X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fdrivers%2Fao_trng_send.c;h=e8df4cea8e69f25861a73a81acfedcc5f372dfad;hp=bac6035cd8dbde1b09fdb929debc5fc4b67a8c80;hb=684741765117611b7d666efbdfafd87c6199752c;hpb=643c2fb03833d658320f476ef731bbb06fe3cc31 diff --git a/src/drivers/ao_trng_send.c b/src/drivers/ao_trng_send.c index bac6035c..e8df4cea 100644 --- a/src/drivers/ao_trng_send.c +++ b/src/drivers/ao_trng_send.c @@ -3,7 +3,8 @@ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; version 2 of the License. + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of @@ -19,47 +20,225 @@ #include #include #include +#include +#include + +static struct ao_task ao_trng_send_task; +static uint8_t trng_running; +static AO_TICK_TYPE trng_power_time; + +#define TRNG_ENABLE_DELAY AO_MS_TO_TICKS(100) + +static uint8_t random_mutex; static void -ao_trng_send(void) +ao_trng_start(void) +{ + if (!trng_running) { + ao_mutex_get(&random_mutex); + if (!trng_running) { + AO_TICK_TYPE delay; + + delay = trng_power_time + TRNG_ENABLE_DELAY - ao_time(); + if (delay > TRNG_ENABLE_DELAY) + delay = TRNG_ENABLE_DELAY; + + /* Delay long enough for the HV power supply + * to stabilize so that the first bits we read + * aren't of poor quality + */ + ao_delay(delay); + trng_running = true; + } + ao_mutex_put(&random_mutex); + } +} + +#if AO_USB_HAS_IN2 + +static struct ao_task ao_trng_send_raw_task; + +static void +ao_trng_get_raw(uint16_t *buf) +{ + uint16_t i; + uint16_t t; + uint16_t v; + + t = ao_adc_get(AO_USB_IN_SIZE>>1); /* one 16-bit value per two output bytes */ + for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { + v = ao_adc_ring[t]; + *buf++ = v; + t = (t + 1) & (AO_ADC_RING_SIZE - 1); + } + ao_adc_ack(AO_USB_IN_SIZE>>1); +} + +static void +ao_trng_send_raw(void) { - static uint16_t *buffer[2]; + uint16_t *buffer[2]; int usb_buf_id; + + usb_buf_id = ao_usb_alloc2(buffer); + + for (;;) { + ao_trng_start(); +#ifdef AO_LED_TRNG_RAW + ao_led_on(AO_LED_TRNG_RAW); +#endif + ao_trng_get_raw(buffer[usb_buf_id]); +#ifdef AO_LED_TRNG_RAW + ao_led_off(AO_LED_TRNG_RAW); +#endif + usb_buf_id = ao_usb_write2(AO_USB_IN_SIZE); + } +} + +#endif + +static uint32_t previous[AO_USB_IN_SIZE / sizeof (uint16_t)]; + +static int +ao_trng_get_cooked(uint16_t *buf) +{ uint16_t i; - uint16_t *buf; uint16_t t; - uint32_t *rnd = (uint32_t *) ao_adc_ring; + uint32_t *rnd = (uint32_t *) (void *) ao_adc_ring; + uint8_t mismatch = 1; + + t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */ + for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { + uint32_t v; + + /* Fetch two values in one operation */ + v = rnd[t]; + if (v != previous[i]) { + mismatch = 1; + previous[i] = v; + } + t = (t + 1) & ((AO_ADC_RING_SIZE >> 1) - 1); - if (!buffer[0]) { - buffer[0] = ao_usb_alloc(); - buffer[1] = ao_usb_alloc(); - if (!buffer[0]) - return; + *buf++ = ao_crc_in_32_out_16(v); } + ao_adc_ack(AO_USB_IN_SIZE); + return mismatch; +} - usb_buf_id = 0; +#define AO_TRNG_START_WAIT 1024 +#define AO_TRNG_START_CHECK 32 + +static void +ao_trng_send(void) +{ + uint16_t *buffer[2]; + int usb_buf_id; + int good_bits; + int failed; + int s; + + usb_buf_id = ao_usb_alloc(buffer); + +#ifdef AO_TRNG_ENABLE_PORT + ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1); +#endif + trng_power_time = ao_time(); ao_crc_reset(); + for (s = 0; s < AO_TRNG_START_WAIT; s++) { + int i; + uint16_t min, max; + uint16_t buf[AO_USB_IN_SIZE>>1]; + + ao_trng_get_raw(buf); + min = max = buf[0]; + for (i = 1; i < (AO_USB_IN_SIZE>>1); i++) { + uint16_t v = buf[i]; + if (v < min) min = v; + if (v > max) max = v; + } + /* Wait for at least 10 bits of range */ + if ((uint16_t) (max - min) >= 1024) + break; + ao_delay(AO_MS_TO_TICKS(10)); + } + + /* Validate the hardware before enabling USB */ + failed = 0; + for (s = 0; s < AO_TRNG_START_CHECK; s++) { + if (!ao_trng_get_cooked(buffer[0])) { + failed++; + ao_delay(AO_MS_TO_TICKS(10)); + } + } + if (failed > AO_TRNG_START_CHECK / 4) + ao_panic(AO_PANIC_DMA); + +#if AO_USB_HAS_IN2 + ao_add_task(&ao_trng_send_raw_task, ao_trng_send_raw, "trng_send_raw"); +#endif + +#ifdef AO_USB_START_DISABLED + ao_usb_enable(); +#endif + for (;;) { - ao_led_on(AO_LED_TRNG_ACTIVE); - t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */ - buf = buffer[usb_buf_id]; - for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) { - *buf++ = ao_crc_in_32_out_16(rnd[t]); - t = (t + 1) & ((AO_ADC_RING_SIZE>>1) - 1); + ao_trng_start(); +#ifdef AO_LED_TRNG_COOKED + ao_led_on(AO_LED_TRNG_COOKED); +#endif + good_bits = ao_trng_get_cooked(buffer[usb_buf_id]); +#ifdef AO_LED_TRNG_COOKED + ao_led_off(AO_LED_TRNG_COOKED); +#endif + if (good_bits) { + usb_buf_id = ao_usb_write(AO_USB_IN_SIZE); + failed = 0; + } else { + failed++; + if (failed > 10) { + ao_usb_disable(); + ao_panic(AO_PANIC_DMA); + } } - ao_adc_ack(AO_USB_IN_SIZE); - ao_led_off(AO_LED_TRNG_ACTIVE); - ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE); - usb_buf_id = 1-usb_buf_id; } } -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 + trng_power_time = ao_time(); +} + +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, 0); + 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"); }