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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | // SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0-or-later /* * Dell Wyse 3020 a.k.a. "Ariel" Power Button Driver * * Copyright (C) 2020 Lubomir Rintel */ #include <linux/device.h> #include <linux/gfp.h> #include <linux/input.h> #include <linux/interrupt.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/spi/spi.h> #define RESP_COUNTER(response) (response.header & 0x3) #define RESP_SIZE(response) ((response.header >> 2) & 0x3) #define RESP_TYPE(response) ((response.header >> 4) & 0xf) struct ec_input_response { u8 reserved; u8 header; u8 data[3]; } __packed; struct ariel_pwrbutton { struct spi_device *client; struct input_dev *input; u8 msg_counter; }; static int ec_input_read(struct ariel_pwrbutton *priv, struct ec_input_response *response) { u8 read_request[] = { 0x00, 0x5a, 0xa5, 0x00, 0x00 }; struct spi_device *spi = priv->client; struct spi_transfer t = { .tx_buf = read_request, .rx_buf = response, .len = sizeof(read_request), }; compiletime_assert(sizeof(read_request) == sizeof(*response), "SPI xfer request/response size mismatch"); return spi_sync_transfer(spi, &t, 1); } static irqreturn_t ec_input_interrupt(int irq, void *dev_id) { struct ariel_pwrbutton *priv = dev_id; struct spi_device *spi = priv->client; struct ec_input_response response; int error; int i; error = ec_input_read(priv, &response); if (error < 0) { dev_err(&spi->dev, "EC read failed: %d\n", error); goto out; } if (priv->msg_counter == RESP_COUNTER(response)) { dev_warn(&spi->dev, "No new data to read?\n"); goto out; } priv->msg_counter = RESP_COUNTER(response); if (RESP_TYPE(response) != 0x3 && RESP_TYPE(response) != 0xc) { dev_dbg(&spi->dev, "Ignoring message that's not kbd data\n"); goto out; } for (i = 0; i < RESP_SIZE(response); i++) { switch (response.data[i]) { case 0x74: input_report_key(priv->input, KEY_POWER, 1); input_sync(priv->input); break; case 0xf4: input_report_key(priv->input, KEY_POWER, 0); input_sync(priv->input); break; default: dev_dbg(&spi->dev, "Unknown scan code: %02x\n", response.data[i]); } } out: return IRQ_HANDLED; } static int ariel_pwrbutton_probe(struct spi_device *spi) { struct ec_input_response response; struct ariel_pwrbutton *priv; int error; if (!spi->irq) { dev_err(&spi->dev, "Missing IRQ.\n"); return -EINVAL; } priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->client = spi; spi_set_drvdata(spi, priv); priv->input = devm_input_allocate_device(&spi->dev); if (!priv->input) return -ENOMEM; priv->input->name = "Power Button"; priv->input->dev.parent = &spi->dev; input_set_capability(priv->input, EV_KEY, KEY_POWER); error = input_register_device(priv->input); if (error) { dev_err(&spi->dev, "error registering input device: %d\n", error); return error; } error = ec_input_read(priv, &response); if (error < 0) { dev_err(&spi->dev, "EC read failed: %d\n", error); return error; } priv->msg_counter = RESP_COUNTER(response); error = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, ec_input_interrupt, IRQF_ONESHOT, "Ariel EC Input", priv); if (error) { dev_err(&spi->dev, "Failed to request IRQ %d: %d\n", spi->irq, error); return error; } return 0; } static const struct of_device_id ariel_pwrbutton_of_match[] = { { .compatible = "dell,wyse-ariel-ec-input" }, { } }; MODULE_DEVICE_TABLE(of, ariel_pwrbutton_of_match); static const struct spi_device_id ariel_pwrbutton_spi_ids[] = { { .name = "wyse-ariel-ec-input" }, { } }; MODULE_DEVICE_TABLE(spi, ariel_pwrbutton_spi_ids); static struct spi_driver ariel_pwrbutton_driver = { .driver = { .name = "dell-wyse-ariel-ec-input", .of_match_table = ariel_pwrbutton_of_match, }, .probe = ariel_pwrbutton_probe, .id_table = ariel_pwrbutton_spi_ids, }; module_spi_driver(ariel_pwrbutton_driver); MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); MODULE_DESCRIPTION("Dell Wyse 3020 Power Button Input Driver"); MODULE_LICENSE("Dual BSD/GPL"); |