add aio reading

src/aio.c

@@ -0,0 +1,85 @@
+#include "aio.h"
+#include "log.h"
+
+#include <unistd.h>
+
+static const uint8_t buf_size = 32; // needs 32 bc of overflow issue on these aios?
+
+static int aio_post(libusb_device_handle *dev, uint8_t *req, const int req_len, uint8_t *resp, const int resp_len) {
+	int transferred;
+	int r = libusb_bulk_transfer(dev, 0x01, req, req_len, &transferred, 1000);
+	usleep(5 * 1000);   /* 5ms — give the device time to prepare the response */
+	if (r < 0)
+		return r;
+
+	r = libusb_bulk_transfer(dev, 0x81, resp, resp_len, &transferred, 1000);
+	return r;
+}
+
+float aio_get_water_temp(libusb_device_handle* aio) {
+	uint8_t req = 0xa9;
+	uint8_t resp[buf_size];
+	aio_post(aio, &req, sizeof(req), resp, 6);
+	return (float)resp[3] + (float)resp[4] / 10.0f;
+}
+
+uint16_t aio_get_pump_speed(libusb_device_handle* aio) {
+	uint8_t req = 0x31;
+	uint8_t resp[buf_size];
+	aio_post(aio, &req, sizeof(req), resp, 5);
+	return resp[3] << 8 | resp[4];
+}
+
+enum aio_pump_mode_t aio_get_pump_mode(libusb_device_handle* aio) {
+	uint8_t req = 0x33;
+	uint8_t resp[buf_size];
+	aio_post(aio, &req, sizeof(req), resp, 4);
+	return (enum aio_pump_mode_t)resp[3];
+}
+
+void aio_get_fan_speed(libusb_device_handle* aio, uint16_t *speeds) {
+	uint8_t req[2] = {0x41};
+	uint8_t resp[buf_size];
+
+	for (uint8_t i = 0; i < 2; i++) {
+		req[1] = i;
+		aio_post(aio, req, sizeof(req), resp, 6);
+		speeds[i] = resp[4] << 8 | resp[5];
+	}
+}
+
+void aio_detect(struct aio_t *aio) {
+	libusb_init(NULL);
+	aio->handle = libusb_open_device_with_vid_pid(NULL, CORSAIR_VID, AIO_PID);
+	if (aio->handle == NULL) {
+		applog(LOG_ERR, "Can't open AIO USB device %x:%x", CORSAIR_VID, AIO_PID);
+		return;
+	}
+
+	/* detach kernel driver if attached */
+	if (libusb_kernel_driver_active(aio->handle, 0))
+		libusb_detach_kernel_driver(aio->handle, 0);
+
+	const int ret = libusb_claim_interface(aio->handle, 0);
+	if (ret == 0)
+		applog(LOG_INF, "found Corsair AIO device at %04x:%04x", CORSAIR_VID, AIO_PID);
+	else
+		applog(LOG_ERR, "failed to claim AIO device");
+}
+
+void aio_update(struct aio_t *aio) {
+	if (aio->handle == NULL)
+		return;
+	aio->water_temp = aio_get_water_temp(aio->handle);
+	aio->pump_speed = aio_get_pump_speed(aio->handle);
+	aio->mode = aio_get_pump_mode(aio->handle);
+	aio_get_fan_speed(aio->handle, aio->fan_speed);
+}
+
+void aio_close(const struct aio_t *aio) {
+	libusb_release_interface(aio->handle, 0);
+	libusb_attach_kernel_driver(aio->handle, 0);  /* reattach so liquidctl still works */
+	libusb_close(aio->handle);
+	libusb_exit(NULL);
+	applog(LOG_INF, "AIO device closed");
+}