpio", .table = { GPIO_LOOKUP_IDX("at91-gpio", AT91_PIN_PB20, NULL, 0, GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN), }, -}; + }; -static struct w1_gpio_platform_data foo_w1_gpio_pdata = { + static struct w1_gpio_platform_data foo_w1_gpio_pdata = { .ext_pullup_enable_pin = -EINVAL, -}; + }; -static struct platform_device foo_w1_device = { + static struct platform_device foo_w1_device = { .name = "w1-gpio", .id = -1, .dev.platform_data = &foo_w1_gpio_pdata, -}; + }; -... + ... at91_set_GPIO_periph(foo_w1_gpio_pdata.pin, 1); at91_set_multi_drive(foo_w1_gpio_pdata.pin, 1); gpiod_add_lookup_table(&foo_w1_gpiod_table); diff --git a/Documentation/w1/slaves/index.rst b/Documentation/w1/slaves/index.rst new file mode 100644 index 000000000000..d0697b202f09 --- /dev/null +++ b/Documentation/w1/slaves/index.rst @@ -0,0 +1,16 @@ +. SPDX-License-Identifier: GPL-2.0 + +==================== +1-wire Slave Drivers +==================== + +.. toctree:: + :maxdepth: 1 + + w1_ds2406 + w1_ds2413 + w1_ds2423 + w1_ds2438 + w1_ds28e04 + w1_ds28e17 + w1_therm diff --git a/Documentation/w1/slaves/w1_ds2406 b/Documentation/w1/slaves/w1_ds2406.rst index 8137fe6f6c3d..d3e68266084f 100644 --- a/Documentation/w1/slaves/w1_ds2406 +++ b/Documentation/w1/slaves/w1_ds2406.rst @@ -1,7 +1,9 @@ +======================= w1_ds2406 kernel driver ======================= Supported chips: + * Maxim DS2406 (and other family 0x12) addressable switches Author: Scott Alfter <scott@alfter.us> @@ -9,7 +11,7 @@ Author: Scott Alfter <scott@alfter.us> Description ----------- -The w1_ds2406 driver allows connected devices to be switched on and off. +The w1_ds2406 driver allows connected devices to be switched on and off. These chips also provide 128 bytes of OTP EPROM, but reading/writing it is not supported. In TSOC-6 form, the DS2406 provides two switch outputs and can be provided with power on a dedicated input. In TO-92 form, it provides diff --git a/Documentation/w1/slaves/w1_ds2413 b/Documentation/w1/slaves/w1_ds2413.rst index 936263a8ccb4..c15bb5b919b7 100644 --- a/Documentation/w1/slaves/w1_ds2413 +++ b/Documentation/w1/slaves/w1_ds2413.rst @@ -1,11 +1,16 @@ +======================= Kernel driver w1_ds2413 ======================= Supported chips: + * Maxim DS2413 1-Wire Dual Channel Addressable Switch supported family codes: + + ================ ==== W1_FAMILY_DS2413 0x3A + ================ ==== Author: Mariusz Bialonczyk <manio@skyboo.net> @@ -20,11 +25,13 @@ Reading state The "state" file provides one-byte value which is in the same format as for the chip PIO_ACCESS_READ command (refer the datasheet for details): +======== ============================================================= Bit 0: PIOA Pin State Bit 1: PIOA Output Latch State Bit 2: PIOB Pin State Bit 3: PIOB Output Latch State Bit 4-7: Complement of Bit 3 to Bit 0 (verified by the kernel module) +======== ============================================================= This file is readonly. @@ -34,9 +41,11 @@ You can set the PIO pins using the "output" file. It is writable, you can write one-byte value to this sysfs file. Similarly the byte format is the same as for the PIO_ACCESS_WRITE command: +======== ====================================== Bit 0: PIOA Bit 1: PIOB Bit 2-7: No matter (driver will set it to "1"s) +======== ====================================== The chip has some kind of basic protection against transmission errors. diff --git a/Documentation/w1/slaves/w1_ds2423 b/Documentation/w1/slaves/w1_ds2423 deleted file mode 100644 index 3f98b505a0ee..000000000000 --- a/Documentation/w1/slaves/w1_ds2423 +++ /dev/null @@ -1,47 +0,0 @@ -Kernel driver w1_ds2423 -======================= - -Supported chips: - * Maxim DS2423 based counter devices. - -supported family codes: - W1_THERM_DS2423 0x1D - -Author: Mika Laitio <lamikr@pilppa.org> - -Description ------------ - -Support is provided through the sysfs w1_slave file. Each opening and -read sequence of w1_slave file initiates the read of counters and ram -available in DS2423 pages 12 - 15. - -Result of each page is provided as an ASCII output where each counter -value and associated ram buffer is outpputed to own line. - -Each lines will contain the values of 42 bytes read from the counter and -memory page along the crc=YES or NO for indicating whether the read operation -was successful and CRC matched. -If the operation was successful, there is also in the end of each line -a counter value expressed as an integer after c= - -Meaning of 42 bytes represented is following: - - 1 byte from ram page - - 4 bytes for the counter value - - 4 zero