| 1 | /* | 
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| 2 |  * soclib_dma.h - soclib Multi Channels DMA driver definition. | 
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| 3 |  * | 
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| 4 |  * Author     Alain Greiner (2017) | 
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| 5 |  * | 
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| 6 |  * Copyright (c) UPMC Sorbonne Universites | 
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| 7 |  * | 
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| 8 |  * This file is part of ALMOS-MKH. | 
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| 9 |  * | 
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| 10 |  * ALMOS-MKH is free software; you can redistribute it and/or modify it | 
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| 11 |  * under the terms of the GNU General Public License as published by | 
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| 12 |  * the Free Software Foundation; version 2.0 of the License. | 
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| 13 |  * | 
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| 14 |  * ALMOS-MKH is distributed in the hope that it will be useful, but | 
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| 15 |  * WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 16 |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | 
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| 17 |  * General Public License for more details. | 
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| 18 |  * | 
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| 19 |  * You should have received a copy of the GNU General Public License | 
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| 20 |  * along with ALMOS-MKH; if not, write to the Free Software Foundation, | 
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| 21 |  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | 
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| 22 |  */ | 
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| 23 |  | 
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| 24 | #ifndef _SOCLIB_DMA_H_ | 
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| 25 | #define _SOCLIB_DMA_H_ | 
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| 26 |  | 
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| 27 | /******************************************************************************************** | 
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| 28 |  * This driver supports the SocLib VciBlockDevice component, that is a simgle channel, | 
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| 29 |  * block oriented, external storage controler, supporting only one I/O transaction, | 
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| 30 |  * at a given time. | 
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| 31 |  *******************************************************************************************/ | 
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| 32 |  | 
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| 33 | /******************************************************************************************** | 
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| 34 |  *       SOCLIB_DMA registers offset  | 
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| 35 |  *******************************************************************************************/ | 
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| 36 |  | 
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| 37 | enum SoclibDmaRegisters  | 
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| 38 | { | 
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| 39 |     DMA_SRC                  = 0,    /*! source buffer 32 LSB address bits                         */ | 
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| 40 |     DMA_DST                  = 1,    /*! source buffer 32 LSB address bits                         */ | 
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| 41 |     DMA_LEN                  = 2,    /*! number of bytes (on write) / transfer status (on read)    */ | 
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| 42 |     DMA_RESET            = 3,    /*! desactivate channel (can be usde to acknowledge IRQ)      */ | 
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| 43 |     DMA_IRQ_DISABLED = 4,    /*! no IRQ generated if non zero                              */ | 
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| 44 |     DMA_SRC_EXT      = 5,    /*! source buffer 32 MSB address bits                         */ | 
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| 45 |     DMA_DST_EXT      = 6,    /*! source buffer 32 MSB address bits                         */ | 
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| 46 |  | 
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| 47 |     DMA_SPAN             = 8,    /*! number of registers per channel                           */ | 
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| 48 | }; | 
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| 49 |  | 
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| 50 | /******************************************************************************************** | 
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| 51 |  *       SOCLIB_DMA status values | 
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| 52 |  *******************************************************************************************/ | 
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| 53 |  | 
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| 54 | #define DMA_SUCCESS       0 | 
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| 55 | #define DMA_IDLE          2 | 
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| 56 | #define DMA_ERROR_READ    1 | 
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| 57 | #define DMA_ERROR_WRITE   3 | 
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| 58 | #define DMA_BUSY          4    // or any value larger than 3 | 
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| 59 |  | 
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| 60 |  | 
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| 61 | /******************************************************************************************** | 
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| 62 |  * This function access the SOCLIB_DMA hardware register to enable interrupts. | 
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| 63 |  ******************************************************************************************** | 
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| 64 |  * @ chdev     : pointer on DMA chdev descriptor. | 
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| 65 |  *******************************************************************************************/ | 
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| 66 | extern void soclib_dma_init( chdev_t * chdev ); | 
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| 67 |  | 
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| 68 | /******************************************************************************************** | 
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| 69 |  * This function is called by the server thread associated to the DMA device. | 
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| 70 |  * It access the command embedded in the calling thread descriptor, (format defined in the  | 
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| 71 |  * dev_dma.h file) and access the SOCLIB_DMA hardware registers to start command execution. | 
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| 72 |  * Then it blocks on the THREAD_BLOCKED_DEV_ISR and deschedules, because each DMA channel  | 
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| 73 |  * can only execute one command at a given time.  | 
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| 74 |  * It is re-activated by the ISR signaling the transfer completion. | 
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| 75 |  ******************************************************************************************** | 
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| 76 |  * @ thread_xp  : extended pointer on the client thread. | 
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| 77 |  *******************************************************************************************/ | 
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| 78 | extern void soclib_dma_cmd( xptr_t thread_xp ); | 
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| 79 |  | 
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| 80 | /******************************************************************************************** | 
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| 81 |  * This Interrupt Service Routine is executed when the IRQ signaling the completion of  | 
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| 82 |  * a DMA command is received by a core. It acknowledge the IRQ by accessing the proper | 
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| 83 |  * SOCLIB_DMA register, unblock the client thread, and unblock the server thread that | 
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| 84 |  * can starts execution of a new command if the waiting queue is not emppty. | 
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| 85 |  ******************************************************************************************** | 
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| 86 |  * @ chdev     : pointer on DMA chdev descriptor. | 
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| 87 |  *******************************************************************************************/ | 
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| 88 | extern void soclib_dma_isr( chdev_t * chdev ); | 
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| 89 |  | 
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| 90 |  | 
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| 91 | #endif  /* _SOCLIB_DMA_H_ */ | 
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