161cd4822SLejun Zhu /* 261cd4822SLejun Zhu * Supports for the button array on SoC tablets originally running 361cd4822SLejun Zhu * Windows 8. 461cd4822SLejun Zhu * 561cd4822SLejun Zhu * (C) Copyright 2014 Intel Corporation 661cd4822SLejun Zhu * 761cd4822SLejun Zhu * This program is free software; you can redistribute it and/or 861cd4822SLejun Zhu * modify it under the terms of the GNU General Public License 961cd4822SLejun Zhu * as published by the Free Software Foundation; version 2 1061cd4822SLejun Zhu * of the License. 1161cd4822SLejun Zhu */ 1261cd4822SLejun Zhu 1361cd4822SLejun Zhu #include <linux/module.h> 1461cd4822SLejun Zhu #include <linux/input.h> 1561cd4822SLejun Zhu #include <linux/init.h> 1661cd4822SLejun Zhu #include <linux/kernel.h> 1761cd4822SLejun Zhu #include <linux/acpi.h> 1861cd4822SLejun Zhu #include <linux/gpio/consumer.h> 1961cd4822SLejun Zhu #include <linux/gpio_keys.h> 20be8e7a7eSBenjamin Tissoires #include <linux/gpio.h> 2161cd4822SLejun Zhu #include <linux/platform_device.h> 2261cd4822SLejun Zhu 2361cd4822SLejun Zhu struct soc_button_info { 2461cd4822SLejun Zhu const char *name; 2561cd4822SLejun Zhu int acpi_index; 2661cd4822SLejun Zhu unsigned int event_type; 2761cd4822SLejun Zhu unsigned int event_code; 2861cd4822SLejun Zhu bool autorepeat; 2961cd4822SLejun Zhu bool wakeup; 3061cd4822SLejun Zhu }; 3161cd4822SLejun Zhu 3261cd4822SLejun Zhu /* 3361cd4822SLejun Zhu * Some of the buttons like volume up/down are auto repeat, while others 3461cd4822SLejun Zhu * are not. To support both, we register two platform devices, and put 3561cd4822SLejun Zhu * buttons into them based on whether the key should be auto repeat. 3661cd4822SLejun Zhu */ 3761cd4822SLejun Zhu #define BUTTON_TYPES 2 3861cd4822SLejun Zhu 3961cd4822SLejun Zhu struct soc_button_data { 4061cd4822SLejun Zhu struct platform_device *children[BUTTON_TYPES]; 4161cd4822SLejun Zhu }; 4261cd4822SLejun Zhu 4361cd4822SLejun Zhu /* 4461cd4822SLejun Zhu * Get the Nth GPIO number from the ACPI object. 4561cd4822SLejun Zhu */ 4661cd4822SLejun Zhu static int soc_button_lookup_gpio(struct device *dev, int acpi_index) 4761cd4822SLejun Zhu { 4861cd4822SLejun Zhu struct gpio_desc *desc; 4961cd4822SLejun Zhu int gpio; 5061cd4822SLejun Zhu 51a01cd170SHans de Goede desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS); 5261cd4822SLejun Zhu if (IS_ERR(desc)) 5361cd4822SLejun Zhu return PTR_ERR(desc); 5461cd4822SLejun Zhu 5561cd4822SLejun Zhu gpio = desc_to_gpio(desc); 5661cd4822SLejun Zhu 5761cd4822SLejun Zhu gpiod_put(desc); 5861cd4822SLejun Zhu 5961cd4822SLejun Zhu return gpio; 6061cd4822SLejun Zhu } 6161cd4822SLejun Zhu 6261cd4822SLejun Zhu static struct platform_device * 63042e1c79SJin Yao soc_button_device_create(struct platform_device *pdev, 6461cd4822SLejun Zhu const struct soc_button_info *button_info, 6561cd4822SLejun Zhu bool autorepeat) 6661cd4822SLejun Zhu { 6761cd4822SLejun Zhu const struct soc_button_info *info; 6861cd4822SLejun Zhu struct platform_device *pd; 6961cd4822SLejun Zhu struct gpio_keys_button *gpio_keys; 7061cd4822SLejun Zhu struct gpio_keys_platform_data *gpio_keys_pdata; 7161cd4822SLejun Zhu int n_buttons = 0; 7261cd4822SLejun Zhu int gpio; 7361cd4822SLejun Zhu int error; 7461cd4822SLejun Zhu 757283b47dSHans de Goede for (info = button_info; info->name; info++) 767283b47dSHans de Goede if (info->autorepeat == autorepeat) 777283b47dSHans de