diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-bus-vmbus | 53 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-siox | 87 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/eeprom/at25.txt | 4 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt | 5 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt | 19 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/slimbus/bus.txt | 50 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/slimbus/slim-qcom-ctrl.txt | 39 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/vendor-prefixes.txt | 1 | ||||
| -rw-r--r-- | Documentation/driver-api/index.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/slimbus.rst | 127 | ||||
| -rw-r--r-- | Documentation/driver-api/soundwire/index.rst | 15 | ||||
| -rw-r--r-- | Documentation/driver-api/soundwire/summary.rst | 207 | ||||
| -rw-r--r-- | Documentation/driver-api/uio-howto.rst | 26 | ||||
| -rw-r--r-- | Documentation/fpga/fpga-mgr.txt | 132 | ||||
| -rw-r--r-- | Documentation/fpga/fpga-region.txt | 95 | ||||
| -rw-r--r-- | Documentation/fpga/overview.txt | 23 |
16 files changed, 795 insertions, 90 deletions
diff --git a/Documentation/ABI/stable/sysfs-bus-vmbus b/Documentation/ABI/stable/sysfs-bus-vmbus index d4077cc60d55..e46be65d0e1d 100644 --- a/Documentation/ABI/stable/sysfs-bus-vmbus +++ b/Documentation/ABI/stable/sysfs-bus-vmbus @@ -42,72 +42,93 @@ Contact: K. Y. Srinivasan <kys@microsoft.com> Description: The 16 bit vendor ID of the device Users: tools/hv/lsvmbus and user level RDMA libraries -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/cpu +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN +Date: September. 2017 +KernelVersion: 4.14 +Contact: Stephen Hemminger <sthemmin@microsoft.com> +Description: Directory for per-channel information + NN is the VMBUS relid associtated with the channel. + +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/cpu Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: VCPU (sub)channel is affinitized to -Users: tools/hv/lsvmbus and other debuggig tools +Users: tools/hv/lsvmbus and other debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/cpu +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/cpu Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: VCPU (sub)channel is affinitized to -Users: tools/hv/lsvmbus and other debuggig tools +Users: tools/hv/lsvmbus and other debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/in_mask +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/in_mask Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> -Description: Inbound channel signaling state +Description: Host to guest channel interrupt mask Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/latency +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/latency Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: Channel signaling latency Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/out_mask +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/out_mask Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> -Description: Outbound channel signaling state +Description: Guest to host channel interrupt mask Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/pending +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/pending Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: Channel interrupt pending state Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/read_avail +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/read_avail Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> -Description: Bytes availabble to read +Description: Bytes available to read Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/write_avail +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/write_avail Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> -Description: Bytes availabble to write +Description: Bytes available to write Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/events +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/events Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: Number of times we have signaled the host Users: Debugging tools -What: /sys/bus/vmbus/devices/vmbus_*/channels/relid/interrupts +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/interrupts Date: September. 2017 KernelVersion: 4.14 Contact: Stephen Hemminger <sthemmin@microsoft.com> Description: Number of times we have taken an interrupt (incoming) Users: Debugging tools + +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/subchannel_id +Date: January. 2018 +KernelVersion: 4.16 +Contact: Stephen Hemminger <sthemmin@microsoft.com> +Description: Subchannel ID associated with VMBUS channel +Users: Debugging tools and userspace drivers + +What: /sys/bus/vmbus/devices/vmbus_*/channels/NN/monitor_id +Date: January. 