2  * Input driver for resistor ladder connected on ADC
14 #include <linux/input.h>
15 #include <linux/input-polldev.h>
38 	struct adc_keys_state *st = dev->private;  in adc_keys_poll()
39 	int i, value, ret;  in adc_keys_poll()  local
43 	ret = iio_read_channel_processed(st->channel, &value);  in adc_keys_poll()
46 		value = st->keyup_voltage;  in adc_keys_poll()
48 		for (i = 0; i < st->num_keys; i++) {  in adc_keys_poll()
49 			diff = abs(st->map[i].voltage - value);  in adc_keys_poll()
52 				keycode = st->map[i].keycode;  in adc_keys_poll()
57 	if (abs(st->keyup_voltage - value) < closest)  in adc_keys_poll()
60 	if (st->last_key && st->last_key != keycode)  in adc_keys_poll()
61 		input_report_key(dev->input, st->last_key, 0);  in adc_keys_poll()
64 		input_report_key(dev->input, keycode, 1);  in adc_keys_poll()
66 	input_sync(dev->input);  in adc_keys_poll()
67 	st->last_key = keycode;  in adc_keys_poll()
76 	st->num_keys = device_get_child_node_count(dev);  in adc_keys_load_keymap()
77 	if (st->num_keys == 0) {  in adc_keys_load_keymap()
79 		return -EINVAL;  in adc_keys_load_keymap()
82 	map = devm_kmalloc_array(dev, st->num_keys, sizeof(*map), GFP_KERNEL);  in adc_keys_load_keymap()
84 		return -ENOMEM;  in adc_keys_load_keymap()
88 		if (fwnode_property_read_u32(child, "press-threshold-microvolt",  in adc_keys_load_keymap()
92 			return -EINVAL;  in adc_keys_load_keymap()
100 			return -EINVAL;  in adc_keys_load_keymap()
106 	st->map = map;  in adc_keys_load_keymap()
112 	struct device *dev = &pdev->dev;  in adc_keys_probe()
115 	struct input_dev *input;  in adc_keys_probe()  local
117 	int i, value;  in adc_keys_probe()  local
122 		return -ENOMEM;  in adc_keys_probe()
124 	st->channel = devm_iio_channel_get(dev, "buttons");  in adc_keys_probe()
125 	if (IS_ERR(st->channel))  in adc_keys_probe()
126 		return PTR_ERR(st->channel);  in adc_keys_probe()
128 	if (!st->channel->indio_dev)  in adc_keys_probe()
129 		return -ENXIO;  in adc_keys_probe()
131 	error = iio_get_channel_type(st->channel, &type);  in adc_keys_probe()
137 		return -EINVAL;  in adc_keys_probe()
140 	if (device_property_read_u32(dev, "keyup-threshold-microvolt",  in adc_keys_probe()
141 				     &st->keyup_voltage)) {  in adc_keys_probe()
143 		return -EINVAL;  in adc_keys_probe()
145 	st->keyup_voltage /= 1000;  in adc_keys_probe()
153 		dev_err(dev, "failed to allocate input device\n");  in adc_keys_probe()
154 		return -ENOMEM;  in adc_keys_probe()
157 	if (!device_property_read_u32(dev, "poll-interval", &value))  in adc_keys_probe()
158 		poll_dev->poll_interval = value;  in adc_keys_probe()
160 	poll_dev->poll = adc_keys_poll;  in adc_keys_probe()
161 	poll_dev->private = st;  in adc_keys_probe()
163 	input = poll_dev->input;  in adc_keys_probe()
165 	input->name = pdev->name;  in adc_keys_probe()
166 	input->phys = "adc-keys/input0";  in adc_keys_probe()
168 	input->id.bustype = BUS_HOST;  in adc_keys_probe()
169 	input->id.vendor = 0x0001;  in adc_keys_probe()
170 	input->id.product = 0x0001;  in adc_keys_probe()
171 	input->id.version = 0x0100;  in adc_keys_probe()
173 	__set_bit(EV_KEY, input->evbit);  in adc_keys_probe()
174 	for (i = 0; i < st->num_keys; i++)  in adc_keys_probe()
175 		__set_bit(st->map[i].keycode, input->keybit);  in adc_keys_probe()
178 		__set_bit(EV_REP, input->evbit);  in adc_keys_probe()
182 		dev_err(dev, "Unable to register input device: %d\n", error);  in adc_keys_probe()
191 	{ .compatible = "adc-keys", },
206 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
207 MODULE_DESCRIPTION("Input driver for resistor ladder connected on ADC");