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@@ -1,388 +1,98 @@
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- VME Device Driver API
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- =====================
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+ TODO
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+ ====
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-Driver registration
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-===================
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+API
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+===
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-As with other subsystems within the Linux kernel, VME device drivers register
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-with the VME subsystem, typically called from the devices init routine. This is
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-achieved via a call to the follwoing function:
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+DMA Resource Allocation incomplete
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+----------------------------------
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- int vme_register_driver (struct vme_driver *driver);
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-
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-If driver registration is successful this function returns zero, if an error
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-occurred a negative error code will be returned.
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-
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-A pointer to a structure of type ???vme_driver??? must be provided to the
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-registration function. The structure is as follows:
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-
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- struct vme_driver {
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- struct list_head node;
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- char *name;
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- const struct vme_device_id *bind_table;
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- int (*probe) (struct device *, int, int);
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- int (*remove) (struct device *, int, int);
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- void (*shutdown) (void);
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- struct device_driver driver;
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- };
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-
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-At the minimum, the ???.name???, ???.probe??? and ???.bind_table??? elements of this
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-structure should be correctly set. The ???.name??? element is a pointer to a string
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-holding the device driver???s name. The ???.probe??? element should contain a pointer
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-to the probe routine.
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-
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-The arguments of the probe routine are as follows:
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-
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- probe(struct device *dev, int bus, int slot);
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-
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-The ???.bind_table??? is a pointer to an array of type ???vme_device_id???:
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-
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- struct vme_device_id {
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- int bus;
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- int slot;
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- };
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-
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-Each structure in this array should provide a bus and slot number where the core
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-should probe, using the driver???s probe routine, for a device on the specified
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-VME bus.
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-
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-The VME subsystem supports a single VME driver per ???slot???. There are considered
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-to be 32 slots per bus, one for each slot-ID as defined in the ANSI/VITA 1-1994
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-specification and are analogious to the physical slots on the VME backplane.
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-
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-A function is also provided to unregister the driver from the VME core and is
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-usually called from the device driver???s exit routine:
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-
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- void vme_unregister_driver (struct vme_driver *driver);
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-
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-
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-Resource management
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-===================
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-
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-Once a driver has registered with the VME core the provided probe routine will
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-be called for each of the bus/slot combination that becomes valid as VME buses
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-are themselves registered. The probe routine is passed a pointer to the devices
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-device structure. This pointer should be saved, it will be required for
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-requesting VME resources.
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-
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-The driver can request ownership of one or more master windows, slave windows
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-and/or dma channels. Rather than allowing the device driver to request a
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-specific window or DMA channel (which may be used by a different driver) this
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-driver allows a resource to be assigned based on the required attributes of the
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-driver in question:
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-
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- struct vme_resource * vme_master_request(struct device *dev,
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- vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
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-
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- struct vme_resource * vme_slave_request(struct device *dev,
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- vme_address_t aspace, vme_cycle_t cycle);
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-
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-TODO: DMA Resource Allocation incomplete. No attribute based selection.
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+The current DMA resource Allocation provides no means of selecting the
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+suitability of a DMA controller based on it's supported modes of operation, as
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+opposed to the resource allocation mechanisms for master and slave windows:
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struct vme_resource *vme_request_dma(struct device *dev);
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-For slave windows these attributes are split into those of type ???vme_address_t???
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-and ???vme_cycle_t???. Master windows add a further set of attributes ???vme_cycle_t???.
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-These attributes are defined as bitmasks and as such any combination of the
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-attributes can be requested for a single window, the core will assign a window
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-that meets the requirements, returning a pointer of type vme_resource that
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-should be used to identify the allocated resource when it is used. If an
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-unallocated window fitting the requirements can not be found a NULL pointer will
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-be returned.
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-
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-Functions are also provided to free window allocations once they are no longer
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-required. These functions should be passed the pointer to the resource provided
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-during resource allocation:
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-
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- void vme_master_free(struct vme_resource *res);
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-
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- void vme_slave_free(struct vme_resource *res);
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-
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- void vme_dma_free(struct vme_resource *res);
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-
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-
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-Master windows
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-==============
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-
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-Master windows provide access from the local processor[s] out onto the VME bus.
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-The number of windows available and the available access modes is dependant on
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-the underlying chipset. A window must be configured before it can be used.
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-
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+As opposed to:
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-Master window configuration
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----------------------------
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-
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-Once a master window has been assigned the following functions can be used to
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-configure it and retrieve the current settings:
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-
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- int vme_master_set (struct vme_resource *res, int enabled,
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- unsigned long long base, unsigned long long size,
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+ struct vme_resource * vme_master_request(struct device *dev,
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vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
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- int vme_master_get (struct vme_resource *res, int *enabled,
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- unsigned long long *base, unsigned long long *size,
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- vme_address_t *aspace, vme_cycle_t *cycle, vme_width_t *width);
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-
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-The address spaces, transfer widths and cycle types are the same as described
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-under resource management, however some of the options are mutually exclusive.
