/*
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* (C) Copyright 2017 Rockchip Electronics Co., Ltd
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <dm.h>
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#include <key.h>
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static int adc_key_ofdata_to_platdata(struct udevice *dev)
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{
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struct dm_key_uclass_platdata *uc_key;
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int t, down_threshold = -1, up_threshold;
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int ret, num = 0, volt_margin = 150000; /* will be div 2 */
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u32 voltage, chn[2];
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ofnode node;
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uc_key = dev_get_uclass_platdata(dev);
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if (!uc_key)
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return -ENXIO;
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uc_key->type = ADC_KEY;
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uc_key->name = dev_read_string(dev, "label");
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ret = dev_read_u32_array(dev_get_parent(dev),
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"io-channels", chn, ARRAY_SIZE(chn));
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if (ret) {
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printf("%s: read 'io-channels' failed, ret=%d\n",
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uc_key->name, ret);
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return -EINVAL;
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}
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up_threshold = dev_read_u32_default(dev_get_parent(dev),
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"keyup-threshold-microvolt", -ENODATA);
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if (up_threshold < 0)
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return -ENODATA;
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uc_key->code = dev_read_u32_default(dev, "linux,code", -ENODATA);
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if (uc_key->code < 0)
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return -ENODATA;
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voltage = dev_read_u32_default(dev, "press-threshold-microvolt", -ENODATA);
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if (voltage < 0)
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return -ENODATA;
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dev_for_each_subnode(node, dev->parent) {
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ret = ofnode_read_s32(node, "press-threshold-microvolt", &t);
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if (ret)
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return ret;
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if (t > voltage && t < up_threshold)
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up_threshold = t;
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else if (t < voltage && t > down_threshold)
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down_threshold = t;
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num++;
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}
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/* although one node only, it doesn't mean only one key on hardware */
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if (num == 1) {
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down_threshold = voltage - volt_margin;
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up_threshold = voltage + volt_margin;
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}
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uc_key->in_volt = 1;
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uc_key->channel = chn[1];
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uc_key->center = voltage;
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/*
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* Define the voltage range such that the button is only pressed
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* when the voltage is closest to its own press-threshold-microvolt
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*/
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if (down_threshold < 0)
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uc_key->min = 0;
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else
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uc_key->min = down_threshold + (voltage - down_threshold) / 2;
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uc_key->max = voltage + (up_threshold - voltage) / 2;
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return 0;
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}
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U_BOOT_DRIVER(adc_key) = {
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.name = "adc_key",
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.id = UCLASS_KEY,
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.ofdata_to_platdata = adc_key_ofdata_to_platdata,
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};
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/* Key Bus */
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static int adc_key_bus_bind(struct udevice *dev)
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{
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return key_bind_children(dev, "adc_key");
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}
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static const struct udevice_id adc_key_bus_match[] = {
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{ .compatible = "adc-keys" },
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{ },
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};
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U_BOOT_DRIVER(adc_key_bus) = {
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.name = "adc_key_bus",
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.id = UCLASS_SIMPLE_BUS,
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.of_match = adc_key_bus_match,
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.bind = adc_key_bus_bind,
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};
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