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Diffstat (limited to '')
-rw-r--r-- | c/src/lib/libbsp/powerpc/mcp750/clock/c_clock.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/powerpc/mcp750/clock/c_clock.c b/c/src/lib/libbsp/powerpc/mcp750/clock/c_clock.c new file mode 100644 index 0000000000..b6fafcb7df --- /dev/null +++ b/c/src/lib/libbsp/powerpc/mcp750/clock/c_clock.c @@ -0,0 +1,215 @@ +/* + * Clock Tick Device Driver + * + * This routine utilizes the Decrementer Register common to the PPC family. + * + * The tick frequency is directly programmed to the configured number of + * microseconds per tick. + * + * COPYRIGHT (c) 1989-1997. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may in + * the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * Modified to support the MPC750. + * Modifications Copyright (c) 1999 Eric Valette valette@crf.canon.fr + * + * $Id$ + */ + +#include <bsp.h> +#include <bsp/irq.h> +#include <rtems/libio.h> +#include <stdlib.h> /* for atexit() */ +#include <assert.h> +#include <libcpu/cpu.h> + +/* + * Clock ticks since initialization + */ + +volatile rtems_unsigned32 Clock_driver_ticks; + +/* + * This is the value programmed into the count down timer. + */ + +rtems_unsigned32 Clock_Decrementer_value; + +/* + * These are set by clock driver during its init + */ + +rtems_device_major_number rtems_clock_major = ~0; +rtems_device_minor_number rtems_clock_minor; + +void clockOff(const rtems_irq_connect_data* unused) +{ + if (BSP_Configuration.ticks_per_timeslice) { + /* + * Nothing to do as we cannot disable all interrupts and + * the decrementer interrupt enable is MSR_EE + */ + } +} +static void clockOn(const rtems_irq_connect_data* unused) +{ + PPC_Set_decrementer( Clock_Decrementer_value ); +} + +/* + * Clock_isr + * + * This is the clock tick interrupt handler. + * + * Input parameters: + * vector - vector number + * + * Output parameters: NONE + * + * Return values: NONE + * + */ +void clockIsr() +{ + /* + * The driver has seen another tick. + */ + + PPC_Set_decrementer( Clock_Decrementer_value ); + + Clock_driver_ticks += 1; + + /* + * Real Time Clock counter/timer is set to automatically reload. + */ + + rtems_clock_tick(); +} + +int clockIsOn(const rtems_irq_connect_data* unused) +{ + unsigned32 msr_value; + + _CPU_MSR_GET( msr_value ); + if (msr_value & MSR_EE) return 1; + return 0; +} + +static rtems_irq_connect_data clockIrqData = {BSP_DECREMENTER, + clockIsr, + clockOn, + clockOff, + clockIsOn}; + + +/* + * Clock_exit + * + * This routine allows the clock driver to exit by masking the interrupt and + * disabling the clock's counter. + * + * Input parameters: NONE + * + * Output parameters: NONE + * + * Return values: NONE + * + */ + +void Clock_exit( void ) +{ + if ( BSP_Configuration.ticks_per_timeslice ) { + BSP_remove_rtems_irq_handler (&clockIrqData); + } +} + +/* + * Clock_initialize + * + * This routine initializes the clock driver. + * + * Input parameters: + * major - clock device major number + * minor - clock device minor number + * parg - pointer to optional device driver arguments + * + * Output parameters: NONE + * + * Return values: + * rtems_device_driver status code + */ + +rtems_device_driver Clock_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + Clock_Decrementer_value = (BSP_bus_frequency/4000)* + (BSP_Configuration.microseconds_per_tick/1000); + + if (!BSP_install_rtems_irq_handler (&clockIrqData)) { + printk("Unable to initialize system clock\n"); + rtems_fatal_error_occurred(1); + } + /* make major/minor avail to others such as shared memory driver */ + + rtems_clock_major = major; + rtems_clock_minor = minor; + + return RTEMS_SUCCESSFUL; +} /* Clock_initialize */ + +/* + * Clock_control + * + * This routine is the clock device driver control entry point. + * + * Input parameters: + * major - clock device major number + * minor - clock device minor number + * parg - pointer to optional device driver arguments + * + * Output parameters: NONE + * + * Return values: + * rtems_device_driver status code + */ + +rtems_device_driver Clock_control( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + rtems_unsigned32 isrlevel; + rtems_libio_ioctl_args_t *args = pargp; + + if (args == 0) + goto done; + + Clock_Decrementer_value = (BSP_bus_frequency/4000)* + (BSP_Configuration.microseconds_per_tick/1000); + + if (args->command == rtems_build_name('I', 'S', 'R', ' ')) + clockIsr(); + else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) + { + if (!BSP_install_rtems_irq_handler (&clockIrqData)) { + printk("Error installing clock interrupt handler!\n"); + rtems_fatal_error_occurred(1); + } + } +done: + return RTEMS_SUCCESSFUL; +} + + + + + + |