-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/
-- | Type-safe communication with USB devices.
--
-- The usb package provides a standard Haskell abstraction layer
-- over bindings-libusb providing: abstract types instead of
-- Ptrs, automatic marshalling and unmarshalling, automatic
-- garbage collection, exceptions instead of integer return codes, etc..
--
-- While all that is very nice there are still some things that you can
-- do wrong. For example doing I/O with a closed device or reading from
-- or writing to an endpoint which doesn't belong to the claimed
-- interface. Or reading from an Out endpoint or writing to an In
-- endpoint.
--
-- usb-safe provides the following guarantees:
--
--
-- - You can't reference handles to devices that are closed. In other
-- words: no I/O with closed handles is possible.
-- - The programmer specifies the region in which devices should
-- remain open. On exit from the region the opened devices will be closed
-- automatically.
-- - You can't reference handles to configurations that have not been
-- set.
-- - You can't reference handles to interfaces that have not been
-- claimed.
-- - Just like with devices, the programmer can specify the region in
-- which interfaces should remain claimed. On exit from the region the
-- claimed interfaces will be released automatically.
-- - You can't reference handles to alternates that have not been
-- set.
-- - You can't reference endpoints that don't belong to a setted
-- alternate.
-- - You can't read from an endpoint with an Out transfer
-- direction.
-- - You can't write to an endpoint with an In transfer direction.
-- - You can't read from or write to endpoints with the unsupported
-- transfer types Control and Isochronous. Only I/O with endpoints with
-- the Bulk and Interrupt transfer types is allowed.
--
--
-- The primary technique used in usb-safe is called "Lightweight monadic
-- regions" which was invented by Oleg Kiselyov and Chung-chieh Shan.
-- See:
--
-- http://okmij.org/ftp/Haskell/regions.html#light-weight
--
-- This technique is implemented in the regions package which is
-- re-exported from usb-safe.
--
-- See the usb-safe-examples package for examples how to use
-- this library:
--
-- darcs get
-- http://code.haskell.org/~basvandijk/code/usb-safe-examples
@package usb-safe
@version 0.6
-- | This modules provides the following guarantees for working with USB
-- devices:
--
--
-- - You can't reference handles to devices that are closed. In other
-- words: no I/O with closed handles is possible.
-- - The programmer can specify the region in which devices
-- should remain open. On exit from the region the opened devices will be
-- closed automatically.
-- - You can't reference handles to configurations that have not been
-- set.
-- - You can't reference handles to interfaces that have not been
-- claimed.
-- - Just like with devices, the programmer can specify the region in
-- which interfaces should remain claimed. On exit from the region the
-- claimed interfaces will be released automatically.
-- - You can't reference handles to alternates that have not been
-- set.
-- - You can't reference endpoints that don't belong to a setted
-- alternate.
-- - You can't read from an endpoint with an Out transfer
-- direction.
-- - You can't write to an endpoint with an In transfer
-- direction.
-- - You can't read from or write to endpoints with the unsupported
-- transfer types Control and Isochronous. Only I/O with
-- endpoints with the supported Bulk and Interrupt transfer
-- types is allowed.
--
--
-- This modules makes use of a technique called Lightweight monadic
-- regions invented by Oleg Kiselyov and Chung-chieh Shan
--
-- See: http://okmij.org/ftp/Haskell/regions.html#light-weight
--
-- This technique is implemented in the regions package of which
-- the Control.Monad.Trans.Region module is re-exported by this
-- module.
--
-- See the usb-safe-examples package for examples how to use
-- this library:
--
-- darcs get
-- http://code.haskell.org/~basvandijk/code/usb-safe-examples
module System.USB.Safe
-- | Handy type synonym for a regional handle to an opened USB device.
--
-- A regional handle to an opened USB device can be created by applying
-- open or with to the USB device you wish to open.
--
-- Note that you can also duplicate a regional device handle by
-- applying dup to it.
type RegionalDeviceHandle r = RegionalHandle Device r
-- | Convenience function for retrieving the device from the given regional
-- handle.
getDevice :: RegionalDeviceHandle r -> Device
-- | Convenience function which finds the first device attached to the
-- system which satisfies the given predicate on its descriptor, then
-- opens that device and applies the given continuation function to the
-- resulting device handle.
