67 static void i2c_wait_for_writes(struct qib_devdata *dd)  in i2c_wait_for_writes()  argument
74 	dd->f_gpio_mod(dd, 0, 0, 0);  in i2c_wait_for_writes()
89 static void scl_out(struct qib_devdata *dd, u8 bit)  in scl_out()  argument
95 	mask = 1UL << dd->gpio_scl_num;  in scl_out()
98 	dd->f_gpio_mod(dd, 0, bit ? 0 : mask, mask);  in scl_out()
110 			if (mask & dd->f_gpio_mod(dd, 0, 0, 0))  in scl_out()
115 			qib_dev_err(dd, "SCL interface stuck low > %d uSec\n",  in scl_out()
118 	i2c_wait_for_writes(dd);  in scl_out()
121 static void sda_out(struct qib_devdata *dd, u8 bit)  in sda_out()  argument
125 	mask = 1UL << dd->gpio_sda_num;  in sda_out()
128 	dd->f_gpio_mod(dd, 0, bit ? 0 : mask, mask);  in sda_out()
130 	i2c_wait_for_writes(dd);  in sda_out()
134 static u8 sda_in(struct qib_devdata *dd, int wait)  in sda_in()  argument
139 	bnum = dd->gpio_sda_num;  in sda_in()
142 	dd->f_gpio_mod(dd, 0, 0, mask);  in sda_in()
143 	read_val = dd->f_gpio_mod(dd, 0, 0, 0);  in sda_in()
145 		i2c_wait_for_writes(dd);  in sda_in()
153 static int i2c_ackrcv(struct qib_devdata *dd)  in i2c_ackrcv()  argument
159 	ack_received = sda_in(dd, 1);  in i2c_ackrcv()
160 	scl_out(dd, 1);  in i2c_ackrcv()
161 	ack_received = sda_in(dd, 1) == 0;  in i2c_ackrcv()
162 	scl_out(dd, 0);  in i2c_ackrcv()
166 static void stop_cmd(struct qib_devdata *dd);
174 static int rd_byte(struct qib_devdata *dd, int last)  in rd_byte()  argument
182 		scl_out(dd, 1);  in rd_byte()
183 		data |= sda_in(dd, 0);  in rd_byte()
184 		scl_out(dd, 0);  in rd_byte()
187 		scl_out(dd, 1);  in rd_byte()
188 		stop_cmd(dd);  in rd_byte()
190 		sda_out(dd, 0);  in rd_byte()
191 		scl_out(dd, 1);  in rd_byte()
192 		scl_out(dd, 0);  in rd_byte()
193 		sda_out(dd, 1);  in rd_byte()
205 static int wr_byte(struct qib_devdata *dd, u8 data)  in wr_byte()  argument
212 		sda_out(dd, bit);  in wr_byte()
213 		scl_out(dd, 1);  in wr_byte()
214 		scl_out(dd, 0);  in wr_byte()
216 	return (!i2c_ackrcv(dd)) ? 1 : 0;  in wr_byte()
223 static void start_seq(struct qib_devdata *dd)  in start_seq()  argument
225 	sda_out(dd, 1);  in start_seq()
226 	scl_out(dd, 1);  in start_seq()
227 	sda_out(dd, 0);  in start_seq()
229 	scl_out(dd, 0);  in start_seq()
238 static void stop_seq(struct qib_devdata *dd)  in stop_seq()  argument
240 	scl_out(dd, 0);  in stop_seq()
241 	sda_out(dd, 0);  in stop_seq()
242 	scl_out(dd, 1);  in stop_seq()
243 	sda_out(dd, 1);  in stop_seq()
252 static void stop_cmd(struct qib_devdata *dd)  in stop_cmd()  argument
254 	stop_seq(dd);  in stop_cmd()
263 int qib_twsi_reset(struct qib_devdata *dd)  in qib_twsi_reset()  argument
272 	mask = (1UL << dd->gpio_scl_num) | (1UL << dd->gpio_sda_num);  in qib_twsi_reset()
279 	dd->f_gpio_mod(dd, 0, 0, mask);  in qib_twsi_reset()
292 		scl_out(dd, 0);  in qib_twsi_reset()
293 		scl_out(dd, 1);  in qib_twsi_reset()
295 		was_high |= sda_in(dd, 0);  in qib_twsi_reset()
304 		pins = dd->f_gpio_mod(dd, 0, 0, 0);  in qib_twsi_reset()
306 			qib_dev_err(dd, "GPIO pins not at rest: %d\n",  in qib_twsi_reset()
310 		sda_out(dd, 0);  in qib_twsi_reset()
313 		sda_out(dd, 1);  in qib_twsi_reset()
327 static int qib_twsi_wr(struct qib_devdata *dd, int data, int flags)  in qib_twsi_wr()  argument
332 		start_seq(dd);  in qib_twsi_wr()
334 	ret = wr_byte(dd, data); /* Leaves SCL low (from i2c_ackrcv()) */  in qib_twsi_wr()
337 		stop_cmd(dd);  in qib_twsi_wr()
356 int qib_twsi_blk_rd(struct qib_devdata *dd, int dev, int addr,  in qib_twsi_blk_rd()  argument
367 		ret = qib_twsi_wr(dd, addr, QIB_TWSI_START);  in qib_twsi_blk_rd()
370 		ret = qib_twsi_wr(dd, dev | WRITE_CMD, QIB_TWSI_START);  in qib_twsi_blk_rd()
372 			stop_cmd(dd);  in qib_twsi_blk_rd()
383 		ret = qib_twsi_wr(dd, addr, 0);  in qib_twsi_blk_rd()
387 			qib_dev_err(dd,  in qib_twsi_blk_rd()
393 		ret = qib_twsi_wr(dd, dev | READ_CMD, QIB_TWSI_START);  in qib_twsi_blk_rd()
396 		stop_cmd(dd);  in qib_twsi_blk_rd()
413 		*bp++ = rd_byte(dd, !len);  in qib_twsi_blk_rd()
434 int qib_twsi_blk_wr(struct qib_devdata *dd, int dev, int addr,  in qib_twsi_blk_wr()  argument
444 			if (qib_twsi_wr(dd, (addr << 1) | WRITE_CMD,  in qib_twsi_blk_wr()
450 			if (qib_twsi_wr(dd, dev | WRITE_CMD, QIB_TWSI_START))  in qib_twsi_blk_wr()
452 			ret = qib_twsi_wr(dd, addr, 0);  in qib_twsi_blk_wr()
454 				qib_dev_err(dd,  in qib_twsi_blk_wr()
466 			if (qib_twsi_wr(dd, *bp++, 0))  in qib_twsi_blk_wr()
469 		stop_cmd(dd);  in qib_twsi_blk_wr()
483 		while (qib_twsi_wr(dd, dev | READ_CMD, QIB_TWSI_START)) {  in qib_twsi_blk_wr()
484 			stop_cmd(dd);  in qib_twsi_blk_wr()
489 		rd_byte(dd, 1);  in qib_twsi_blk_wr()
496 	stop_cmd(dd);  in qib_twsi_blk_wr()