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>
This commit is contained in:
Mauro Carvalho Chehab
Jonathan Corbet
parent
f139291c71
commit
e9bb627561
@ -6,6 +6,6 @@ Description: Bus scanning interval, microseconds component.
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control systems are attached/generate presence for as short as
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100 ms - hence the tens-to-hundreds milliseconds scan intervals
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are required.
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see Documentation/w1/w1.generic for detailed information.
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see Documentation/w1/w1-generic.rst for detailed information.
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Users: any user space application which wants to know bus scanning
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interval
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@ -2,7 +2,7 @@ What: /sys/bus/w1/devices/.../pio
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Date: May 2012
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Contact: Markus Franke <franm@hrz.tu-chemnitz.de>
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Description: read/write the contents of the two PIO's of the DS28E04-100
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see Documentation/w1/slaves/w1_ds28e04 for detailed information
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see Documentation/w1/slaves/w1_ds28e04.rst for detailed information
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Users: any user space application which wants to communicate with DS28E04-100
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@ -11,5 +11,5 @@ What: /sys/bus/w1/devices/.../eeprom
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Date: May 2012
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Contact: Markus Franke <franm@hrz.tu-chemnitz.de>
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Description: read/write the contents of the EEPROM memory of the DS28E04-100
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see Documentation/w1/slaves/w1_ds28e04 for detailed information
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see Documentation/w1/slaves/w1_ds28e04.rst for detailed information
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Users: any user space application which wants to communicate with DS28E04-100
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@ -2,5 +2,5 @@ What: /sys/bus/w1/devices/.../w1_seq
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Date: Apr 2015
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Contact: Matt Campbell <mattrcampbell@gmail.com>
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Description: Support for the DS28EA00 chain sequence function
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see Documentation/w1/slaves/w1_therm for detailed information
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see Documentation/w1/slaves/w1_therm.rst for detailed information
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Users: any user space application which wants to communicate with DS28EA00
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@ -117,6 +117,7 @@ needed).
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target/index
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timers/index
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spi/index
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w1/index
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watchdog/index
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virtual/index
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input/index
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21
Documentation/w1/index.rst
Normal file
21
Documentation/w1/index.rst
Normal file
@ -0,0 +1,21 @@
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. SPDX-License-Identifier: GPL-2.0
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================
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1-Wire Subsystem
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================
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.. toctree::
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:maxdepth: 1
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w1-generic.rst
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w1-netlink.rst
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masters/index
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slaves/index
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.. only:: subproject and html
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Indices
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=======
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* :ref:`genindex`
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@ -1,13 +1,19 @@
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====================
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Kernel driver ds2482
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====================
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Supported chips:
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* Maxim DS2482-100, Maxim DS2482-800
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Prefix: 'ds2482'
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Addresses scanned: None
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Datasheets:
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http://datasheets.maxim-ic.com/en/ds/DS2482-100.pdf
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http://datasheets.maxim-ic.com/en/ds/DS2482-800.pdf
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- http://datasheets.maxim-ic.com/en/ds/DS2482-100.pdf
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- http://datasheets.maxim-ic.com/en/ds/DS2482-800.pdf
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Author: Ben Gardner <bgardner@wabtec.com>
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@ -23,9 +29,11 @@ General Remarks
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---------------
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Valid addresses are 0x18, 0x19, 0x1a, and 0x1b.
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However, the device cannot be detected without writing to the i2c bus, so no
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detection is done. You should instantiate the device explicitly.
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$ modprobe ds2482
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$ echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-0/new_device
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::
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$ modprobe ds2482
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$ echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-0/new_device
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@ -1,7 +1,9 @@
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====================
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Kernel driver ds2490
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====================
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Supported chips:
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* Maxim DS2490 based
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Author: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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@ -18,6 +20,7 @@ which has 0x81 family ID integrated chip and DS2490
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low-level operational chip.
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Notes and limitations.
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- The weak pullup current is a minimum of 0.9mA and maximum of 6.0mA.
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- The 5V strong pullup is supported with a minimum of 5.9mA and a
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maximum of 30.4 mA. (From DS2490.pdf)
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@ -65,4 +68,5 @@ Notes and limitations.
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reattaching would clear the problem. usbmon output in the guest and
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host did not explain the problem. My guess is a bug in either qemu
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or the host OS and more likely the host OS.
