haiku/headers/private/drivers/scsi_periph.h

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/*
* Copyright 2004-2008, Haiku, Inc. All RightsReserved.
* Copyright 2002/03, Thomas Kurschel. All rights reserved.
*
* Distributed under the terms of the MIT License.
*/
#ifndef _SCSI_PERIPH_H
#define _SCSI_PERIPH_H
/*! Use this module to minimize work required to write a SCSI
peripheral driver.
It takes care of:
- error handling
- medium changes (including restarting the medium)
- detection of medium capacity
*/
#include <bus/SCSI.h>
#include <scsi_cmds.h>
#include <Drivers.h>
// cookie issued by module per device
typedef struct scsi_periph_device_info *scsi_periph_device;
// cookie issued by module per file handle
typedef struct scsi_periph_handle_info *scsi_periph_handle;
// "standardized" error code to simplify handling of scsi errors
typedef enum {
err_act_ok, // executed successfully
err_act_retry, // failed, retry 3 times
err_act_fail, // failed, don't retry
err_act_many_retries, // failed, retry multiple times (currently 10 times)
err_act_start, // devices requires a "start" command
err_act_invalid_req // request is invalid
} err_act;
// packed scsi command result
typedef struct err_res {
status_t error_code : 32; // Be error code
uint32 action : 8; // err_act code
} err_res;
#define MK_ERROR( aaction, code ) ({ \
err_res res = {error_code: (code), action: (aaction) }; \
res; \
})
// cookie issued by driver to identify itself
//typedef struct periph_info *periph_cookie;
// cookie issued by driver per device
typedef struct periph_device_info *periph_device_cookie;
// cookie issued by driver per file handle
typedef struct periph_handle_info *periph_handle_cookie;
typedef struct IOOperation io_operation;
// callbacks to be provided by peripheral driver
typedef struct scsi_periph_callbacks {
// *** block devices ***
// informs of new size of medium
// (set to NULL if not a block device)
void (*set_capacity)(periph_device_cookie cookie, uint64 capacity,
uint32 blockSize);
// *** removable devices
// called when media got changed (can be NULL if medium is not changable)
// (you don't need to call periph->media_changed, but it's doesn't if you do)
// ccb - request at your disposal
void (*media_changed)(periph_device_cookie cookie, scsi_ccb *request);
} scsi_periph_callbacks;
// functions provided by this module
typedef struct scsi_periph_interface {
module_info info;
// *** init/cleanup ***
// preferred_ccb_size - preferred command size; if zero, the shortest is used
status_t (*register_device)(periph_device_cookie cookie,
scsi_periph_callbacks *callbacks, scsi_device scsiDevice,
scsi_device_interface *scsi, device_node *node, bool removable,
int preferredCcbSize, scsi_periph_device *driver);
status_t (*unregister_device)(scsi_periph_device driver);
// *** basic command execution ***
// exec command, retrying on problems
status_t (*safe_exec)(scsi_periph_device periphCookie, scsi_ccb *request);
// exec simple command
status_t (*simple_exec)(scsi_periph_device device, void *cdb,
uint8 cdbLength, void *data, size_t dataLength, int ccbFlags);
// *** file handling ***
// to be called when a new file is opened
status_t (*handle_open)(scsi_periph_device device,
periph_handle_cookie periph_handle, scsi_periph_handle *_handle);
// to be called when a file is closed
status_t (*handle_close)(scsi_periph_handle handle);
// to be called when a file is freed
status_t (*handle_free)(scsi_periph_handle handle);
// *** default implementation for block devices ***
status_t (*read_write)(scsi_periph_device_info *device, scsi_ccb *request,
uint64 offset, size_t numBlocks, physical_entry* vecs, size_t vecCount,
bool isWrite, size_t* _bytesTransferred);
status_t (*io)(scsi_periph_device device, io_operation *operation,
size_t *_bytesTransferred);
// block ioctls
status_t (*ioctl)(scsi_periph_handle handle, int op, void *buffer,
size_t length);
// check medium capacity (calls set_capacity callback on success)
// request - ccb for this device; is used to talk to device
status_t (*check_capacity)(scsi_periph_device device, scsi_ccb *request);
// *** removable media ***
// to be called when a medium change is detected to block subsequent commands
void (*media_changed)(scsi_periph_device device);
// convert result of *request to err_res
err_res (*check_error)(scsi_periph_device device, scsi_ccb *request);
// send start or stop command to device
// withLoadEject = true - include loading/ejecting,
// false - only do allow/deny
err_res (*send_start_stop)(scsi_periph_device device, scsi_ccb *request,
bool start, bool withLoadEject);
// checks media status and waits for device to become ready
// returns: B_OK, B_DEV_MEDIA_CHANGE_REQUESTED, B_NO_MEMORY or
// pending error reported by handle_get_error
status_t (*get_media_status)(scsi_periph_handle handle);
// synchronizes (flush) the device cache
err_res(*synchronize_cache)(scsi_periph_device device, scsi_ccb *request);
// compose device name consisting of prefix and path/target/LUN
// (result must be freed by caller)
char *(*compose_device_name)(device_node *device_node, const char *prefix);
} scsi_periph_interface;
#define SCSI_PERIPH_MODULE_NAME "generic/scsi_periph/v1"
#endif /* _SCSI_PERIPH_H */