bytes - - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes - - 31 remaining bytes from the ram page - - crc=YES/NO indicating whether read was ok and crc matched - - c=<int> current counter value - -example from the successful read: -00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 -00 02 00 00 00 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 -00 29 c6 5d 18 00 00 00 00 04 37 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=408798761 -00 05 00 00 00 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=YES c=5 - -example from the read with crc errors: -00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 -00 02 00 00 22 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO -00 e1 61 5d 19 00 00 00 00 df 0b 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO -00 05 00 00 20 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=NO diff --git a/Documentation/w1/slaves/w1_ds2423.rst b/Documentation/w1/slaves/w1_ds2423.rst new file mode 100644 index 000000000000..755d659ad997 --- /dev/null +++ b/Documentation/w1/slaves/w1_ds2423.rst @@ -0,0 +1,54 @@ +Kernel driver w1_ds2423 +======================= + +Supported chips: + + * Maxim DS2423 based counter devices. + +supported family codes: + + =============== ==== + W1_THERM_DS2423 0x1D + =============== ==== + +Author: Mika Laitio <lamikr@pilppa.org> + +Description +----------- + +Support is provided through the sysfs w1_slave file. Each opening and +read sequence of w1_slave file initiates the read of counters and ram +available in DS2423 pages 12 - 15. + +Result of each page is provided as an ASCII output where each counter +value and associated ram buffer is outpputed to own line. + +Each lines will contain the values of 42 bytes read from the counter and +memory page along the crc=YES or NO for indicating whether the read operation +was successful and CRC matched. +If the operation was successful, there is also in the end of each line +a counter value expressed as an integer after c= + +Meaning of 42 bytes represented is following: + + - 1 byte from ram page + - 4 bytes for the counter value + - 4 zero bytes + - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes + - 31 remaining bytes from the ram page + - crc=YES/NO indicating whether read was ok and crc matched + - c=<int> current counter value + +example from the successful read:: + + 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 + 00 02 00 00 00 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 + 00 29 c6 5d 18 00 00 00 00 04 37 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=408798761 + 00 05 00 00 00 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=YES c=5 + +example from the read with crc errors:: + + 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2 + 00 02 00 00 22 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO + 00 e1 61 5d 19 00 00 00 00 df 0b 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO + 00 05 00 00 20 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=NO diff --git a/Documentation/w1/slaves/w1_ds2438 b/Documentation/w1/slaves/w1_ds2438.rst index e64f65a09387..a29309a3f8e5 100644 --- a/Documentation/w1/slaves/w1_ds2438 +++ b/Documentation/w1/slaves/w1_ds2438.rst @@ -2,10 +2,13 @@ Kernel driver w1_ds2438 ======================= Supported chips: + * Maxim DS2438 Smart Battery Monitor supported family codes: + ================ ==== W1_FAMILY_DS2438 0x26 + ================ ==== Author: Mariusz Bialonczyk <manio@skyboo.net> @@ -56,8 +59,11 @@ Opening and reading this file initiates the CONVERT_V (voltage conversion) command of the chip. Depending on a sysfs filename a different input for the A/D will be selected: -vad: general purpose A/D input (VAD) -vdd: battery input (VDD) + +vad: + general purpose A/D input (VAD) +vdd: + battery input (VDD) After the voltage conversion the value is returned as decimal ASCII. Note: To get a volts the value has to be divided by 100. diff --git a/Documentation/w1/slaves/w1_ds28e04 b/Documentation/w1/slaves/w1_ds28e04.rst index 7819b65cfa48..b12b118890d3 100644 --- a/Documentation/w1/slaves/w1_ds28e04 +++ b/Documentation/w1/slaves/w1_ds28e04.rst @@ -1,11 +1,16 @@ +======================== Kernel driver w1_ds28e04 ======================== Supported chips: + * Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO supported family codes: + + ================= ==== W1_FAMILY_DS28E04 0x1C + ================= ==== Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de> diff --git a/Documentation/w1/slaves/w1_ds28e17 b/Documentation/w1/slaves/w1_ds28e17.rst index 7fcfad5b4a37..e2d9f96d8f2c 100644 --- a/Documentation/w1/slaves/w1_ds28e17 +++ b/Documentation/w1/slaves/w1_ds28e17.rst @@ -1,11 +1,16 @@ +======================== Kernel driver w1_ds28e17 ======================== Supported chips: + * Maxim DS28E17 1-Wire-to-I2C Master Bridge supported family codes: + + ================= ==== W1_FAMILY_DS28E17 0x19 + ================= ==== Author: Jan Kandziora <jjj@gmx.de> @@ -20,11 +25,11 @@ a DS28E17 can be accessed by the kernel or userspace tools as if they were connected to a "native" I2C bus master. -An udev rule like the following -------------------------------------------------------------------------------- -SUBSYSTEM=="i2c-dev", KERNEL=="i2c-[0-9]*", ATTRS{name}=="w1-19-*", \ - SYMLINK+="i2c-$attr{name}" -------------------------------------------------------------------------------- +An udev rule like the following:: + + SUBSYSTEM=="i2c-dev", KERNEL=="i2c-[0-9]*", ATTRS{name}=="w1-19-*", \ + SYMLINK+="i2c-$attr{name}" + may be used to create stable /dev/i2c- entries based on the unique id of the DS28E17 chip. @@ -65,4 +70,3 @@ structure is created. See https://github.com/ianka/w1_ds28e17 for even more information. - diff --git a/Documentation/w1/slaves/w1_therm b/Documentation/w1/slaves/w1_therm.rst index d1f93af36f38..90531c340a07 100644 --- a/Documentation/w1/slaves/w1_therm +++ b/Documentation/w1/slaves/w1_therm.rst @@ -1,7 +1,9 @@ +====================== Kernel driver w1_therm -==================== +====================== Supported chips: + * Maxim ds18*20 based temperature sensors. * Maxim ds1825 based temperature sensors. @@ -13,12 +15,16 @@ Description w1_therm provides basic temperature conversion for ds18*20 devices, and the ds28ea00 device. -supported family codes: + +Supported family codes: + +==================== ==== W1_THERM_DS18S20 0x10 W1_THERM_DS1822 0x22 W1_THERM_DS18B20 0x28 W1_THERM_DS1825 0x3B W1_THERM_DS28EA00 0x42 +==================== ==== Support is provided through the sysfs w1_slave file. Each open and read sequence will initiate a temperature conversion then provide two @@ -51,6 +57,7 @@ If so, it will activate the master's strong pullup. In case the detection of parasite devices using this command fails (seems to be the case with some DS18S20) the strong pullup can be force-enabled. + If the strong pullup is enabled, the master's strong pullup will be driven when the conversion is taking place, provided the master driver does support the strong pullup (or it falls back to a pullup diff --git a/Documentation/w1/w1.generic b/Documentation/w1/w1-generic.rst index c51b1ab012d0..da4e8b4e9b01 100644 --- a/Documentation/w1/w1.generic +++ b/Documentation/w1/w1-generic.rst @@ -1,5 +1,7 @@ -The 1-wire (w1) subsystem ------------------------------------------------------------------- +========================================= +Introduction to the 1-wire (w1) subsystem +========================================= + The 1-wire bus is a simple master-slave bus that communicates via a single signal wire (plus ground, so two wires). @@ -12,14 +14,16 @@ communication with slaves. All w1 slave devices must be connected to a w1 bus master device. Example w1 master devices: - DS9490 usb device - W1-over-GPIO - DS2482 (i2c to w1 bridge) - Emulated devices, such as a RS232 converter, parallel port adapter, etc + + - DS9490 usb device + - W1-over-GPIO + - DS2482 (i2c to w1 bridge) + - Emulated devices, such as a RS232 converter, parallel port adapter, etc What does the w1 subsystem do? ------------------------------------------------------------------- +------------------------------ + When a w1 master driver registers with the w1 subsystem, the following occurs: - sysfs entries for that w1 master are created @@ -43,24 +47,28 @@ be read, since no device was selected. W1 device families ------------------------------------------------------------------- +------------------ + Slave devices are handled by a driver written for a family of w1 devices. A family driver populates a struct w1_family_ops (see w1_family.h) and registers with the w1 subsystem. Current family drivers: -w1_therm - (ds18?20 thermal sensor family driver) + +w1_therm + - (ds18?20 thermal sensor family driver) provides temperature reading function which is bound to ->rbin() method of the above w1_family_ops structure. -w1_smem - driver for simple 64bit memory cell provides ID reading method. +w1_smem + - driver for simple 64bit memory cell provides ID reading method. You can call above methods by reading appropriate sysfs files. What does a w1 master driver need to implement? ------------------------------------------------------------------- +----------------------------------------------- The