Lines Matching +full:i2c +full:- +full:sda +full:- +full:delay

1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
32  * Helper code to recover a hung i2c bus by bit-banging a recovery sequence.
34  * An i2c bus can be hung by a slave driving the clock (rare) or data lines low.
35  * The most common cause is a partially-completed transaction such as rebooting
36  * while a slave is sending a byte of data.  Because i2c allows the clock to
42  * Any i2c driver which is able to manually set the level of the clock and data
44  * embedded i2c controllers, the i2c pins can be temporarily reassigned as gpio
45  * pins to do the bus recovery, then can be assigned back to the i2c hardware.
67 	pins->setsda(pins->ctx, 1);  in iic_recover_bus()
68 	pins->setscl(pins->ctx, 1);  in iic_recover_bus()
72 	 * bus is doing clock-stretching and we should wait a while.  If that  in iic_recover_bus()
75 	 * cheap eeprom has a max post-write delay of only 10ms), and also long  in iic_recover_bus()
79 		if (pins->getscl(pins->ctx))  in iic_recover_bus()
81 		DELAY(delay_us);  in iic_recover_bus()
96 		if (pins->getsda(pins->ctx))  in iic_recover_bus()
100 		pins->setscl(pins->ctx, 0);  in iic_recover_bus()
101 		DELAY(5);  in iic_recover_bus()
102 		pins->setscl(pins->ctx, 1);  in iic_recover_bus()
103 		DELAY(5);  in iic_recover_bus()
111 	 *  - START: SDA transitions high->low while SCL remains high.  in iic_recover_bus()
112 	 *  - STOP:  SDA transitions low->high while SCL remains high.  in iic_recover_bus()
116 	pins->setsda(pins->ctx, 0);  in iic_recover_bus()
117 	DELAY(5);  in iic_recover_bus()
118 	pins->setsda(pins->ctx, 1);  in iic_recover_bus()
119 	DELAY(5);  in iic_recover_bus()