source: soft/giet_vm/giet_drivers/dma_driver.h

Last change on this file was 529, checked in by alain, 9 years ago

1) Removing the IOC driver (integrated in the FAT library).
2) Simplifying the BDV, HBA, SDC, RDK drivers: they support
only two modes (synchronous => polling / descheduling => IRQ),
and only one access function (for both read/write).
File size: 7.0 KB
Line 
1//////////////////////////////////////////////////////////////////////////////////
2// File     : dma_driver.h
3// Date     : 01/11/2013
4// Author   : alain greiner
5// Copyright (c) UPMC-LIP6
6//////////////////////////////////////////////////////////////////////////////////
7// The dma_driver.c and dma_driver.h files are part ot the GIET-VM nano-kernel.
8// This driver supports the SoCLib vci_multi_dma component.
9//
10// It can exist several DMA controlers in the architecture (one per cluster),
11// and each controller can contain several channels.
12//
13// There is  (NB_CLUSTERS * NB_DMA_CHANNELS) channels, indexed by a global index:
14//        dma_id = cluster_xy * NB_DMA_CHANNELS + loc_id
15//
16// A DMA channel is a private ressource allocated to a given processor.
17// It is exclusively used by the kernel to speedup data transfers, and
18// there is no lock protecting exclusive access to the channel.
19// As the kernel uses a polling policy on the DMA_STATUS register to detect
20// transfer completion, the DMA IRQ is not used.
21//
22// The virtual base address of the segment associated to a channel is:
23//    SEG_DMA_BASE + cluster_xy * PERI_CLUSTER_INCREMENT + DMA_SPAN * channel_id
24//
25// The SEG_DMA_BASE virtual address must be defined in the hard_config.h file.
26//////////////////////////////////////////////////////////////////////////////////
27
28#ifndef _GIET_DMA_DRIVER_H_
29#define _GIET_DMA_DRIVER_H_
30
31//////////////////////////////////////////////////////////////////////////////////
32// Multi DMA registers offset
33//////////////////////////////////////////////////////////////////////////////////
34
35enum DMA_registers
36{
37    DMA_SRC         = 0,
38    DMA_DST         = 1,
39    DMA_LEN         = 2,
40    DMA_RESET       = 3,
41    DMA_IRQ_DISABLE = 4,
42    DMA_SRC_EXT     = 5,
43    DMA_DST_EXT     = 6,
44    /**/
45    DMA_END         = 7,
46    DMA_SPAN        = 8,
47};
48
49enum SoclibDmaStatus
50{
51    DMA_SUCCESS      = 0,
52    DMA_READ_ERROR   = 1,
53    DMA_IDLE         = 2,
54    DMA_WRITE_ERROR  = 3,
55    DMA_BUSY         = 4,
56};
57
58
59//////////////////////////////////////////////////////////////////////////////////
60//                  low-level access functions 
61//////////////////////////////////////////////////////////////////////////////////
62
63//////////////////////////////////////////////////////////////////////////////////
64// This function disables interrupts for one DMA channel in one cluster.
65// In case of error (illegal DMA channel), an error
66// message is displayed on TTY0, and system crash.
67//////////////////////////////////////////////////////////////////////////////////
68extern void _dma_disable_irq( unsigned int cluster_xy,
69                              unsigned int channel_id );
70
71//////////////////////////////////////////////////////////////////////////////////
72// This function re-initialises one DMA channel in one cluster after transfer
73// completion. It actually forces the channel to return in IDLE state.
74// In case of error (illegal DMA channel), an error
75// message is displayed on TTY0, and system crash.
76//////////////////////////////////////////////////////////////////////////////////
77extern void _dma_reset_channel( unsigned int  cluster_xy, 
78                                unsigned int  channel_id );
79
80//////////////////////////////////////////////////////////////////////////////////
81// This function returns the status of a DMA channel in a given cluster.
82// In case of error (illegal DMA channel), an error
83// message is displayed on TTY0, and system crash.
84//////////////////////////////////////////////////////////////////////////////////
85extern void _dma_get_status( unsigned int  cluster_xy, 
86                             unsigned int  channel_id,
87                             unsigned int* status );
88
89//////////////////////////////////////////////////////////////////////////////////
90// This function sets the physical address (including 64 bits extension)
91// for the source and destination buffers in a DMA channel in a given cluster
92// and sets the transfer size to lauch the transfer.
93// In case of error (illegal DMA channel), an error
94// message is displayed on TTY0, and system crash.
95//////////////////////////////////////////////////////////////////////////////////
96extern void _dma_start_transfer( unsigned int       cluster_xy,
97                                 unsigned int       channel_id,
98                                 unsigned long long dst_paddr,
99                                 unsigned long long src_paddr,
100                                 unsigned int       size );
101
102//////////////////////////////////////////////////////////////////////////////////
103//                     higher level access function
104//////////////////////////////////////////////////////////////////////////////////
105
106//////////////////////////////////////////////////////////////////////////////////
107// This function copies a source memory buffer to a destination memory buffer,
108// using directly physical addresses.
109// This blocking function is supposed to be used by the kernel only,
110// and uses a polling policy on DMA_STATUS register to detect completion.
111// Therefore, the DMA_IRQ is NOT used.
112// The source and destination buffers base addresses must be word aligned,
113// and the buffer's size must be multiple of 4.
114// In case of error (buffer unmapped, unaligned, or DMA_STATUS error), an error
115// message is displayed on TTY0, and system crash.
116//////////////////////////////////////////////////////////////////////////////////
117extern void _dma_physical_copy( unsigned int       cluster_xy,
118                                unsigned int       channel_id,
119                                unsigned long long dst_paddr,
120                                unsigned long long src_paddr,
121                                unsigned int       size ); 
122
123//////////////////////////////////////////////////////////////////////////////////
124// This function copies a source memory buffer to a destination memory buffer,
125// making virtual to physical address translation: the MMU should be activated.
126// The source and destination buffers base addresses must be word aligned,
127// and the buffer's size must be multiple of 4.
128// In case of error (buffer unmapped, unaligned, or DMA_STATUS error), an error
129// message is displayed on TTY0, and system crash.
130//////////////////////////////////////////////////////////////////////////////////
131extern void _dma_copy(  unsigned int cluster_xy,
132                        unsigned int channel_id,
133                        unsigned int dst_vaddr,
134                        unsigned int src_vaddr,
135                        unsigned int size ); 
136
137//////////////////////////////////////////////////////////////////////////////////
138// Interrupt Service Routine.
139//////////////////////////////////////////////////////////////////////////////////
140extern void _dma_isr( unsigned int irq_type,
141                      unsigned int irq_id,
142                      unsigned int channel );
143
144
145#endif
146
147// Local Variables:
148// tab-width: 4
149// c-basic-offset: 4
150// c-file-offsets:((innamespace . 0)(inline-open . 0))
151// indent-tabs-mode: nil
152// End:
153// vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
154
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