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authorLubomir Rintel <lkundrak@v3.sk>2020-12-09 17:45:14 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-12-09 17:47:39 -0800
commit3d82a4d736a662e352027686b8a373bf3e70820e (patch)
treeed33ed79b5ef1de4b56f2f95b3d9b8b9350a9165
parentb2cc3bfef6aa9a0d66034b48e95cf24f6a5b0e35 (diff)
Input: add driver for power button on Dell Wyse 3020
This adds support for the power button attached to the Embedded Controller on a Dell Wyse 3020 "Ariel" board. The Embedded Controller's SPI interface is actually capable sending and receiving the PS/2 keyboard and mouse protocol data, which looks like a good fit for a serio driver. Howerver, I don't know of any machines where this is actually used. My board only has a single power button and no way to connect an actual keyboard or a mouse. Using the atkbd driver with serio would be an overkill and would be inconvenient for the userspace. Therefore this driver registers an input device that is only capable of reporting the power button presses and releases. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Link: https://lore.kernel.org/r/20201201083533.1724287-3-lkundrak@v3.sk Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
-rw-r--r--drivers/input/misc/Kconfig11
-rw-r--r--drivers/input/misc/Makefile1
-rw-r--r--drivers/input/misc/ariel-pwrbutton.c169
3 files changed, 181 insertions, 0 deletions
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 362e8a01980c..e7bb572e1518 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -73,6 +73,17 @@ config INPUT_AD714X_SPI
To compile this driver as a module, choose M here: the
module will be called ad714x-spi.
+config INPUT_ARIEL_PWRBUTTON
+ tristate "Dell Wyse 3020 Power Button Driver"
+ depends on SPI
+ depends on MACH_MMP3_DT || COMPILE_TEST
+ help
+ Say Y to enable support for reporting power button status on
+ on Dell Wyse 3020 ("Ariel") thin client.
+
+ To compile this driver as a module, choose M here: the module
+ will be called ariel-pwrbutton.
+
config INPUT_ARIZONA_HAPTICS
tristate "Arizona haptics support"
depends on MFD_ARIZONA && SND_SOC
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index a48e5f2d859d..062cea9f181c 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_INPUT_ADXL34X) += adxl34x.o
obj-$(CONFIG_INPUT_ADXL34X_I2C) += adxl34x-i2c.o
obj-$(CONFIG_INPUT_ADXL34X_SPI) += adxl34x-spi.o
obj-$(CONFIG_INPUT_APANEL) += apanel.o
+obj-$(CONFIG_INPUT_ARIEL_PWRBUTTON) += ariel-pwrbutton.o
obj-$(CONFIG_INPUT_ARIZONA_HAPTICS) += arizona-haptics.o
obj-$(CONFIG_INPUT_ATI_REMOTE2) += ati_remote2.o
obj-$(CONFIG_INPUT_ATLAS_BTNS) += atlas_btns.o
diff --git a/drivers/input/misc/ariel-pwrbutton.c b/drivers/input/misc/ariel-pwrbutton.c
new file mode 100644
index 000000000000..eda86ab552b9
--- /dev/null
+++ b/drivers/input/misc/ariel-pwrbutton.c
@@ -0,0 +1,169 @@
+// 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_id_table[] = {
+ { "wyse-ariel-ec-input", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ariel_pwrbutton_id_table);
+
+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,
+};
+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");