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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