driver for w1 bus master must provide at minimum two functions. @@ -75,25 +83,26 @@ See struct w1_bus_master definition in w1.h for details. w1 master sysfs interface ------------------------------------------------------------------- -<xx-xxxxxxxxxxxx> - A directory for a found device. The format is family-serial -bus - (standard) symlink to the w1 bus -driver - (standard) symlink to the w1 driver -w1_master_add - (rw) manually register a slave device -w1_master_attempts - (ro) the number of times a search was attempted -w1_master_max_slave_count - - (rw) maximum number of slaves to search for at a time -w1_master_name - (ro) the name of the device (w1_bus_masterX) -w1_master_pullup - (rw) 5V strong pullup 0 enabled, 1 disabled -w1_master_remove - (rw) manually remove a slave device -w1_master_search - (rw) the number of searches left to do, - -1=continual (default) -w1_master_slave_count - - (ro) the number of slaves found -w1_master_slaves - (ro) the names of the slaves, one per line -w1_master_timeout - (ro) the delay in seconds between searches -w1_master_timeout_us - - (ro) the delay in microseconds beetwen searches +------------------------- + +========================= ===================================================== +<xx-xxxxxxxxxxxx> A directory for a found device. The format is + family-serial +bus (standard) symlink to the w1 bus +driver (standard) symlink to the w1 driver +w1_master_add (rw) manually register a slave device +w1_master_attempts (ro) the number of times a search was attempted +w1_master_max_slave_count (rw) maximum number of slaves to search for at a time +w1_master_name (ro) the name of the device (w1_bus_masterX) +w1_master_pullup (rw) 5V strong pullup 0 enabled, 1 disabled +w1_master_remove (rw) manually remove a slave device +w1_master_search (rw) the number of searches left to do, + -1=continual (default) +w1_master_slave_count (ro) the number of slaves found +w1_master_slaves (ro) the names of the slaves, one per line +w1_master_timeout (ro) the delay in seconds between searches +w1_master_timeout_us (ro) the delay in microseconds beetwen searches +========================= ===================================================== If you have a w1 bus that never changes (you don't add or remove devices), you can set the module parameter search_count to a small positive number @@ -111,11 +120,14 @@ decrements w1_master_search by 1 (down to 0) and increments w1_master_attempts by 1. w1 slave sysfs interface ------------------------------------------------------------------- -bus - (standard) symlink to the w1 bus -driver - (standard) symlink to the w1 driver -name - the device name, usually the same as the directory name -w1_slave - (optional) a binary file whose meaning depends on the - family driver -rw - (optional) created for slave devices which do not have - appropriate family driver. Allows to read/write binary data. +------------------------ + +=================== ============================================================ +bus (standard) symlink to the w1 bus +driver (standard) symlink to the w1 driver +name the device name, usually the same as the directory name +w1_slave (optional) a binary file whose meaning depends on the + family driver +rw (optional) created for slave devices which do not have + appropriate family driver. Allows to read/write binary data. +=================== ============================================================ diff --git a/Documentation/w1/w1.netlink b/Documentation/w1/w1-netlink.rst index 94ad4c420828..aaa13243a5e4 100644 --- a/Documentation/w1/w1.netlink +++ b/Documentation/w1/w1-netlink.rst @@ -1,22 +1,26 @@ -Userspace communication protocol over connector [1]. +=============================================== +Userspace communication protocol over connector +=============================================== - -Message types. +Message types ============= There are three types of messages between w1 core and userspace: + 1. Events. They are generated each time a new master or slave device - is found either due to automatic or requested search. + is found either due to automatic or requested search. 2. Userspace commands. 