Raspberries/mraa
Private
Public Access
2
0
Fork 0
Code Activity

ftdi_ft4222: Refactored GPIO expander ISR code

Browse Source 
GPIO expander ISRs were dropping interrupts as each pin had its own
thread which cleared the INT signal when reading the GPIO register.
Thus pending interrupts for GPIO on threads waiting to be scheduled
were dropped. Now a single thread polls the GPIO register when INT goes
low and sets interrupt flags for each GPIO line. The threads created
by mraa_gpio_isr() now poll the appropriate interrupt flag.

Signed-off-by: Henry Bruce <henry.bruce@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Henry Bruce
2016-02-23 15:17:21 -08:00
committed by Brendan Le Foll
parent c770c4c669
commit 65514bb432
1 changed files with 87 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

96
src/usb/ftdi_ft4222.c
View File

@@ -664,6 +664,89 @@ mraa_ftdi_ft4222_has_internal_gpio_triggered(int pin)
return FALSE;
}
static struct {
pthread_t thread;
pthread_mutex_t mutex;
mraa_boolean_t should_stop;
mraa_boolean_t is_interrupt_detected[PCA9672_PINS];
int num_active_pins;
} gpio_monitor = {0};
// INT pin of i2c PCA9672 GPIO expander is connected to FT4222 GPIO #3
// We use INT to detect any expander GPIO level change
static void*
mraa_ftdi_ft4222_gpio_monitor(void *arg)
{
uint8_t prev_value = 0;
pthread_mutex_lock(&ft4222_lock);
mraa_ftdi_ft4222_i2c_read_internal(ftHandleI2c, PCA9672_ADDR, &prev_value, 1);
pthread_mutex_unlock(&ft4222_lock);
while (!gpio_monitor.should_stop) {
mraa_boolean_t gpio_activity_detected = mraa_ftdi_ft4222_has_internal_gpio_triggered(GPIO_PORT_IO_INT);
if (gpio_activity_detected) {
uint8_t value;
pthread_mutex_lock(&ft4222_lock);
int bytes_read = mraa_ftdi_ft4222_i2c_read_internal(ftHandleI2c, PCA9672_ADDR, &value, 1);
pthread_mutex_unlock(&ft4222_lock);
if (bytes_read == 1) {
pthread_mutex_lock(&gpio_monitor.mutex);
uint8_t change_value = prev_value ^ value;
int i;
for (i = 0; i < PCA9672_PINS; ++i) {
uint8_t mask = 1 << i;
gpio_monitor.is_interrupt_detected[i] = change_value & mask ? 1 : 0;
}
pthread_mutex_unlock(&gpio_monitor.mutex);
prev_value = value;
}
}
mraa_ftdi_ft4222_sleep_ms(20);
}
printf("gpio_monitor_thread stopped\n");
}
static void
mraa_ftdi_ft4222_gpio_monitor_add_pin(int pin)
{
if (gpio_monitor.num_active_pins == 0) {
pthread_mutex_init(&gpio_monitor.mutex, NULL);
pthread_create(&gpio_monitor.thread, NULL, mraa_ftdi_ft4222_gpio_monitor, NULL);
}
pthread_mutex_lock(&gpio_monitor.mutex);
gpio_monitor.num_active_pins++;
pthread_mutex_unlock(&gpio_monitor.mutex);
}
static void
mraa_ftdi_ft4222_gpio_monitor_remove_pin(int pin)
{
pthread_mutex_lock(&gpio_monitor.mutex);
gpio_monitor.num_active_pins--;
if (gpio_monitor.num_active_pins == 0) {
pthread_mutex_unlock(&gpio_monitor.mutex);
gpio_monitor.should_stop = TRUE;
pthread_join(gpio_monitor.thread, NULL);
pthread_mutex_destroy(&gpio_monitor.mutex);
} else
pthread_mutex_unlock(&gpio_monitor.mutex);
}
static mraa_boolean_t
mraa_ftdi_ft4222_gpio_monitor_is_interrupt_detected(int pin)
{
mraa_boolean_t is_interrupt_detected = FALSE;
pthread_mutex_lock(&gpio_monitor.mutex);
if (gpio_monitor.is_interrupt_detected[pin]) {
gpio_monitor.is_interrupt_detected[pin] = FALSE;
is_interrupt_detected = TRUE;
}
pthread_mutex_unlock(&gpio_monitor.mutex);
return is_interrupt_detected;
}
static mraa_result_t
mraa_ftdi_ft4222_gpio_interrupt_handler_init_replace(mraa_gpio_context dev)
{
@@ -673,6 +756,7 @@ mraa_ftdi_ft4222_gpio_interrupt_handler_init_replace(mraa_gpio_context dev)
ftdi_ft4222_set_internal_gpio_dir(GPIO_PORT_IO_INT, GPIO_INPUT);
ftdi_ft4222_set_internal_gpio_trigger(GPIO_PORT_IO_INT, GPIO_TRIGGER_FALLING);
mraa_ftdi_ft4222_has_internal_gpio_triggered(GPIO_PORT_IO_INT);
mraa_ftdi_ft4222_gpio_monitor_add_pin(dev->phy_pin);
}
return MRAA_SUCCESS;
}
@@ -684,24 +768,18 @@ mraa_ftdi_ft4222_gpio_wait_interrupt_replace(mraa_gpio_context dev)
mraa_boolean_t is_internal_pin = mraa_ftdi_ft4222_is_internal_gpio(dev->pin);
mraa_boolean_t interrupt_detected = FALSE;
// INT pin of i2c PCA9672 GPIO expander is connected to FT4222 GPIO #3
// We use INT to detect any expander GPIO level change
while (!dev->isr_thread_terminating && !interrupt_detected) {
if (is_internal_pin) {
interrupt_detected = mraa_ftdi_ft4222_has_internal_gpio_triggered(dev->phy_pin);
}
else {
mraa_boolean_t gpio_activity_detected = mraa_ftdi_ft4222_has_internal_gpio_triggered(GPIO_PORT_IO_INT);
if (gpio_activity_detected) {
int level = mraa_ftdi_ft4222_gpio_read_replace(dev);
if (level != prev_level) {
interrupt_detected = TRUE;
}
}
interrupt_detected = mraa_ftdi_ft4222_gpio_monitor_is_interrupt_detected(dev->phy_pin);
}
if (!interrupt_detected)
mraa_ftdi_ft4222_sleep_ms(20);
}
if (dev->isr_thread_terminating)
mraa_ftdi_ft4222_gpio_monitor_remove_pin(dev->phy_pin);
return MRAA_SUCCESS;
}