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bsps/powerpc: Add PPC405 support for shared clock

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This commit is contained in:
Sebastian Huber
2013-06-21 17:16:37 +02:00
parent 7d0e88f240
commit 509e0f3ff3
1 changed files with 79 additions and 31 deletions
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110
c/src/lib/libbsp/powerpc/shared/clock/clock.c
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@@ -7,7 +7,7 @@
*/ */
/* /*
* Copyright (c) 2008-2012 embedded brains GmbH. All rights reserved. * Copyright (c) 2008-2013 embedded brains GmbH. All rights reserved.
* *
* embedded brains GmbH * embedded brains GmbH
* Obere Lagerstr. 30 * Obere Lagerstr. 30
@@ -36,6 +36,8 @@
*/ */
extern uint32_t bsp_time_base_frequency; extern uint32_t bsp_time_base_frequency;
#define PPC405_PIT 0x3db
#define PPC_CLOCK_DECREMENTER_MAX UINT32_MAX #define PPC_CLOCK_DECREMENTER_MAX UINT32_MAX
volatile uint32_t Clock_driver_ticks = 0; volatile uint32_t Clock_driver_ticks = 0;
@@ -132,6 +134,28 @@ static int ppc_clock_exception_handler_booke( BSP_Exception_frame *frame, unsign
return 0; return 0;
} }
static int ppc_clock_exception_handler_ppc405(BSP_Exception_frame *frame, unsigned number)
{
uint32_t msr;
/* Acknowledge PIT request */
PPC_SET_SPECIAL_PURPOSE_REGISTER(PPC405_TSR, BOOKE_TSR_DIS);
/* Increment clock ticks */
Clock_driver_ticks += 1;
/* Enable external exceptions */
msr = ppc_external_exceptions_enable();
/* Call clock ticker */
ppc_clock_tick();
/* Restore machine state */
ppc_external_exceptions_disable(msr);
return 0;
}
static uint32_t ppc_clock_nanoseconds_since_last_tick(void) static uint32_t ppc_clock_nanoseconds_since_last_tick(void)
{ {
uint64_t k = ppc_clock_factor; uint64_t k = ppc_clock_factor;
@@ -141,6 +165,19 @@ static uint32_t ppc_clock_nanoseconds_since_last_tick(void)
return (uint32_t) (((i - c) * k) >> 32); return (uint32_t) (((i - c) * k) >> 32);
} }
static uint32_t ppc_clock_nanoseconds_since_last_tick_ppc405(void)
{
uint64_t k = ppc_clock_factor;
uint32_t i = ppc_clock_decrementer_value;
uint32_t c = i - PPC_SPECIAL_PURPOSE_REGISTER(PPC405_PIT);
if ((PPC_SPECIAL_PURPOSE_REGISTER(PPC405_TSR) & BOOKE_TSR_DIS) != 0) {
c = i - PPC_SPECIAL_PURPOSE_REGISTER(PPC405_PIT) + i;
}
return (uint32_t) ((c * k) >> 32);
}
void Clock_exit(void) void Clock_exit(void)
{ {
/* Set the decrementer to the maximum value */ /* Set the decrementer to the maximum value */
@@ -156,9 +193,6 @@ rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_dev
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick(); uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint32_t interval = (uint32_t) ((frequency * us_per_tick) / 1000000); uint32_t interval = (uint32_t) ((frequency * us_per_tick) / 1000000);
/* Current CPU type */
ppc_cpu_id_t cpu_type = get_ppc_cpu_type();
/* Make major/minor available to others such as shared memory driver */ /* Make major/minor available to others such as shared memory driver */
rtems_clock_major = major; rtems_clock_major = major;
rtems_clock_minor = minor; rtems_clock_minor = minor;
@@ -172,46 +206,60 @@ rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_dev
*/ */
ppc_clock_tick = (void (*)(void)) rtems_clock_tick; ppc_clock_tick = (void (*)(void)) rtems_clock_tick;
/* Set the decrementer to the maximum value */
ppc_set_decrementer_register( PPC_CLOCK_DECREMENTER_MAX);
/* Factor for nano seconds extension */ /* Factor for nano seconds extension */
ppc_clock_factor = (1000000000ULL << 32) / frequency; ppc_clock_factor = (1000000000ULL << 32) / frequency;
/* Decrementer value */ if (ppc_cpu_is_bookE() != PPC_BOOKE_405) {
ppc_clock_decrementer_value = interval - 1; /* Decrementer value */
ppc_clock_decrementer_value = interval - 1;
/* Check decrementer value */ /* Check decrementer value */
if (ppc_clock_decrementer_value == 0) { if (ppc_clock_decrementer_value == 0) {
ppc_clock_decrementer_value = PPC_CLOCK_DECREMENTER_MAX; ppc_clock_decrementer_value = PPC_CLOCK_DECREMENTER_MAX;
RTEMS_SYSLOG_ERROR( "decrementer value would be zero, will be set to maximum value instead\n"); RTEMS_SYSLOG_ERROR( "decrementer value would be zero, will be set to maximum value instead\n");
} }
/* Set the nanoseconds since last tick handler */ /* Set the nanoseconds since last tick handler */
rtems_clock_set_nanoseconds_extension( ppc_clock_nanoseconds_since_last_tick); rtems_clock_set_nanoseconds_extension( ppc_clock_nanoseconds_since_last_tick);
if (ppc_cpu_is_bookE()) { if (ppc_cpu_is_bookE()) {
/* Set decrementer auto-reload value */ /* Set decrementer auto-reload value */
PPC_SET_SPECIAL_PURPOSE_REGISTER( BOOKE_DECAR, ppc_clock_decrementer_value); PPC_SET_SPECIAL_PURPOSE_REGISTER( BOOKE_DECAR, ppc_clock_decrementer_value);
/* Install exception handler */ /* Install exception handler */
ppc_exc_set_handler( ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_booke); ppc_exc_set_handler( ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_booke);
/* Enable decrementer and auto-reload */ /* Enable decrementer and auto-reload */
PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( BOOKE_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE); PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( BOOKE_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE);
} else {
/* Here the decrementer value is actually the interval */
++ppc_clock_decrementer_value;
/* Initialize next time base */
ppc_clock_next_time_base = ppc_time_base() + ppc_clock_decrementer_value;
/* Install exception handler */
ppc_exc_set_handler( ASM_DEC_VECTOR, ppc_clock_exception_handler_first);
}
/* Set the decrementer value */
ppc_set_decrementer_register( ppc_clock_decrementer_value);
} else { } else {
/* Here the decrementer value is actually the interval */ /* PIT interval value */
++ppc_clock_decrementer_value; ppc_clock_decrementer_value = interval;
/* Initialize next time base */ /* Set the nanoseconds since last tick handler */
ppc_clock_next_time_base = ppc_time_base() + ppc_clock_decrementer_value; rtems_clock_set_nanoseconds_extension(ppc_clock_nanoseconds_since_last_tick_ppc405);
/* Install exception handler */ /* Install exception handler */
ppc_exc_set_handler( ASM_DEC_VECTOR, ppc_clock_exception_handler_first); ppc_exc_set_handler(ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_ppc405);
}
/* Set the decrementer value */ /* Enable PIT and auto-reload */
ppc_set_decrementer_register( ppc_clock_decrementer_value); PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS(PPC405_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE);
/* Set PIT auto-reload and initial value */
PPC_SET_SPECIAL_PURPOSE_REGISTER(PPC405_PIT, interval);
}
return RTEMS_SUCCESSFUL; return RTEMS_SUCCESSFUL;
} }