3. Replies to userspace commands. -Protocol. +Protocol ======== -[struct cn_msg] - connector header. +:: + + [struct cn_msg] - connector header. Its length field is equal to size of the attached data -[struct w1_netlink_msg] - w1 netlink header. + [struct w1_netlink_msg] - w1 netlink header. __u8 type - message type. W1_LIST_MASTERS list current bus masters @@ -40,7 +44,7 @@ Protocol. } mst; } id; -[struct w1_netlink_cmd] - command for given master or slave device. + [struct w1_netlink_cmd] - command for given master or slave device. __u8 cmd - command opcode. W1_CMD_READ - read command W1_CMD_WRITE - write command @@ -71,18 +75,18 @@ when it is added to w1 core. Currently replies to userspace commands are only generated for read command request. One reply is generated exactly for one w1_netlink_cmd read request. Replies are not combined when sent - i.e. typical reply -messages looks like the following: +messages looks like the following:: -[cn_msg][w1_netlink_msg][w1_netlink_cmd] -cn_msg.len = sizeof(struct w1_netlink_msg) + + [cn_msg][w1_netlink_msg][w1_netlink_cmd] + cn_msg.len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd->len; -w1_netlink_msg.len = sizeof(struct w1_netlink_cmd) + cmd->len; -w1_netlink_cmd.len = cmd->len; + w1_netlink_msg.len = sizeof(struct w1_netlink_cmd) + cmd->len; + w1_netlink_cmd.len = cmd->len; Replies to W1_LIST_MASTERS should send a message back to the userspace which will contain list of all registered master ids in the following -format: +format:: cn_msg (CN_W1_IDX.CN_W1_VAL as id, len is equal to sizeof(struct w1_netlink_msg) plus number of masters multiplied by 4) @@ -90,39 +94,47 @@ format: number of masters multiplied by 4 (u32 size)) id0 ... idN - Each message is at most 4k in size, so if number of master devices - exceeds this, it will be split into several messages. +Each message is at most 4k in size, so if number of master devices +exceeds this, it will be split into several messages. W1 search and alarm search commands. -request: -[cn_msg] - [w1_netlink_msg type = W1_MASTER_CMD - id is equal to the bus master id to use for searching] - [w1_netlink_cmd cmd = W1_CMD_SEARCH or W1_CMD_ALARM_SEARCH] -reply: +request:: + + [cn_msg] + [w1_netlink_msg type = W1_MASTER_CMD + id is equal to the bus master id to use for searching] + [w1_netlink_cmd cmd = W1_CMD_SEARCH or W1_CMD_ALARM_SEARCH] + +reply:: + [cn_msg, ack = 1 and increasing, 0 means the last message, - seq is equal to the request seq] + seq is equal to the request seq] [w1_netlink_msg type = W1_MASTER_CMD] [w1_netlink_cmd cmd = W1_CMD_SEARCH or W1_CMD_ALARM_SEARCH len is equal to number of IDs multiplied by 8] [64bit-id0 ... 64bit-idN] + Length in each header corresponds to the size of the data behind it, so w1_netlink_cmd->len = N * 8; where N is number of IDs in this message. - Can be zero. -w1_netlink_msg->len = sizeof(struct w1_netlink_cmd) + N * 8; -cn_msg->len = sizeof(struct w1_netlink_msg) + +Can be zero. + +:: + + w1_netlink_msg->len = sizeof(struct w1_netlink_cmd) + N * 8; + cn_msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + N*8; -W1 reset command. -[cn_msg] - [w1_netlink_msg type = W1_MASTER_CMD - id is equal to the bus master id to use for searching] - [w1_netlink_cmd cmd = W1_CMD_RESET] +W1 reset command:: + [cn_msg] + [w1_netlink_msg type = W1_MASTER_CMD + id is equal to the bus master id to use for searching] + [w1_netlink_cmd cmd = W1_CMD_RESET] -Command status replies. + +Command status replies ====================== Each command (either root, master or slave with or without w1_netlink_cmd @@ -150,7 +162,7 @@ All w1_netlink_cmd command structures are handled in every w1_netlink_msg, even if there were errors, only length mismatch interrupts message processing. -Operation steps in w1 core when new command is received. +Operation steps in w1 core when new command is received ======================================================= When new message (w1_netlink_msg) is received w1 core detects if it is @@ -167,7 +179,7 @@ When all commands (w1_netlink_cmd) are processed master device is unlocked and next w1_netlink_msg header processing started. -Connector [1] specific documentation. +Connector [1] specific documentation ==================================== Each connector message includes two u32 fields as "address". @@ -180,10 +192,11 @@ Sequence number for reply is the same as was in request, and acknowledge number is set to seq+1. -Additional documantion, source code examples. -============================================ +Additional documentation, source code examples +============================================== 1. Documentation/driver-api/connector.rst 2. http://www.ioremap.net/archive/w1 -This archive includes userspace application w1d.c which uses -read/write/search commands for all master/slave devices found on the bus. + + This archive includes userspace application w1d.c which uses + read/write/search commands for all master/slave devices found on the bus. |