11  * See file:Documentation/input/devices/rotary-encoder.rst for more information
26 #define DRV_NAME "rotary-encoder"
56 static unsigned int rotary_encoder_get_state(struct rotary_encoder *encoder)  in rotary_encoder_get_state()  argument
61 	for (i = 0; i < encoder->gpios->ndescs; ++i) {  in rotary_encoder_get_state()
62 		int val = gpiod_get_value_cansleep(encoder->gpios->desc[i]);  in rotary_encoder_get_state()
65 		if (encoder->encoding == ROTENC_GRAY && ret & 1)  in rotary_encoder_get_state()
74 static void rotary_encoder_report_event(struct rotary_encoder *encoder)  in rotary_encoder_report_event()  argument
76 	if (encoder->relative_axis) {  in rotary_encoder_report_event()
77 		input_report_rel(encoder->input,  in rotary_encoder_report_event()
78 				 encoder->axis, encoder->dir);  in rotary_encoder_report_event()
80 		unsigned int pos = encoder->pos;  in rotary_encoder_report_event()
82 		if (encoder->dir < 0) {  in rotary_encoder_report_event()
84 			if (encoder->rollover)  in rotary_encoder_report_event()
85 				pos += encoder->steps;  in rotary_encoder_report_event()
90 			if (encoder->rollover || pos < encoder->steps)  in rotary_encoder_report_event()
94 		if (encoder->rollover)  in rotary_encoder_report_event()
95 			pos %= encoder->steps;  in rotary_encoder_report_event()
97 		encoder->pos = pos;  in rotary_encoder_report_event()
98 		input_report_abs(encoder->input, encoder->axis, encoder->pos);  in rotary_encoder_report_event()
101 	input_sync(encoder->input);  in rotary_encoder_report_event()
106 	struct rotary_encoder *encoder = dev_id;  in rotary_encoder_irq()  local
109 	mutex_lock(&encoder->access_mutex);  in rotary_encoder_irq()
111 	state = rotary_encoder_get_state(encoder);  in rotary_encoder_irq()
115 		if (encoder->armed) {  in rotary_encoder_irq()
116 			rotary_encoder_report_event(encoder);  in rotary_encoder_irq()
117 			encoder->armed = false;  in rotary_encoder_irq()
123 		if (encoder->armed)  in rotary_encoder_irq()
124 			encoder->dir = 2 - state;  in rotary_encoder_irq()
128 		encoder->armed = true;  in rotary_encoder_irq()
132 	mutex_unlock(&encoder->access_mutex);  in rotary_encoder_irq()
139 	struct rotary_encoder *encoder = dev_id;  in rotary_encoder_half_period_irq()  local
142 	mutex_lock(&encoder->access_mutex);  in rotary_encoder_half_period_irq()
144 	state = rotary_encoder_get_state(encoder);  in rotary_encoder_half_period_irq()
147 		encoder->dir = ((encoder->last_stable - state + 1) % 4) - 1;  in rotary_encoder_half_period_irq()
149 		if (state != encoder->last_stable) {  in rotary_encoder_half_period_irq()
150 			rotary_encoder_report_event(encoder);  in rotary_encoder_half_period_irq()
151 			encoder->last_stable = state;  in rotary_encoder_half_period_irq()
155 	mutex_unlock(&encoder->access_mutex);  in rotary_encoder_half_period_irq()
162 	struct rotary_encoder *encoder = dev_id;  in rotary_encoder_quarter_period_irq()  local
165 	mutex_lock(&encoder->access_mutex);  in rotary_encoder_quarter_period_irq()
167 	state = rotary_encoder_get_state(encoder);  in rotary_encoder_quarter_period_irq()
169 	if ((encoder->last_stable + 1) % 4 == state)  in rotary_encoder_quarter_period_irq()
170 		encoder->dir = 1;  in rotary_encoder_quarter_period_irq()
171 	else if (encoder->last_stable == (state + 1) % 4)  in rotary_encoder_quarter_period_irq()
172 		encoder->dir = -1;  in rotary_encoder_quarter_period_irq()
176 	rotary_encoder_report_event(encoder);  in rotary_encoder_quarter_period_irq()
179 	encoder->last_stable = state;  in rotary_encoder_quarter_period_irq()