2018 +KernelVersion: 4.16 +Contact: Stephen Hemminger <sthemmin@microsoft.com> +Description: Monitor bit associated with channel +Users: Debugging tools and userspace drivers diff --git a/Documentation/ABI/testing/sysfs-bus-siox b/Documentation/ABI/testing/sysfs-bus-siox new file mode 100644 index 000000000000..fed7c3765a4e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-siox @@ -0,0 +1,87 @@ +What: /sys/bus/siox/devices/siox-X/active +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + On reading represents the current state of the bus. If it + contains a "0" the bus is stopped and connected devices are + expected to not do anything because their watchdog triggered. + When the file contains a "1" the bus is operated and periodically + does a push-pull cycle to write and read data from the + connected devices. + When writing a "0" or "1" the bus moves to the described state. + +What: /sys/bus/siox/devices/siox-X/device_add +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Write-only file. Write + + <type> <inbytes> <outbytes> <statustype> + + to add a new device dynamically. <type> is the name that is used to match + to a driver (similar to the platform bus). <inbytes> and <outbytes> define + the length of the input and output shift register in bytes respectively. + <statustype> defines the 4 bit device type that is check to identify connection + problems. + The new device is added to the end of the existing chain. + +What: /sys/bus/siox/devices/siox-X/device_remove +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Write-only file. A single write removes the last device in the siox chain. + +What: /sys/bus/siox/devices/siox-X/poll_interval_ns +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Defines the interval between two poll cycles in nano seconds. + Note this is rounded to jiffies on writing. On reading the current value + is returned. + +What: /sys/bus/siox/devices/siox-X-Y/connected +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value. "0" means the Yth device on siox bus X isn't "connected" i.e. + communication with it is not ensured. "1" signals a working connection. + +What: /sys/bus/siox/devices/siox-X-Y/inbytes +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value reporting the inbytes value provided to siox-X/device_add + +What: /sys/bus/siox/devices/siox-X-Y/status_errors +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Counts the number of time intervals when the read status byte doesn't yield the + expected value. + +What: /sys/bus/siox/devices/siox-X-Y/type +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value reporting the type value provided to siox-X/device_add. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value reporting if the watchdog of the siox device is + active. "0" means the watchdog is not active and the device is expected to + be operational. "1" means the watchdog keeps the device in reset. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog_errors +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value reporting the number to time intervals when the + watchdog was active. + +What: /sys/bus/siox/devices/siox-X-Y/outbytes +KernelVersion: 4.16 +Contact: Gavin Schenk <g.schenk@eckelmann.de>, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> +Description: + Read-only value reporting the outbytes value provided to siox-X/device_add. diff --git a/Documentation/devicetree/bindings/eeprom/at25.txt b/Documentation/devicetree/bindings/eeprom/at25.txt index e823d90b802f..b3bde97dc199 100644 --- a/Documentation/devicetree/bindings/eeprom/at25.txt +++ b/Documentation/devicetree/bindings/eeprom/at25.txt @@ -11,7 +11,9 @@ Required properties: - spi-max-frequency : max spi frequency to use - pagesize : size of the eeprom page - size : total eeprom size in bytes -- address-width : number of address bits (one of 8, 16, or 24) +- address-width : number of address bits (one of 8, 9, 16, or 24). + For 9 bits, the MSB of the address is sent as bit 3 of the instruction + byte, before the address byte. Optional properties: - spi-cpha : SPI shifted clock phase, as per spi-bus bindings. diff --git a/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt index 60bec4782806..265bdb7dc8aa 100644 --- a/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt +++ b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt @@ -6,12 +6,17 @@ Required properties: - "rockchip,rk3188-efuse" - for RK3188 SoCs. - "rockchip,rk3228-efuse" - for RK3228 SoCs. - "rockchip,rk3288-efuse" - for RK3288 SoCs. + - "rockchip,rk3328-efuse" - for RK3328 SoCs. - "rockchip,rk3368-efuse" - for RK3368 SoCs. - "rockchip,rk3399-efuse" - for RK3399 SoCs. - reg: Should contain the registers location and exact eFuse size - clocks: Should be the clock id of eFuse - clock-names: Should be "pclk_efuse" +Optional properties: +- rockchip,efuse-size: Should be exact eFuse size in byte, the eFuse + size in property <reg> will be invalid if define this property. + Deprecated properties: - compatible: "rockchip,rockchip-efuse" Old efuse compatible value compatible to rk3066a, rk3188 and rk3288 diff --git a/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt b/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt new file mode 100644 index 000000000000..55259cf39c25 --- /dev/null +++ b/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt @@ -0,0 +1,19 @@ +Eckelmann SIOX GPIO bus + +Required properties: +- compatible : "eckelmann,siox-gpio" +- din-gpios, dout-gpios, dclk-gpios, dld-gpios: references gpios for the + corresponding bus signals. + +Examples: + + siox { + compatible = "eckelmann,siox-gpio"; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_siox>; + + din-gpios = <&gpio6 11 0>; + dout-gpios = <&gpio6 8 0>; + dclk-gpios = <&gpio6 9 0>; + dld-gpios = <&gpio6 10 0>; + }; diff --git a/Documentation/devicetree/bindings/slimbus/bus.txt b/Documentation/devicetree/bindings/slimbus/bus.txt new file mode 100644 index 000000000000..52fa6426388c --- /dev/null +++ b/Documentation/devicetree/bindings/slimbus/bus.txt @@ -0,0 +1,50 @@ +SLIM(Serial Low Power Interchip Media Bus) bus + +SLIMbus is a 2-wire bus, and is used to communicate with peripheral +components like audio-codec. + +Required property for SLIMbus controller node: +- compatible - name of SLIMbus controller + +Child nodes: +Every SLIMbus controller node can contain zero or more child nodes +representing slave devices on the bus. Every SLIMbus slave device is +uniquely determined by the enumeration address containing 4 fields: +Manufacturer ID, Product code, Device index, and Instance value for +the device. +If child node is not present and it is instantiated after device +discovery (slave device reporting itself present). + +In some cases it may be necessary to describe non-probeable device +details such as non-standard ways of powering up a device. In +such cases, child nodes for those devices will be present as +slaves of the SLIMbus controller, as detailed below. + +Required property for SLIMbus child node if it is present: +- reg - Should be ('Device index', 'Instance ID') from SLIMbus + Enumeration Address. + Device Index Uniquely identifies multiple Devices within + a single Component. + Instance ID Is for the cases where multiple Devices of the + same type or Class are attached to the bus. + +- compatible -"slimMID,PID". The textual representation of Manufacturer ID, + Product Code, shall be in lower case hexadecimal with leading + zeroes suppressed + +SLIMbus example for Qualcomm's slimbus manager component: + + slim@28080000 { + compatible = "qcom,apq8064-slim", "qcom,slim"; + reg = <0x28080000 0x2000>, + interrupts = <0 33 0>; + clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>; + clock-names = "iface", "core"; + #address-cells = <2>; + #size-cell = <0>; + + codec: wcd9310@1,0{ + compatible = "slim217,60"; + reg = <1 0>; + }; + }; diff --git a/Documentation/devicetree/bindings/slimbus/slim-qcom-ctrl.txt b/Documentation/devicetree/bindings/slimbus/slim-qcom-ctrl.txt new file mode 100644 index 000000000000..922dcb8ff24a --- /dev/null +++ b/Documentation/devicetree/bindings/slimbus/slim-qcom-ctrl.txt @@ -0,0 +1,39 @@ +Qualcomm SLIMbus controller +This controller is used if applications processor driver controls SLIMbus +master component. + +Required properties: + + - #address-cells - refer to Documentation/devicetree/bindings/slimbus/bus.txt + - #size-cells - refer to Documentation/devicetree/bindings/slimbus/bus.txt + + - reg : Offset and length of the register region(s) for the device + - reg-names : Register region name(s) referenced in reg above + Required register resource entries are: + "ctrl": Physical address of controller register blocks + "slew": required for "qcom,apq8064-slim" SOC. + - compatible : should be "qcom,<SOC-NAME>-slim" for SOC specific compatible + followed by "qcom,slim" for fallback. + - interrupts : Interrupt number used by this controller + - clocks : Interface and core clocks used by this SLIMbus controller + - clock-names : Required clock-name entries are: + "iface" : Interface clock for this controller + "core" : Interrupt for controller core's BAM + +Example: + + slim@28080000 { + compatible = "qcom,apq8064-slim", "qcom,slim"; + reg = <0x28080000 0x2000>, <0x80207C 4>; + reg-names = "ctrl", "slew"; + interrupts = <0 33 0>; + clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>; + clock-names = "iface", "core"; + #address-cells = <2>; + #size-cell = <0>; + + wcd9310: audio-codec@1,0{ + compatible = "slim217,60"; + reg = <1 0>; + }; + }; diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt index f776fb804a8c..6ec1a028a3a8 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.txt +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt @@ -97,6 +97,7 @@ dptechnics DPTechnics dragino Dragino Technology Co., Limited ea Embedded Artists AB ebv EBV Elektronik +eckelmann Eckelmann AG edt Emerging Display Technologies eeti eGalax_eMPIA Technology Inc elan Elan Microelectronic Corp. diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index d17a9876b473..e9b41b1634f3 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -47,6 +47,8 @@ available subsections can be seen below. gpio misc_devices dmaengine/index + slimbus + soundwire/index .. only:: subproject and html diff --git a/Documentation/driver-api/slimbus.rst b/Documentation/driver-api/slimbus.rst new file mode 100644 index 000000000000..7555ecd538de --- /dev/null +++ b/Documentation/driver-api/slimbus.rst @@ -0,0 +1,127 @@ +============================ +Linux kernel SLIMbus support +============================ + +Overview +======== + +What is SLIMbus? +---------------- +SLIMbus (Serial Low Power Interchip Media Bus) is a specification developed by +MIPI (Mobile Industry Processor Interface) alliance. The bus uses master/slave +configuration, and is a 2-wire multi-drop implementation (clock, and data). + +Currently, SLIMbus is used to interface between application processors of SoCs +(System-on-Chip) and peripheral components (typically codec). SLIMbus uses +Time-Division-Multiplexing to accommodate multiple data channels, and +a control channel. + +The control channel is used for various control functions such as bus +management, configuration and status updates. These messages can be unicast (e.g. +reading/writing device specific values), or multicast (e.g. data channel +reconfiguration sequence is a broadcast message announced to all devices) + +A data channel is used for data-transfer