This patch ports the bcm2835 system timer driver in the arm/raspberrypi directory to the shared directory.
Made some changes in the include section to adapt to rpi4 BSP. --- bsps/shared/dev/clock/bcm2835-system-timer.c | 114 +++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 bsps/shared/dev/clock/bcm2835-system-timer.c diff --git a/bsps/shared/dev/clock/bcm2835-system-timer.c b/bsps/shared/dev/clock/bcm2835-system-timer.c new file mode 100644 index 0000000000..f59c9e5424 --- /dev/null +++ b/bsps/shared/dev/clock/bcm2835-system-timer.c @@ -0,0 +1,114 @@ +/** + * @file + * + * @ingroup RTEMSDriverClockImpl + * + * @brief This source file contains the implementation of the BCM2835 Clock + * Driver. + */ + +/* + * Copyright (c) 2013 Alan Cudmore + * Copyright (c) 2016 Pavel Pisa + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * + * http://www.rtems.org/license/LICENSE + * +*/ + +#include <rtems.h> +#include <bsp.h> +#include <bsp/irq.h> +#include <bsp/irq-generic.h> + +#if RTEMS_BSP == raspberrypi4b +#include <bsp/bcm2711.h> +#else +#include <bsp/raspberrypi.h> +#endif /* RTEMS_BSP */ + +#include <rtems/timecounter.h> + +#define BCM2835_REG(addr) *(volatile uint32_t*)(addr) + +/* This is defined in ../../../shared/dev/clock/clockimpl.h */ +void Clock_isr(rtems_irq_hdl_param arg); + +static struct timecounter raspberrypi_tc; + +static uint32_t raspberrypi_clock_get_timecount(struct timecounter *tc) +{ + return BCM2835_REG(BCM2835_GPU_TIMER_CLO); +} + +static void raspberrypi_clock_at_tick(void) +{ + uint32_t act_val; + uint32_t next_cmp = BCM2835_REG(BCM2835_GPU_TIMER_C3); + next_cmp += rtems_configuration_get_microseconds_per_tick(); + BCM2835_REG(BCM2835_GPU_TIMER_C3) = next_cmp; + act_val = BCM2835_REG(BCM2835_GPU_TIMER_CLO); + + /* + * Clear interrupt only if there is time left to the next tick. + * If time of the next tick has already passed then interrupt + * request stays active and fires immediately after current tick + * processing is finished. + */ + if ((int32_t)(next_cmp - act_val) > 0) + BCM2835_REG(BCM2835_GPU_TIMER_CS) = BCM2835_GPU_TIMER_CS_M3; +} + +static void raspberrypi_clock_handler_install_isr( + rtems_isr_entry clock_isr +) +{ + rtems_status_code sc = RTEMS_SUCCESSFUL; + + if (clock_isr != NULL) { + sc = rtems_interrupt_handler_install( + BCM2835_IRQ_ID_GPU_TIMER_M3, + "Clock", + RTEMS_INTERRUPT_UNIQUE, + (rtems_interrupt_handler) clock_isr, + NULL + ); + } else { + /* Remove interrupt handler */ + sc = rtems_interrupt_handler_remove( + BCM2835_IRQ_ID_GPU_TIMER_M3, + (rtems_interrupt_handler) Clock_isr, + NULL + ); + } + if ( sc != RTEMS_SUCCESSFUL ) { + rtems_fatal_error_occurred(0xdeadbeef); + } +} + +static void raspberrypi_clock_initialize_hardware(void) +{ + uint32_t next_cmp = BCM2835_REG(BCM2835_GPU_TIMER_CLO); + next_cmp += rtems_configuration_get_microseconds_per_tick(); + BCM2835_REG(BCM2835_GPU_TIMER_C3) = next_cmp; + BCM2835_REG(BCM2835_GPU_TIMER_CS) = BCM2835_GPU_TIMER_CS_M3; + + raspberrypi_tc.tc_get_timecount = raspberrypi_clock_get_timecount; + raspberrypi_tc.tc_counter_mask = 0xffffffff; + raspberrypi_tc.tc_frequency = 1000000; /* 1 MHz */ + raspberrypi_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER; + rtems_timecounter_install(&raspberrypi_tc); +} + +#define Clock_driver_support_at_tick() raspberrypi_clock_at_tick() + +#define Clock_driver_support_initialize_hardware() raspberrypi_clock_initialize_hardware() + +#define Clock_driver_support_install_isr(clock_isr) \ + raspberrypi_clock_handler_install_isr(clock_isr) + +#define CLOCK_DRIVER_USE_ONLY_BOOT_PROCESSOR 1 + +#include "../../../shared/dev/clock/clockimpl.h" -- 2.34.1 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
