diff options
Diffstat (limited to 'bsps/powerpc/ss555/clock/clock.c')
| -rw-r--r-- | bsps/powerpc/ss555/clock/clock.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/bsps/powerpc/ss555/clock/clock.c b/bsps/powerpc/ss555/clock/clock.c new file mode 100644 index 0000000000..9f843cee4f --- /dev/null +++ b/bsps/powerpc/ss555/clock/clock.c @@ -0,0 +1,144 @@ +/* + * 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) 1989-2007. + * 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.org/license/LICENSE. + */ + +#include <rtems.h> +#include <rtems/clockdrv.h> +#include <rtems/libio.h> +#include <libcpu/irq.h> + +#include <stdlib.h> /* for atexit() */ +#include <mpc5xx.h> + +volatile uint32_t Clock_driver_ticks; +extern int BSP_connect_clock_handler(rtems_isr_entry); +extern int BSP_disconnect_clock_handler(void); +extern uint32_t bsp_clicks_per_usec; + +void Clock_exit( void ); + +/* + * 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; + uint32_t pit_value; + + /* calculate and set modulus */ + pit_value = (rtems_configuration_get_microseconds_per_tick() * + bsp_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 (); +} + +static void Install_clock(rtems_isr_entry clock_isr) +{ + Clock_driver_ticks = 0; + + BSP_connect_clock_handler (clock_isr); + atexit(Clock_exit); +} + +rtems_device_driver Clock_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *pargp +) +{ + Install_clock( Clock_isr ); + + return RTEMS_SUCCESSFUL; +} |