{-# LANGUAGE UnicodeSyntax, NoImplicitPrelude, DeriveDataTypeable #-} module System.USB.Internal where -------------------------------------------------------------------------------- -- Imports -------------------------------------------------------------------------------- -- from base: import Prelude ( Num, (+), (-), fromInteger, (^) , Integral, fromIntegral, div , Enum, fromEnum, toEnum , error ) import Foreign ( unsafePerformIO ) import Foreign.C.Types ( CUChar, CInt, CUInt ) import Foreign.Marshal.Alloc ( alloca ) import Foreign.Marshal.Array ( peekArray, allocaArray ) import Foreign.Storable ( Storable, peek, peekElemOff ) import Foreign.Ptr ( Ptr, castPtr, plusPtr, nullPtr ) import Foreign.ForeignPtr ( ForeignPtr, newForeignPtr, withForeignPtr) import Control.Applicative ( liftA2 ) import Control.Exception ( Exception , throwIO , bracket, bracket_ , block, unblock , onException ) import Control.Monad ( Monad, return, (>>=), (>>), (=<<), fail , when, forM, mapM ) import Control.Arrow ( (&&&) ) import Data.Function ( ($), flip ) import Data.Functor ( Functor, fmap, (<$), (<$>) ) import Data.Data ( Data ) import Data.Typeable ( Typeable ) import Data.Maybe ( fromMaybe ) import Data.List ( lookup, map ) import Data.Int ( Int ) import Data.Word ( Word8, Word16 ) import Data.Char ( String ) import Data.Eq ( Eq, (==) ) import Data.Ord ( Ord, (<), (>) ) import Data.Bool ( Bool(False, True), not, otherwise ) import Data.Bits ( Bits , (.|.), (.&.) , setBit, testBit , shiftR, shiftL , bitSize ) import System.IO ( IO ) import Text.Show ( Show ) -- from base-unicode-symbols: import Prelude.Unicode ( (⋅) ) import Data.Function.Unicode ( (∘) ) import Data.Bool.Unicode ( (∧), (∨) ) import Data.Eq.Unicode ( (≢), (≡) ) import Data.Ord.Unicode ( (≥), (≤) ) -- from bytestring: import qualified Data.ByteString as B ( ByteString , packCStringLen , drop , head , length , unpack ) import qualified Data.ByteString.Internal as BI ( createAndTrim , createAndTrim' , toForeignPtr ) -- from text: import qualified Data.Text as T ( unpack ) import qualified Data.Text.Encoding as TE ( decodeUtf16LE ) -- from bindings-libusb: import Bindings.Libusb -------------------------------------------------------------------------------- -- * Initialization -------------------------------------------------------------------------------- {-| Abstract type representing a USB session. The concept of individual sessions allows your program to use multiple threads that can independently use this library without interfering with eachother. Sessions are created and initialized by 'newCtx' and are automatically closed when they are garbage collected. The only functions that receive a @Ctx@ are 'setDebug' and 'getDevices'. -} newtype Ctx = Ctx { unCtx ∷ ForeignPtr C'libusb_context } withCtxPtr ∷ Ctx → (Ptr C'libusb_context → IO α) → IO α withCtxPtr = withForeignPtr ∘ unCtx -- | Create and initialize a new USB context. -- -- This function may throw 'USBException's. newCtx ∷ IO Ctx newCtx = alloca $ \ctxPtrPtr → do handleUSBException $ c'libusb_init ctxPtrPtr peek ctxPtrPtr >>= fmap Ctx ∘ newForeignPtr p'libusb_exit {-| Set message verbosity. The default level is 'PrintNothing'. This means no messages are ever printed. If you choose to increase the message verbosity level you must ensure that your application does not close the @stdout@/@stderr@ file descriptors. You are advised to set the debug level to 'PrintWarnings'. Libusb is conservative with its message logging. Most of the time it will only log messages that explain error conditions and other oddities. This will help you debug your software. The LIBUSB_DEBUG environment variable overrules the debug level set by this function. The message verbosity is fixed to the value in the environment variable if it is defined. If @libusb@ was compiled without any message logging, this function does nothing: you'll never get any messages. If @libusb@ was compiled with verbose debug message logging, this function does nothing: you'll always get messages from all levels. -} setDebug ∷ Ctx → Verbosity → IO () setDebug ctx verbosity = withCtxPtr ctx $ \ctxPtr → c'libusb_set_debug ctxPtr $ genFromEnum verbosity -- | Message verbosity data Verbosity = PrintNothing -- ^ No messages are ever printed by the library | PrintErrors -- ^ Error messages are printed to stderr | PrintWarnings -- ^ Warning and error messages are printed to stderr | PrintInfo -- ^ Informational messages are printed to stdout, -- warning and error messages are printed to stderr deriving Enum -------------------------------------------------------------------------------- -- * Enumeration -------------------------------------------------------------------------------- {-| Abstract type representing a USB device detected on the system. You can only obtain a USB device from the 'getDevices' function. Certain operations can be performed on a device, but in order to do any I/O you will have to first obtain a 'DeviceHandle' using 'openDevice'. Alternatively you can use the /usb-safe/ package which provides type-safe device handling. See: <http://hackage.haskell.org/package/usb-safe> Just because you have a reference to a device does not mean it is necessarily usable. The device may have been unplugged, you may not have permission to operate such device or another process or driver may be using the device. To get additional information about a device you can retrieve its descriptor using 'deviceDesc'. -} data Device = Device { _ctx ∷ Ctx -- ^ This reference to the 'Ctx' is needed so that it won't -- get garbage collected. The finalizer "p'libusb_exit" is -- run only when all references to 'Devices' are gone. , getDevFrgnPtr ∷ ForeignPtr C'libusb_device , deviceDesc ∷ DeviceDesc -- ^ Get the descriptor of the device. } withDevicePtr ∷ Device → (Ptr C'libusb_device → IO α) → IO α withDevicePtr = withForeignPtr ∘ getDevFrgnPtr {-| Returns a list of USB devices currently attached to the system. This is your entry point into finding a USB device. Exceptions: * 'NoMemException' on a memory allocation failure. -} {- Visual description of the 'devPtrArrayPtr': D ^ D D │ ^ ^ │ │ │ │ │ devPtrArrayPtr: ┏━┷━┳━┷━┳━━━┳━━━┳━┷━┓ P ───> ┃ P ┃ P ┃ P ┃ P ┃ P ┃ ┗━━━┻━━━┻━┯━┻━┯━┻━━━┛ │ │ P = pointer v │ D = device structure D │ v D -} getDevices ∷ Ctx → IO [Device] getDevices ctx = withCtxPtr ctx $ \ctxPtr → alloca $ \devPtrArrayPtr → block $ do numDevs ← c'libusb_get_device_list ctxPtr devPtrArrayPtr devPtrArray ← peek devPtrArrayPtr let freeDevPtrArray = c'libusb_free_device_list devPtrArray 0 devs ← flip onException freeDevPtrArray $ unblock $ case numDevs of n | n ≡ c'LIBUSB_ERROR_NO_MEM → throwIO NoMemException | n < 0 → unknownLibUsbError | otherwise → do devPtrs ← peekArray (fromIntegral numDevs) devPtrArray forM devPtrs $ \devPtr → liftA2 (Device ctx) (newForeignPtr p'libusb_unref_device devPtr) (getDeviceDesc devPtr) freeDevPtrArray return devs -- | The number of the bus that a device is connected to. busNumber ∷ Device → Word8 busNumber dev = -- Getting the bus number from libusb is a side-effect free -- operation. The bus number is a static variable in the device -- structure. That's why it's safe to use: unsafePerformIO $ withDevicePtr dev c'libusb_get_bus_number -- | The address of the device on the bus it is connected to. deviceAddress ∷ Device → Word8 deviceAddress dev = -- Getting the device address from libusb is a side-effect -- free operation. The device address is a static variable -- in the device structure. That's why it's safe to use: unsafePerformIO $ withDevicePtr dev c'libusb_get_device_address -------------------------------------------------------------------------------- -- * Device handling -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- -- ** Opening & closing devices -------------------------------------------------------------------------------- {-| Abstract type representing a handle of a USB device. You can acquire a handle from 'openDevice'. A device handle is used to perform I/O and other operations. When finished with a device handle you should close it by applying 'closeDevice' to it. -} data DeviceHandle = DeviceHandle { getDevice ∷ Device -- This reference is needed for keeping the 'Device' -- and therefor the 'Ctx' alive. -- ^ Retrieve the 'Device' from the 'DeviceHandle'. , getDevHndlPtr ∷ Ptr C'libusb_device_handle } {-| Open a device and obtain a device handle. A handle allows you to perform I/O on the device in question. This is a non-blocking function; no requests are sent over the bus. It is advisable to use 'withDeviceHandle' because it automatically closes the device when the computation terminates. Exceptions: * 'NoMemException' if there is a memory allocation failure. * 'AccessException' if the user has insufficient permissions. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} openDevice ∷ Device → IO DeviceHandle openDevice dev = withDevicePtr dev $ \devPtr → alloca $ \devHndlPtrPtr → do handleUSBException $ c'libusb_open devPtr devHndlPtrPtr DeviceHandle dev <$> peek devHndlPtrPtr {-| Close a device handle. Should be called on all open handles before your application exits. This is a non-blocking function; no requests are sent over the bus. -} closeDevice ∷ DeviceHandle → IO () closeDevice = c'libusb_close ∘ getDevHndlPtr {-| @withDeviceHandle dev act@ opens the 'Device' @dev@ and passes the resulting handle to the computation @act@. The handle will be closed on exit from @withDeviceHandle@ whether by normal termination or by raising an exception. -} withDeviceHandle ∷ Device → (DeviceHandle → IO α) → IO α withDeviceHandle dev = bracket (openDevice dev) closeDevice -------------------------------------------------------------------------------- -- ** Getting & setting the configuration -------------------------------------------------------------------------------- -- | Identifier for configurations. -- -- Can be retrieved by 'getConfig' or by 'configValue'. type ConfigValue = Word8 {-| Determine the value of the currently active configuration. You could formulate your own control request to obtain this information, but this function has the advantage that it may be able to retrieve the information from operating system caches (no I/O involved). If the OS does not cache this information, then this function will block while a control transfer is submitted to retrieve the information. This function will return a value of 0 if the device is in unconfigured state. Exceptions: * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} getConfig ∷ DeviceHandle → IO ConfigValue getConfig devHndl = alloca $ \configPtr → do handleUSBException $ c'libusb_get_configuration (getDevHndlPtr devHndl) configPtr fromIntegral <$> peek configPtr {-| Set the active configuration for a device. 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 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 your application has claimed interfaces - you should free them with 'releaseInterface' first. You cannot change/reset configuration if other applications or drivers have claimed interfaces. A configuration value of -1 will put the device in an unconfigured state. The USB specification states that a configuration value of 0 does this, however buggy devices exist which actually have a configuration 0. You should always use this function rather than formulating your own SET_CONFIGURATION control request. This is because the underlying operating system needs to know when such changes happen. This is a blocking function. Exceptions: * 'NotFoundException' if the requested configuration does not exist. * 'BusyException' if interfaces are currently claimed. * 'NoDeviceException' if the device has been disconnected * Another 'USBException'. -} setConfig ∷ DeviceHandle → ConfigValue → IO () setConfig devHndl = handleUSBException ∘ c'libusb_set_configuration (getDevHndlPtr devHndl) ∘ fromIntegral -------------------------------------------------------------------------------- -- ** Claiming & releasing interfaces -------------------------------------------------------------------------------- {-| Identifier for interfaces. Can be retrieved by 'interfaceNumber'. -} type InterfaceNumber = Word8 {-| Claim an interface on a given device handle. You must claim the interface you wish to use before you can perform I/O on any of its endpoints. It is legal to attempt to claim an already-claimed interface, in which case this function just returns without doing anything. 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: * 'NotFoundException' if the requested interface does not exist. * 'BusyException' if the interface is already claimed. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} claimInterface ∷ DeviceHandle → InterfaceNumber → IO () claimInterface (DeviceHandle _ devHndlPtr) ifNum = handleUSBException $ c'libusb_claim_interface devHndlPtr (fromIntegral ifNum) {-| Release an interface previously claimed with 'claimInterface'. You should release all claimed interfaces before closing a device handle. This is a blocking function. A SET_INTERFACE control request will be sent to the device, resetting interface state to the first alternate setting. Exceptions: * 'NotFoundException' if the interface was not claimed. * 'NoDeviceException' if the device has been disconnected * Another 'USBException'. -} releaseInterface ∷ DeviceHandle → InterfaceNumber → IO () releaseInterface (DeviceHandle _ devHndlPtr) ifNum = handleUSBException $ c'libusb_release_interface devHndlPtr (fromIntegral ifNum) {-| @withClaimedInterface@ claims the interface on the given device handle then executes the given computation. On exit from @withClaimedInterface@, the interface is released whether by normal termination or by raising an exception. -} withClaimedInterface ∷ DeviceHandle → InterfaceNumber → IO α → IO α withClaimedInterface devHndl ifNum = bracket_ (claimInterface devHndl ifNum) (releaseInterface devHndl ifNum) -------------------------------------------------------------------------------- -- ** Setting interface alternate settings -------------------------------------------------------------------------------- -- | Identifier for interface alternate settings. -- -- Can be retrieved by 'interfaceAltSetting'. type InterfaceAltSetting = Word8 {-| Activate an alternate setting for an interface. The interface must have been previously claimed with 'claimInterface' or 'withInterfaceHandle'. You should always use this function rather than formulating your own SET_INTERFACE control request. This is because the underlying operating system needs to know when such changes happen. This is a blocking function. Exceptions: * 'NotFoundException' if the interface was not claimed or the requested alternate setting does not exist. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} setInterfaceAltSetting ∷ DeviceHandle → InterfaceNumber → InterfaceAltSetting → IO () setInterfaceAltSetting devHndl ifNum alternateSetting = handleUSBException $ c'libusb_set_interface_alt_setting (getDevHndlPtr devHndl) (fromIntegral ifNum) (fromIntegral alternateSetting) -------------------------------------------------------------------------------- -- ** Clearing & Resetting devices -------------------------------------------------------------------------------- {-| 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: * 'NotFoundException' if the endpoint does not exist. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} clearHalt ∷ DeviceHandle → EndpointAddress → IO () clearHalt devHndl = handleUSBException ∘ c'libusb_clear_halt (getDevHndlPtr devHndl) ∘ marshalEndpointAddress {-| 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. 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. This is a blocking function which usually incurs a noticeable delay. Exceptions: * 'NotFoundException' if re-enumeration is required, or if the device has been disconnected. * Another 'USBException'. -} resetDevice ∷ DeviceHandle → IO () resetDevice = handleUSBException ∘ c'libusb_reset_device ∘ getDevHndlPtr -------------------------------------------------------------------------------- -- ** USB kernel drivers -------------------------------------------------------------------------------- {-| 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: * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} kernelDriverActive ∷ DeviceHandle → InterfaceNumber → IO Bool kernelDriverActive devHndl ifNum = do r ← c'libusb_kernel_driver_active (getDevHndlPtr devHndl) (fromIntegral ifNum) case r of 0 → return False 1 → return True _ → throwIO $ convertUSBException r {-| Detach a kernel driver from an interface. If successful, you will then be able to claim the interface and perform I/O. Exceptions: * 'NotFoundException' if no kernel driver was active. * 'InvalidParamException' if the interface does not exist. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} detachKernelDriver ∷ DeviceHandle → InterfaceNumber → IO () detachKernelDriver devHndl ifNum = handleUSBException $ c'libusb_detach_kernel_driver (getDevHndlPtr devHndl) (fromIntegral ifNum) {-| Re-attach an interface's kernel driver, which was previously detached using 'detachKernelDriver'. Exceptions: * 'NotFoundException' if no kernel driver was active. * 'InvalidParamException' if the interface does not exist. * 'NoDeviceException' if the device has been disconnected. * 'BusyException' if the driver cannot be attached because the interface is claimed by a program or driver. * Another 'USBException'. -} attachKernelDriver ∷ DeviceHandle → InterfaceNumber → IO () attachKernelDriver devHndl ifNum = handleUSBException $ c'libusb_attach_kernel_driver (getDevHndlPtr devHndl) (fromIntegral ifNum) {-| 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: * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} withDetachedKernelDriver ∷ DeviceHandle → InterfaceNumber → IO α → IO α withDetachedKernelDriver devHndl ifNum action = ifM (kernelDriverActive devHndl ifNum) (bracket_ (detachKernelDriver devHndl ifNum) (attachKernelDriver devHndl ifNum) action) action -------------------------------------------------------------------------------- -- * Descriptors -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- -- ** Device descriptor -------------------------------------------------------------------------------- {-| A structure representing the standard USB device descriptor. This descriptor is documented in section 9.6.1 of the USB 2.0 specification. This structure can be retrieved by 'deviceDesc'. -} data DeviceDesc = DeviceDesc { -- | USB specification release number in binary-coded decimal. deviceUSBSpecReleaseNumber ∷ BCD4 -- | USB-IF class code for the device. , deviceClass ∷ Word8 -- | USB-IF subclass code for the device, qualified by the 'deviceClass' -- value. , deviceSubClass ∷ Word8 -- | USB-IF protocol code for the device, qualified by the 'deviceClass' -- and 'deviceSubClass' values. , deviceProtocol ∷ Word8 -- | Maximum packet size for endpoint 0. , deviceMaxPacketSize0 ∷ Word8 -- | USB-IF vendor ID. , deviceVendorId ∷ VendorId -- | USB-IF product ID. , deviceProductId ∷ ProductId -- | Device release number in binary-coded decimal. , deviceReleaseNumber ∷ BCD4 -- | Index of string descriptor describing manufacturer. , deviceManufacturerStrIx ∷ StrIx -- | Index of string descriptor describing product. , deviceProductStrIx ∷ StrIx -- | Index of string descriptor containing device serial number. , deviceSerialNumberStrIx ∷ StrIx -- | Number of possible configurations. , deviceNumConfigs ∷ Word8 -- | List of configurations supported by the device. , deviceConfigs ∷ [ConfigDesc] } deriving (Show, Eq, Data, Typeable) type VendorId = Word16 type ProductId = Word16 -------------------------------------------------------------------------------- -- ** Configuration