2  * i2c.c - driver for ADI TWI/I2C
4  * Copyright (c) 2006-2014 Analog Devices Inc.
6  * Licensed under the GPL-2 or later.
9  * Please see doc/driver-model/i2c-howto.txt for instructions.
25 	ureg(clkdiv);
66 # error "The I2C hardware can only operate 20KHz - 400KHz"
85  * wait_for_completion - manage the actual i2c transfer
94 		int_stat = readw(&twi->int_stat);  in wait_for_completion()
97 			writew(XMTSERV, &twi->int_stat);  in wait_for_completion()
98 			if (msg->alen) {  in wait_for_completion()
99 				writew(*(msg->abuf++), &twi->xmt_data8);  in wait_for_completion()
100 				--msg->alen;  in wait_for_completion()
101 			} else if (!(msg->flags & I2C_M_COMBO) && msg->len) {  in wait_for_completion()
102 				writew(*(msg->buf++), &twi->xmt_data8);  in wait_for_completion()
103 				--msg->len;  in wait_for_completion()
105 				ctl = readw(&twi->master_ctl);  in wait_for_completion()
106 				if (msg->flags & I2C_M_COMBO)  in wait_for_completion()
108 							&twi->master_ctl);  in wait_for_completion()
110 					writew(ctl | STOP, &twi->master_ctl);  in wait_for_completion()
114 			writew(RCVSERV, &twi->int_stat);  in wait_for_completion()
115 			if (msg->len) {  in wait_for_completion()
116 				*(msg->buf++) = readw(&twi->rcv_data8);  in wait_for_completion()
117 				--msg->len;  in wait_for_completion()
118 			} else if (msg->flags & I2C_M_STOP) {  in wait_for_completion()
119 				ctl = readw(&twi->master_ctl);  in wait_for_completion()
120 				writew(ctl | STOP, &twi->master_ctl);  in wait_for_completion()
124 			writew(MERR, &twi->int_stat);  in wait_for_completion()
125 			return msg->len;  in wait_for_completion()
128 			writew(MCOMP, &twi->int_stat);  in wait_for_completion()
129 			if (msg->flags & I2C_M_COMBO && msg->len) {  in wait_for_completion()
130 				ctl = readw(&twi->master_ctl);  in wait_for_completion()
132 					(min(msg->len, 0xff) << 6) | MEN | MDIR;  in wait_for_completion()
133 				writew(ctl, &twi->master_ctl);  in wait_for_completion()
144 	return msg->len;  in wait_for_completion()
167 	while (readw(&twi->master_stat) & BUSBUSY)  in i2c_transfer()
172 	writew(chip, &twi->master_addr);  in i2c_transfer()
175 	writew(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl);  in i2c_transfer()
176 	writew(0, &twi->fifo_ctl);  in i2c_transfer()
181 		writew(*(msg.abuf++), &twi->xmt_data8);  in i2c_transfer()
182 		--msg.alen;  in i2c_transfer()
184 		writew(*(msg.buf++), &twi->xmt_data8);  in i2c_transfer()
185 		--msg.len;  in i2c_transfer()
189 	writew(-1, &twi->master_stat);  in i2c_transfer()
190 	writew(-1, &twi->int_stat);  in i2c_transfer()
191 	writew(0, &twi->int_mask);  in i2c_transfer()
194 	ctl = readw(&twi->master_ctl);  in i2c_transfer()
197 	writew(ctl, &twi->master_ctl);  in i2c_transfer()
203 		ctl = readw(&twi->master_ctl) & ~MEN;  in i2c_transfer()
204 		writew(ctl, &twi->master_ctl);  in i2c_transfer()
205 		ctl = readw(&twi->control) & ~TWI_ENA;  in i2c_transfer()
206 		writew(ctl, &twi->control);  in i2c_transfer()
207 		ctl = readw(&twi->control) | TWI_ENA;  in i2c_transfer()
208 		writew(ctl, &twi->control);  in i2c_transfer()
217 	u16 clkdiv = I2C_SPEED_TO_DUTY(speed);  in adi_i2c_setspeed()  local
220 	if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)  in adi_i2c_setspeed()
221 		return -1;  in adi_i2c_setspeed()
222 	clkdiv = (clkdiv << 8) | (clkdiv & 0xff);  in adi_i2c_setspeed()
223 	writew(clkdiv, &twi->clkdiv);  in adi_i2c_setspeed()
226 	writew(speed > 100000 ? FAST : 0, &twi->master_ctl);  in adi_i2c_setspeed()
237 	writew(prescale, &twi->control);  in adi_i2c_init()
243 	writew(TWI_ENA | prescale, &twi->control);  in adi_i2c_init()
267 	switch (adap->hwadapnr) {  in i2c_get_base()
280 		printf("wrong hwadapnr: %d\n", adap->hwadapnr);  in i2c_get_base()