between 2 SLIMbus devices. Data +channel uses dedicated ports on the device. + +Hardware description: +--------------------- +SLIMbus specification has different types of device classifications based on +their capabilities. +A manager device is responsible for enumeration, configuration, and dynamic +channel allocation. Every bus has 1 active manager. + +A generic device is a device providing application functionality (e.g. codec). + +Framer device is responsible for clocking the bus, and transmitting frame-sync +and framing information on the bus. + +Each SLIMbus component has an interface device for monitoring physical layer. + +Typically each SoC contains SLIMbus component having 1 manager, 1 framer device, +1 generic device (for data channel support), and 1 interface device. +External peripheral SLIMbus component usually has 1 generic device (for +functionality/data channel support), and an associated interface device. +The generic device's registers are mapped as 'value elements' so that they can +be written/read using SLIMbus control channel exchanging control/status type of +information. +In case there are multiple framer devices on the same bus, manager device is +responsible to select the active-framer for clocking the bus. + +Per specification, SLIMbus uses "clock gears" to do power management based on +current frequency and bandwidth requirements. There are 10 clock gears and each +gear changes the SLIMbus frequency to be twice its previous gear. + +Each device has a 6-byte enumeration-address and the manager assigns every +device with a 1-byte logical address after the devices report presence on the +bus. + +Software description: +--------------------- +There are 2 types of SLIMbus drivers: + +slim_controller represents a 'controller' for SLIMbus. This driver should +implement duties needed by the SoC (manager device, associated +interface device for monitoring the layers and reporting errors, default +framer device). + +slim_device represents the 'generic device/component' for SLIMbus, and a +slim_driver should implement driver for that slim_device. + +Device notifications to the driver: +----------------------------------- +Since SLIMbus devices have mechanisms for reporting their presence, the +framework allows drivers to bind when corresponding devices report their +presence on the bus. +However, it is possible that the driver needs to be probed +first so that it can enable corresponding SLIMbus device (e.g. power it up and/or +take it out of reset). To support that behavior, the framework allows drivers +to probe first as well (e.g. using standard DeviceTree compatibility field). +This creates the necessity for the driver to know when the device is functional +(i.e. reported present). device_up callback is used for that reason when the +device reports present and is assigned a logical address by the controller. + +Similarly, SLIMbus devices 'report absent' when they go down. A 'device_down' +callback notifies the driver when the device reports absent and its logical +address assignment is invalidated by the controller. + +Another notification "boot_device" is used to notify the slim_driver when +controller resets the bus. This notification allows the driver to take necessary +steps to boot the device so that it's functional after the bus has been reset. + +Driver and Controller APIs: +-------------------------- +.. kernel-doc:: include/linux/slimbus.h + :internal: + +.. kernel-doc:: drivers/slimbus/slimbus.h + :internal: + +.. kernel-doc:: drivers/slimbus/core.c + :export: + +Clock-pause: +------------ +SLIMbus mandates that a reconfiguration sequence (known as clock-pause) be +broadcast to all active devices on the bus before the bus can enter low-power +mode. Controller uses this sequence when it decides to enter low-power mode so +that corresponding clocks and/or power-rails can be turned off to save power. +Clock-pause is exited by waking up framer device (if controller driver initiates +exiting low power mode), or by toggling the data line (if a slave device wants +to initiate it). + +Clock-pause APIs: +~~~~~~~~~~~~~~~~~ +.. kernel-doc:: drivers/slimbus/sched.c + :export: + +Messaging: +---------- +The framework supports regmap and read/write apis to exchange control-information +with a SLIMbus device. APIs can be synchronous or asynchronous. +The header file <linux/slimbus.h> has more documentation about messaging APIs. + +Messaging APIs: +~~~~~~~~~~~~~~~ +.. kernel-doc:: drivers/slimbus/messaging.c + :export: diff --git a/Documentation/driver-api/soundwire/index.rst b/Documentation/driver-api/soundwire/index.rst new file mode 100644 index 000000000000..647e94654752 --- /dev/null +++ b/Documentation/driver-api/soundwire/index.rst @@ -0,0 +1,15 @@ +======================= +SoundWire Documentation +======================= + +.. toctree:: + :maxdepth: 1 + + summary + +.. only:: subproject + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/driver-api/soundwire/summary.rst b/Documentation/driver-api/soundwire/summary.rst new file mode 100644 index 000000000000..8193125a2bfb --- /dev/null +++ b/Documentation/driver-api/soundwire/summary.rst @@ -0,0 +1,207 @@ +=========================== +SoundWire Subsystem Summary +=========================== + +SoundWire is a new interface ratified in 2015 by the MIPI Alliance. +SoundWire is used for transporting data typically related to audio +functions. SoundWire