descriptor -------------------------------------------------------------------------------- {-| A structure representing the standard USB configuration descriptor. This descriptor is documented in section 9.6.3 of the USB 2.0 specification. This structure can be retrieved by 'deviceConfigs'. -} data ConfigDesc = ConfigDesc { -- | Identifier value for the configuration. configValue ∷ ConfigValue -- | Index of string descriptor describing the configuration. , configStrIx ∷ StrIx -- | Configuration characteristics. , configAttribs ∷ ConfigAttribs -- | Maximum power consumption of the USB device from the bus in the -- configuration when the device is fully operational. Expressed in 2 mA -- units (i.e., 50 = 100 mA). , configMaxPower ∷ Word8 -- | Number of interfaces supported by the configuration. , configNumInterfaces ∷ Word8 -- | List of interfaces supported by the configuration. Note that the -- length of this list should equal 'configNumInterfaces'. , configInterfaces ∷ [Interface] -- | Extra descriptors. If @libusb@ encounters unknown configuration -- descriptors, it will store them here, should you wish to parse them. , configExtra ∷ B.ByteString } deriving (Show, Eq, Data, Typeable) -- | An interface is represented as a list of alternate interface settings. type Interface = [InterfaceDesc] -------------------------------------------------------------------------------- -- *** Configuration attributes -------------------------------------------------------------------------------- -- | The USB 2.0 specification specifices that the configuration attributes only -- describe the device status. type ConfigAttribs = DeviceStatus data DeviceStatus = DeviceStatus { remoteWakeup ∷ Bool -- ^ The Remote Wakeup field indicates whether the -- device is currently enabled to request remote -- wakeup. The default mode for devices that -- support remote wakeup is disabled. , selfPowered ∷ Bool -- ^ The Self Powered field indicates whether the -- device is currently self-powered } deriving (Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- ** Interface descriptor -------------------------------------------------------------------------------- {-| A structure representing the standard USB interface descriptor. This descriptor is documented in section 9.6.5 of the USB 2.0 specification. This structure can be retrieved using 'configInterfaces'. -} data InterfaceDesc = InterfaceDesc { -- | Number of the interface. interfaceNumber ∷ InterfaceNumber -- | Value used to select the alternate setting for the interface. , interfaceAltSetting ∷ InterfaceAltSetting -- | USB-IF class code for the interface. , interfaceClass ∷ Word8 -- | USB-IF subclass code for the interface, qualified by the -- 'interfaceClass' value. , interfaceSubClass ∷ Word8 -- | USB-IF protocol code for the interface, qualified by the -- 'interfaceClass' and 'interfaceSubClass' values. , interfaceProtocol ∷ Word8 -- | Index of string descriptor describing the interface. , interfaceStrIx ∷ StrIx -- | List of endpoints supported by the interface. , interfaceEndpoints ∷ [EndpointDesc] -- | Extra descriptors. If @libusb@ encounters unknown interface -- descriptors, it will store them here, should you wish to parse them. , interfaceExtra ∷ B.ByteString } deriving (Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- ** Endpoint descriptor -------------------------------------------------------------------------------- {-| A structure representing the standard USB endpoint descriptor. This descriptor is documented in section 9.6.3 of the USB 2.0 specification. All multiple-byte fields are represented in host-endian format. -} data EndpointDesc = EndpointDesc { -- | The address of the endpoint described by the descriptor. endpointAddress ∷ EndpointAddress -- | Attributes which apply to the endpoint when it is configured using the -- 'configValue'. , endpointAttribs ∷ EndpointAttribs -- | Maximum packet size the endpoint is capable of sending/receiving. , endpointMaxPacketSize ∷ MaxPacketSize -- | Interval for polling endpoint for data transfers. Expressed in frames -- or microframes depending on the device operating speed (i.e., either 1 -- millisecond or 125 μs units). , endpointInterval ∷ Word8 -- | /For audio devices only:/ the rate at which synchronization feedback -- is provided. , endpointRefresh ∷ Word8 -- | /For audio devices only:/ the address if the synch endpoint. , endpointSynchAddress ∷ Word8 -- | Extra descriptors. If @libusb@ encounters unknown endpoint descriptors, -- it will store them here, should you wish to parse them. , endpointExtra ∷ B.ByteString } deriving (Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- *** Endpoint address -------------------------------------------------------------------------------- -- | The address of an endpoint. data EndpointAddress = EndpointAddress { endpointNumber ∷ Int -- ^ Must be >= 0 and <= 15 , transferDirection ∷ TransferDirection } deriving (Show, Eq, Data, Typeable) -- | The direction of data transfer relative to the host. data TransferDirection = Out -- ^ Out transfer direction (host -> device) used -- for writing. | In -- ^ In transfer direction (device -> host) used -- for reading. deriving (Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- *** Endpoint attributes -------------------------------------------------------------------------------- -- | The USB 2.0 specification specifies that the endpoint attributes only -- describe the endpoint transfer type. type EndpointAttribs = TransferType -- | Describes what types of transfers are allowed on the endpoint. data TransferType = -- | Control transfers are typically used for command and status -- operations. Control -- | Isochronous transfers occur continuously and periodically. | Isochronous Synchronization Usage -- | Bulk transfers can be used for large bursty data. | Bulk -- | Interrupt transfers are typically non-periodic, small device -- \"initiated\" communication requiring bounded latency. | Interrupt deriving (Show, Eq, Data, Typeable) data Synchronization = NoSynchronization | Asynchronous | Adaptive | Synchronous deriving (Enum, Show, Eq, Data, Typeable) data Usage = Data | Feedback | Implicit deriving (Enum, Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- *** Endpoint max packet size -------------------------------------------------------------------------------- data MaxPacketSize = MaxPacketSize { maxPacketSize ∷ Size , transactionOpportunities ∷ TransactionOpportunities } deriving (Show, Eq, Data, Typeable) -- | Number of additional transactions. data