1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * (C) Copyright 2017 Rockchip Electronics Co., Ltd
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <dm.h>
9*4882a593Smuzhiyun #include <key.h>
10*4882a593Smuzhiyun
adc_key_ofdata_to_platdata(struct udevice * dev)11*4882a593Smuzhiyun static int adc_key_ofdata_to_platdata(struct udevice *dev)
12*4882a593Smuzhiyun {
13*4882a593Smuzhiyun struct dm_key_uclass_platdata *uc_key;
14*4882a593Smuzhiyun int t, down_threshold = -1, up_threshold;
15*4882a593Smuzhiyun int ret, num = 0, volt_margin = 150000; /* will be div 2 */
16*4882a593Smuzhiyun u32 voltage, chn[2];
17*4882a593Smuzhiyun ofnode node;
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun uc_key = dev_get_uclass_platdata(dev);
20*4882a593Smuzhiyun if (!uc_key)
21*4882a593Smuzhiyun return -ENXIO;
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun uc_key->type = ADC_KEY;
24*4882a593Smuzhiyun uc_key->name = dev_read_string(dev, "label");
25*4882a593Smuzhiyun ret = dev_read_u32_array(dev_get_parent(dev),
26*4882a593Smuzhiyun "io-channels", chn, ARRAY_SIZE(chn));
27*4882a593Smuzhiyun if (ret) {
28*4882a593Smuzhiyun printf("%s: read 'io-channels' failed, ret=%d\n",
29*4882a593Smuzhiyun uc_key->name, ret);
30*4882a593Smuzhiyun return -EINVAL;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun up_threshold = dev_read_u32_default(dev_get_parent(dev),
34*4882a593Smuzhiyun "keyup-threshold-microvolt", -ENODATA);
35*4882a593Smuzhiyun if (up_threshold < 0)
36*4882a593Smuzhiyun return -ENODATA;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun uc_key->code = dev_read_u32_default(dev, "linux,code", -ENODATA);
39*4882a593Smuzhiyun if (uc_key->code < 0)
40*4882a593Smuzhiyun return -ENODATA;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun voltage = dev_read_u32_default(dev, "press-threshold-microvolt", -ENODATA);
43*4882a593Smuzhiyun if (voltage < 0)
44*4882a593Smuzhiyun return -ENODATA;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun dev_for_each_subnode(node, dev->parent) {
47*4882a593Smuzhiyun ret = ofnode_read_s32(node, "press-threshold-microvolt", &t);
48*4882a593Smuzhiyun if (ret)
49*4882a593Smuzhiyun return ret;
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun if (t > voltage && t < up_threshold)
52*4882a593Smuzhiyun up_threshold = t;
53*4882a593Smuzhiyun else if (t < voltage && t > down_threshold)
54*4882a593Smuzhiyun down_threshold = t;
55*4882a593Smuzhiyun num++;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun /* although one node only, it doesn't mean only one key on hardware */
59*4882a593Smuzhiyun if (num == 1) {
60*4882a593Smuzhiyun down_threshold = voltage - volt_margin;
61*4882a593Smuzhiyun up_threshold = voltage + volt_margin;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun uc_key->in_volt = 1;
65*4882a593Smuzhiyun uc_key->channel = chn[1];
66*4882a593Smuzhiyun uc_key->center = voltage;
67*4882a593Smuzhiyun /*
68*4882a593Smuzhiyun * Define the voltage range such that the button is only pressed
69*4882a593Smuzhiyun * when the voltage is closest to its own press-threshold-microvolt
70*4882a593Smuzhiyun */
71*4882a593Smuzhiyun if (down_threshold < 0)
72*4882a593Smuzhiyun uc_key->min = 0;
73*4882a593Smuzhiyun else
74*4882a593Smuzhiyun uc_key->min = down_threshold + (voltage - down_threshold) / 2;
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun uc_key->max = voltage + (up_threshold - voltage) / 2;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun return 0;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun U_BOOT_DRIVER(adc_key) = {
82*4882a593Smuzhiyun .name = "adc_key",
83*4882a593Smuzhiyun .id = UCLASS_KEY,
84*4882a593Smuzhiyun .ofdata_to_platdata = adc_key_ofdata_to_platdata,
85*4882a593Smuzhiyun };
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun /* Key Bus */
adc_key_bus_bind(struct udevice * dev)88*4882a593Smuzhiyun static int adc_key_bus_bind(struct udevice *dev)
89*4882a593Smuzhiyun {
90*4882a593Smuzhiyun return key_bind_children(dev, "adc_key");
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun static const struct udevice_id adc_key_bus_match[] = {
94*4882a593Smuzhiyun { .compatible = "adc-keys" },
95*4882a593Smuzhiyun { },
96*4882a593Smuzhiyun };
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun U_BOOT_DRIVER(adc_key_bus) = {
99*4882a593Smuzhiyun .name = "adc_key_bus",
100*4882a593Smuzhiyun .id = UCLASS_SIMPLE_BUS,
101*4882a593Smuzhiyun .of_match = adc_key_bus_match,
102*4882a593Smuzhiyun .bind = adc_key_bus_bind,
103*4882a593Smuzhiyun };
104