// 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/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");