TransactionOpportunities = Zero | One | Two deriving (Enum, Show, Eq, Data, Typeable) -------------------------------------------------------------------------------- -- Retrieving and converting descriptors -------------------------------------------------------------------------------- getDeviceDesc ∷ Ptr C'libusb_device → IO DeviceDesc getDeviceDesc devPtr = alloca $ \devDescPtr → do handleUSBException $ c'libusb_get_device_descriptor devPtr devDescPtr peek devDescPtr >>= convertDeviceDesc devPtr convertDeviceDesc ∷ Ptr C'libusb_device → C'libusb_device_descriptor → IO DeviceDesc convertDeviceDesc devPtr d = do let numConfigs = c'libusb_device_descriptor'bNumConfigurations d configs ← forM [0..numConfigs-1] $ getConfigDesc devPtr return DeviceDesc { deviceUSBSpecReleaseNumber = unmarshalBCD4 $ c'libusb_device_descriptor'bcdUSB d , deviceClass = c'libusb_device_descriptor'bDeviceClass d , deviceSubClass = c'libusb_device_descriptor'bDeviceSubClass d , deviceProtocol = c'libusb_device_descriptor'bDeviceProtocol d , deviceMaxPacketSize0 = c'libusb_device_descriptor'bMaxPacketSize0 d , deviceVendorId = c'libusb_device_descriptor'idVendor d , deviceProductId = c'libusb_device_descriptor'idProduct d , deviceReleaseNumber = unmarshalBCD4 $ c'libusb_device_descriptor'bcdDevice d , deviceManufacturerStrIx = c'libusb_device_descriptor'iManufacturer d , deviceProductStrIx = c'libusb_device_descriptor'iProduct d , deviceSerialNumberStrIx = c'libusb_device_descriptor'iSerialNumber d , deviceNumConfigs = numConfigs , deviceConfigs = configs } getConfigDesc ∷ Ptr C'libusb_device → Word8 → IO ConfigDesc getConfigDesc devPtr ix = bracket getConfigDescPtr c'libusb_free_config_descriptor ((convertConfigDesc =<<) ∘ peek) where getConfigDescPtr = alloca $ \configDescPtrPtr → do handleUSBException $ c'libusb_get_config_descriptor devPtr ix configDescPtrPtr peek configDescPtrPtr convertConfigDesc ∷ C'libusb_config_descriptor → IO ConfigDesc convertConfigDesc c = do let numInterfaces = c'libusb_config_descriptor'bNumInterfaces c interfaces ← mapPeekArray convertInterface (fromIntegral numInterfaces) (c'libusb_config_descriptor'interface c) extra ← getExtra (c'libusb_config_descriptor'extra c) (c'libusb_config_descriptor'extra_length c) return ConfigDesc { configValue = c'libusb_config_descriptor'bConfigurationValue c , configStrIx = c'libusb_config_descriptor'iConfiguration c , configAttribs = unmarshalConfigAttribs $ c'libusb_config_descriptor'bmAttributes c , configMaxPower = c'libusb_config_descriptor'MaxPower c , configNumInterfaces = numInterfaces , configInterfaces = interfaces , configExtra = extra } unmarshalConfigAttribs ∷ Word8 → ConfigAttribs unmarshalConfigAttribs a = DeviceStatus { remoteWakeup = testBit a 5 , selfPowered = testBit a 6 } getExtra ∷ Ptr CUChar → CInt → IO B.ByteString getExtra extra extraLength = B.packCStringLen ( castPtr extra , fromIntegral extraLength ) convertInterface∷ C'libusb_interface → IO [InterfaceDesc] convertInterface i = mapPeekArray convertInterfaceDesc (fromIntegral $ c'libusb_interface'num_altsetting i) (c'libusb_interface'altsetting i) convertInterfaceDesc ∷ C'libusb_interface_descriptor → IO InterfaceDesc convertInterfaceDesc i = do let n = c'libusb_interface_descriptor'bNumEndpoints i endpoints ← mapPeekArray convertEndpointDesc (fromIntegral n) (c'libusb_interface_descriptor'endpoint i) extra ← getExtra (c'libusb_interface_descriptor'extra i) (c'libusb_interface_descriptor'extra_length i) return InterfaceDesc { interfaceNumber = c'libusb_interface_descriptor'bInterfaceNumber i , interfaceAltSetting = c'libusb_interface_descriptor'bAlternateSetting i , interfaceClass = c'libusb_interface_descriptor'bInterfaceClass i , interfaceSubClass = c'libusb_interface_descriptor'bInterfaceSubClass i , interfaceStrIx = c'libusb_interface_descriptor'iInterface i , interfaceProtocol = c'libusb_interface_descriptor'bInterfaceProtocol i , interfaceEndpoints = endpoints , interfaceExtra = extra } convertEndpointDesc ∷ C'libusb_endpoint_descriptor → IO EndpointDesc convertEndpointDesc e = do extra ← getExtra (c'libusb_endpoint_descriptor'extra e) (c'libusb_endpoint_descriptor'extra_length e) return EndpointDesc { endpointAddress = unmarshalEndpointAddress $ c'libusb_endpoint_descriptor'bEndpointAddress e , endpointAttribs = unmarshalEndpointAttribs $ c'libusb_endpoint_descriptor'bmAttributes e , endpointMaxPacketSize = unmarshalMaxPacketSize $ c'libusb_endpoint_descriptor'wMaxPacketSize e , endpointInterval = c'libusb_endpoint_descriptor'bInterval e , endpointRefresh = c'libusb_endpoint_descriptor'bRefresh e , endpointSynchAddress = c'libusb_endpoint_descriptor'bSynchAddress e , endpointExtra = extra } unmarshalEndpointAddress ∷ Word8 → EndpointAddress unmarshalEndpointAddress a = EndpointAddress { endpointNumber = fromIntegral $ bits 0 3 a , transferDirection = if testBit a 7 then In else Out } marshalEndpointAddress ∷ (Bits a, Num a) ⇒ EndpointAddress → a marshalEndpointAddress (EndpointAddress num transDir) | between num 0 15 = let n = fromIntegral num in case transDir of Out → n In → setBit n 7 | otherwise = error "marshalEndpointAddress: endpointNumber not >= 0 and <= 15" unmarshalEndpointAttribs ∷ Word8 → EndpointAttribs unmarshalEndpointAttribs a = case bits 0 1 a of 0 → Control 1 → Isochronous (genToEnum $ bits 2 3 a) (genToEnum $ bits 4 5 a) 2 → Bulk 3 → Interrupt _ → error "unmarshalEndpointAttribs: this can't happen!" unmarshalMaxPacketSize ∷ Word16 → MaxPacketSize unmarshalMaxPacketSize m = MaxPacketSize { maxPacketSize = fromIntegral $ bits 0 10 m , transactionOpportunities = genToEnum $ bits 11 12 m } -------------------------------------------------------------------------------- -- ** String descriptors -------------------------------------------------------------------------------- strDescHeaderSize ∷ Size strDescHeaderSize = 2 {-| Retrieve a list of supported languages. This function may throw 'USBException's. -} getLanguages ∷ DeviceHandle → IO [LangId] getLanguages devHndl = let maxSize = 255 -- Some devices choke on size > 255 in allocaArray maxSize $ \dataPtr → do reportedSize ← putStrDesc devHndl 0 0 maxSize dataPtr map unmarshalLangId <$> peekArray ((reportedSize - strDescHeaderSize) `div` 2) (castPtr $ dataPtr `plusPtr` strDescHeaderSize) {-| @putStrDesc devHndl strIx langId maxSize dataPtr@ retrieves the string descriptor @strIx@ in the language @langId@ from the @devHndl@ and writes at most @maxSize@ bytes from that string descriptor to the location that @dataPtr@ points to. So ensure there is at least space for @maxSize@ bytes