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-For example, only one address space may be specified.
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+The TSI148 can perform, VME-to-PCI, PCI-to-VME, PATTERN-to-VME, PATTERN-to-PCI,
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+VME-to-VME and PCI-to-PCI transfers. The CA91C142 can only provide VME-to-PCI
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+and PCI-to-VME.
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-These functions return 0 on success or an error code should the call fail.
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+Add a mechanism to select a VME controller based on source/target type,
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+required aspace, cycle and width requirements.
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Master window broadcast select mask
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-----------------------------------
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-TODO: Add functions to set and get Broadcast Select mask:
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+API currently provides no method to set or get Broadcast Select mask. Suggest
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+somthing like:
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int vme_master_bmsk_set (struct vme_resource *res, int mask);
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int vme_master_bmsk_get (struct vme_resource *res, int *mask);
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-Master window access
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---------------------
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-
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-The following functions can be used to read from and write to configured master
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-windows. These functions return the number of bytes copied:
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-
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- ssize_t vme_master_read(struct vme_resource *res, void *buf,
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- size_t count, loff_t offset);
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-
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- ssize_t vme_master_write(struct vme_resource *res, void *buf,
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- size_t count, loff_t offset);
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-
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-In addition to simple reads and writes, a function is provided to do a
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-read-modify-write transaction. This function returns the original value of the
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-VME bus location :
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-
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- unsigned int vme_master_rmw (struct vme_resource *res,
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- unsigned int mask, unsigned int compare, unsigned int swap,
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- loff_t offset);
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-
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-This functions by reading the offset, applying the mask. If the bits selected in
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-the mask match with the values of the corresponding bits in the compare field,
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-the value of swap is written the specified offset.
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-
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-
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-Slave windows
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-=============
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-
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-Slave windows provide devices on the VME bus access into mapped portions of the
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-local memory. The number of windows available and the access modes that can be
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-used is dependant on the underlying chipset. A window must be configured before
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-it can be used.
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-
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-
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-Slave window configuration
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---------------------------
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-
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-Once a slave window has been assigned the following functions can be used to
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-configure it and retrieve the current settings:
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-
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- int vme_slave_set (struct vme_resource *res, int enabled,
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- unsigned long long base, unsigned long long size,
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- dma_addr_t mem, vme_address_t aspace, vme_cycle_t cycle);
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-
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- int vme_slave_get (struct vme_resource *res, int *enabled,
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- unsigned long long *base, unsigned long long *size,
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- dma_addr_t *mem, vme_address_t *aspace, vme_cycle_t *cycle);
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-
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-The address spaces, transfer widths and cycle types are the same as described
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-under resource management, however some of the options are mutually exclusive.
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-For example, only one address space may be specified.
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-
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-These functions return 0 on success or an error code should the call fail.
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-
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-
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-Slave window buffer allocation
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-------------------------------
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-
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-Functions are provided to allow the user to allocate and free a contiguous
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-buffers which will be accessible by the VME bridge. These functions do not have
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-to be used, other methods can be used to allocate a buffer, though care must be
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-taken to ensure that they are contiguous and accessible by the VME bridge:
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-
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- void * vme_alloc_consistent(struct vme_resource *res, size_t size,
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- dma_addr_t *mem);
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-
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- void vme_free_consistent(struct vme_resource *res, size_t size,
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- void *virt, dma_addr_t mem);
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-
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-
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-Slave window access
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--------------------
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-
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-Slave windows map local memory onto the VME bus, the standard methods for
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-accessing memory should be used.
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-
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-
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-DMA channels
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-============
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-
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-The VME DMA transfer provides the ability to run link-list DMA transfers. The
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-API introduces the concept of DMA lists. Each DMA list is a link-list which can
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-be passed to a DMA controller. Multiple lists can be created, extended,
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-executed, reused and destroyed.
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-
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-
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-List Management
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----------------
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-
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-The following functions are provided to create and destroy DMA lists. Execution
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-of a list will not automatically destroy the list, thus enabling a list to be
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-reused for repetitive tasks:
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-
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- struct vme_dma_list *vme_new_dma_list(struct vme_resource *res);
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-
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- int vme_dma_list_free(struct vme_dma_list *list);
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-
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-
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-List Population
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----------------
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-
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-An item can be added to a list using the following function ( the source and
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-destination attributes need to be created before calling this function, this is
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-covered under "Transfer Attributes"):
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-
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- int vme_dma_list_add(struct vme_dma_list *list,
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- struct vme_dma_attr *src, struct vme_dma_attr *dest,
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- size_t count);
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-
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-
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-Transfer Attributes
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--------------------
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-
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-The attributes for the source and destination are handled separately from adding
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-an item to a list. This is due to the diverse attributes required for each type
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-of source and destination. There are functions to create attributes for PCI, VME
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-and pattern sources and destinations (where appropriate):
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-
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-Pattern source:
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-
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- struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern,
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- vme_pattern_t type);
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-
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-PCI source or destination:
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-
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- struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t mem);
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-
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-VME source or destination:
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-
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- struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long base,
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- vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
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-
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-The following function should be used to free an attribute:
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-
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- void vme_dma_free_attribute(struct vme_dma_attr *attr);
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-
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-
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-List Execution
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---------------
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-
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-The following function queues a list for execution. The function will return
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-once the list has been executed:
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-
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- int vme_dma_list_exec(struct vme_dma_list *list);
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-
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-
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-Interrupts
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-==========
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-
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-The VME API provides functions to attach and detach callbacks to specific VME
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-level and status ID combinations and for the generation of VME interrupts with
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-specific VME level and status IDs.
