source: rtems/bsps/arm/raspberrypi/clock/clockdrv.c @ 7632906

5
Last change on this file since 7632906 was 7632906, checked in by Sebastian Huber <sebastian.huber@…>, on 04/19/18 at 04:35:52

bsps: Move clock drivers to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

  • Property mode set to 100644
File size: 3.1 KB
RevLine 
[98eb7e78]1/**
2 * @file
3 *
4 * @ingroup bsp_clock
5 *
6 * @brief Raspberry Pi clock support.
7 */
8
[c32b1ef]9/*
10 * BCM2835 Clock driver
11 *
12 * Copyright (c) 2013 Alan Cudmore
[5d369c85]13 * Copyright (c) 2016 Pavel Pisa
[c32b1ef]14 *
15 *  The license and distribution terms for this file may be
16 *  found in the file LICENSE in this distribution or at
17 *
[c499856]18 *  http://www.rtems.org/license/LICENSE
[c32b1ef]19 *
20*/
21
22#include <rtems.h>
23#include <bsp.h>
24#include <bsp/irq.h>
[5d369c85]25#include <bsp/irq-generic.h>
[c32b1ef]26#include <bsp/raspberrypi.h>
[5d369c85]27#include <rtems/timecounter.h>
[c32b1ef]28
[7632906]29/* This is defined in ../../../shared/dev/clock/clockimpl.h */
[c32b1ef]30void Clock_isr(rtems_irq_hdl_param arg);
31
[5d369c85]32static struct timecounter raspberrypi_tc;
33
34static uint32_t raspberrypi_clock_get_timecount(struct timecounter *tc)
35{
36  return BCM2835_REG(BCM2835_GPU_TIMER_CLO);
37}
38
[c32b1ef]39static void raspberrypi_clock_at_tick(void)
40{
[5d369c85]41  uint32_t act_val;
42  uint32_t next_cmp = BCM2835_REG(BCM2835_GPU_TIMER_C3);
43  next_cmp += rtems_configuration_get_microseconds_per_tick();
44  BCM2835_REG(BCM2835_GPU_TIMER_C3) = next_cmp;
45  act_val = BCM2835_REG(BCM2835_GPU_TIMER_CLO);
46
47  /*
48   * Clear interrupt only if there is time left to the next tick.
49   * If time of the next tick has already passed then interrupt
50   * request stays active and fires immediately after current tick
51   * processing is finished.
52   */
53  if ((int32_t)(next_cmp - act_val) > 0)
54    BCM2835_REG(BCM2835_GPU_TIMER_CS) = BCM2835_GPU_TIMER_CS_M3;
[c32b1ef]55}
56
[5d369c85]57static void raspberrypi_clock_handler_install_isr(
58  rtems_isr_entry clock_isr
59)
[c32b1ef]60{
61  rtems_status_code sc = RTEMS_SUCCESSFUL;
62
[5d369c85]63  if (clock_isr != NULL) {
64    sc = rtems_interrupt_handler_install(
65      BCM2835_IRQ_ID_GPU_TIMER_M3,
66      "Clock",
67      RTEMS_INTERRUPT_UNIQUE,
68      (rtems_interrupt_handler) clock_isr,
69      NULL
70    );
71  } else {
72    /* Remove interrupt handler */
73    sc = rtems_interrupt_handler_remove(
74      BCM2835_IRQ_ID_GPU_TIMER_M3,
75      (rtems_interrupt_handler) Clock_isr,
76      NULL
77    );
78  }
79  if ( sc != RTEMS_SUCCESSFUL ) {
[c32b1ef]80    rtems_fatal_error_occurred(0xdeadbeef);
81  }
82}
83
[5d369c85]84static void raspberrypi_clock_initialize_hardware(void)
[c32b1ef]85{
[5d369c85]86  uint32_t next_cmp = BCM2835_REG(BCM2835_GPU_TIMER_CLO);
87  next_cmp += rtems_configuration_get_microseconds_per_tick();
88  BCM2835_REG(BCM2835_GPU_TIMER_C3) = next_cmp;
89  BCM2835_REG(BCM2835_GPU_TIMER_CS) = BCM2835_GPU_TIMER_CS_M3;
90
91  raspberrypi_tc.tc_get_timecount = raspberrypi_clock_get_timecount;
92  raspberrypi_tc.tc_counter_mask = 0xffffffff;
93  raspberrypi_tc.tc_frequency = 1000000; /* 1 MHz */
94  raspberrypi_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
95  rtems_timecounter_install(&raspberrypi_tc);
[c32b1ef]96}
97
98static void raspberrypi_clock_cleanup(void)
99{
[5d369c85]100  bsp_interrupt_vector_disable(BCM2835_IRQ_ID_GPU_TIMER_M3);
[c32b1ef]101}
102
103#define Clock_driver_support_at_tick() raspberrypi_clock_at_tick()
104
[5d369c85]105#define Clock_driver_support_initialize_hardware() raspberrypi_clock_initialize_hardware()
[c32b1ef]106
[5d369c85]107#define Clock_driver_support_shutdown_hardware() raspberrypi_clock_cleanup()
108
[f3b29236]109#define Clock_driver_support_install_isr(clock_isr) \
110  raspberrypi_clock_handler_install_isr(clock_isr)
[c32b1ef]111
[5d369c85]112#define CLOCK_DRIVER_USE_ONLY_BOOT_PROCESSOR 1
[c32b1ef]113
[7632906]114#include "../../../shared/dev/clock/clockimpl.h"
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