interface is optimized to integrate audio devices in +mobile or mobile inspired systems. + +SoundWire is a 2-pin multi-drop interface with data and clock line. It +facilitates development of low cost, efficient, high performance systems. +Broad level key features of SoundWire interface include: + + (1) Transporting all of payload data channels, control information, and setup + commands over a single two-pin interface. + + (2) Lower clock frequency, and hence lower power consumption, by use of DDR + (Dual Data Rate) data transmission. + + (3) Clock scaling and optional multiple data lanes to give wide flexibility + in data rate to match system requirements. + + (4) Device status monitoring, including interrupt-style alerts to the Master. + +The SoundWire protocol supports up to eleven Slave interfaces. All the +interfaces share the common Bus containing data and clock line. Each of the +Slaves can support up to 14 Data Ports. 13 Data Ports are dedicated to audio +transport. Data Port0 is dedicated to transport of Bulk control information, +each of the audio Data Ports (1..14) can support up to 8 Channels in +transmit or receiving mode (typically fixed direction but configurable +direction is enabled by the specification). Bandwidth restrictions to +~19.2..24.576Mbits/s don't however allow for 11*13*8 channels to be +transmitted simultaneously. + +Below figure shows an example of connectivity between a SoundWire Master and +two Slave devices. :: + + +---------------+ +---------------+ + | | Clock Signal | | + | Master |-------+-------------------------------| Slave | + | Interface | | Data Signal | Interface 1 | + | |-------|-------+-----------------------| | + +---------------+ | | +---------------+ + | | + | | + | | + +--+-------+--+ + | | + | Slave | + | Interface 2 | + | | + +-------------+ + + +Terminology +=========== + +The MIPI SoundWire specification uses the term 'device' to refer to a Master +or Slave interface, which of course can be confusing. In this summary and +code we use the term interface only to refer to the hardware. We follow the +Linux device model by mapping each Slave interface connected on the bus as a +device managed by a specific driver. The Linux SoundWire subsystem provides +a framework to implement a SoundWire Slave driver with an API allowing +3rd-party vendors to enable implementation-defined functionality while +common setup/configuration tasks are handled by the bus. + +Bus: +Implements SoundWire Linux Bus which handles the SoundWire protocol. +Programs all the MIPI-defined Slave registers. Represents a SoundWire +Master. Multiple instances of Bus may be present in a system. + +Slave: +Registers as SoundWire Slave device (Linux Device). Multiple Slave devices +can register to a Bus instance. + +Slave driver: +Driver controlling the Slave device. MIPI-specified registers are controlled +directly by the Bus (and transmitted through the Master driver/interface). +Any implementation-defined Slave register is controlled by Slave driver. In +practice, it is expected that the Slave driver relies on regmap and does not +request direct register access. + +Programming interfaces (SoundWire Master interface Driver) +========================================================== + +SoundWire Bus supports programming interfaces for the SoundWire Master +implementation and SoundWire Slave devices. All the code uses the "sdw" +prefix commonly used by SoC designers and 3rd party vendors. + +Each of the SoundWire Master interfaces needs to be registered to the Bus. +Bus implements API to read standard Master MIPI properties and also provides +callback in Master ops for Master driver to implement its own functions that +provides capabilities information. DT support is not implemented at this +time but should be trivial to add since capabilities are enabled with the +``device_property_`` API. + +The Master interface along with the Master interface capabilities are +registered based on board file, DT or ACPI. + +Following is the Bus API to register the SoundWire Bus: + +.. code-block:: c + + int sdw_add_bus_master(struct sdw_bus *bus) + { + if (!bus->dev) + return -ENODEV; + + mutex_init(&bus->lock); + INIT_LIST_HEAD(&bus->slaves); + + /* Check ACPI for Slave devices */ + sdw_acpi_find_slaves(bus); + + /* Check DT for Slave devices */ + sdw_of_find_slaves(bus); + + return 0; + } + +This will initialize sdw_bus object for Master device. "sdw_master_ops" and +"sdw_master_port_ops" callback functions are provided to the Bus. + +"sdw_master_ops" is used by Bus to control the Bus in the hardware specific +way. It includes Bus control functions such as sending the SoundWire +read/write messages on Bus, setting up clock frequency & Stream +Synchronization Point (SSP). The "sdw_master_ops" structure abstracts the +hardware details of the Master from the Bus. + +"sdw_master_port_ops" is used by Bus to setup the Port parameters of the +Master interface Port. Master interface Port register map is not defined by +MIPI specification, so Bus calls the "sdw_master_port_ops" callback +function to do Port operations like "Port Prepare", "Port Transport params +set", "Port enable and disable". The implementation of the Master driver can +then perform hardware-specific configurations. + +Programming interfaces (SoundWire Slave Driver) +=============================================== + +The MIPI specification requires each Slave interface