platform/surface: Remove Surface 3 Button driver

The Surface 3 buttons are now handled by the generic soc_button_array
driver. As part of adding support to soc_button_array the ACPI code
now instantiates a platform_device rather then an i2c_client so there
no longer is an i2c_client for this driver to bind to.

Signed-off-by: Hans de Goede <[e-mail]>
Reviewed-by: Maximilian Luz <[e-mail]
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/platform/surface/Kconfig

···
 	  To compile this driver as a module, choose M here: the module will
 	  be called surface3-wmi.
 
-config SURFACE_3_BUTTON
-	tristate "Power/home/volume buttons driver for Microsoft Surface 3 tablet"
-	depends on ACPI
-	depends on KEYBOARD_GPIO && I2C
-	help
-	  This driver handles the power/home/volume buttons on the Microsoft Surface 3 tablet.
-
 config SURFACE_3_POWER_OPREGION
 	tristate "Surface 3 battery platform operation region support"
 	depends on ACPI

drivers/platform/surface/Makefile

···
 #
 
 obj-$(CONFIG_SURFACE3_WMI)		+= surface3-wmi.o
-obj-$(CONFIG_SURFACE_3_BUTTON)		+= surface3_button.o
 obj-$(CONFIG_SURFACE_3_POWER_OPREGION)	+= surface3_power.o
 obj-$(CONFIG_SURFACE_ACPI_NOTIFY)	+= surface_acpi_notify.o
 obj-$(CONFIG_SURFACE_AGGREGATOR)	+= aggregator/

drivers/platform/surface/surface3_button.c

···
-// 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 <[e-mail]>");
-MODULE_DESCRIPTION("surface3 button array driver");
-MODULE_LICENSE("GPL v2");