Modified: trunk/drivers/char/bfin_timer_latency.c (5311 => 5312)
--- trunk/drivers/char/bfin_timer_latency.c 2008-09-18 06:50:20 UTC (rev 5311)
+++ trunk/drivers/char/bfin_timer_latency.c 2008-09-18 08:53:29 UTC (rev 5312)
@@ -47,34 +47,53 @@
struct timer_latency_data_t {
char value;
- unsigned long latency;
+ unsigned long last_latency;
+ unsigned long worst_latency;
+ unsigned long average_latency;
+ unsigned long test_number;
+ unsigned int period_sclk;
+ unsigned int period_cclk;
};
struct proc_dir_entry *timer_latency_file;
struct timer_latency_data_t timer_latency_data;
static int read_timer_latency(char *page, char **start,
- off_t offset, int count, int *eof,
- void *data)
+ off_t offset, int count, int *eof, void *data)
{
- return sprintf(page, "%lu", timer_latency_data.latency);
+ return sprintf(page,
+ "number, worst latency, average latency\n %lu, %lu, %lu\n",
+ timer_latency_data.test_number,
+ timer_latency_data.worst_latency,
+ timer_latency_data.average_latency);
}
-
static int write_timer_latency(struct file *file, const char *buffer,
- unsigned long count, void *data)
+ unsigned long count, void *data)
{
- unsigned long sclk;
- char user_value;
+ unsigned long sclk, cclk;
+ char user_value[8];
+ unsigned int wd_period_us;
+ unsigned int period_sclk;
+ unsigned int period_cclk;
- copy_from_user(&(user_value), buffer, 1);
+ copy_from_user(user_value, buffer, count);
+ wd_period_us = strict_strtoul(user_value, NULL, 0);
- if ((user_value == '1') && (timer_latency_data.value == 0)) {
+ if ((wd_period_us >= 100) && (timer_latency_data.value == 0)) {
DPRINTK("start timer_latency\n");
timer_latency_data.value = 1;
- sclk = get_sclk();
- bfin_write_WDOG_CNT(5 * sclk); /* set count time to 5 seconds */
- /* set CYCLES counter to 0 and start it*/
+ sclk = get_sclk() / 1000000;
+ cclk = get_cclk() / 1000000;
+
+ /* convert from us to cycles */
+ timer_latency_data.period_sclk = wd_period_us * sclk;
+ timer_latency_data.period_cclk = wd_period_us * cclk;
+
+ /* set count timer cycles */
+ bfin_write_WDOG_CNT(timer_latency_data.period_sclk);
+
+ /* set CYCLES counter to 0 and start it */
__asm__(
"R2 = 0;\n\t"
"CYCLES = R2;\n\t"
@@ -85,17 +104,16 @@
"P2.H = 0xffc0;\n\t"
"P2.L = 0x0200;\n\t"
"R3 = 0x0004;\n\t"
- "W[P2] = R3;\n\t"
+ "W[P2] = R3;\n\t" /* start watchdog timer */
"SYSCFG = R2;\n\t" /* start cycles counter */
: : : "R2", "R3", "P2"
);
}
- return 1; /* always write 1 byte*/
+ return 1; /* always write 1 byte */
}
-
static irqreturn_t timer_latency_irq(int irq, void *dev_id)
{
struct timer_latency_data_t *data = ""
@@ -105,16 +123,15 @@
/* unsigned long first_latency, second_latency, third_latency; */
-
/* get current cycle counter */
/*
- asm("%0 = CYCLES; p2 = 0xFFE07040; %1 = [p2]; p2 = 0xFFE07044; %2 = [p2]; p2 = 0xFFE07048; %3 = [p2];"
- : "=d" (cycles_past), "=d" (first_latency), "=d" (second_latency), "=d" (third_latency):); */
+ asm("%0 = CYCLES; p2 = 0xFFE07040; %1 = [p2]; p2 = 0xFFE07044; %2 = [p2]; p2 = 0xFFE07048; %3 = [p2];"
+ : "=d" (cycles_past), "=d" (first_latency), "=d" (second_latency), "=d" (third_latency):); */
- asm("%0 = CYCLES;" : "=d" (cycles_past));
+ asm("%0 = CYCLES;":"=d"(cycles_past));
- bfin_write_WDOG_CTL(0x8AD6); /* close counter */
- bfin_write_WDOG_CTL(0x8AD6); /* have to write it twice to disable the timer */
+ bfin_write_WDOG_CTL(0x8AD6); /* close counter */
+ bfin_write_WDOG_CTL(0x8AD6); /* have to write it twice to disable the timer */
__asm__( /* stop CYCLES counter */
"R2 = SYSCFG;\n\t"
@@ -123,25 +140,43 @@
: : : "R2"
);
- cclk = get_cclk();
+ latency = cycles_past - data->period_cclk; /* latency in cycles */
- /* printk("first_latency is %lu, second is %lu, third is %lu, latency is %lu\n", first_latency, second_latency, third_latency, cycles_past); */
+ DPRINTK("latecy is %lu\n", latency);
- latency = cycles_past - (cclk * 5); /* latency in us */
- DPRINTK("latecy is %lu\n",latency);
-
if (bfin_read_WDOG_STAT() != 0) {
DPRINTK("timer_latency error!\n");
return IRQ_HANDLED;
}
- data->latency = latency;
- timer_latency_data.value = 0;
+ if (latency > data->worst_latency)
+ data->worst_latency = latency;
+ data->last_latency = latency;
+ data->test_number++;
+ data->average_latency =
+ ((data->average_latency * (data->test_number - 1)) +
+ latency) / (data->test_number);
+ /* restart watchdog timer again */
+ bfin_write_WDOG_CNT(data->period_sclk);
+
+ __asm__(
+ "R2 = 0;\n\t"
+ "CYCLES = R2;\n\t"
+ "CYCLES2 = R2;\n\t"
+ "R2 = SYSCFG;\n\t"
+ "BITSET(R2,1);\n\t"
+ "P2.H = 0xffc0;\n\t"
+ "P2.L = 0x0200;\n\t"
+ "R3 = 0x0004;\n\t"
+ "W[P2] = R3;\n\t" /* start watchdog timer */
+ "SYSCFG = R2;\n\t" /* start cycles counter */
+ : : : "R2", "R3", "P2"
+ );
+
return IRQ_HANDLED;
}
-
static int __init timer_latency_init(void)
{
DPRINTK("timer_latency start!\n");
@@ -152,21 +187,23 @@
/* default value is 0 (timer is stopped) */
timer_latency_data.value = 0;
- timer_latency_data.latency = 0;
+ timer_latency_data.worst_latency = 0;
+ timer_latency_data.average_latency = 0;
+ timer_latency_data.last_latency = 0;
timer_latency_file->data = ""
timer_latency_file->read_proc = &read_timer_latency;
timer_latency_file->write_proc = &write_timer_latency;
timer_latency_file->owner = THIS_MODULE;
- request_irq(IRQ_WATCH, timer_latency_irq, IRQF_DISABLED, "timer_latency", &timer_latency_data);
+ request_irq(IRQ_WATCH, timer_latency_irq, IRQF_DISABLED,
+ "timer_latency", &timer_latency_data);
printk(KERN_INFO "timer_latency module loaded\n");
- return 0; /* everything's OK */
+ return 0; /* everything's OK */
}
-
static void __exit timer_latency_exit(void)
{
remove_proc_entry("timer_latency", NULL);
