i2c/algos/i2c-algo-bit.c

48 #define setsda(adap, val)	adap->setsda(adap->data, val)
49 #define setscl(adap, val)	adap->setscl(adap->data, val)
50 #define getsda(adap)		adap->getsda(adap->data)
51 #define getscl(adap)		adap->getscl(adap->data)
53 static inline void sdalo(struct i2c_algo_bit_data *adap)
55 	setsda(adap, 0);
56 	udelay((adap->udelay + 1) / 2);
59 static inline void sdahi(struct i2c_algo_bit_data *adap)
61 	setsda(adap, 1);
62 	udelay((adap->udelay + 1) / 2);
65 static inline void scllo(struct i2c_algo_bit_data *adap)
67 	setscl(adap, 0);
68 	udelay(adap->udelay / 2);
75 static int sclhi(struct i2c_algo_bit_data *adap)
79 	setscl(adap, 1);
82 	if (!adap->getscl)
86 	while (!getscl(adap)) {
92 		if (time_after(jiffies, start + adap->timeout)) {
96 			if (getscl(adap))
109 	udelay(adap->udelay);
115 static void i2c_start(struct i2c_algo_bit_data *adap)
118 	setsda(adap, 0);
119 	udelay(adap->udelay);
120 	scllo(adap);
123 static void i2c_repstart(struct i2c_algo_bit_data *adap)
126 	sdahi(adap);
127 	sclhi(adap);
128 	setsda(adap, 0);
129 	udelay(adap->udelay);
130 	scllo(adap);
134 static void i2c_stop(struct i2c_algo_bit_data *adap)
137 	sdalo(adap);
138 	sclhi(adap);
139 	setsda(adap, 1);
140 	udelay(adap->udelay);
157 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
162 		setsda(adap, sb);
163 		udelay((adap->udelay + 1) / 2);
164 		if (sclhi(adap) < 0) { /* timed out */
171 		 * if (sb && !getsda(adap)) -> ouch! Get out of here.
176 		scllo(adap);
178 	sdahi(adap);
179 	if (sclhi(adap) < 0) { /* timeout */
189 	ack = !adap->getsda || !getsda(adap);    /* ack: sda is pulled low -> success */
193 	scllo(adap);
205 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
208 	sdahi(adap);
210 		if (sclhi(adap) < 0) { /* timeout */
217 		if (getsda(adap))
219 		setscl(adap, 0);
220 		udelay(i == 7 ? adap->udelay / 2 : adap->udelay);
232 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
236 	if (adap->pre_xfer) {
237 		ret = adap->pre_xfer(i2c_adap);
242 	if (adap->getsda == NULL)
244 	if (adap->getscl == NULL)
247 	sda = adap->getsda ? getsda(adap) : 1;
248 	scl = adap->getscl ? getscl(adap) : 1;
254 	sdalo(adap);
255 	if (adap->getsda && getsda(adap)) {
259 	if (adap->getscl && !getscl(adap)) {
264 	sdahi(adap);
265 	if (adap->getsda && !getsda(adap)) {
269 	if (adap->getscl && !getscl(adap)) {
274 	scllo(adap);
275 	if (adap->getscl && getscl(adap)) {
279 	if (adap->getsda && !getsda(adap)) {
284 	sclhi(adap);
285 	if (adap->getscl && !getscl(adap)) {
289 	if (adap->getsda && !getsda(adap)) {
294 	if (adap->post_xfer)
295 		adap->post_xfer(i2c_adap);
300 	sdahi(adap);
301 	sclhi(adap);
303 	if (adap->post_xfer)
304 		adap->post_xfer(i2c_adap);
322 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
330 		i2c_stop(adap);
331 		udelay(adap->udelay);
334 		i2c_start(adap);
387 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
391 		setsda(adap, 0);
392 	udelay((adap->udelay + 1) / 2);
393 	if (sclhi(adap) < 0) {	/* timeout */
397 	scllo(adap);
408 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
410 	if (!adap->getsda)
470 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
498 			i2c_repstart(adap);
524 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
528 	if (adap->pre_xfer) {
529 		ret = adap->pre_xfer(i2c_adap);
535 	i2c_start(adap);
544 					i2c_stop(adap);
545 					i2c_start(adap);
549 					i2c_repstart(adap);
588 	i2c_stop(adap);
590 	if (adap->post_xfer)
591 		adap->post_xfer(i2c_adap);
604 	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
606 	if (!adap->can_do_atomic)
612 static u32 bit_func(struct i2c_adapter *adap)
635 static int __i2c_bit_add_bus(struct i2c_adapter *adap,
638 	struct i2c_algo_bit_data *bit_adap = adap->algo_data;
642 		ret = test_bus(adap);
648 	adap->algo = &i2c_bit_algo;
649 	adap->retries = 3;
651 		adap->quirks = &i2c_bit_quirk_no_clk_stretch;
658 	ret = add_adapter(adap);
663 		dev_warn(&adap->dev, "Not I2C compliant: can't read SDA\n");
666 		dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n");
669 		dev_warn(&adap->dev, "Bus may be unreliable\n");
674 int i2c_bit_add_bus(struct i2c_adapter *adap)
676 	return __i2c_bit_add_bus(adap, i2c_add_adapter);
680 int i2c_bit_add_numbered_bus(struct i2c_adapter *adap)
682 	return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter);