drivers/input/adc_key.c

4  * SPDX-License-Identifier:     GPL-2.0+
14 	int t, down_threshold = -1, up_threshold;  in adc_key_ofdata_to_platdata()
21 		return -ENXIO;  in adc_key_ofdata_to_platdata()
23 	uc_key->type = ADC_KEY;  in adc_key_ofdata_to_platdata()
24 	uc_key->name = dev_read_string(dev, "label");  in adc_key_ofdata_to_platdata()
26 				 "io-channels", chn, ARRAY_SIZE(chn));  in adc_key_ofdata_to_platdata()
28 		printf("%s: read 'io-channels' failed, ret=%d\n",  in adc_key_ofdata_to_platdata()
29 		       uc_key->name, ret);  in adc_key_ofdata_to_platdata()
30 		return -EINVAL;  in adc_key_ofdata_to_platdata()
34 				    "keyup-threshold-microvolt", -ENODATA);  in adc_key_ofdata_to_platdata()
36 		return -ENODATA;  in adc_key_ofdata_to_platdata()
38 	uc_key->code = dev_read_u32_default(dev, "linux,code", -ENODATA);  in adc_key_ofdata_to_platdata()
39 	if (uc_key->code < 0)  in adc_key_ofdata_to_platdata()
40 		return -ENODATA;  in adc_key_ofdata_to_platdata()
42 	voltage = dev_read_u32_default(dev, "press-threshold-microvolt", -ENODATA);  in adc_key_ofdata_to_platdata()
44 		return -ENODATA;  in adc_key_ofdata_to_platdata()
46 	dev_for_each_subnode(node, dev->parent) {  in adc_key_ofdata_to_platdata()
47 		ret = ofnode_read_s32(node, "press-threshold-microvolt", &t);  in adc_key_ofdata_to_platdata()
60 		down_threshold = voltage - volt_margin;  in adc_key_ofdata_to_platdata()
64 	uc_key->in_volt = 1;  in adc_key_ofdata_to_platdata()
65 	uc_key->channel = chn[1];  in adc_key_ofdata_to_platdata()
66 	uc_key->center = voltage;  in adc_key_ofdata_to_platdata()
68 	 * Define the voltage range such that the button is only pressed  in adc_key_ofdata_to_platdata()
69 	 * when the voltage is closest to its own press-threshold-microvolt  in adc_key_ofdata_to_platdata()
72 		uc_key->min = 0;  in adc_key_ofdata_to_platdata()
74 		uc_key->min = down_threshold + (voltage - down_threshold) / 2;  in adc_key_ofdata_to_platdata()
76 	uc_key->max = voltage + (up_threshold - voltage) / 2;  in adc_key_ofdata_to_platdata()
87 /* Key Bus */
94 	{ .compatible = "adc-keys" },