diff options
Diffstat (limited to 'drivers/input/misc/ariel-pwrbutton.c')
| -rw-r--r-- | drivers/input/misc/ariel-pwrbutton.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/input/misc/ariel-pwrbutton.c b/drivers/input/misc/ariel-pwrbutton.c new file mode 100644 index 000000000..cdc80715b --- /dev/null +++ b/drivers/input/misc/ariel-pwrbutton.c @@ -0,0 +1,170 @@ +// 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"); |