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2011-03-04 Till Straumann <strauman@slac.stanford.edu>

Browse Source 
PR 1738/bsps
	* clock/clock.c, include/bsp.h, network/network.c: system clock driver
	programs the PIT w/o assuming the CPU clock frequency being a power
	of two.
This commit is contained in:
Joel Sherrill
2011-03-04 16:03:53 +00:00
parent 6481895a2e
commit 8d45df8368
4 changed files with 64 additions and 29 deletions
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7
c/src/lib/libbsp/m68k/uC5282/ChangeLog
View File

@@ -1,3 +1,10 @@
2011-03-04 Till Straumann <strauman@slac.stanford.edu>
PR 1738/bsps
* clock/clock.c, include/bsp.h, network/network.c: system clock driver
programs the PIT w/o assuming the CPU clock frequency being a power
of two.
2011-02-17 Till Straumann <strauman@slac.stanford.edu>
PR 1738/bsps

52
c/src/lib/libbsp/m68k/uC5282/clock/clock.c
View File

@@ -26,19 +26,19 @@
* CPU load counters
* Place in static RAM so updates don't hit the SDRAM
*/
extern int __SRAMBASE[];
#define IDLE_COUNTER __SRAMBASE[0]
#define FILTERED_IDLE __SRAMBASE[1]
#define MAX_IDLE_COUNT __SRAMBASE[2]
#define USEC_PER_TICK __SRAMBASE[3]
#define IDLE_COUNTER __SRAMBASE.idle_counter
#define FILTERED_IDLE __SRAMBASE.filtered_idle
#define MAX_IDLE_COUNT __SRAMBASE.max_idle_count
#define PITC_PER_TICK __SRAMBASE.pitc_per_tick
#define NSEC_PER_PITC __SRAMBASE.nsec_per_pitc
#define FILTER_SHIFT 6
uint32_t bsp_clock_nanoseconds_since_last_tick(void)
{
int i = MCF5282_PIT3_PCNTR;
if (MCF5282_PIT3_PCSR & MCF5282_PIT_PCSR_PIF)
i = MCF5282_PIT3_PCNTR - USEC_PER_TICK;
return (USEC_PER_TICK - i) * 1000;
i = MCF5282_PIT3_PCNTR - PITC_PER_TICK;
return (PITC_PER_TICK - i) * NSEC_PER_PITC;
}
#define Clock_driver_nanoseconds_since_last_tick bsp_clock_nanoseconds_since_last_tick
@@ -48,7 +48,7 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
*/
#define Clock_driver_support_at_tick() \
do { \
int idle = IDLE_COUNTER; \
unsigned idle = IDLE_COUNTER; \
IDLE_COUNTER = 0; \
if (idle > MAX_IDLE_COUNT) \
MAX_IDLE_COUNT = idle; \
@@ -75,20 +75,31 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
/*
* Set up the clock hardware
*
* Prescale so that it counts in microseconds
* System clock frequency better be 2**n (1<=n<=16) MHz!
* f_pit = f_clk / 2^(preScaleCode+1) / N = 1/(us_per_tick/us_per_s)
*
* N = f_clk / 2^(preScaleCode+1) * us_per_tick / us_per_s
*
* ns_per_pit_clk = ns_per_s / (f_clk / 2^(preScaleCode+1))
* = ns_per_s * 2^(preScaleCode+1) / f_clk;
*/
#define Clock_driver_support_initialize_hardware() \
do { \
unsigned long long N; \
int level; \
int preScaleCode = -2; \
int preScaleDivisor = bsp_get_CPU_clock_speed() / 1000000; \
while (preScaleDivisor) { \
preScaleDivisor >>= 1; \
preScaleCode++; \
} \
IDLE_COUNTER = 0; \
FILTERED_IDLE = 0; \
int preScaleCode = 0; \
N = bsp_get_CPU_clock_speed(); \
N *= rtems_configuration_get_microseconds_per_tick(); \
N /= 2*1000000; /* min_prescale * us_per_s */ \
while ( N > 0x10000 ) { \
preScaleCode++; \
N >>= 1; \
} \
PITC_PER_TICK = N; \
N = 2000000000ULL << preScaleCode; \
N /= bsp_get_CPU_clock_speed(); \
NSEC_PER_PITC = N; \
IDLE_COUNTER = 0; \
FILTERED_IDLE = 0; \
MAX_IDLE_COUNT = 0; \
bsp_allocate_interrupt(PIT3_IRQ_LEVEL, PIT3_IRQ_PRIORITY); \
MCF5282_INTC0_ICR58 = MCF5282_INTC_ICR_IL(PIT3_IRQ_LEVEL) | \
@@ -101,8 +112,7 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
MCF5282_PIT_PCSR_OVW | \
MCF5282_PIT_PCSR_PIE | \
MCF5282_PIT_PCSR_RLD; \
USEC_PER_TICK = rtems_configuration_get_microseconds_per_tick(); \
MCF5282_PIT3_PMR = USEC_PER_TICK - 1; \
MCF5282_PIT3_PMR = PITC_PER_TICK - 1; \
MCF5282_PIT3_PCSR = MCF5282_PIT_PCSR_PRE(preScaleCode) | \
MCF5282_PIT_PCSR_PIE | \
MCF5282_PIT_PCSR_RLD | \
@@ -115,7 +125,7 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
Thread bsp_idle_thread(uint32_t ignored)
{
for(;;)
asm volatile ("addq.l #1,__SRAMBASE"); /* Atomic increment */
asm volatile ("addq.l #1,%0"::"m"(IDLE_COUNTER)); /* Atomic increment */
}
int rtems_bsp_cpu_load_percentage(void)

