diff options
Diffstat (limited to 'c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c')
-rw-r--r-- | c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c b/c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c new file mode 100644 index 0000000000..eac471218e --- /dev/null +++ b/c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c @@ -0,0 +1,196 @@ +/* clock.c + * + * This routine initializes the PIT on the MPC5xx. + * The tick frequency is specified by the bsp. + * + * + * MPC5xx port sponsored by Defence Research and Development Canada - Suffield + * Copyright (C) 2004, Real-Time Systems Inc. (querbach@realtime.bc.ca) + * + * Derived from c/src/lib/libcpu/powerpc/mpc8xx/clock/clock.c: + * + * Author: Jay Monkman (jmonkman@frasca.com) + * Copyright (C) 1998 by Frasca International, Inc. + * + * Derived from c/src/lib/libcpu/ppc/ppc403/clock/clock.c: + * + * Author: Andrew Bray <andy@i-cubed.co.uk> + * + * COPYRIGHT (c) 1995 by i-cubed ltd. + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of i-cubed limited not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * i-cubed limited makes no representations about the suitability + * of this software for any purpose. + * + * Derived from c/src/lib/libcpu/hppa1_1/clock/clock.c: + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#include <rtems.h> +#include <clockdrv.h> +#include <rtems/libio.h> +#include <libcpu/irq.h> + +#include <stdlib.h> /* for atexit() */ +#include <mpc5xx.h> + +volatile rtems_unsigned32 Clock_driver_ticks; +extern int BSP_connect_clock_handler(rtems_isr_entry); +extern int BSP_disconnect_clock_handler(); + +void Clock_exit( void ); + +/* + * These are set by clock driver during its init + */ + +rtems_device_major_number rtems_clock_major = ~0; +rtems_device_minor_number rtems_clock_minor; + +/* + * ISR Handler + */ +rtems_isr Clock_isr(rtems_vector_number vector) +{ + usiu.piscrk = USIU_UNLOCK_KEY; + usiu.piscr |= USIU_PISCR_PS; /* acknowledge interrupt */ + usiu.piscrk = 0; + + Clock_driver_ticks++; + rtems_clock_tick(); +} + +void clockOn(void* unused) +{ + unsigned desiredLevel; + rtems_unsigned32 pit_value; + + /* calculate and set modulus */ + pit_value = (rtems_configuration_get_microseconds_per_tick() * + rtems_cpu_configuration_get_clicks_per_usec()) - 1 ; + + if (pit_value > 0xffff) { /* pit is only 16 bits long */ + rtems_fatal_error_occurred(-1); + } + usiu.sccrk = USIU_UNLOCK_KEY; + usiu.sccr &= ~USIU_SCCR_RTDIV; /* RTC and PIT clock is divided by 4 */ + usiu.sccrk = 0; + + usiu.pitck = USIU_UNLOCK_KEY; + usiu.pitc = pit_value; + usiu.pitck = 0; + + /* set PIT irq level, enable PIT, PIT interrupts */ + /* and clear int. status */ + desiredLevel = CPU_irq_level_from_symbolic_name(CPU_PERIODIC_TIMER); + + usiu.piscrk = USIU_UNLOCK_KEY; + usiu.piscr = USIU_PISCR_PIRQ(desiredLevel) /* set interrupt priority */ + | USIU_PISCR_PS /* acknowledge interrupt */ + | USIU_PISCR_PIE /* enable interrupt */ + | USIU_PISCR_PITF /* freeze during debug */ + | USIU_PISCR_PTE; /* enable timer */ + usiu.piscrk = 0; +} + +void +clockOff(void* unused) +{ + /* disable PIT and PIT interrupts */ + usiu.piscrk = USIU_UNLOCK_KEY; + usiu.piscr &= ~(USIU_PISCR_PTE | USIU_PISCR_PIE); + usiu.piscrk = 0; +} + +int clockIsOn(void* unused) +{ + if (usiu.piscr & USIU_PISCR_PIE) + return 1; + return 0; +} + +/* + * Called via atexit() + * Remove the clock interrupt handler by setting handler to NULL + */ +void +Clock_exit(void) +{ + (void) BSP_disconnect_clock_handler (); +} + +void Install_clock(rtems_isr_entry clock_isr) +{ + Clock_driver_ticks = 0; + + BSP_connect_clock_handler (clock_isr); + atexit(Clock_exit); +} + +void +ReInstall_clock(rtems_isr_entry new_clock_isr) +{ + BSP_connect_clock_handler (new_clock_isr); +} + + +rtems_device_driver Clock_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + Install_clock( Clock_isr ); + + /* + * make major/minor avail to others such as shared memory driver + */ + + rtems_clock_major = major; + rtems_clock_minor = minor; + + return RTEMS_SUCCESSFUL; +} + +rtems_device_driver Clock_control( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + rtems_libio_ioctl_args_t *args = pargp; + + if (args == 0) + goto done; + + /* + * This is hokey, but until we get a defined interface + * to do this, it will just be this simple... + */ + + if (args->command == rtems_build_name('I', 'S', 'R', ' ')) { + Clock_isr(0); /* vector number ignored */ + } + else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) { + ReInstall_clock(args->buffer); + } + + done: + return RTEMS_SUCCESSFUL; +} + |