to expose a unique +48-bit identifier, stored in 6 read-only dev_id registers. This dev_id +identifier contains vendor and part information, as well as a field enabling +to differentiate between identical components. An additional class field is +currently unused. Slave driver is written for a specific vendor and part +identifier, Bus enumerates the Slave device based on these two ids. +Slave device and driver match is done based on these two ids . Probe +of the Slave driver is called by Bus on successful match between device and +driver id. A parent/child relationship is enforced between Master and Slave +devices (the logical representation is aligned with the physical +connectivity). + +The information on Master/Slave dependencies is stored in platform data, +board-file, ACPI or DT. The MIPI Software specification defines additional +link_id parameters for controllers that have multiple Master interfaces. The +dev_id registers are only unique in the scope of a link, and the link_id +unique in the scope of a controller. Both dev_id and link_id are not +necessarily unique at the system level but the parent/child information is +used to avoid ambiguity. + +.. code-block:: c + + static const struct sdw_device_id slave_id[] = { + SDW_SLAVE_ENTRY(0x025d, 0x700, 0), + {}, + }; + MODULE_DEVICE_TABLE(sdw, slave_id); + + static struct sdw_driver slave_sdw_driver = { + .driver = { + .name = "slave_xxx", + .pm = &slave_runtime_pm, + }, + .probe = slave_sdw_probe, + .remove = slave_sdw_remove, + .ops = &slave_slave_ops, + .id_table = slave_id, + }; + + +For capabilities, Bus implements API to read standard Slave MIPI properties +and also provides callback in Slave ops for Slave driver to implement own +function that provides capabilities information. Bus needs to know a set of +Slave capabilities to program Slave registers and to control the Bus +reconfigurations. + +Future enhancements to be done +============================== + + (1) Bulk Register Access (BRA) transfers. + + + (2) Multiple data lane support. + +Links +===== + +SoundWire MIPI specification 1.1 is available at: +https://members.mipi.org/wg/All-Members/document/70290 + +SoundWire MIPI DisCo (Discovery and Configuration) specification is +available at: +https://www.mipi.org/specifications/mipi-disco-soundwire + +(publicly accessible with registration or directly accessible to MIPI +members) + +MIPI Alliance Manufacturer ID Page: mid.mipi.org diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst index f73d660b2956..693e3bd84e79 100644 --- a/Documentation/driver-api/uio-howto.rst +++ b/Documentation/driver-api/uio-howto.rst @@ -667,27 +667,28 @@ Making the driver recognize the device Since the driver does not declare any device GUID's, it will not get loaded automatically and will not automatically bind to any devices, you must load it and allocate id to the driver yourself. For example, to use -the network device GUID:: +the network device class GUID:: modprobe uio_hv_generic echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" > /sys/bus/vmbus/drivers/uio_hv_generic/new_id If there already is a hardware specific kernel driver for the device, the generic driver still won't bind to it, in this case if you want to -use the generic driver (why would you?) you'll have to manually unbind -the hardware specific driver and bind the generic driver, like this:: +use the generic driver for a userspace library you'll have to manually unbind +the hardware specific driver and bind the generic driver, using the device specific GUID +like this:: - echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/hv_netvsc/unbind - echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/uio_hv_generic/bind + echo -n ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/hv_netvsc/unbind + echo -n ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/uio_hv_generic/bind You can verify that the device has been bound to the driver by looking for it in sysfs, for example like the following:: - ls -l /sys/bus/vmbus/devices/vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver + ls -l /sys/bus/vmbus/devices/ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver Which if successful should print:: - .../vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver -> ../../../bus/vmbus/drivers/uio_hv_generic + .../ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver -> ../../../bus/vmbus/drivers/uio_hv_generic Things to know about uio_hv_generic ----------------------------------- @@ -697,6 +698,17 @@ prevents the device from generating further interrupts until the bit is cleared. The userspace driver should clear this bit before blocking and waiting for more interrupts. +When host rescinds a device, the interrupt file descriptor is marked down +and any reads of the interrupt file descriptor will return -EIO. Similar +to a closed socket or disconnected serial device. + +The vmbus device regions are mapped into uio device resources: + 0) Channel ring buffers: guest to host and host to guest + 1) Guest to host interrupt signalling pages + 2) Guest to host monitor page + 3) Network receive buffer region + 4) Network send buffer region + Further information =================== diff --git a/Documentation/fpga/fpga-mgr.txt b/Documentation/fpga/fpga-mgr.txt index 78f197fadfd1..cc6413ed6fc9 100644 --- a/Documentation/fpga/fpga-mgr.txt +++ b/Documentation/fpga/fpga-mgr.txt @@ -11,61 +11,65 @@ hidden away in a low level driver which registers a set of ops with the core. The FPGA image data itself is very manufacturer specific, but for our purposes it's just binary data. The FPGA manager core won't parse it. +The FPGA image to be programmed can be in a scatter gather list, a single +contiguous buffer, or a firmware file. Because allocating contiguous kernel +memory for the buffer should be avoided, users are encouraged to use a scatter +gather list instead if possible. + +The particulars for programming the image are presented in a structure (struct +fpga_image_info). This struct contains parameters such as pointers to the +FPGA image as well as image-specific particulars such as whether the image was +built for full or partial reconfiguration. API Functions: ============== -To program the FPGA from a file or from a buffer: -------------------------------------------------- - - int fpga_mgr_buf_load(struct fpga_manager *mgr, - struct fpga_image_info *info, - const char *buf, size_t count); - -Load the FPGA from an image which exists as a contiguous buffer in -memory. Allocating contiguous kernel memory for the buffer should be avoided, -users are encouraged to use the _sg interface instead of this. - - int fpga_mgr_buf_load_sg(struct fpga_manager *mgr, - struct fpga_image_info *info, - struct sg_table *sgt); +To program the FPGA: +-------------------- -Load the FPGA from an image from non-contiguous in memory. Callers can -construct a sg_table using alloc_page backed memory. + int fpga_mgr_load(struct fpga_manager *mgr, + struct fpga_image_info *info); - int fpga_mgr_firmware_load(struct fpga_manager *mgr, - struct fpga_image_info *info, - const char *image_name); - -Load the FPGA from an image which exists as a file. The image file must be on -the firmware search path (see the firmware class documentation). If successful, +Load the FPGA from an image which is indicated in the info. If successful, the FPGA ends up in operating mode. Return 0 on success or a negative error code. -A FPGA design contained in a FPGA image file will likely have particulars that -affect how the image is programmed to the FPGA. These are contained in struct -fpga_image_info. Currently the only such particular is a single flag bit -indicating whether the image is for full or partial reconfiguration. +To allocate or free a struct fpga_image_info: +--------------------------------------------- + + struct fpga_image_info *fpga_image_info_alloc(struct device *dev); + + void fpga_image_info_free(struct fpga_image_info *info); To get/put a reference to a FPGA manager: ----------------------------------------- struct fpga_manager *of_fpga_mgr_get(struct device_node *node); struct fpga_manager *fpga_mgr_get(struct device *dev); + void fpga_mgr_put(struct fpga_manager *mgr); -Given a DT node or device, get an exclusive reference to a FPGA manager. +Given a DT node or device, get a reference to a FPGA manager. This pointer +can be saved until you are ready to program the FPGA. fpga_mgr_put releases +the reference. - void fpga_mgr_put(struct fpga_manager *mgr); -Release the reference. +To get exclusive control of a FPGA manager: +------------------------------------------- + + int fpga_mgr_lock(struct fpga_manager *mgr); + void fpga_mgr_unlock(struct fpga_manager *mgr); + +The user should call fpga_mgr_lock and verify that it returns 0 before +attempting to program the FPGA. Likewise, the user should call +fpga_mgr_unlock when done programming the FPGA. To register or unregister the low level FPGA-specific driver: ------------------------------------------------------------- int fpga_mgr_register(struct device *dev, const char *name, - const struct fpga_manager_ops *mops, - void *priv); + const struct fpga_manager_ops *mops, + void *priv); void fpga_mgr_unregister(struct device *dev); @@ -75,62 +79,58 @@ device." How to write an image buffer to a supported FPGA ================================================ -/* Include to get the API */ #include <linux/fpga/fpga-mgr.h> -/* device node that specifies the FPGA manager to use */ -struct device_node *mgr_node = ... +struct fpga_manager *mgr; +struct fpga_image_info *info; +int ret; -/* FPGA image is in this buffer. count is size of the buffer. */ -char *buf = ... -int count = ... +/* + * Get a reference to FPGA manager. The manager is not locked, so you can + * hold onto this reference without it preventing programming. + * + * This example uses the device node of the manager. Alternatively, use + * fpga_mgr_get(dev) instead if you have the device. + */ +mgr = of_fpga_mgr_get(mgr_node); /* struct with information about the FPGA image to program. */ -struct fpga_image_info info; +info = fpga_image_info_alloc(dev); /* flags indicates whether to do full or partial reconfiguration */ -info.flags = 0; +info->flags = FPGA_MGR_PARTIAL_RECONFIG; -int ret; +/* + * At this point, indicate where the image is. This is pseudo-code; you're + * going to use one of these three. + */ +if (image is in a scatter gather table) { -/* Get exclusive control of FPGA manager */ -struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node); + info->sgt = [your scatter gather table] -/* Load the buffer to the FPGA */ -ret = fpga_mgr_buf_load(mgr, &info, buf, count); - -/* Release the FPGA manager */ -fpga_mgr_put(mgr); - - -How to write an image file to a supported FPGA -============================================== -/* Include