4  * SPDX-License-Identifier: Apache-2.0
9  * @brief Software driven 'bit-banging' library for I2C
13  * the Standard-mode and Fast-mode speeds and doesn't support optional
14  * protocol feature like 10-bit addresses or clock stretching.
17  * https://www.nxp.com/docs/en/user-guide/UM10204.pdf
46 		return -ENOTSUP;  in i2c_bitbang_configure()
52 		context->delays[T_LOW]  = NS_TO_SYS_CLOCK_HW_CYCLES(4700);  in i2c_bitbang_configure()
53 		context->delays[T_HIGH] = NS_TO_SYS_CLOCK_HW_CYCLES(4000);  in i2c_bitbang_configure()
56 		context->delays[T_LOW]  = NS_TO_SYS_CLOCK_HW_CYCLES(1300);  in i2c_bitbang_configure()
57 		context->delays[T_HIGH] = NS_TO_SYS_CLOCK_HW_CYCLES(600);  in i2c_bitbang_configure()
60 		return -ENOTSUP;  in i2c_bitbang_configure()
63 	context->dev_config = dev_config;  in i2c_bitbang_configure()
70 	if (context->dev_config == 0) {  in i2c_bitbang_get_config()
71 		return -EIO;  in i2c_bitbang_get_config()
74 	*config = context->dev_config;  in i2c_bitbang_get_config()
81 	context->io->set_scl(context->io_context, state);  in i2c_set_scl()
86 	context->io->set_sda(context->io_context, state);  in i2c_set_sda()
91 	return context->io->get_sda(context->io_context);  in i2c_get_sda()
99 	while (k_cycle_get_32() - start < cycles_to_wait) {  in i2c_delay()
111 		i2c_delay(context->delays[T_LOW]);  in i2c_start()
113 		i2c_delay(context->delays[T_SU_STA]);  in i2c_start()
116 	i2c_delay(context->delays[T_HD_STA]);  in i2c_start()
119 	i2c_delay(context->delays[T_LOW]);  in i2c_start()
126 	i2c_delay(context->delays[T_HIGH]);  in i2c_repeated_start()
128 	i2c_delay(context->delays[T_SU_STA]);  in i2c_repeated_start()
135 	i2c_delay(context->delays[T_LOW]);  in i2c_stop()
138 	i2c_delay(context->delays[T_HIGH]);  in i2c_stop()
140 	i2c_delay(context->delays[T_SU_STP]);  in i2c_stop()
142 	i2c_delay(context->delays[T_BUF]); /* In case we start again too soon */  in i2c_stop()
145 static void i2c_write_bit(struct i2c_bitbang *context, int bit)  in i2c_write_bit()  argument
148 	i2c_set_sda(context, bit);  in i2c_write_bit()
150 	i2c_delay(context->delays[T_HIGH]);  in i2c_write_bit()
152 	i2c_delay(context->delays[T_LOW]);  in i2c_write_bit()
157 	bool bit;  in i2c_read_bit()  local
163 	i2c_delay(context->delays[T_HIGH]);  in i2c_read_bit()
165 	bit = i2c_get_sda(context);  in i2c_read_bit()
168 	i2c_delay(context->delays[T_LOW]);  in i2c_read_bit()
169 	return bit;  in i2c_read_bit()
180 	/* Return inverted ACK bit, i.e. 'true' for ACK, 'false' for NACK */  in i2c_write_byte()
202 	int result = -EIO;  in i2c_bitbang_transfer()
227 		} else if (msgs->flags & I2C_MSG_RESTART) {  in i2c_bitbang_transfer()
232 		flags |= msgs->flags;  in i2c_bitbang_transfer()
246 		buf = msgs->buf;  in i2c_bitbang_transfer()
247 		buf_end = buf + msgs->len;  in i2c_bitbang_transfer()
266 		num_msgs--;  in i2c_bitbang_transfer()
282 	 * The I2C-bus specification and user manual (NXP UM10204  in i2c_bitbang_recover_bus()
313 		return -EBUSY;  in i2c_bitbang_recover_bus()
320 	context->io = io;  in i2c_bitbang_init()
321 	context->io_context = io_context;  in i2c_bitbang_init()