180 	mutex_unlock(&encoder->access_mutex);  in rotary_encoder_quarter_period_irq()
188 	struct rotary_encoder *encoder;  in rotary_encoder_probe()  local
195 	encoder = devm_kzalloc(dev, sizeof(struct rotary_encoder), GFP_KERNEL);  in rotary_encoder_probe()
196 	if (!encoder)  in rotary_encoder_probe()
199 	mutex_init(&encoder->access_mutex);  in rotary_encoder_probe()
201 	device_property_read_u32(dev, "rotary-encoder,steps", &encoder->steps);  in rotary_encoder_probe()
203 	err = device_property_read_u32(dev, "rotary-encoder,steps-per-period",  in rotary_encoder_probe()
214 					"rotary-encoder,half-period") ? 2 : 1;  in rotary_encoder_probe()
217 	encoder->rollover =  in rotary_encoder_probe()
218 		device_property_read_bool(dev, "rotary-encoder,rollover");  in rotary_encoder_probe()
220 	if (!device_property_present(dev, "rotary-encoder,encoding") ||  in rotary_encoder_probe()
221 	    !device_property_match_string(dev, "rotary-encoder,encoding",  in rotary_encoder_probe()
224 		encoder->encoding = ROTENC_GRAY;  in rotary_encoder_probe()
225 	} else if (!device_property_match_string(dev, "rotary-encoder,encoding",  in rotary_encoder_probe()
228 		encoder->encoding = ROTENC_BINARY;  in rotary_encoder_probe()
234 	device_property_read_u32(dev, "linux,axis", &encoder->axis);  in rotary_encoder_probe()
235 	encoder->relative_axis =  in rotary_encoder_probe()
236 		device_property_read_bool(dev, "rotary-encoder,relative-axis");  in rotary_encoder_probe()
238 	encoder->gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN);  in rotary_encoder_probe()
239 	if (IS_ERR(encoder->gpios))  in rotary_encoder_probe()
240 		return dev_err_probe(dev, PTR_ERR(encoder->gpios), "unable to get gpios\n");  in rotary_encoder_probe()
241 	if (encoder->gpios->ndescs < 2) {  in rotary_encoder_probe()
250 	encoder->input = input;  in rotary_encoder_probe()
255 	if (encoder->relative_axis)  in rotary_encoder_probe()
256 		input_set_capability(input, EV_REL, encoder->axis);  in rotary_encoder_probe()
259 				     encoder->axis, 0, encoder->steps, 0, 1);  in rotary_encoder_probe()
261 	switch (steps_per_period >> (encoder->gpios->ndescs - 2)) {  in rotary_encoder_probe()
264 		encoder->last_stable = rotary_encoder_get_state(encoder);  in rotary_encoder_probe()
268 		encoder->last_stable = rotary_encoder_get_state(encoder);  in rotary_encoder_probe()
279 	encoder->irq =  in rotary_encoder_probe()
281 			     encoder->gpios->ndescs, sizeof(*encoder->irq),  in rotary_encoder_probe()
283 	if (!encoder->irq)  in rotary_encoder_probe()
286 	for (i = 0; i < encoder->gpios->ndescs; ++i) {  in rotary_encoder_probe()
287 		encoder->irq[i] = gpiod_to_irq(encoder->gpios->desc[i]);  in rotary_encoder_probe()
289 		err = devm_request_threaded_irq(dev, encoder->irq[i],  in rotary_encoder_probe()
293 				DRV_NAME, encoder);  in rotary_encoder_probe()
296 				encoder->irq[i], i);  in rotary_encoder_probe()
310 	platform_set_drvdata(pdev, encoder);  in rotary_encoder_probe()
317 	struct rotary_encoder *encoder = dev_get_drvdata(dev);  in rotary_encoder_suspend()  local
321 		for (i = 0; i < encoder->gpios->ndescs; ++i)  in rotary_encoder_suspend()
322 			enable_irq_wake(encoder->irq[i]);  in rotary_encoder_suspend()
330 	struct rotary_encoder *encoder = dev_get_drvdata(dev);  in rotary_encoder_resume()  local
334 		for (i = 0; i < encoder->gpios->ndescs; ++i)  in rotary_encoder_resume()
335 			disable_irq_wake(encoder->irq[i]);  in rotary_encoder_resume()
346 	{ .compatible = "rotary-encoder", },
363 MODULE_DESCRIPTION("GPIO rotary encoder driver");