1 // SPDX-License-Identifier: GPL-2.0+
11 #include <i2c.h>
21 #define SDA	BIT(1)  macro
25 	u32 delay;  member
30 	writel(SDA, priv->base + (state ? I2C_SET_REG : I2C_CLEAR_REG));  in versatile_sda_set()
31 	udelay(priv->delay);  in versatile_sda_set()
36 	int v = !!(readl(priv->base + I2C_CONTROL_REG) & SDA);  in versatile_sda_get()
38 	udelay(priv->delay);  in versatile_sda_get()
44 	writel(SCL, priv->base + (state ? I2C_SET_REG : I2C_CLEAR_REG));  in versatile_scl_set()
45 	udelay(priv->delay);  in versatile_scl_set()
50 	int v = !!(readl(priv->base + I2C_CONTROL_REG) & SCL);  in versatile_scl_get()
52 	udelay(priv->delay);  in versatile_scl_get()
56 /* start: SDA goes from high to low while SCL is high */
59 	udelay(priv->delay);  in versatile_i2c_start()
65 /* stop: SDA goes from low to high while SCL is high */
74 /* read a bit from the SDA line (data or ACK/NACK) */
80 	udelay(priv->delay);  in versatile_i2c_read_bit()
84 /* write a bit on the SDA line */
90 	udelay(priv->delay);  in versatile_i2c_write_bit()
93 /* send a reset sequence of 9 clocks with SDA high */
143 	if (msg->flags & I2C_M_TEN) {  in versatile_i2c_send_slave_addr()
144 		/* 10-bit address, send extended address code first */  in versatile_i2c_send_slave_addr()
145 		addr = 0xf0 | ((msg->addr >> 7) & 0x06);  in versatile_i2c_send_slave_addr()
149 			return -EIO;  in versatile_i2c_send_slave_addr()
153 		ret = versatile_i2c_write_byte(priv, msg->addr & 0xff);  in versatile_i2c_send_slave_addr()
156 			return -EIO;  in versatile_i2c_send_slave_addr()
159 		if (msg->flags & I2C_M_RD) {  in versatile_i2c_send_slave_addr()
165 				return -EIO;  in versatile_i2c_send_slave_addr()
169 		/* normal 7-bit address */  in versatile_i2c_send_slave_addr()
170 		addr = msg->addr << 1;  in versatile_i2c_send_slave_addr()
171 		if (msg->flags & I2C_M_RD)  in versatile_i2c_send_slave_addr()
176 			return -EIO;  in versatile_i2c_send_slave_addr()
191 		return -EIO;  in versatile_i2c_message_xfer()
193 	for (i = 0; i < msg->len; i++) {  in versatile_i2c_message_xfer()
194 		if (msg->flags & I2C_M_RD) {  in versatile_i2c_message_xfer()
195 			ack = (msg->len - i - 1) == 0 ? 1 : 0;  in versatile_i2c_message_xfer()
196 			ret = versatile_i2c_read_byte(priv, &msg->buf[i], ack);  in versatile_i2c_message_xfer()
198 			ret = versatile_i2c_write_byte(priv, msg->buf[i]);  in versatile_i2c_message_xfer()
216 	for ( ; nmsgs > 0; nmsgs--, msg++) {  in versatile_i2c_xfer()
219 			return -EREMOTEIO;  in versatile_i2c_xfer()
228 	/* probe the presence of a slave by writing a 0-size message */  in versatile_i2c_chip_probe()
240 	priv->delay = 1000000 / (speed << 2);  in versatile_i2c_set_bus_speed()
251 	priv->base = (phys_addr_t)dev_read_addr(dev);  in versatile_i2c_probe()
252 	priv->delay = 25;	/* 25us * 4 = 100kHz */  in versatile_i2c_probe()
254 	 * U-Boot still doesn't assign automatically  in versatile_i2c_probe()
257 	dev->req_seq = 1;  in versatile_i2c_probe()
269 	{ .compatible = "arm,versatile-i2c" },
274 	.name = "i2c-bus-versatile",