--
-- Exceptions:
--
--
withDeviceWhich :: (MonadCatchIO pr) => Ctx -> (DeviceDesc -> Bool) -> (forall s. RegionalDeviceHandle (RegionT s pr) -> RegionT s pr α) -> pr α
-- | This exception can be thrown in withDeviceWhich,
-- setConfigWhich, withInterfaceWhich or
-- setAlternateWhich to indicate that no value was found which
-- satisfied the given predicate.
data NotFound
NotFound :: NotFound
class GetDescriptor α desc | α -> desc, desc -> α
getDesc :: (GetDescriptor α desc) => α -> desc
-- | Perform a USB port reset to reinitialize a device. The system will
-- attempt to restore the previous configuration and alternate settings
-- after the reset has completed.
--
-- Note the constraint: pr `ParentOf` cr. This allows this
-- function to be executed in any child region cr of the parent
-- region pr in which the given regional handle was created.
--
-- You can only reset a device when all computations passed to
-- setConfig, useActiveConfig and setConfigWhich
-- have been terminated. If you call resetDevice and such a
-- computation is still running a SettingAlreadySet exception is
-- thrown.
--
-- If the reset fails, the descriptors change, or the previous state
-- cannot be restored, the device will appear to be disconnected and
-- reconnected. This means that the device handle is no longer valid (you
-- should close it) and rediscover the device. A NotFoundException
-- is raised to indicate that this is the case.
--
-- TODO: Think about how to handle the implications of the the
-- previous paragraph!
--
-- This is a blocking function which usually incurs a noticeable delay.
--
-- Exceptions:
--
--
resetDevice :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> cr ()
-- | A supported configuration of a USB device parameterized by the region
-- r in which it was created.
--
-- Note that, just like a regional device handle, a configuration can be
-- duplicated to a parent region using dup.
--
-- Also note that you can get the descriptor of the configuration by
-- applying getDesc to it.
data Config r :: (* -> *)
-- | Retrieve the supported configurations from the given regional handle.
--
-- Note that the configuration is parameterized by the same region
-- r in which the regional handle was created. This ensures you
-- can never use a configuration outside that region.
getConfigs :: RegionalDeviceHandle r -> [Config r]
-- | A handle to an active Config which you can get using:
-- setConfig, useActiveConfig or setConfigWhich.
--
-- The type variable sCfg is used to ensure that you can't
-- return this handle from these functions.
data ConfigHandle sCfg
-- | Set the active configuration for a device and then apply the given
-- continuation function to the resulting configuration handle.
--
-- USB devices support multiple configurations of which only one can be
-- active at any given time. When a configuration is set using
-- setConfig, useActiveConfig or setConfigWhich no
-- threads can set a new configuration until the computation passed to
-- these functions terminates. If you do try to set one a
-- SettingAlreadySet exception will be thrown.
--
-- The operating system may or may not have already set an active
-- configuration on the device. It is up to your application to ensure
-- the correct configuration is selected before you attempt to claim
-- interfaces and perform other operations. If you want to use the
-- current active configuration use useActiveConfig.
--
-- If you call this function on a device already configured with the
-- selected configuration, then this function will act as a lightweight
-- device reset: it will issue a SET_CONFIGURATION request using the
-- current configuration, causing most USB-related device state to be
-- reset (altsetting reset to zero, endpoint halts cleared, toggles
-- reset).
--
-- You cannot change/reset configuration if other applications or drivers
-- have claimed interfaces.
--
-- This is a blocking function.
--
-- Exceptions:
--
--
setConfig :: (ParentOf pr cr, MonadCatchIO cr) => Config pr -> (forall sCfg. ConfigHandle sCfg -> cr α) -> cr α
-- | This exception can be thrown in:
--
--
--
-- to indicate that the device was already configured with a setting.
data SettingAlreadySet
SettingAlreadySet :: SettingAlreadySet
-- | Apply the given continuation function to the configuration handle of
-- the current active configuration of the given device handle.
--
-- This function needs to determine the current active configuration.
-- This information may be cached by the operating system. If it isn't
-- cached this function will block while a control transfer is submitted
-- to retrieve the information.