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-- 03-06-2008 David Fries <David@Fries.net>
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03-06-2008 David Fries <David@Fries.net>
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14
Documentation/w1/masters/index.rst
Normal file
14
Documentation/w1/masters/index.rst
Normal file
@ -0,0 +1,14 @@
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. SPDX-License-Identifier: GPL-2.0
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=====================
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1-wire Master Drivers
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=====================
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.. toctree::
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:maxdepth: 1
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ds2482
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ds2490
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mxc-w1
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omap-hdq
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w1-gpio
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@ -1,12 +0,0 @@
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Kernel driver mxc_w1
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====================
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Supported chips:
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* Freescale MX27, MX31 and probably other i.MX SoCs
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Datasheets:
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http://www.freescale.com/files/32bit/doc/data_sheet/MCIMX31.pdf?fpsp=1
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http://cache.freescale.com/files/dsp/doc/archive/MCIMX27.pdf?fsrch=1&WT_TYPE=
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Data%20Sheets&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation
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Author: Originally based on Freescale code, prepared for mainline by
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Sascha Hauer <s.hauer@pengutronix.de>
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17
Documentation/w1/masters/mxc-w1.rst
Normal file
17
Documentation/w1/masters/mxc-w1.rst
Normal file
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====================
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Kernel driver mxc_w1
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====================
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Supported chips:
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* Freescale MX27, MX31 and probably other i.MX SoCs
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Datasheets:
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- http://www.freescale.com/files/32bit/doc/data_sheet/MCIMX31.pdf?fpsp=1
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- 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
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Author:
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Originally based on Freescale code, prepared for mainline by
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Sascha Hauer <s.hauer@pengutronix.de>
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@ -1,9 +1,10 @@
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Kernel driver for omap HDQ/1-wire module.
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========================================
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Kernel driver for omap HDQ/1-wire module
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========================================
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Supported chips:
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================
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HDQ/1-wire controller on the TI OMAP 2430/3430 platforms.
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HDQ/1-wire controller on the TI OMAP 2430/3430 platforms.
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A useful link about HDQ basics:
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===============================
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@ -40,9 +41,10 @@ driver(drivers/w1/slaves/w1_bq27000.c) sets the ID to 1.
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Please note to load both the modules with a different ID if required, but note
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that the ID used should be same for both master and slave driver loading.
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e.g:
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insmod omap_hdq.ko W1_ID=2
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inamod w1_bq27000.ko F_ID=2
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e.g::
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insmod omap_hdq.ko W1_ID=2
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inamod w1_bq27000.ko F_ID=2
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The driver also supports 1-wire mode. In this mode, there is no need to
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pass slave ID as parameter. The driver will auto-detect slaves connected
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@ -1,3 +1,4 @@
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=====================
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Kernel driver w1-gpio
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=====================
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@ -16,28 +17,30 @@ Documentation/devicetree/bindings/w1/w1-gpio.txt
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Example (mach-at91)
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-------------------
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#include <linux/gpio/machine.h>
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#include <linux/w1-gpio.h>
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::
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static struct gpiod_lookup_table foo_w1_gpiod_table = {
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#include <linux/gpio/machine.h>
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#include <linux/w1-gpio.h>
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static struct gpiod_lookup_table foo_w1_gpiod_table = {
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.dev_id = "w1-gpio",
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.table = {
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GPIO_LOOKUP_IDX("at91-gpio", AT91_PIN_PB20, NULL, 0,
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GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN),
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},
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};
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};
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static struct w1_gpio_platform_data foo_w1_gpio_pdata = {
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static struct w1_gpio_platform_data foo_w1_gpio_pdata = {
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.ext_pullup_enable_pin = -EINVAL,
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};
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};
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static struct platform_device foo_w1_device = {
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static struct platform_device foo_w1_device = {
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.name = "w1-gpio",
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.id = -1,
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.dev.platform_data = &foo_w1_gpio_pdata,
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};
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};
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...
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...
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at91_set_GPIO_periph(foo_w1_gpio_pdata.pin, 1);
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at91_set_multi_drive(foo_w1_gpio_pdata.pin, 1);
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gpiod_add_lookup_table(&foo_w1_gpiod_table);
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16
Documentation/w1/slaves/index.rst
Normal file
16
Documentation/w1/slaves/index.rst
Normal file
@ -0,0 +1,16 @@
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. SPDX-License-Identifier: GPL-2.0
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====================
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1-wire Slave Drivers
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====================
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.. toctree::
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:maxdepth: 1
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w1_ds2406
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w1_ds2413
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w1_ds2423
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w1_ds2438
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w1_ds28e04
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w1_ds28e17
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w1_therm
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@ -1,7 +1,9 @@
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=======================
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w1_ds2406 kernel driver
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=======================
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Supported chips:
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* Maxim DS2406 (and other family 0x12) addressable switches
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Author: Scott Alfter <scott@alfter.us>
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@ -1,11 +1,16 @@
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=======================
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Kernel driver w1_ds2413
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=======================
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Supported chips:
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* Maxim DS2413 1-Wire Dual Channel Addressable Switch
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supported family codes:
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================ ====
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W1_FAMILY_DS2413 0x3A
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================ ====
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Author: Mariusz Bialonczyk <manio@skyboo.net>
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@ -20,11 +25,13 @@ Reading state
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The "state" file provides one-byte value which is in the same format as for
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the chip PIO_ACCESS_READ command (refer the datasheet for details):
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======== =============================================================
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Bit 0: PIOA Pin State
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Bit 1: PIOA Output Latch State
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Bit 2: PIOB Pin State
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Bit 3: PIOB Output Latch State
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Bit 4-7: Complement of Bit 3 to Bit 0 (verified by the kernel module)
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======== =============================================================
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This file is readonly.
