@@ -666,4 +666,14 @@ config INPUT_IDEAPAD_SLIDEBAR
To compile this driver as a module, choose M here: the
module will be called ideapad_slidebar.
+config INPUT_SOC_BUTTON_ARRAY
+ tristate "Windows-compatible SoC Button Array"
+ depends on KEYBOARD_GPIO
+ help
+ Say Y here if you have a SoC-based tablet that originally
+ runs Windows 8.
+
+ To compile this driver as a module, choose M here: the
+ module will be called soc_button_array.
+
endif
@@ -53,6 +53,7 @@ obj-$(CONFIG_INPUT_RETU_PWRBUTTON) += retu-pwrbutton.o
obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER) += rotary_encoder.o
obj-$(CONFIG_INPUT_SGI_BTNS) += sgi_btns.o
obj-$(CONFIG_INPUT_SIRFSOC_ONKEY) += sirfsoc-onkey.o
+obj-$(CONFIG_INPUT_SOC_BUTTON_ARRAY) += soc_button_array.o
obj-$(CONFIG_INPUT_SPARCSPKR) += sparcspkr.o
obj-$(CONFIG_INPUT_TWL4030_PWRBUTTON) += twl4030-pwrbutton.o
obj-$(CONFIG_INPUT_TWL4030_VIBRA) += twl4030-vibra.o
new file mode 100644
@@ -0,0 +1,216 @@
+/*
+ * 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/input.h>
+#include <linux/platform_device.h>
+#include <linux/pnp.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);
+ 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 pnp_dev *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);
+ gpio_keys = (void *)(gpio_keys_pdata++);
+
+ for (info = button_info; info->name; info++) {
+ if (info->autorepeat != autorepeat)
+ continue;
+
+ gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
+ 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 void soc_button_remove(struct pnp_dev *pdev)
+{
+ struct soc_button_data *priv = pnp_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < BUTTON_TYPES; i++)
+ if (priv->children[i])
+ platform_device_unregister(priv->children[i]);
+}
+
+static int soc_button_pnp_probe(struct pnp_dev *pdev,
+ const struct pnp_device_id *id)
+{
+ const struct soc_button_info *button_info = (void *)id->driver_data;
+ struct soc_button_data *priv;
+ struct platform_device *pd;
+ int i;
+ int error;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ pnp_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;
+ }
+ }
+
+ priv->children[i] = pd;
+ }
+
+ if (!priv->children[0] && !priv->children[1])
+ return -ENODEV;
+
+ return 0;
+}
+
+static struct soc_button_info soc_button_INTCFD9[] = {
+ { "power", 0, EV_KEY, KEY_POWER, false, true },
+ { "home", 1, EV_KEY, KEY_HOME, 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 pnp_device_id soc_button_pnp_match[] = {
+ { .id = "INTCFD9", .driver_data = (long)soc_button_INTCFD9 },
+ { .id = "" }
+};
+MODULE_DEVICE_TABLE(pnp, soc_button_pnp_match);
+
+static struct pnp_driver soc_button_pnp_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = soc_button_pnp_match,
+ .probe = soc_button_pnp_probe,
+ .remove = soc_button_remove,
+};
+
+static int __init soc_button_init(void)
+{
+ return pnp_register_driver(&soc_button_pnp_driver);
+}
+
+static void __exit soc_button_exit(void)
+{
+ pnp_unregister_driver(&soc_button_pnp_driver);
+}
+
+module_init(soc_button_init);
+module_exit(soc_button_exit);
+
+MODULE_LICENSE("GPL");