there. Next, the header of the string descriptor is checked for correctness. If it's incorrect an 'IOException' is thrown. Finally, the size reported in the header is returned. -} putStrDesc ∷ DeviceHandle → StrIx → Word16 → Size → Ptr CUChar → IO Size putStrDesc devHndl strIx langId maxSize dataPtr = do actualSize ← checkUSBException $ c'libusb_get_string_descriptor (getDevHndlPtr devHndl) strIx langId dataPtr (fromIntegral maxSize) -- if there are enough bytes, parse the header when (actualSize < strDescHeaderSize) $ throwIO IOException reportedSize ← peek dataPtr descType ← peekElemOff dataPtr 1 -- Check header incorrectness: when ( descType ≢ c'LIBUSB_DT_STRING ∨ reportedSize > fromIntegral actualSize ) $ throwIO IOException return $ fromIntegral reportedSize {-| The language ID consists of the primary language identifier and the sublanguage identififier as described in: <http://www.usb.org/developers/docs/USB_LANGIDs.pdf> For a mapping between IDs and languages see the @usb-id-database@ package at: <http://hackage.haskell.org/package/usb-id-database> To see which 'LangId's are supported by a device see 'getLanguages'. -} type LangId = (PrimaryLangId, SubLangId) type PrimaryLangId = Word16 type SubLangId = Word16 unmarshalLangId ∷ Word16 → LangId unmarshalLangId = bits 0 9 &&& bits 10 15 marshalLangId ∷ LangId → Word16 marshalLangId (p, s) = p .|. s `shiftL`10 -- | Type of indici of string descriptors. -- -- Can be retrieved by all the *StrIx functions. type StrIx = Word8 {-| 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 'USBException's. -} getStrDesc ∷ DeviceHandle → StrIx → LangId → Size → IO String getStrDesc devHndl strIx langId size = fmap (T.unpack ∘ TE.decodeUtf16LE ∘ B.drop strDescHeaderSize) $ BI.createAndTrim size $ putStrDesc devHndl strIx (marshalLangId langId) size ∘ castPtr {-| 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 'USBException's. -} getStrDescFirstLang ∷ DeviceHandle → StrIx → Size → IO String getStrDescFirstLang devHndl strIx size = do langIds ← getLanguages devHndl case langIds of [] → throwIO IOException langId : _ → getStrDesc devHndl strIx langId size -------------------------------------------------------------------------------- -- * Asynchronous device I/O -------------------------------------------------------------------------------- -- TODO: Not implemented yet. I'm not sure if I should implement it because you -- can simulate asynchronous IO using threads. -------------------------------------------------------------------------------- -- * Synchronous device I/O -------------------------------------------------------------------------------- {-| Handy type synonym for read transfers. A @ReadAction@ is a function which takes a 'Size' which defines how many bytes to read and a 'Timeout'. The function returns an 'IO' action which, when executed, performs the actual read and returns the 'B.ByteString' that was read paired with a flag which indicates whether a transfer timed out. -} type ReadAction = Size → Timeout → IO (B.ByteString, Bool) {-| Handy type synonym for write transfers. A @WriteAction@ is a function which takes a 'B.ByteString' to write and a 'Timeout'. The function returns an 'IO' action which, when exectued, returns the number of bytes that were actually written paired with an flag which indicates whether a transfer timed out. -} type WriteAction = B.ByteString → Timeout → IO (Size, Bool) -- | A timeout in milliseconds. A timeout defines how long a transfer should wait -- before giving up due to no response being received. For no timeout, use value -- 0. type Timeout = Int -- | Number of bytes transferred. type Size = Int ------------------------------------------------------------------------------- -- ** Control transfers ------------------------------------------------------------------------------- -- | Handy type synonym that names the parameters of a control transfer. type ControlAction α = RequestType → Recipient → Request → Value → Index → α data RequestType = Standard | Class | Vendor deriving (Enum, Show, Eq, Data, Typeable) data Recipient = ToDevice | ToInterface | ToEndpoint | ToOther deriving (Enum, Show, Eq, Data, Typeable) type Request = Word8 -- | (Host-endian) type Value = Word16 -- | (Host-endian) type Index = Word16 marshalRequestType ∷ RequestType → Recipient → Word8 marshalRequestType t r = genFromEnum t `shiftL` 5 .|. genFromEnum r {-| Perform a USB /control/ request that does not transfer data. Exceptions: * 'TimeoutException' if the transfer timed out. * 'PipeException' if the control request was not supported by the device * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} control ∷ DeviceHandle → ControlAction (Timeout → IO ()) control devHndl = \reqType reqRecipient request value index → \timeout → void $ checkUSBException $ c'libusb_control_transfer (getDevHndlPtr devHndl) (marshalRequestType reqType reqRecipient) request value index nullPtr 0 (fromIntegral timeout) {-| Perform a USB /control/ read. Exceptions: * 'PipeException' if the control request was not supported by the device * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} readControl ∷ DeviceHandle → ControlAction ReadAction readControl devHndl = \reqType reqRecipient request value index → \size timeout → BI.createAndTrim' size $ \dataPtr → do err ← c'libusb_control_transfer (getDevHndlPtr devHndl) (marshalRequestType reqType reqRecipient `setBit` 7) request value index (castPtr dataPtr) (fromIntegral size) (fromIntegral timeout) let timedOut = err ≡ c'LIBUSB_ERROR_TIMEOUT if err < 0 ∧ not timedOut then throwIO $ convertUSBException err else return (0, fromIntegral err, timedOut) {-| Perform a USB /control/ write. Exceptions: * 'PipeException' if the control request was not supported by the device * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} writeControl ∷ DeviceHandle → ControlAction WriteAction writeControl devHndl = \reqType reqRecipient request value index → \input timeout → input `writeWith` \size dataPtr → do err ← c'libusb_control_transfer (getDevHndlPtr devHndl) (marshalRequestType reqType reqRecipient) request value index (castPtr dataPtr) (fromIntegral size) (fromIntegral timeout) let timedOut = err ≡ c'LIBUSB_ERROR_TIMEOUT if err < 0 ∧ not timedOut then throwIO $ convertUSBException err else return (fromIntegral err, timedOut) -------------------------------------------------------------------------------- -- *** Standard Device Requests ------------------------------------------------------------------------------- -- See: USB 2.0 Spec. section 9.4 -- Standard Feature Selectors: -- See: USB 2.0 Spec. table 9-6 haltFeature, remoteWakeupFeature, testModeFeature ∷ Word16 remoteWakeupFeature = 1 haltFeature = 0 testModeFeature = 2 -- | See: USB 2.0 Spec. section 9.4.9 setHalt ∷ DeviceHandle → EndpointAddress → Timeout → IO () setHalt devHndl endpointAddr = control devHndl Standard ToEndpoint c'LIBUSB_REQUEST_SET_FEATURE haltFeature (marshalEndpointAddress endpointAddr) -- | See: USB 2.0 Spec. section 9.4.1 clearRemoteWakeup ∷ DeviceHandle → Timeout → IO () clearRemoteWakeup devHndl = control devHndl Standard ToDevice c'LIBUSB_REQUEST_CLEAR_FEATURE remoteWakeupFeature 0 -- | See: USB 2.0 Spec. section 9.4.9 setRemoteWakeup ∷ DeviceHandle → Timeout → IO () setRemoteWakeup devHndl = control devHndl Standard ToDevice c'LIBUSB_REQUEST_SET_FEATURE remoteWakeupFeature 0 -- | See: USB 2.0 Spec. section 9.4.9 -- TODO: What about vendor-specific test modes? setStandardTestMode ∷ DeviceHandle → TestMode → Timeout → IO () setStandardTestMode devHndl testMode = control devHndl Standard ToDevice c'LIBUSB_REQUEST_SET_FEATURE testModeFeature (genFromEnum testMode + 1 `shiftL` 8) -- | See: USB 2.0 Spec. table 9-7 data TestMode = Test_J | Test_K | Test_SE0_NAK | Test_Packet | Test_Force_Enable deriving (Show, Enum, Data, Typeable) -- | See: USB 2.0 Spec. section 9.4.4 getInterfaceAltSetting ∷ DeviceHandle → InterfaceNumber → Timeout → IO InterfaceAltSetting getInterfaceAltSetting devHndl ifNum = \timeout → do (bs, _) ← readControl devHndl Standard ToInterface c'LIBUSB_REQUEST_GET_INTERFACE 0 (fromIntegral ifNum) 1 timeout if B.length bs ≢ 1 then throwIO IOException else return $ B.head bs -- | See: USB 2.0 Spec. section 9.4.5 getDeviceStatus ∷ DeviceHandle → Timeout → IO DeviceStatus getDeviceStatus devHndl = \timeout → do (bs, _) ← readControl devHndl Standard ToDevice c'LIBUSB_REQUEST_GET_STATUS 0 0 2 timeout if B.length bs ≢ 2 then throwIO IOException else return $ unmarshalDeviceStatus $ B.head bs where unmarshalDeviceStatus ∷ Word8 → DeviceStatus unmarshalDeviceStatus a = DeviceStatus { remoteWakeup = testBit a 1 , selfPowered = testBit a 0 } -- | See: USB 2.0 Spec. section 9.4.5 getEndpointStatus ∷ DeviceHandle → EndpointAddress → Timeout → IO Bool getEndpointStatus devHndl endpointAddr = \timeout → do (bs, _) ← readControl devHndl Standard ToEndpoint c'LIBUSB_REQUEST_GET_STATUS 0 (marshalEndpointAddress endpointAddr) 2 timeout if B.length bs ≢ 2 then throwIO IOException else return $ B.head bs ≡ 1 -- | See: USB 2.0 Spec. section 9.4.6 setDeviceAddress ∷ DeviceHandle → Word16 → Timeout → IO () setDeviceAddress devHndl deviceAddr = control devHndl Standard ToDevice c'LIBUSB_REQUEST_SET_ADDRESS deviceAddr 0 -- TODO: setDescriptor See: USB 2.0 Spec. section 9.4.8 -- | See: USB 2.0 Spec. section 9.4.11 synchFrame ∷ DeviceHandle → EndpointAddress → Timeout → IO Int synchFrame devHndl endpointAddr = \timeout → do (bs, _) ← readControl devHndl Standard ToEndpoint c'LIBUSB_REQUEST_SYNCH_FRAME 0 (marshalEndpointAddress endpointAddr) 2 timeout if B.length bs ≢ 2 then throwIO IOException else return $ let [h, l] = B.unpack bs in fromIntegral h ⋅ 256 + fromIntegral l -------------------------------------------------------------------------------- -- ** Bulk transfers -------------------------------------------------------------------------------- {-| Perform a USB /bulk/ read. Exceptions: * 'PipeException' if the endpoint halted. * 'OverflowException' if the device offered more data, see /Packets and overflows/ in the @libusb@ documentation: <http://libusb.sourceforge.net/api-1.0/packetoverflow.html>. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} readBulk ∷ DeviceHandle -- ^ A handle for the device to communicate with. → EndpointAddress -- ^ The address of a valid 'In' and 'Bulk' endpoint -- to communicate with. Make sure the endpoint -- belongs to the current alternate setting of a -- claimed interface which belongs to the device. → ReadAction readBulk = readTransfer c'libusb_bulk_transfer {-| Perform a USB /bulk/ write. Exceptions: * 'PipeException' if the endpoint halted. * 'OverflowException' if the device offered more data, see /Packets and overflows/ in the @libusb@ documentation: <http://libusb.sourceforge.net/api-1.0/packetoverflow.html>. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} writeBulk ∷ DeviceHandle -- ^ A handle for the device to communicate with. → EndpointAddress -- ^ The address of a valid 'Out' and 'Bulk' -- endpoint to communicate with. Make sure the -- endpoint belongs to the current alternate -- setting of a claimed interface which belongs to -- the device. → WriteAction writeBulk = writeTransfer c'libusb_bulk_transfer -------------------------------------------------------------------------------- -- ** Interrupt transfers -------------------------------------------------------------------------------- {-| Perform a USB /interrupt/ read. Exceptions: * 'PipeException' if the endpoint halted. * 'OverflowException' if the device offered more data, see /Packets and overflows/ in the libusb documentation: <http://libusb.sourceforge.net/api-1.0/packetoverflow.html>. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} readInterrupt ∷ DeviceHandle -- ^ A handle for the device to communicate -- with. → EndpointAddress -- ^ The address of a valid 'In' and 'Interrupt' -- endpoint to communicate with. Make sure the -- endpoint belongs to the current alternate -- setting of a claimed interface which -- belongs to the device. → ReadAction readInterrupt = readTransfer c'libusb_interrupt_transfer {-| Perform a USB /interrupt/ write. Exceptions: * 'PipeException' if the endpoint halted. * 'OverflowException' if the device offered more data, see /Packets and overflows/ in the @libusb@ documentation: <http://libusb.sourceforge.net/api-1.0/packetoverflow.html>. * 'NoDeviceException' if the device has been disconnected. * Another 'USBException'. -} writeInterrupt ∷ DeviceHandle -- ^ A handle for the device to communicate -- with. → EndpointAddress -- ^ The address of a valid 'Out' and -- 'Interrupt' endpoint to communicate -- with. Make sure the endpoint belongs to -- the current alternate setting of a claimed -- interface which belongs to the device. → WriteAction writeInterrupt = writeTransfer c'libusb_interrupt_transfer -------------------------------------------------------------------------------- type C'TransferFunc = Ptr C'libusb_device_handle -- devHndlPtr → CUChar -- endpoint address → Ptr CUChar -- dataPtr → CInt -- size → Ptr CInt -- transferredPtr → CUInt -- timeout → IO CInt -- error readTransfer ∷ C'TransferFunc → (DeviceHandle → EndpointAddress → ReadAction) readTransfer c'transfer = \devHndl endpointAddr → \size timeout → BI.createAndTrim' size $ \dataPtr → do (transferred, timedOut) ← transfer c'transfer devHndl endpointAddr timeout size dataPtr return (0, transferred, timedOut) writeTransfer ∷ C'TransferFunc → (DeviceHandle → EndpointAddress → WriteAction) writeTransfer c'transfer = \devHndl endpointAddr → \input timeout → input `writeWith` transfer c'transfer devHndl endpointAddr timeout transfer ∷ C'TransferFunc → DeviceHandle → EndpointAddress → Timeout → Size → Ptr Word8 → IO (Size, Bool) transfer c'transfer devHndl endpointAddr timeout size dataPtr = alloca $ \transferredPtr → do err ← c'transfer (getDevHndlPtr devHndl) (marshalEndpointAddress endpointAddr) (castPtr dataPtr) (fromIntegral size) transferredPtr (fromIntegral timeout) let timedOut = err ≡ c'LIBUSB_ERROR_TIMEOUT if err ≢ c'LIBUSB_SUCCESS ∧ not timedOut then throwIO $ convertUSBException err else do transferred ← peek transferredPtr return (fromIntegral transferred, timedOut) -------------------------------------------------------------------------------- -- * Exceptions -------------------------------------------------------------------------------- -- | @handleUSBException action@ executes @action@. If @action@ returned an -- error code other than 'c\'LIBUSB_SUCCESS', the error is converted to a -- 'USBException' and thrown. handleUSBException ∷ IO CInt → IO () handleUSBException action = do err ← action when (err ≢ c'LIBUSB_SUCCESS) (throwIO $ convertUSBException err) -- | @checkUSBException action@ executes @action@. If @action@ returned a -- negative integer the integer is converted to a 'USBException' and thrown. If -- not, the integer is returned. checkUSBException ∷ IO CInt → IO Int checkUSBException action = do r ← action if r < 0 then throwIO $ convertUSBException r else return $ fromIntegral r -- | Convert a 'C\'libusb_error' to a 'USBException'. If the C'libusb_error is -- unknown an 'error' is thrown. convertUSBException ∷ CInt → USBException convertUSBException err = fromMaybe unknownLibUsbError $ lookup err libusb_error_to_USBException unknownLibUsbError ∷ error unknownLibUsbError = error "Unknown Libusb error" -- | Association list mapping 'C'libusb_error's to 'USBException's. libusb_error_to_USBException ∷ [(CInt, USBException)] libusb_error_to_USBException = [ (c'LIBUSB_ERROR_IO, IOException) , (c'LIBUSB_ERROR_INVALID_PARAM, InvalidParamException) , (c'LIBUSB_ERROR_ACCESS, AccessException) , (c'LIBUSB_ERROR_NO_DEVICE, NoDeviceException) , (c'LIBUSB_ERROR_NOT_FOUND, NotFoundException) , (c'LIBUSB_ERROR_BUSY, BusyException) , (c'LIBUSB_ERROR_TIMEOUT, TimeoutException) , (c'LIBUSB_ERROR_OVERFLOW, OverflowException) , (c'LIBUSB_ERROR_PIPE, PipeException) , (c'LIBUSB_ERROR_INTERRUPTED, InterruptedException) , (c'LIBUSB_ERROR_NO_MEM, NoMemException) , (c'LIBUSB_ERROR_NOT_SUPPORTED, NotSupportedException) , (c'LIBUSB_ERROR_OTHER, OtherException) ] -- | Type of USB exceptions. data USBException = IOException -- ^ Input/output exception. | InvalidParamException -- ^ Invalid parameter. | AccessException -- ^ Access denied (insufficient permissions). | NoDeviceException -- ^ No such device (it may have been disconnected). | NotFoundException -- ^ Entity not found. | BusyException -- ^ Resource busy. | TimeoutException -- ^ Operation timed out. | OverflowException -- ^ Overflow. | PipeException -- ^ Pipe exception. | InterruptedException -- ^ System call interrupted (perhaps due to signal). | NoMemException -- ^ Insufficient memory. | NotSupportedException -- ^ Operation not supported or unimplemented on this -- platform. | OtherException -- ^ Other exception. deriving (Eq, Show, Data, Typeable) instance Exception USBException -------------------------------------------------------------------------------- -- * Binary Coded Decimals -------------------------------------------------------------------------------- -- | A decoded 16 bits Binary Coded Decimal using 4 bits for each digit. type BCD4 = (Int, Int, Int, Int) -- | Decode a @Word16@ as a Binary Coded Decimal using 4 bits per digit. unmarshalBCD4 ∷ Word16 → BCD4 unmarshalBCD4 bcd = let [a, b, c, d] = map fromIntegral $ decodeBCD 4 bcd in (a, b, c, d) {-| @decodeBCD bitsInDigit n@ decodes the Binary Coded Decimal @n@ to a list of its encoded digits. @bitsInDigit@, which is usually 4, is the number of bits used to encode a single digit. See: <http://en.wikipedia.org/wiki/Binary-coded_decimal> -} decodeBCD ∷ Bits α ⇒ Int → α → [α] decodeBCD bitsInDigit n = go shftR [] where shftR = bitSize n - bitsInDigit go shftL ds | shftL < 0 = ds | otherwise = go (shftL - bitsInDigit) (((n `shiftL` shftL) `shiftR` shftR) : ds) -------------------------------------------------------------------------------- -- * Utils -------------------------------------------------------------------------------- -- | @bits s e b@ extract bit @s@ to @e@ (including) from @b@. bits ∷ Bits α ⇒ Int → Int → α → α bits s e b = (2 ^ (e - s + 1) - 1) .&. (b `shiftR` s) -- | @between n b e@ tests if @n@ is between the given bounds @b@ and @e@ -- (including). between ∷ Ord α ⇒ α → α → α → Bool between n b e = n ≥ b ∧ n ≤ e -- | Execute the given action but ignore the result. void ∷ Functor m ⇒ m α → m () void = (() <$) -- | A generalized 'toEnum' that works on any 'Integral' type. genToEnum ∷ (Integral i, Enum e) ⇒ i → e genToEnum = toEnum ∘ fromIntegral -- | A generalized 'fromEnum' that returns any 'Integral' type. genFromEnum ∷ (Integral i, Enum e) ⇒ e → i genFromEnum = fromIntegral ∘ fromEnum -- | @mapPeekArray f n a@ applies the monadic function @f@ to each of the @n@ -- elements of the array @a@ and returns the results in a list. mapPeekArray ∷ Storable α ⇒ (α → IO β) → Int → Ptr α → IO [β] mapPeekArray f n a = peekArray n a >>= mapM f -- | @input `writeWith` doWrite@ first converts the @input@ @ByteString@ to an -- array of @Word8@s, then @doWrite@ is executed by pointing it to the size of -- this array and the array itself. Finally, the result of @doWrite@ is -- returned. -- -- /Make sure not to return the pointer to the array from @doWrite@!/ -- -- /Note that the converion from the @ByteString@ to the @Word8@ array is O(1)./ writeWith ∷ B.ByteString → (Size → Ptr Word8 → IO α) → IO α input `writeWith` doWrite = let (dataFrgnPtr, _, size) = BI.toForeignPtr input in withForeignPtr dataFrgnPtr $ doWrite size -- | Monadic if...then...else... ifM ∷ Monad m ⇒ m Bool → m α → m α → m α ifM cM tM eM = do c ← cM if c then tM else eM -- The End ---------------------------------------------------------------------