diff options
| author | Keith Packard <keithp@keithp.com> | 2016-02-07 00:14:22 +1100 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2016-02-07 15:42:28 -0800 |
| commit | 235198b85f1583d2792c7028decace61d1b4229e (patch) | |
| tree | 0b508d595d9d1196a43edbcfa4d4df7a799ef9c5 /src/drivers/ao_trng_send.c | |
| parent | 2ad756bd1b63a2c8450edd7001628b92279fd1b8 (diff) | |
altos: Add power management to TRNG driver
Support suspend/resume of the TRNG power supply, delaying after resume
to wait for it to stabilize.
Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'src/drivers/ao_trng_send.c')
| -rw-r--r-- | src/drivers/ao_trng_send.c | 46 |
1 files changed, 41 insertions, 5 deletions
diff --git a/src/drivers/ao_trng_send.c b/src/drivers/ao_trng_send.c index 99994900..63366d3e 100644 --- a/src/drivers/ao_trng_send.c +++ b/src/drivers/ao_trng_send.c @@ -20,6 +20,9 @@ #include <ao_crc.h> #include <ao_trng_send.h> #include <ao_exti.h> +#include <ao_power.h> + +static uint8_t trng_running; static void ao_trng_send_raw(uint16_t *buf) @@ -72,12 +75,15 @@ ao_trng_send(void) ao_crc_reset(); - /* Delay long enough for the HV power supply to stabilize so that the - * first bits we read aren't of poor quality - */ - ao_delay(AO_MS_TO_TICKS(250)); - for (;;) { + if (!trng_running) { + /* Delay long enough for the HV power supply + * to stabilize so that the first bits we read + * aren't of poor quality + */ + ao_delay(AO_MS_TO_TICKS(10)); + trng_running = TRUE; + } if (ao_send_raw()) { ao_led_on(AO_LED_TRNG_RAW); ao_trng_send_raw(buffer[usb_buf_id]); @@ -95,9 +101,39 @@ ao_trng_send(void) static struct ao_task ao_trng_send_task; +#if AO_POWER_MANAGEMENT + +static void ao_trng_suspend(void *arg) +{ + (void) arg; +#ifdef AO_TRNG_ENABLE_PORT + ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 0); +#endif + trng_running = FALSE; +} + +static void ao_trng_resume(void *arg) +{ + (void) arg; +#ifdef AO_TRNG_ENABLE_PORT + ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1); +#endif +} + +static struct ao_power ao_trng_power = { + .suspend = ao_trng_suspend, + .resume = ao_trng_resume +}; + +#endif + void ao_trng_send_init(void) { +#ifdef AO_TRNG_ENABLE_PORT + ao_enable_output(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1); + ao_power_register(&ao_trng_power); +#endif ao_enable_input(AO_RAW_PORT, AO_RAW_BIT, AO_EXTI_MODE_PULL_UP); ao_add_task(&ao_trng_send_task, ao_trng_send, "trng_send"); } |