--
-- Exceptions:
--
--
useActiveConfig :: (ParentOf pr cr, MonadCatchIO cr) => RegionalDeviceHandle pr -> (forall sCfg. ConfigHandle sCfg -> cr α) -> cr α
-- | This exception can be thrown in useActiveConfig to indicate
-- that the device is currently not configured.
data NoActiveConfig
NoActiveConfig :: NoActiveConfig
-- | Convenience function which finds the first configuration of the given
-- device handle which satisfies the given predicate on its descriptor,
-- then sets that configuration and applies the given function to the
-- resulting configuration handle.
--
-- This function calls setConfig so do see its documentation.
--
-- Exceptions:
--
--
setConfigWhich :: (ParentOf pr cr, MonadCatchIO cr) => RegionalDeviceHandle pr -> (ConfigDesc -> Bool) -> (forall sCfg. ConfigHandle sCfg -> cr α) -> cr α
-- | A supported interface of a configuration which you can retrieve using
-- getInterfaces.
--
-- To retrieve the Interface descriptors of an interface use
-- getDesc.
data Interface sCfg
-- | Retrieve the supported interfaces from the configuration handle.
--
-- Note that the interface is parameterized by the sCfg of the
-- configuration handle it is derived from. This ensures that it can
-- never be returned from the functions that created this configuration
-- handle: setConfig, useActiveConfig and
-- setConfigWhich.
--
-- The latter is useful because outside those functions the active
-- configuration may change. If at that moment you still have an
-- interface of the old configuration claiming it would be an error.
getInterfaces :: ConfigHandle sCfg -> [Interface sCfg]
-- | Handy type synonym for a regional handle to a claimed interface.
--
-- A regional handle to a claimed interface can be created by applying
-- claim (= open) or with to the interface
-- you wish to claim.
type RegionalIfHandle sCfg r = RegionalHandle (Interface sCfg) r
-- | Claim the given interface in the interface region.
--
-- Note that: claim = open which just reads better when
-- applied to an interface.
--
-- Note that it is allowed to claim an already-claimed interface.
--
-- Claiming of interfaces is a purely logical operation; it does not
-- cause any requests to be sent over the bus. Interface claiming is used
-- to instruct the underlying operating system that your application
-- wishes to take ownership of the interface.
--
-- This is a non-blocking function.
--
-- Exceptions:
--
--
claim :: (MonadCatchIO pr) => Interface sCfg -> RegionT s pr (RegionalIfHandle sCfg (RegionT s pr))
-- | Convenience function which finds the first interface of the given
-- configuration handle which satisfies the given predicate on its
-- descriptors, then claims that interfaces and applies the given
-- continuation function to the resulting regional handle.
--
-- Exceptions:
--
--
withInterfaceWhich :: (MonadCatchIO pr) => ConfigHandle sCfg -> (Interface -> Bool) -> (forall s. RegionalIfHandle sCfg (RegionT s pr) -> RegionT s pr α) -> pr α
-- | A supported Interface alternate setting which you can retrieve
-- using getAlternates.
data Alternate sCfg r :: (* -> *)
-- | Retrieve the supported alternate settings from the given interface
-- handle.
--
-- Note that the alternate setting is parameterized by the same type
-- variables as the interface handle. This ensures you can never use an
-- alternate setting outside the region in which the interface handle was
-- created.
getAlternates :: RegionalIfHandle sCfg r -> [Alternate sCfg r]
-- | A handle to a setted alternate setting.
--
-- You get a handle to an alternate using setAlternate,
-- useActiveAlternate or setAlternateWhich. The type
-- variable sAlt is used to ensure that you can't return this
-- handle from these functions.
data AlternateHandle sCfg sAlt r :: (* -> *)
-- | Activate an alternate setting for an interface and then apply the
-- given continuation function to the resulting alternate handle.
--
-- Simillary to configurations, interfaces support multiple alternate
-- settings of which only one can be active at any given time. When an
-- alternate is set using setAlternate, useActiveAlternate
-- or setAlternateWhich no threads can set a new alternate until
-- the computation passed to these functions terminates. If you do try to
-- set one a SettingAlreadySet exception will be thrown.
--
-- The operating system may already have set an alternate for the
-- interface. If you want to use this current active alternate use
-- useActiveAlternate.
--
-- This is a blocking function.