25
c/src/lib/libbsp/m68k/uC5282/include/bsp.h
View File

@@ -134,6 +134,31 @@ int BSP_vme2local_adrs(unsigned am, unsigned long vmeaddr, unsigned long *plocal
void *bsp_idle_thread( uintptr_t ignored );
#define BSP_IDLE_TASK_BODY bsp_idle_thread
/*
* SRAM. The BSP uses SRAM for maintaining some clock-driver data
* and for ethernet descriptors (and the initial stack during
* early boot).
*/
typedef struct mcf5282BufferDescriptor_ {
volatile uint16_t status;
uint16_t length;
volatile void *buffer;
} mcf5282BufferDescriptor_t;
extern struct {
uint32_t idle_counter;
uint32_t filtered_idle;
uint32_t max_idle_count;
uint32_t pitc_per_tick;
uint32_t nsec_per_pitc;
uint32_t pad[3]; /* align to 16-bytes for descriptors */
mcf5282BufferDescriptor_t fec_descriptors[];
/* buffer descriptors are allocated from here */
/* initial stack is at top of SRAM (start.S) */
} __SRAMBASE;
#ifdef __cplusplus
}
#endif

9
c/src/lib/libbsp/m68k/uC5282/network/network.c
View File

@@ -81,12 +81,6 @@
#error "Driver must have MCLBYTES > RBUF_SIZE"
#endif
typedef struct mcf5282BufferDescriptor_ {
volatile uint16_t status;
uint16_t length;
volatile void *buffer;
} mcf5282BufferDescriptor_t;
/*
* Per-device data
*/
@@ -197,11 +191,10 @@ mcf5282_mii_interrupt_handler( rtems_vector_number v )
* Ensure 128-bit (16-byte) alignment
* Allow some space at the beginning for other diagnostic counters
*/
extern char __SRAMBASE[];
static mcf5282BufferDescriptor_t *
mcf5282_bd_allocate(unsigned int count)
{
static mcf5282BufferDescriptor_t *bdp = (mcf5282BufferDescriptor_t *)(__SRAMBASE+16);
static mcf5282BufferDescriptor_t *bdp = __SRAMBASE.fec_descriptors;
mcf5282BufferDescriptor_t *p = bdp;
bdp += count;