Lines Matching +full:bit +full:- +full:banging

1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
31  * Generic I2C bit-banging code
42  * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
136 	device_set_desc(dev, "I2C bit-banging driver");
146 	sc->iicbus = device_add_child(dev, "iicbus", DEVICE_UNIT_ANY);
147 	if (!sc->iicbus)
150 	sc->scl_low_timeout = DEFAULT_SCL_LOW_TIMEOUT;
154 	    "delay", CTLFLAG_RD, &sc->udelay,
159 	    "scl_low_timeout", CTLFLAG_RWTUN, &sc->scl_low_timeout,
163 	    "io_latency", CTLFLAG_RWTUN, &sc->io_latency,
185 	if (child == sc->iicbus)
186 		sc->iicbus = NULL;
200 		retval += printf(" on %s master-only\n",
219     &i2c_debug, 0, "Enable i2c bit-banging driver debug");
243 	timeout = now + sc->scl_low_timeout * SBT_1US;
252 		pause_sbt("iicbb-scl-low", SBT_1MS, 0, C_PREL(2));
270 	 * - set SDA to the value;
271 	 * - release SCL and wait until it's high.
274 	 * There should be a data set-up time, 250 ns minimum, between setting
295 	 * - pull SCL low and hold for udelay.
298 	DELAY(sc->udelay);
302 iicbb_sendbit(device_t dev, int bit)
307 	err = iicbb_clockin(dev, bit);
310 	DELAY(sc->udelay);
344 	for (t = 0; t < sc->udelay; t++) {
351 	DELAY(sc->udelay - t);
354 	I2C_DEBUG(printf("%c ", noack ? '-' : '+'));
363 	for (i = 7; i >= 0; i--) {
387 	for (i = 7; i >= 0; i--) {
394 		DELAY((sc->udelay + 1) / 2);
397 		DELAY((sc->udelay + 1) / 2);
402 	 * Send master->slave ACK (low) for more data,
406 	I2C_DEBUG(printf("r%02x%c ", *data, last ? '-' : '+'));
444 		DELAY((sc->udelay + 1) / 2);
456 	/* Start: SDA high->low. */
460 	DELAY((sc->udelay + 1) / 2);
502 	DELAY((sc->udelay + 1) / 2);
504 	DELAY((sc->udelay + 1) / 2);
527 		len--;
548 		len--;
579 	busfreq = IICBUS_GET_FREQUENCY(sc->iicbus, speed);
580 	period = 1000000 / 2 / busfreq;	/* Hz -> uS */
581 	period -= sc->io_latency;
582 	sc->udelay = MAX(period, 1);