--
-- Exceptions:
--
--
setAlternate :: (ParentOf pr cr, MonadCatchIO cr) => Alternate sCfg pr -> (forall sAlt. AlternateHandle sCfg sAlt pr -> cr α) -> cr α
-- | Apply the given function to the alternate handle of the current active
-- alternate of the give interface handle.
--
-- To determine the current active alternate this function will block
-- while a control transfer is submitted to retrieve the information.
--
-- Exceptions:
--
--
useActiveAlternate :: (ParentOf pr cr, MonadCatchIO cr) => RegionalIfHandle sCfg pr -> (forall sAlt. AlternateHandle sCfg sAlt pr -> cr α) -> cr α
-- | Convenience function which finds the first alternate of the given
-- interface handle which satisfies the given predicate on its
-- descriptor, then sets that alternate and applies the given function to
-- the resulting alternate handle.
--
-- This function calls setAlternate so do see its documentation.
--
-- Exceptions:
--
--
setAlternateWhich :: (ParentOf pr cr, MonadCatchIO cr) => RegionalIfHandle sCfg pr -> (InterfaceDesc -> Bool) -> (forall sAlt. AlternateHandle sCfg sAlt pr -> cr α) -> cr α
-- | I/O operations on endpoints are type-safe. You can only read from an
-- endpoint with an In transfer direction and you can only write
-- to an endpoint with an Out transfer direction.
--
-- Reading and writing also have different implementations for the
-- different endpoint transfer types like: Bulk and
-- Interrupt. I/O with endpoints of other transfer types like
-- Control and Isochronous is not possible.
--
-- This type lifts the transfer direction and transfer type information
-- to the type-level so that I/O operations like readEndpoint and
-- writeEndpoint can specify which endpoints they support.
--
-- You can retrieve the endpoints of an alternate using
-- getEndpoints.
data Endpoint transDir transType sAlt r :: (* -> *)
-- | Retrieve all the endpoints from the given alternate handle which are
-- of the given transfer direction and transfer type.
getEndpoints :: AlternateHandle sCfg sAlt r -> TransferDirection transDir -> TransferType transType -> [Endpoint transDir transType sAlt r]
-- | Clear the halt/stall condition for an endpoint.
--
-- Endpoints with halt status are unable to receive or transmit data
-- until the halt condition is stalled.
--
-- You should cancel all pending transfers before attempting to clear the
-- halt condition.
--
-- This is a blocking function.
--
-- Exceptions:
--
--
clearHalt :: (ParentOf pr cr, MonadIO cr) => Endpoint transDir transType sAlt pr -> cr ()
data TransferDirection transDir
Out :: TransferDirection Out
In :: TransferDirection In
-- | Out transfer direction (host -> device) used for writing.
data Out
-- | In transfer direction (device -> host) used for reading.
data In
data TransferType transType
Control :: TransferType Control
Isochronous :: TransferType Isochronous
Bulk :: TransferType Bulk
Interrupt :: TransferType Interrupt
data Control
data Isochronous
data Bulk
data Interrupt
-- | Handy type synonym for read transfers.
--
-- A ReadAction is a function which takes a timeout and a size
-- which defines how many bytes to read. The function returns an action
-- which, when executed, performs the actual read and returns the
-- bytestring that was read paired with an indication if the transfer
-- timed out.
type ReadAction r = Timeout -> Size -> r (ByteString, Bool)
-- | Handy type synonym for write transfers.
--
-- A WriteAction is a function which takes a timeout and the
-- bytestring to write. The function returns an action which, when
-- exectued, returns the number of bytes that were actually written
-- paired with an indication if the transfer timed out.
type WriteAction r = Timeout -> ByteString -> r (Size, Bool)
-- | Read bytes from an In endpoint with either a Bulk or
-- Interrupt transfer type.
--
-- Exceptions:
--
--
readEndpoint :: (ReadEndpoint transType, ParentOf pr cr, MonadIO cr) => Endpoint In transType sAlt pr -> ReadAction cr
-- | Write bytes to an Out endpoint with either a Bulk or
-- Interrupt transfer type.
