Initial import

1 files changed, 222 insertions, 0 deletions

diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
new file mode 100644
index 000000000..e8e010a85
--- /dev/null
+++ b/drivers/input/misc/soc_button_array.c
@@ -0,0 +1,222 @@
+/*
+ * Supports for the button array on SoC tablets originally running
+ * Windows 8.
+ *
+ * (C) Copyright 2014 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio_keys.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+
+/*
+ * Definition of buttons on the tablet. The ACPI index of each button
+ * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
+ * Platforms"
+ */
+#define MAX_NBUTTONS	5
+
+struct soc_button_info {
+	const char *name;
+	int acpi_index;
+	unsigned int event_type;
+	unsigned int event_code;
+	bool autorepeat;
+	bool wakeup;
+};
+
+/*
+ * 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
+
+struct soc_button_data {
+	struct platform_device *children[BUTTON_TYPES];
+};
+
+/*
+ * Get the Nth GPIO number from the ACPI object.
+ */
+static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
+{
+	struct gpio_desc *desc;
+	int gpio;
+
+	desc = gpiod_get_index(dev, KBUILD_MODNAME, 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 *
+soc_button_device_create(struct platform_device *pdev,
+			 const struct soc_button_info *button_info,
+			 bool autorepeat)
+{
+	const struct soc_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(&pdev->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 = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
+		if (gpio < 0)
+			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 = 1;
+		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(&pdev->dev, gpio_keys_pdata);
+	return ERR_PTR(error);
+}
+
+static int soc_button_remove(struct platform_device *pdev)
+{
+	struct soc_button_data *priv = platform_get_drvdata(pdev);
+
+	int i;
+
+	for (i = 0; i < BUTTON_TYPES; i++)
+		if (priv->children[i])
+			platform_device_unregister(priv->children[i]);
+
+	return 0;
+}
+
+static int soc_button_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct acpi_device_id *id;
+	struct soc_button_info *button_info;
+	struct soc_button_data *priv;
+	struct platform_device *pd;
+	int i;
+	int error;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -ENODEV;
+
+	button_info = (struct soc_button_info *)id->driver_data;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	for (i = 0; i < BUTTON_TYPES; i++) {
+		pd = soc_button_device_create(pdev, button_info, i == 0);
+		if (IS_ERR(pd)) {
+			error = PTR_ERR(pd);
+			if (error != -ENODEV) {
+				soc_button_remove(pdev);
+				return error;
+			}
+			continue;
+		}
+
+		priv->children[i] = pd;
+	}
+
+	if (!priv->children[0] && !priv->children[1])
+		return -ENODEV;
+
+	return 0;
+}
+
+static struct soc_button_info soc_button_PNP0C40[] = {
+	{ "power", 0, EV_KEY, KEY_POWER, false, true },
+	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
+	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
+	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false },
+	{ "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false },
+	{ }
+};
+
+static const struct acpi_device_id soc_button_acpi_match[] = {
+	{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
+
+static struct platform_driver soc_button_driver = {
+	.probe          = soc_button_probe,
+	.remove		= soc_button_remove,
+	.driver		= {
+		.name = KBUILD_MODNAME,
+		.acpi_match_table = ACPI_PTR(soc_button_acpi_match),
+	},
+};
+module_platform_driver(soc_button_driver);
+
+MODULE_LICENSE("GPL");