source: rtems/c/src/lib/libbsp/arm/shared/lpc/clock/lpc-clock-config.c @ c468f18b

4.104.11
Last change on this file since c468f18b was c468f18b, checked in by Thomas Doerfler <Thomas.Doerfler@…>, on Dec 15, 2009 at 3:20:47 PM

add support for LPC32xx

  • Property mode set to 100644
File size: 2.8 KB
Line 
1/**
2 * @file
3 *
4 * @ingroup lpc
5 *
6 * @brief Clock driver configuration.
7 */
8
9/*
10 * Copyright (c) 2009
11 * embedded brains GmbH
12 * Obere Lagerstr. 30
13 * D-82178 Puchheim
14 * Germany
15 * <rtems@embedded-brains.de>
16 *
17 * The license and distribution terms for this file may be
18 * found in the file LICENSE in this distribution or at
19 * http://www.rtems.com/license/LICENSE.
20 */
21
22#include <bsp/lpc-clock-config.h>
23#include <bsp/lpc-timer.h>
24
25/* This is defined in ../../../shared/clockdrv_shell.h */
26rtems_isr Clock_isr(rtems_vector_number vector);
27
28static volatile lpc_timer *const lpc_clock = 
29  (volatile lpc_timer *) LPC_CLOCK_TIMER_BASE;
30
31static void lpc_clock_at_tick(void)
32{
33  lpc_clock->ir = LPC_TIMER_IR_MR0;
34}
35
36static void lpc_clock_handler_install(void)
37{
38  rtems_status_code sc = RTEMS_SUCCESSFUL;
39
40  sc = rtems_interrupt_handler_install(
41    LPC_CLOCK_INTERRUPT,
42    "Clock",
43    RTEMS_INTERRUPT_UNIQUE,
44    (rtems_interrupt_handler) Clock_isr,
45    NULL
46  );
47  if (sc != RTEMS_SUCCESSFUL) {
48    rtems_fatal_error_occurred(0xdeadbeef);
49  }
50}
51
52static void lpc_clock_initialize(void)
53{
54  uint64_t interval = ((uint64_t) LPC_CLOCK_REFERENCE
55    * (uint64_t) rtems_configuration_get_microseconds_per_tick()) / 1000000;
56
57  /* Enable module */
58  LPC_CLOCK_MODULE_ENABLE();
59
60  /* Reset timer */
61  lpc_clock->tcr = LPC_TIMER_TCR_RST;
62
63  /* Clear interrupt flags */
64  lpc_clock->ir = LPC_TIMER_IR_ALL;
65
66  /* Set timer mode */
67  lpc_clock->ccr = 0;
68
69  /* Timer is incremented every PERIPH_CLK tick */
70  lpc_clock->pr = 0;
71
72  /* Set match registers */
73  lpc_clock->mr0 = (uint32_t) interval;
74
75  /* Generate interrupt and reset counter on match with MR0 */
76  lpc_clock->mcr = LPC_TIMER_MCR_MR0_INTR | LPC_TIMER_MCR_MR0_RST;
77
78  /* No external match */
79  lpc_clock->emr = 0x0;
80
81  /* Enable timer */
82  lpc_clock->tcr = LPC_TIMER_TCR_EN;
83}
84
85static void lpc_clock_cleanup(void)
86{
87  rtems_status_code sc = RTEMS_SUCCESSFUL;
88
89  /* Disable timer */
90  lpc_clock->tcr = 0x0;
91
92  /* Remove interrupt handler */
93  sc = rtems_interrupt_handler_remove(
94    LPC_CLOCK_INTERRUPT,
95    (rtems_interrupt_handler) Clock_isr,
96    NULL
97  );
98  if (sc != RTEMS_SUCCESSFUL) {
99    rtems_fatal_error_occurred(0xdeadbeef);
100  }
101}
102
103static uint32_t lpc_clock_nanoseconds_since_last_tick(void)
104{
105  uint64_t clock = LPC_CLOCK_REFERENCE;
106  uint64_t clicks = lpc_clock->tc;
107  uint64_t ns = (clicks * 1000000000) / clock;
108
109  return (uint32_t) ns;
110}
111
112#define Clock_driver_support_at_tick() lpc_clock_at_tick()
113#define Clock_driver_support_initialize_hardware() lpc_clock_initialize()
114#define Clock_driver_support_install_isr(isr, old_isr) \
115  lpc_clock_handler_install()
116#define Clock_driver_support_shutdown_hardware() lpc_clock_cleanup()
117#define Clock_driver_nanoseconds_since_last_tick \
118  lpc_clock_nanoseconds_since_last_tick
119
120/* Include shared source clock driver code */
121#include "../../../../shared/clockdrv_shell.h"
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