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@ -34,9 +41,11 @@ You can set the PIO pins using the "output" file.
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It is writable, you can write one-byte value to this sysfs file.
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Similarly the byte format is the same as for the PIO_ACCESS_WRITE command:
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======== ======================================
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Bit 0: PIOA
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Bit 1: PIOB
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Bit 2-7: No matter (driver will set it to "1"s)
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======== ======================================
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The chip has some kind of basic protection against transmission errors.
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@ -1,47 +0,0 @@
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Kernel driver w1_ds2423
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=======================
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Supported chips:
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* Maxim DS2423 based counter devices.
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supported family codes:
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W1_THERM_DS2423 0x1D
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Author: Mika Laitio <lamikr@pilppa.org>
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Description
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-----------
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Support is provided through the sysfs w1_slave file. Each opening and
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read sequence of w1_slave file initiates the read of counters and ram
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available in DS2423 pages 12 - 15.
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Result of each page is provided as an ASCII output where each counter
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value and associated ram buffer is outpputed to own line.
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Each lines will contain the values of 42 bytes read from the counter and
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memory page along the crc=YES or NO for indicating whether the read operation
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was successful and CRC matched.
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If the operation was successful, there is also in the end of each line
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a counter value expressed as an integer after c=
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Meaning of 42 bytes represented is following:
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- 1 byte from ram page
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- 4 bytes for the counter value
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- 4 zero bytes
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- 2 bytes for crc16 which was calculated from the data read since the previous crc bytes
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- 31 remaining bytes from the ram page
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- crc=YES/NO indicating whether read was ok and crc matched
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- c=<int> current counter value
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example from the successful read:
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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
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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
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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
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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
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example from the read with crc errors:
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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
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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
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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
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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
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54
Documentation/w1/slaves/w1_ds2423.rst
Normal file
54
Documentation/w1/slaves/w1_ds2423.rst
Normal file
@ -0,0 +1,54 @@
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Kernel driver w1_ds2423
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=======================
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Supported chips:
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* Maxim DS2423 based counter devices.
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supported family codes:
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=============== ====
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W1_THERM_DS2423 0x1D
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=============== ====
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Author: Mika Laitio <lamikr@pilppa.org>
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Description
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-----------
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Support is provided through the sysfs w1_slave file. Each opening and
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read sequence of w1_slave file initiates the read of counters and ram
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available in DS2423 pages 12 - 15.
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Result of each page is provided as an ASCII output where each counter
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value and associated ram buffer is outpputed to own line.
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Each lines will contain the values of 42 bytes read from the counter and
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memory page along the crc=YES or NO for indicating whether the read operation
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was successful and CRC matched.
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If the operation was successful, there is also in the end of each line
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a counter value expressed as an integer after c=
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Meaning of 42 bytes represented is following:
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- 1 byte from ram page
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- 4 bytes for the counter value
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- 4 zero bytes
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- 2 bytes for crc16 which was calculated from the data read since the previous crc bytes
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- 31 remaining bytes from the ram page
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- crc=YES/NO indicating whether read was ok and crc matched
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- c=<int> current counter value
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example from the successful read::
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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
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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
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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
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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
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example from the read with crc errors::
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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
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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
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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
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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
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@ -2,10 +2,13 @@ Kernel driver w1_ds2438
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=======================
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Supported chips:
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* Maxim DS2438 Smart Battery Monitor
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supported family codes:
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================ ====
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W1_FAMILY_DS2438 0x26
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================ ====
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Author: Mariusz Bialonczyk <manio@skyboo.net>
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@ -56,8 +59,11 @@ Opening and reading this file initiates the CONVERT_V (voltage conversion)
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command of the chip.
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|
||||
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.
|
||||
@ -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>
|
||||
|
||||
@ -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-*", \
|
||||
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.
|
||||
|
||||
@ -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
|
||||
@ -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,
|
||||
-------------------------
|
||||
|
||||
========================= =====================================================
|
||||
<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
|
||||
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
|
||||
------------------------
|
||||
|
||||
=================== ============================================================
|
||||
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
|
||||
rw (optional) created for slave devices which do not have
|
||||
appropriate family driver. Allows to read/write binary data.
|
||||
=================== ============================================================
|
||||
@ -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.
|
||||
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]
|
||||
|
||||
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:
|
||||
reply::
|
||||
|
||||
[cn_msg, ack = 1 and increasing, 0 means the last message,
|
||||
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 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.
|
||||
Loading…
Reference in New Issue
Block a user