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-
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-
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-Attaching Interrupt Handlers
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-----------------------------
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-
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-The following functions can be used to attach and free a specific VME level and
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-status ID combination. Any given combination can only be assigned a single
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-callback function. A void pointer parameter is provided, the value of which is
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-passed to the callback function, the use of this pointer is user undefined:
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-
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- int vme_request_irq(struct device *dev, int level, int statid,
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- void (*callback)(int, int, void *), void *priv);
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-
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- void vme_free_irq(struct device *dev, int level, int statid);
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-
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-The callback parameters are as follows. Care must be taken in writing a callback
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-function, callback functions run in interrupt context:
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-
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- void callback(int level, int statid, void *priv);
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-
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-
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Interrupt Generation
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--------------------
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-The following function can be used to generate a VME interrupt at a given VME
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-level and VME status ID:
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-
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- int vme_generate_irq(struct device *dev, int level, int statid);
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-
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-
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-Location monitors
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-=================
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-
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-The VME API provides the following functionality to configure the location
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-monitor.
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-
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+Add optional timeout when waiting for an IACK.
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-Location Monitor Management
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----------------------------
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-The following functions are provided to request the use of a block of location
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-monitors and to free them after they are no longer required:
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+CR/CSR Buffer
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+-------------
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- struct vme_resource * vme_lm_request(struct device *dev);
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+The VME API provides no functions to access the buffer mapped into the CR/CSR
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+space.
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- void vme_lm_free(struct vme_resource * res);
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-Each block may provide a number of location monitors, monitoring adjacent
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-locations. The following function can be used to determine how many locations
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-are provided:
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+Mailboxes
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+---------
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- int vme_lm_count(struct vme_resource * res);
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+Whilst not part of the VME specification, they are provided by a number of
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+chips. They are currently not supported at all by the API.
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-Location Monitor Configuration
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-------------------------------
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+Core
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+====
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-Once a bank of location monitors has been allocated, the following functions
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-are provided to configure the location and mode of the location monitor:
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+- Rename vme_master_resource's "pci_resource" to be bus agnostic.
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+- Improve generic sanity checks (Such as does an offset and size fit within a
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+ window and parameter checking).
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- int vme_lm_set(struct vme_resource *res, unsigned long long base,
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- vme_address_t aspace, vme_cycle_t cycle);
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-
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- int vme_lm_get(struct vme_resource *res, unsigned long long *base,
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- vme_address_t *aspace, vme_cycle_t *cycle);
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-
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-
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-Location Monitor Use
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---------------------
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-
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-The following functions allow a callback to be attached and detached from each
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-location monitor location. Each location monitor can monitor a number of
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-adjacent locations:
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-
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- int vme_lm_attach(struct vme_resource *res, int num,
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- void (*callback)(int));
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-
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- int vme_lm_detach(struct vme_resource *res, int num);
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-
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-The callback function is declared as follows.
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-
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- void callback(int num);
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-
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-
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-CR/CSR
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-======
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-
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-TODO: The VME API needs functions to access the CR/CSR buffer.
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-
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-Slot Detection
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+Bridge Support
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==============
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-This function returns the slot ID of the provided bridge.
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+Tempe (tsi148)
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+--------------
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+
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+- Driver can currently only support a single bridge.
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+- 2eSST Broadcast mode.
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+- Mailboxes unsupported.
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+- Improve error detection.
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+- Control of prefetch size, threshold.
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+- Arbiter control
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+- Requestor control
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+
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+Universe II (ca91c142)
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+----------------------
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+
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+- Driver can currently only support a single bridge.
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+- DMA unsupported.
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+- RMW transactions unsupported.
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+- Location Monitors unsupported.
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+- Mailboxes unsupported.
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+- Error Detection.
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+- Control of prefetch size, threshold.
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+- Arbiter control
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+- Requestor control
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+- Slot detection
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+
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+Universe I (ca91x042)
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+---------------------
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+
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+Currently completely unsupported.
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- int vme_slot_get(struct device *dev);
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