+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Supports for the button array on the Surface tablets.
- *
- * (C) Copyright 2016 Red Hat, Inc
- *
- * Based on soc_button_array.c:
- *
- * {C} Copyright 2014 Intel Corporation
- */
-
-#include <linux/module.h>
-#include <linux/input.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/i2c.h>
-#include <linux/slab.h>
-#include <linux/acpi.h>
-#include <linux/gpio/consumer.h>
-#include <linux/gpio_keys.h>
-#include <linux/gpio.h>
-#include <linux/platform_device.h>
-
-
-#define SURFACE_BUTTON_OBJ_NAME "TEV2"
-#define MAX_NBUTTONS 4
-
-/*
- * Some of the buttons like volume up/down are auto repeat, while others
- * are not. To support both, we register two platform devices, and put
- * buttons into them based on whether the key should be auto repeat.
- */
-#define BUTTON_TYPES 2
-
-/*
- * Power button, Home button, Volume buttons support is supposed to
- * be covered by drivers/input/misc/soc_button_array.c, which is implemented
- * according to "Windows ACPI Design Guide for SoC Platforms".
- * However surface 3 seems not to obey the specs, instead it uses
- * device TEV2(MSHW0028) for declaring the GPIOs. The gpios are also slightly
- * different in which the Home button is active high.
- * Compared to surfacepro3_button.c which also handles MSHW0028, the Surface 3
- * is a reduce platform and thus uses GPIOs, not ACPI events.
- * We choose an I2C driver here because we need to access the resources
- * declared under the device node, while surfacepro3_button.c only needs
- * the ACPI companion node.
- */
-static const struct acpi_device_id surface3_acpi_match[] = {
- { "MSHW0028", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(acpi, surface3_acpi_match);
-
-struct surface3_button_info {
- const char *name;
- int acpi_index;
- unsigned int event_type;
- unsigned int event_code;
- bool autorepeat;
- bool wakeup;
- bool active_low;
-};
-
-struct surface3_button_data {
- struct platform_device *children[BUTTON_TYPES];
-};
-
-/*
- * Get the Nth GPIO number from the ACPI object.
- */
-static int surface3_button_lookup_gpio(struct device *dev, int acpi_index)
-{
- struct gpio_desc *desc;
- int gpio;
-
- desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
- if (IS_ERR(desc))
- return PTR_ERR(desc);
-
- gpio = desc_to_gpio(desc);
-
- gpiod_put(desc);
-
- return gpio;
-}
-
-static struct platform_device *
-surface3_button_device_create(struct i2c_client *client,
- const struct surface3_button_info *button_info,
- bool autorepeat)
-{
- const struct surface3_button_info *info;
- struct platform_device *pd;
- struct gpio_keys_button *gpio_keys;
- struct gpio_keys_platform_data *gpio_keys_pdata;
- int n_buttons = 0;
- int gpio;
- int error;
-
- gpio_keys_pdata = devm_kzalloc(&client->dev,
- sizeof(*gpio_keys_pdata) +
- sizeof(*gpio_keys) * MAX_NBUTTONS,
- GFP_KERNEL);
- if (!gpio_keys_pdata)
- return ERR_PTR(-ENOMEM);
-
- gpio_keys = (void *)(gpio_keys_pdata + 1);
-
- for (info = button_info; info->name; info++) {
- if (info->autorepeat != autorepeat)
- continue;
-
- gpio = surface3_button_lookup_gpio(&client->dev,
- info->acpi_index);
- if (!gpio_is_valid(gpio))
- continue;
-
- gpio_keys[n_buttons].type = info->event_type;
- gpio_keys[n_buttons].code = info->event_code;
- gpio_keys[n_buttons].gpio = gpio;
- gpio_keys[n_buttons].active_low = info->active_low;
- gpio_keys[n_buttons].desc = info->name;
- gpio_keys[n_buttons].wakeup = info->wakeup;
- n_buttons++;
- }
-
- if (n_buttons == 0) {
- error = -ENODEV;
- goto err_free_mem;
- }
-
- gpio_keys_pdata->buttons = gpio_keys;
- gpio_keys_pdata->nbuttons = n_buttons;
- gpio_keys_pdata->rep = autorepeat;
-
- pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
- if (!pd) {
- error = -ENOMEM;
- goto err_free_mem;
- }
-
- error = platform_device_add_data(pd, gpio_keys_pdata,
- sizeof(*gpio_keys_pdata));
- if (error)
- goto err_free_pdev;
-
- error = platform_device_add(pd);
- if (error)
- goto err_free_pdev;
-
- return pd;
-
-err_free_pdev:
- platform_device_put(pd);
-err_free_mem:
- devm_kfree(&client->dev, gpio_keys_pdata);
- return ERR_PTR(error);
-}
-
-static int surface3_button_remove(struct i2c_client *client)
-{
- struct surface3_button_data *priv = i2c_get_clientdata(client);
-
- int i;
-
- for (i = 0; i < BUTTON_TYPES; i++)
- if (priv->children[i])
- platform_device_unregister(priv->children[i]);
-
- return 0;
-}
-
-static struct surface3_button_info surface3_button_surface3[] = {
- { "power", 0, EV_KEY, KEY_POWER, false, true, true },
- { "home", 1, EV_KEY, KEY_LEFTMETA, false, true, false },
- { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false, true },
- { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false, true },
- { }
-};
-
-static int surface3_button_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
-{
- struct device *dev = &client->dev;
- struct surface3_button_data *priv;
- struct platform_device *pd;
- int i;
- int error;
-
- if (strncmp(acpi_device_bid(ACPI_COMPANION(&client->dev)),
- SURFACE_BUTTON_OBJ_NAME,
- strlen(SURFACE_BUTTON_OBJ_NAME)))
- return -ENODEV;
-
- error = gpiod_count(dev, NULL);
- if (error < 0) {
- dev_dbg(dev, "no GPIO attached, ignoring...\n");
- return error;
- }
-
- priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
-
- i2c_set_clientdata(client, priv);
-
- for (i = 0; i < BUTTON_TYPES; i++) {
- pd = surface3_button_device_create(client,
- surface3_button_surface3,
- i == 0);
- if (IS_ERR(pd)) {
- error = PTR_ERR(pd);
- if (error != -ENODEV) {
- surface3_button_remove(client);
- return error;
- }
- continue;
- }
-
- priv->children[i] = pd;
- }
-
- if (!priv->children[0] && !priv->children[1])
- return -ENODEV;
-
- return 0;
-}
-
-static const struct i2c_device_id surface3_id[] = {
- { }
-};
-MODULE_DEVICE_TABLE(i2c, surface3_id);
-
-static struct i2c_driver surface3_driver = {
- .probe = surface3_button_probe,
- .remove = surface3_button_remove,
- .id_table = surface3_id,
- .driver = {
- .name = "surface3",
- .acpi_match_table = ACPI_PTR(surface3_acpi_match),
- },
-};
-module_i2c_driver(surface3_driver);
-
-MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
-MODULE_DESCRIPTION("surface3 button array driver");
-MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff