[~andy/linux] / drivers / staging / octeon-usb / cvmx-usb.h

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/**
 * "cvmx-usb.h" defines a set of low level USB functions to help
 * developers create Octeon USB drivers for various operating
 * systems. These functions provide a generic API to the Octeon
 * USB blocks, hiding the internal hardware specific
 * operations.
 *
 * At a high level the device driver needs to:
 *
 * - Call cvmx_usb_get_num_ports() to get the number of
 *   supported ports.
 * - Call cvmx_usb_initialize() for each Octeon USB port.
 * - Enable the port using cvmx_usb_enable().
 * - Either periodically, or in an interrupt handler, call
 *   cvmx_usb_poll() to service USB events.
 * - Manage pipes using cvmx_usb_open_pipe() and
 *   cvmx_usb_close_pipe().
 * - Manage transfers using cvmx_usb_submit_*() and
 *   cvmx_usb_cancel*().
 * - Shutdown USB on unload using cvmx_usb_shutdown().
 *
 * To monitor USB status changes, the device driver must use
 * cvmx_usb_register_callback() to register for events that it
 * is interested in. Below are a few hints on successfully
 * implementing a driver on top of this API.
 *
 * == Initialization ==
 *
 * When a driver is first loaded, it is normally not necessary
 * to bring up the USB port completely. Most operating systems
 * expect to initialize and enable the port in two independent
 * steps. Normally an operating system will probe hardware,
 * initialize anything found, and then enable the hardware.
 *
 * In the probe phase you should:
 * - Use cvmx_usb_get_num_ports() to determine the number of
 *   USB port to be supported.
 * - Allocate space for a struct cvmx_usb_state for each
 *   port.
 * - Tell the operating system about each port
 *
 * In the initialization phase you should:
 * - Use cvmx_usb_initialize() on each port.
 * - Do not call cvmx_usb_enable(). This leaves the USB port in
 *   the disabled state until the operating system is ready.
 *
 * Finally, in the enable phase you should:
 * - Call cvmx_usb_enable() on the appropriate port.
 * - Note that some operating system use a RESET instead of an
 *   enable call. To implement RESET, you should call
 *   cvmx_usb_disable() followed by cvmx_usb_enable().
 *
 * == Locking ==
 *
 * All of the functions in the cvmx-usb API assume exclusive
 * access to the USB hardware and internal data structures. This
 * means that the driver must provide locking as necessary.
 *
 * In the single CPU state it is normally enough to disable
 * interrupts before every call to cvmx_usb*() and enable them
 * again after the call is complete. Keep in mind that it is
 * very common for the callback handlers to make additional
 * calls into cvmx-usb, so the disable/enable must be protected
 * against recursion. As an example, the Linux kernel
 * local_irq_save() and local_irq_restore() are perfect for this
 * in the non SMP case.
 *
 * In the SMP case, locking is more complicated. For SMP you not
 * only need to disable interrupts on the local core, but also
 * take a lock to make sure that another core cannot call
 * cvmx-usb.
 *
 * == Port callback ==
 *
 * The port callback prototype needs to look as follows:
 *
 * void port_callback(struct cvmx_usb_state *usb,
 *                    enum cvmx_usb_callback reason,
 *                    enum cvmx_usb_complete status,
 *                    int pipe_handle,
 *                    int submit_handle,
 *                    int bytes_transferred,
 *                    void *user_data);
 * - "usb" is the struct cvmx_usb_state for the port.
 * - "reason" will always be CVMX_USB_CALLBACK_PORT_CHANGED.
 * - "status" will always be CVMX_USB_COMPLETE_SUCCESS.
 * - "pipe_handle" will always be -1.
 * - "submit_handle" will always be -1.
 * - "bytes_transferred" will always be 0.
 * - "user_data" is the void pointer originally passed along
 *   with the callback. Use this for any state information you
 *   need.
 *
 * The port callback will be called whenever the user plugs /
 * unplugs a device from the port. It will not be called when a
 * device is plugged / unplugged from a hub connected to the
 * root port. Normally all the callback needs to do is tell the
 * operating system to poll the root hub for status. Under
 * Linux, this is performed by calling usb_hcd_poll_rh_status().
 * In the Linux driver we use "user_data". to pass around the
 * Linux "hcd" structure. Once the port callback completes,
 * Linux automatically calls octeon_usb_hub_status_data() which
 * uses cvmx_usb_get_status() to determine the root port status.
 *
 * == Complete callback ==
 *
 * The completion callback prototype needs to look as follows:
 *
 * void complete_callback(struct cvmx_usb_state *usb,
 *                        enum cvmx_usb_callback reason,
 *                        enum cvmx_usb_complete status,
 *                        int pipe_handle,
 *                        int submit_handle,
 *                        int bytes_transferred,
 *                        void *user_data);
 * - "usb" is the struct cvmx_usb_state for the port.
 * - "reason" will always be CVMX_USB_CALLBACK_TRANSFER_COMPLETE.
 * - "status" will be one of the cvmx_usb_complete enumerations.
 * - "pipe_handle" is the handle to the pipe the transaction
 *   was originally submitted on.
 * - "submit_handle" is the handle returned by the original
 *   cvmx_usb_submit_* call.
 * - "bytes_transferred" is the number of bytes successfully
 *   transferred in the transaction. This will be zero on most
 *   error conditions.
 * - "user_data" is the void pointer originally passed along
 *   with the callback. Use this for any state information you
 *   need. For example, the Linux "urb" is stored in here in the
 *   Linux driver.
 *
 * In general your callback handler should use "status" and
 * "bytes_transferred" to tell the operating system the how the
 * transaction completed. Normally the pipe is not changed in
 * this callback.
 *
 * == Canceling transactions ==
 *
 * When a transaction is cancelled using cvmx_usb_cancel*(), the
 * actual length of time until the complete callback is called
 * can vary greatly. It may be called before cvmx_usb_cancel*()
 * returns, or it may be called a number of usb frames in the
 * future once the hardware frees the transaction. In either of
 * these cases, the complete handler will receive
 * CVMX_USB_COMPLETE_CANCEL.
 *
 * == Handling pipes ==
 *
 * USB "pipes" is a software construct created by this API to
 * enable the ordering of usb transactions to a device endpoint.
 * Octeon's underlying hardware doesn't have any concept
 * equivalent to "pipes". The hardware instead has eight
 * channels that can be used simultaneously to have up to eight
 * transaction in process at the same time. In order to maintain
 * ordering in a pipe, the transactions for a pipe will only be
 * active in one hardware channel at a time. From an API user's
 * perspective, this doesn't matter but it can be helpful to
 * keep this in mind when you are probing hardware while
 * debugging.
 *
 * Also keep in mind that usb transactions contain state
 * information about the previous transaction to the same
 * endpoint. Each transaction has a PID toggle that changes 0/1
 * between each sub packet. This is maintained in the pipe data
 * structures. For this reason, you generally cannot create and
 * destroy a pipe for every transaction. A sequence of
 * transaction to the same endpoint must use the same pipe.
 *
 * == Root Hub ==
 *
 * Some operating systems view the usb root port as a normal usb
 * hub. These systems attempt to control the root hub with
 * messages similar to the usb 2.0 spec for hub control and
 * status. For these systems it may be necessary to write
 * function to decode standard usb control messages into
 * equivalent cvmx-usb API calls.
 *
 * == Interrupts ==
 *
 * If you plan on using usb interrupts, cvmx_usb_poll() must be
 * called on every usb interrupt. It will read the usb state,
 * call any needed callbacks, and schedule transactions as
 * needed. Your device driver needs only to hookup an interrupt
 * handler and call cvmx_usb_poll(). Octeon's usb port 0 causes
 * CIU bit CIU_INT*_SUM0[USB] to be set (bit 56). For port 1,
 * CIU bit CIU_INT_SUM1[USB1] is set (bit 17). How these bits
 * are turned into interrupt numbers is operating system
 * specific. For Linux, there are the convenient defines
 * OCTEON_IRQ_USB0 and OCTEON_IRQ_USB1 for the IRQ numbers.
 *
 * If you aren't using interrupts, simple call cvmx_usb_poll()
 * in your main processing loop.
 */

