1 | /* |
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2 | * Clock Driver for MCF5206eLITE board |
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3 | * |
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4 | * This driver initailizes timer1 on the MCF5206E as the |
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5 | * main system clock |
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6 | */ |
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7 | |
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8 | /* |
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9 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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10 | * |
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11 | * Based on work: |
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12 | * David Fiddes, D.J@fiddes.surfaid.org |
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13 | * http://www.calm.hw.ac.uk/davidf/coldfire/ |
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14 | * |
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15 | * COPYRIGHT (c) 1989-1998. |
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16 | * On-Line Applications Research Corporation (OAR). |
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17 | * |
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18 | * The license and distribution terms for this file may be |
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19 | * found in the file LICENSE in this distribution or at |
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20 | * http://www.rtems.org/license/LICENSE. |
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21 | */ |
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22 | |
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23 | #include <stdlib.h> |
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24 | #include <bsp.h> |
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25 | #include <rtems/libio.h> |
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26 | #include <rtems/clockdrv.h> |
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27 | #include "mcf5206/mcf5206e.h" |
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28 | |
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29 | /* |
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30 | * Clock_driver_ticks is a monotonically increasing counter of the |
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31 | * number of clock ticks since the driver was initialized. |
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32 | */ |
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33 | volatile uint32_t Clock_driver_ticks; |
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34 | |
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35 | rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL; |
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36 | |
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37 | static rtems_isr |
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38 | Clock_isr (rtems_vector_number vector) |
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39 | { |
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40 | /* Clear pending interrupt... */ |
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41 | *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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42 | |
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43 | /* Announce the clock tick */ |
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44 | Clock_driver_ticks++; |
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45 | rtems_clock_tick(); |
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46 | if (rtems_clock_hook != NULL) |
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47 | rtems_clock_hook(vector); |
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48 | } |
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49 | |
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50 | void |
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51 | Clock_exit(void) |
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52 | { |
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53 | /* disable all timer1 interrupts */ |
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54 | *MCF5206E_IMR(MBAR) |= MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1); |
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55 | |
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56 | /* reset timer1 */ |
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57 | *MCF5206E_TMR(MBAR,1) = MCF5206E_TMR_ICLK_STOP; |
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58 | |
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59 | /* clear pending */ |
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60 | *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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61 | } |
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62 | |
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63 | |
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64 | static void |
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65 | Install_clock(rtems_isr_entry clock_isr) |
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66 | { |
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67 | Clock_driver_ticks = 0; |
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68 | |
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69 | /* Configure timer1 interrupts */ |
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70 | *MCF5206E_ICR(MBAR,MCF5206E_INTR_TIMER_1) = |
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71 | MCF5206E_ICR_AVEC | |
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72 | ((BSP_INTLVL_TIMER1 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) | |
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73 | ((BSP_INTPRIO_TIMER1 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP); |
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74 | |
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75 | /* Register the interrupt handler */ |
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76 | set_vector(clock_isr, BSP_INTVEC_TIMER1, 1); |
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77 | |
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78 | /* Reset timer 1 */ |
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79 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST; |
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80 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_ICLK_STOP; |
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81 | *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST; |
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82 | *MCF5206E_TCN(MBAR, 1) = 0; /* Reset counter */ |
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83 | *MCF5206E_TER(MBAR, 1) = MCF5206E_TER_REF | MCF5206E_TER_CAP; |
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84 | |
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85 | /* Set Timer 1 prescaler so that it counts in microseconds */ |
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86 | *MCF5206E_TMR(MBAR, 1) = |
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87 | (((BSP_SYSTEM_FREQUENCY/1000000 - 1) << MCF5206E_TMR_PS_S) & |
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88 | MCF5206E_TMR_PS) | |
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89 | MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR | |
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90 | MCF5206E_TMR_RST; |
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91 | |
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92 | /* Set the timer timeout value from the BSP config */ |
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93 | *MCF5206E_TRR(MBAR, 1) = rtems_configuration_get_microseconds_per_tick() - 1; |
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94 | |
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95 | /* Feed system frequency to the timer */ |
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96 | *MCF5206E_TMR(MBAR, 1) |= MCF5206E_TMR_ICLK_MSCLK; |
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97 | |
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98 | /* Enable timer 1 interrupts */ |
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99 | *MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1); |
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100 | |
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101 | /* Register the driver exit procedure so we can shutdown */ |
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102 | atexit(Clock_exit); |
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103 | } |
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104 | |
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105 | rtems_device_driver |
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106 | Clock_initialize(rtems_device_major_number major, |
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107 | rtems_device_minor_number minor, |
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108 | void *pargp) |
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109 | { |
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110 | Install_clock (Clock_isr); |
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111 | |
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112 | return RTEMS_SUCCESSFUL; |
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113 | } |
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