--
-- Exceptions:
--
--
writeEndpoint :: (WriteEndpoint transType, ParentOf pr cr, MonadIO cr) => Endpoint Out transType sAlt pr -> WriteAction cr
-- | Control transfers can have three request types: Standard,
-- Class and Vendor. We disallow Standard
-- requests however because with them you can destroy the safety
-- guarantees that this module provides.
data RequestType
Class :: RequestType
Vendor :: RequestType
-- | Perform a USB control request that does not transfer data.
--
-- The value and index values should be given in
-- host-endian byte order.
--
-- Exceptions:
--
--
control :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> RequestType -> Recipient -> Word8 -> Word16 -> Word16 -> Timeout -> cr ()
-- | Perform a USB control read.
--
-- The value and index values should be given in
-- host-endian byte order.
--
-- Exceptions:
--
--
readControl :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> RequestType -> Recipient -> Word8 -> Word16 -> Word16 -> ReadAction cr
-- | Perform a USB control write.
--
-- The value and index values should be given in
-- host-endian byte order.
--
-- Exceptions:
--
--
writeControl :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> RequestType -> Recipient -> Word8 -> Word16 -> Word16 -> WriteAction cr
-- | Retrieve a list of supported languages.
--
-- This function may throw USBExceptions.
getLanguages :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> cr [LangId]
-- | Retrieve a string descriptor from a device.
--
-- This is a convenience function which formulates the appropriate
-- control message to retrieve the descriptor. The string returned is
-- Unicode, as detailed in the USB specifications.
--
-- This function may throw USBExceptions.
--
-- TODO: The following can be made more type-safe!
--
-- When I call getStrDesc I would like the type system to
-- guarantee that the given StrIx and LangId actually
-- belong to the given Handle. In other words I would like to
-- get a type error when they are some arbitrary number or come from
-- another device.
getStrDesc :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> StrIx -> LangId -> Size -> cr String
-- | Retrieve a string descriptor from a device using the first supported
-- language.
--
-- This is a convenience function which formulates the appropriate
-- control message to retrieve the descriptor. The string returned is
-- Unicode, as detailed in the USB specifications.
--
-- This function may throw USBExceptions.
getStrDescFirstLang :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> StrIx -> Size -> cr String
-- | Determine if a kernel driver is active on an interface.
--
-- If a kernel driver is active, you cannot claim the interface, and
-- libusb will be unable to perform I/O.
--
-- Exceptions:
--
--
kernelDriverActive :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> InterfaceNumber -> cr Bool
-- | Detach a kernel driver from an interface.
--
-- If successful, you will then be able to claim the interface and
-- perform I/O.
--
-- Exceptions:
--
--
detachKernelDriver :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> InterfaceNumber -> cr ()
-- | Re-attach an interface's kernel driver, which was previously detached
-- using detachKernelDriver.
--
-- Exceptions:
--
--
attachKernelDriver :: (ParentOf pr cr, MonadIO cr) => RegionalDeviceHandle pr -> InterfaceNumber -> cr ()
-- | If a kernel driver is active on the specified interface the driver is
-- detached and the given action is executed. If the action terminates,
-- whether by normal termination or by raising an exception, the kernel
-- driver is attached again. If a kernel driver is not active on the
-- specified interface the action is just executed.
--
-- Exceptions:
--
--
withDetachedKernelDriver :: (ParentOf pr cr, MonadCatchIO cr) => RegionalDeviceHandle pr -> InterfaceNumber -> cr α -> cr α
instance Typeable NoActiveConfig
instance Typeable SettingAlreadySet
instance Typeable NotFound
instance Show NoActiveConfig
instance Show SettingAlreadySet
instance Show NotFound
instance WriteEndpoint Interrupt
instance WriteEndpoint Bulk
instance ReadEndpoint Interrupt
instance ReadEndpoint Bulk
instance GetDescriptor (Endpoint transDir transType sAlt r) EndpointDesc
instance Dup (Alternate sCfg)
instance GetDescriptor (Alternate sIntrf r) InterfaceDesc
instance Resource (Interface sCfg)
instance GetDescriptor (Interface sCfg) Interface
instance Exception NoActiveConfig
instance Exception SettingAlreadySet
instance Dup Config
instance GetDescriptor (Config r) ConfigDesc
instance GetDescriptor Device DeviceDesc
instance Exception NotFound
instance Resource Device