to get the API */ -#include <linux/fpga/fpga-mgr.h> +} else if (image is in a buffer) { -/* device node that specifies the FPGA manager to use */ -struct device_node *mgr_node = ... + info->buf = [your image buffer] + info->count = [image buffer size] -/* FPGA image is in this file which is in the firmware search path */ -const char *path = "fpga-image-9.rbf" +} else if (image is in a firmware file) { -/* struct with information about the FPGA image to program. */ -struct fpga_image_info info; - -/* flags indicates whether to do full or partial reconfiguration */ -info.flags = 0; + info->firmware_name = devm_kstrdup(dev, firmware_name, GFP_KERNEL); -int ret; +} /* Get exclusive control of FPGA manager */ -struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node); +ret = fpga_mgr_lock(mgr); -/* Get the firmware image (path) and load it to the FPGA */ -ret = fpga_mgr_firmware_load(mgr, &info, path); +/* Load the buffer to the FPGA */ +ret = fpga_mgr_buf_load(mgr, &info, buf, count); /* Release the FPGA manager */ +fpga_mgr_unlock(mgr); fpga_mgr_put(mgr); +/* Deallocate the image info if you're done with it */ +fpga_image_info_free(info); How to support a new FPGA device ================================ diff --git a/Documentation/fpga/fpga-region.txt b/Documentation/fpga/fpga-region.txt new file mode 100644 index 000000000000..139a02ba1ff6 --- /dev/null +++ b/Documentation/fpga/fpga-region.txt @@ -0,0 +1,95 @@ +FPGA Regions + +Alan Tull 2017 + +CONTENTS + - Introduction + - The FPGA region API + - Usage example + +Introduction +============ + +This document is meant to be an brief overview of the FPGA region API usage. A +more conceptual look at regions can be found in [1]. + +For the purposes of this API document, let's just say that a region associates +an FPGA Manager and a bridge (or bridges) with a reprogrammable region of an +FPGA or the whole FPGA. The API provides a way to register a region and to +program a region. + +Currently the only layer above fpga-region.c in the kernel is the Device Tree +support (of-fpga-region.c) described in [1]. The DT support layer uses regions +to program the FPGA and then DT to handle enumeration. The common region code +is intended to be used by other schemes that have other ways of accomplishing +enumeration after programming. + +An fpga-region can be set up to know the following things: +* which FPGA manager to use to do the programming +* which bridges to disable before programming and enable afterwards. + +Additional info needed to program the FPGA image is passed in the struct +fpga_image_info [2] including: +* pointers to the image as either a scatter-gather buffer, a contiguous + buffer, or the name of firmware file +* flags indicating specifics such as whether the image if for partial + reconfiguration. + +=================== +The FPGA region API +=================== + +To register or unregister a region: +----------------------------------- + + int fpga_region_register(struct device *dev, + struct fpga_region *region); + int fpga_region_unregister(struct fpga_region *region); + +An example of usage can be seen in the probe function of [3] + +To program an FPGA: +------------------- + int fpga_region_program_fpga(struct fpga_region *region); + +This function operates on info passed in the fpga_image_info +(region->info). + +This function will attempt to: + * lock the region's mutex + * lock the region's FPGA manager + * build a list of FPGA bridges if a method has been specified to do so + * disable the bridges + * program the FPGA + * re-enable the bridges + * release the locks + +============= +Usage example +============= + +First, allocate the info struct: + + info = fpga_image_info_alloc(dev); + if (!info) + return -ENOMEM; + +Set flags as needed, i.e. + + info->flags |= FPGA_MGR_PARTIAL_RECONFIG; + +Point to your FPGA image, such as: + + info->sgt = &sgt; + +Add info to region and do the programming: + + region->info = info; + ret = fpga_region_program_fpga(region); + +Then enumerate whatever hardware has appeared in the FPGA. + +-- +[1] ../devicetree/bindings/fpga/fpga-region.txt +[2] ./fpga-mgr.txt +[3] ../../drivers/fpga/of-fpga-region.c diff --git a/Documentation/fpga/overview.txt b/Documentation/fpga/overview.txt new file mode 100644 index 000000000000..0f1236e7e675 --- /dev/null +++ b/Documentation/fpga/overview.txt @@ -0,0 +1,23 @@ +Linux kernel FPGA support + +Alan Tull 2017 + +The main point of this project has been to separate the out the upper layers +that know when to reprogram a FPGA from the lower layers that know how to +reprogram a specific FPGA device. The intention is to make this manufacturer +agnostic, understanding that of course the FPGA images are very device specific +themselves. + +The framework in the kernel includes: +* low level FPGA manager drivers that know how to program a specific device +* the fpga-mgr framework they are registered with +* low level FPGA bridge drivers for hard/soft bridges which are intended to + be disable during FPGA programming +* the fpga-bridge framework they are registered with +* the fpga-region framework which associates and controls managers and bridges + as reconfigurable regions +* the of-fpga-region support for reprogramming FPGAs when device tree overlays + are applied. + +I would encourage you the user to add code that creates FPGA regions rather +that trying to control managers and bridges separately. |