#ifndef __CVMX_USB_H__
#define __CVMX_USB_H__

/**
 * enum cvmx_usb_speed - the possible USB device speeds
 *
 * @CVMX_USB_SPEED_HIGH: Device is operation at 480Mbps
 * @CVMX_USB_SPEED_FULL: Device is operation at 12Mbps
 * @CVMX_USB_SPEED_LOW:  Device is operation at 1.5Mbps
 */
enum cvmx_usb_speed {
        CVMX_USB_SPEED_HIGH = 0,
        CVMX_USB_SPEED_FULL = 1,
        CVMX_USB_SPEED_LOW = 2,
};

/**
 * enum cvmx_usb_transfer - the possible USB transfer types
 *
 * @CVMX_USB_TRANSFER_CONTROL:     USB transfer type control for hub and status
 *                                 transfers
 * @CVMX_USB_TRANSFER_ISOCHRONOUS: USB transfer type isochronous for low
 *                                 priority periodic transfers
 * @CVMX_USB_TRANSFER_BULK:        USB transfer type bulk for large low priority
 *                                 transfers
 * @CVMX_USB_TRANSFER_INTERRUPT:   USB transfer type interrupt for high priority
 *                                 periodic transfers
 */
enum cvmx_usb_transfer {
        CVMX_USB_TRANSFER_CONTROL = 0,
        CVMX_USB_TRANSFER_ISOCHRONOUS = 1,
        CVMX_USB_TRANSFER_BULK = 2,
        CVMX_USB_TRANSFER_INTERRUPT = 3,
};

/**
 * enum cvmx_usb_direction - the transfer directions
 *
 * @CVMX_USB_DIRECTION_OUT: Data is transferring from Octeon to the device/host
 * @CVMX_USB_DIRECTION_IN:  Data is transferring from the device/host to Octeon
 */
enum cvmx_usb_direction {
        CVMX_USB_DIRECTION_OUT,
        CVMX_USB_DIRECTION_IN,
};

/**
 * enum cvmx_usb_complete - possible callback function status codes
 *
 * @CVMX_USB_COMPLETE_SUCCESS:    The transaction / operation finished without
 *                                any errors
 * @CVMX_USB_COMPLETE_SHORT:      FIXME: This is currently not implemented
 * @CVMX_USB_COMPLETE_CANCEL:     The transaction was canceled while in flight by
 *                                a user call to cvmx_usb_cancel
 * @CVMX_USB_COMPLETE_ERROR:      The transaction aborted with an unexpected
 *                                error status
 * @CVMX_USB_COMPLETE_STALL:      The transaction received a USB STALL response
 *                                from the device
 * @CVMX_USB_COMPLETE_XACTERR:    The transaction failed with an error from the
 *                                device even after a number of retries
 * @CVMX_USB_COMPLETE_DATATGLERR: The transaction failed with a data toggle
 *                                error even after a number of retries
 * @CVMX_USB_COMPLETE_BABBLEERR:  The transaction failed with a babble error
 * @CVMX_USB_COMPLETE_FRAMEERR:   The transaction failed with a frame error
 *                                even after a number of retries
 */
enum cvmx_usb_complete {
        CVMX_USB_COMPLETE_SUCCESS,
        CVMX_USB_COMPLETE_SHORT,
        CVMX_USB_COMPLETE_CANCEL,
        CVMX_USB_COMPLETE_ERROR,
        CVMX_USB_COMPLETE_STALL,
        CVMX_USB_COMPLETE_XACTERR,
        CVMX_USB_COMPLETE_DATATGLERR,
        CVMX_USB_COMPLETE_BABBLEERR,
        CVMX_USB_COMPLETE_FRAMEERR,
};

/**
 * struct cvmx_usb_port_status - the USB port status information
 *
 * @port_enabled:       1 = Usb port is enabled, 0 = disabled
 * @port_over_current:  1 = Over current detected, 0 = Over current not
 *                      detected. Octeon doesn't support over current detection.
 * @port_powered:       1 = Port power is being supplied to the device, 0 =
 *                      power is off. Octeon doesn't support turning port power
 *                      off.
 * @port_speed:         Current port speed.
 * @connected:          1 = A device is connected to the port, 0 = No device is
 *                      connected.
 * @connect_change:     1 = Device connected state changed since the last set
 *                      status call.
 */
struct cvmx_usb_port_status {
        uint32_t reserved               : 25;
        uint32_t port_enabled           : 1;
        uint32_t port_over_current      : 1;
        uint32_t port_powered           : 1;
        enum cvmx_usb_speed port_speed  : 2;
        uint32_t connected              : 1;
        uint32_t connect_change         : 1;
};

/**
 * union cvmx_usb_control_header - the structure of a Control packet header
 *
 * @s.request_type:     Bit 7 tells the direction: 1=IN, 0=OUT
 * @s.request           The standard usb request to make
 * @s.value             Value parameter for the request in little endian format
 * @s.index             Index for the request in little endian format
 * @s.length            Length of the data associated with this request in
 *                      little endian format
 */
union cvmx_usb_control_header {
        uint64_t u64;
        struct {
                uint64_t request_type   : 8;
                uint64_t request        : 8;
                uint64_t value          : 16;
                uint64_t index          : 16;
                uint64_t length         : 16;
        } s;
};

/**
 * struct cvmx_usb_iso_packet - descriptor for Isochronous packets
 *
 * @offset:     This is the offset in bytes into the main buffer where this data
 *              is stored.
 * @length:     This is the length in bytes of the data.
 * @status:     This is the status of this individual packet transfer.
 */
struct cvmx_usb_iso_packet {
        int offset;
        int length;
        enum cvmx_usb_complete status;
};

/**
 * enum cvmx_usb_callback - possible callback reasons for the USB API
 *
 * @CVMX_USB_CALLBACK_TRANSFER_COMPLETE: A callback of this type is called when
 *                                       a submitted transfer completes. The
 *                                       completion callback will be called even
 *                                       if the transfer fails or is canceled.
 *                                       The status parameter will contain
 *                                       details of why he callback was called.
 * @CVMX_USB_CALLBACK_PORT_CHANGED:      The status of the port changed. For
 *                                       example, someone may have plugged a
 *                                       device in. The status parameter
 *                                       contains CVMX_USB_COMPLETE_SUCCESS. Use
 *                                       cvmx_usb_get_status() to get the new
 *                                       port status.
 * @__CVMX_USB_CALLBACK_END:             Do not use. Used internally for array
 *                                       bounds.
 */
enum cvmx_usb_callback {
        CVMX_USB_CALLBACK_TRANSFER_COMPLETE,
        CVMX_USB_CALLBACK_PORT_CHANGED,
        __CVMX_USB_CALLBACK_END
};

/**
 * USB state internal data. The contents of this structure
 * may change in future SDKs. No data in it should be referenced
 * by user's of this API.
 */
struct cvmx_usb_state {
        char data[65536];
};

/**
 * USB callback functions are always of the following type.
 * The parameters are as follows:
 *      - state = USB device state populated by
 *        cvmx_usb_initialize().
 *      - reason = The enum cvmx_usb_callback used to register
 *        the callback.
 *      - status = The enum cvmx_usb_complete representing the
 *        status code of a transaction.
 *      - pipe_handle = The Pipe that caused this callback, or
 *        -1 if this callback wasn't associated with a pipe.
 *      - submit_handle = Transfer submit handle causing this
 *        callback, or -1 if this callback wasn't associated
 *        with a transfer.
 *      - Actual number of bytes transfer.
 *      - user_data = The user pointer supplied to the
 *        function cvmx_usb_submit() or
 *        cvmx_usb_register_callback() */
typedef void (*cvmx_usb_callback_func_t)(struct cvmx_usb_state *state,
                                         enum cvmx_usb_callback reason,
                                         enum cvmx_usb_complete status,
                                         int pipe_handle, int submit_handle,
                                         int bytes_transferred, void *user_data);

/**
 * enum cvmx_usb_initialize_flags - flags used by the initialization function
 *
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI:    The USB port uses a 12MHz crystal
 *                                            as clock source at USB_XO and
 *                                            USB_XI.
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND:   The USB port uses 12/24/48MHz 2.5V
 *                                            board clock source at USB_XO.
 *                                            USB_XI should be tied to GND.
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK: Mask for clock speed field
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ:    Speed of reference clock or
 *                                            crystal
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ:    Speed of reference clock
 * @CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ:    Speed of reference clock
 * @CVMX_USB_INITIALIZE_FLAGS_NO_DMA:         Disable DMA and used polled IO for
 *                                            data transfer use for the USB
 */
enum cvmx_usb_initialize_flags {
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI           = 1 << 0,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND          = 1 << 1,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK        = 3 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ           = 1 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ           = 2 << 3,
        CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ           = 3 << 3,
        /* Bits 3-4 used to encode the clock frequency */
        CVMX_USB_INITIALIZE_FLAGS_NO_DMA                = 1 << 5,
};

/**
 * enum cvmx_usb_pipe_flags - flags for passing when a pipe is created.
 *                            Currently no flags need to be passed.
 *
 * @__CVMX_USB_PIPE_FLAGS_OPEN:      Used internally to determine if a pipe is
 *                                   open. Do not use.
 * @__CVMX_USB_PIPE_FLAGS_SCHEDULED: Used internally to determine if a pipe is
 *                                   actively using hardware. Do not use.
 * @__CVMX_USB_PIPE_FLAGS_NEED_PING: Used internally to determine if a high
 *                                   speed pipe is in the ping state. Do not
 *                                   use.
 */
enum cvmx_usb_pipe_flags {
        __CVMX_USB_PIPE_FLAGS_OPEN      = 1 << 16,
        __CVMX_USB_PIPE_FLAGS_SCHEDULED = 1 << 17,
        __CVMX_USB_PIPE_FLAGS_NEED_PING = 1 << 18,
};

extern int cvmx_usb_get_num_ports(void);
extern int cvmx_usb_initialize(struct cvmx_usb_state *state,
                               int usb_port_number);
extern int cvmx_usb_shutdown(struct cvmx_usb_state *state);
extern int cvmx_usb_enable(struct cvmx_usb_state *state);
extern int cvmx_usb_disable(struct cvmx_usb_state *state);
extern struct cvmx_usb_port_status cvmx_usb_get_status(struct cvmx_usb_state *state);
extern void cvmx_usb_set_status(struct cvmx_usb_state *state, struct cvmx_usb_port_status port_status);
extern int cvmx_usb_open_pipe(struct cvmx_usb_state *state,
                              enum cvmx_usb_pipe_flags flags,
                              int device_addr, int endpoint_num,
                              enum cvmx_usb_speed device_speed, int max_packet,
                              enum cvmx_usb_transfer transfer_type,
                              enum cvmx_usb_direction transfer_dir, int interval,
                              int multi_count, int hub_device_addr,
                              int hub_port);
extern int cvmx_usb_submit_bulk(struct cvmx_usb_state *state, int pipe_handle,
                                uint64_t buffer, int buffer_length,
                                cvmx_usb_callback_func_t callback,
                                void *user_data);
extern int cvmx_usb_submit_interrupt(struct cvmx_usb_state *state, int pipe_handle,
                                     uint64_t buffer, int buffer_length,
                                     cvmx_usb_callback_func_t callback,
                                     void *user_data);
extern int cvmx_usb_submit_control(struct cvmx_usb_state *state, int pipe_handle,
                                   uint64_t control_header,
                                   uint64_t buffer, int buffer_length,
                                   cvmx_usb_callback_func_t callback,
                                   void *user_data);

/**
 * enum cvmx_usb_isochronous_flags - flags to pass the
 *                                   cvmx_usb_submit_isochronous() function.
 *
 * @CVMX_USB_ISOCHRONOUS_FLAGS_ALLOW_SHORT: Do not return an error if a transfer
 *                                          is less than the maximum packet size
 *                                          of the device.
 * @CVMX_USB_ISOCHRONOUS_FLAGS_ASAP:        Schedule the transaction as soon as
 *                                          possible.
 */
enum cvmx_usb_isochronous_flags {
        CVMX_USB_ISOCHRONOUS_FLAGS_ALLOW_SHORT  = 1 << 0,
        CVMX_USB_ISOCHRONOUS_FLAGS_ASAP         = 1 << 1,
};

extern int cvmx_usb_submit_isochronous(struct cvmx_usb_state *state, int pipe_handle,
                                       int start_frame, int flags,
                                       int number_packets,
                                       struct cvmx_usb_iso_packet packets[],
                                       uint64_t buffer, int buffer_length,
                                       cvmx_usb_callback_func_t callback,
                                       void *user_data);
extern int cvmx_usb_cancel(struct cvmx_usb_state *state, int pipe_handle,
                           int submit_handle);
extern int cvmx_usb_cancel_all(struct cvmx_usb_state *state, int pipe_handle);
extern int cvmx_usb_close_pipe(struct cvmx_usb_state *state, int pipe_handle);
extern int cvmx_usb_register_callback(struct cvmx_usb_state *state,
                                      enum cvmx_usb_callback reason,
                                      cvmx_usb_callback_func_t callback,
                                      void *user_data);
extern int cvmx_usb_get_frame_number(struct cvmx_usb_state *state);
extern int cvmx_usb_poll(struct cvmx_usb_state *state);

#endif  /* __CVMX_USB_H__ */