1 | /* RTEMS Clock Tick Driver for Blackfin. Uses Blackfin Core Timer. |
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2 | */ |
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3 | |
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4 | /* |
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5 | * Copyright (c) 2008 Kallisti Labs, Los Gatos, CA, USA |
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6 | * written by Allan Hessenflow <allanh@kallisti.com> |
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7 | * |
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8 | * The license and distribution terms for this file may be |
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9 | * found in the file LICENSE in this distribution or at |
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10 | * http://www.rtems.org/license/LICENSE. |
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11 | */ |
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12 | |
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13 | |
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14 | #include <rtems.h> |
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15 | #include <stdlib.h> |
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16 | #include <rtems/libio.h> |
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17 | #include <bsp.h> |
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18 | |
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19 | #include <libcpu/cecRegs.h> |
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20 | #include <libcpu/coreTimerRegs.h> |
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21 | |
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22 | #if (BFIN_ON_SKYEYE) |
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23 | #define CLOCK_DRIVER_USE_FAST_IDLE 1 |
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24 | #endif |
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25 | |
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26 | volatile uint32_t Clock_driver_ticks; |
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27 | |
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28 | void Clock_exit(void); |
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29 | |
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30 | static rtems_isr clockISR(rtems_vector_number vector) { |
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31 | |
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32 | Clock_driver_ticks += 1; |
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33 | |
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34 | #if CLOCK_DRIVER_USE_FAST_IDLE |
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35 | do { |
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36 | rtems_clock_tick(); |
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37 | } while ( |
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38 | _Thread_Heir == _Thread_Executing |
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39 | && _Thread_Executing->Start.entry_point |
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40 | == rtems_configuration_get_idle_task() |
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41 | ); |
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42 | #else |
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43 | rtems_clock_tick(); |
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44 | #endif |
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45 | } |
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46 | |
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47 | /* |
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48 | * Clock_exit |
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49 | * |
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50 | * This routine allows the clock driver to exit by masking the interrupt and |
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51 | * disabling the clock's counter. |
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52 | */ |
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53 | void Clock_exit(void) |
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54 | { |
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55 | *(uint32_t volatile *) TCNTL = 0; |
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56 | } |
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57 | |
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58 | /* |
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59 | * Clock_initialize |
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60 | * |
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61 | * This routine initializes the clock driver. |
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62 | */ |
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63 | rtems_device_driver Clock_initialize( |
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64 | rtems_device_major_number major, |
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65 | rtems_device_minor_number minor, |
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66 | void *pargp |
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67 | ) |
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68 | { |
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69 | Clock_driver_ticks = 0; |
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70 | |
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71 | set_vector(clockISR, CEC_CORE_TIMER_VECTOR, 1); |
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72 | |
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73 | *(uint32_t volatile *) TCNTL = TCNTL_TMPWR | TCNTL_TAUTORLD; |
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74 | *(uint32_t volatile *) TSCALE = 0; |
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75 | *(uint32_t volatile *) TPERIOD = CCLK / 1000000 * |
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76 | rtems_configuration_get_microseconds_per_tick(); |
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77 | *(uint32_t volatile *) TCNTL = TCNTL_TMPWR | TCNTL_TAUTORLD | TCNTL_TMREN; |
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78 | |
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79 | atexit(Clock_exit); |
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80 | |
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81 | return RTEMS_SUCCESSFUL; |
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82 | } |
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