Goede n_buttons++; 787283b47dSHans de Goede 7961cd4822SLejun Zhu gpio_keys_pdata = devm_kzalloc(&pdev->dev, 8061cd4822SLejun Zhu sizeof(*gpio_keys_pdata) + 817283b47dSHans de Goede sizeof(*gpio_keys) * n_buttons, 8261cd4822SLejun Zhu GFP_KERNEL); 8391cf07cdSPramod Gurav if (!gpio_keys_pdata) 8491cf07cdSPramod Gurav return ERR_PTR(-ENOMEM); 8591cf07cdSPramod Gurav 8661cd4822SLejun Zhu gpio_keys = (void *)(gpio_keys_pdata + 1); 877283b47dSHans de Goede n_buttons = 0; 8861cd4822SLejun Zhu 8961cd4822SLejun Zhu for (info = button_info; info->name; info++) { 9061cd4822SLejun Zhu if (info->autorepeat != autorepeat) 9161cd4822SLejun Zhu continue; 9261cd4822SLejun Zhu 9361cd4822SLejun Zhu gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index); 94be8e7a7eSBenjamin Tissoires if (!gpio_is_valid(gpio)) 9561cd4822SLejun Zhu continue; 9661cd4822SLejun Zhu 9761cd4822SLejun Zhu gpio_keys[n_buttons].type = info->event_type; 9861cd4822SLejun Zhu gpio_keys[n_buttons].code = info->event_code; 9961cd4822SLejun Zhu gpio_keys[n_buttons].gpio = gpio; 10061cd4822SLejun Zhu gpio_keys[n_buttons].active_low = 1; 10161cd4822SLejun Zhu gpio_keys[n_buttons].desc = info->name; 10261cd4822SLejun Zhu gpio_keys[n_buttons].wakeup = info->wakeup; 1035c4fa2a6SHans de Goede /* These devices often use cheap buttons, use 50 ms debounce */ 1045c4fa2a6SHans de Goede gpio_keys[n_buttons].debounce_interval = 50; 10561cd4822SLejun Zhu n_buttons++; 10661cd4822SLejun Zhu } 10761cd4822SLejun Zhu 10861cd4822SLejun Zhu if (n_buttons == 0) { 10961cd4822SLejun Zhu error = -ENODEV; 11061cd4822SLejun Zhu goto err_free_mem; 11161cd4822SLejun Zhu } 11261cd4822SLejun Zhu 11361cd4822SLejun Zhu gpio_keys_pdata->buttons = gpio_keys; 11461cd4822SLejun Zhu gpio_keys_pdata->nbuttons = n_buttons; 11561cd4822SLejun Zhu gpio_keys_pdata->rep = autorepeat; 11661cd4822SLejun Zhu 11761cd4822SLejun Zhu pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO); 11861cd4822SLejun Zhu if (!pd) { 11961cd4822SLejun Zhu error = -ENOMEM; 12061cd4822SLejun Zhu goto err_free_mem; 12161cd4822SLejun Zhu } 12261cd4822SLejun Zhu 12361cd4822SLejun Zhu error = platform_device_add_data(pd, gpio_keys_pdata, 12461cd4822SLejun Zhu sizeof(*gpio_keys_pdata)); 12561cd4822SLejun Zhu if (error) 12661cd4822SLejun Zhu goto err_free_pdev; 12761cd4822SLejun Zhu 12861cd4822SLejun Zhu error = platform_device_add(pd); 12961cd4822SLejun Zhu if (error) 13061cd4822SLejun Zhu goto err_free_pdev; 13161cd4822SLejun Zhu 13261cd4822SLejun Zhu return pd; 13361cd4822SLejun Zhu 13461cd4822SLejun Zhu err_free_pdev: 13561cd4822SLejun Zhu platform_device_put(pd); 13661cd4822SLejun Zhu err_free_mem: 13761cd4822SLejun Zhu devm_kfree(&pdev->dev, gpio_keys_pdata); 13861cd4822SLejun Zhu return ERR_PTR(error); 13961cd4822SLejun Zhu } 14061cd4822SLejun Zhu 141042e1c79SJin Yao static int soc_button_remove(struct platform_device *pdev) 14261cd4822SLejun Zhu { 143042e1c79SJin Yao struct soc_button_data *priv = platform_get_drvdata(pdev); 144042e1c79SJin Yao 14561cd4822SLejun Zhu int i; 14661cd4822SLejun Zhu 14761cd4822SLejun Zhu for (i = 0; i < BUTTON_TYPES; i++) 14861cd4822SLejun Zhu if (priv->children[i]) 14961cd4822SLejun Zhu platform_device_unregister(priv->children[i]); 150042e1c79SJin Yao 151042e1c79SJin Yao return 0; 15261cd4822SLejun Zhu } 15361cd4822SLejun Zhu 154042e1c79SJin Yao static int soc_button_probe(struct platform_device *pdev) 15561cd4822SLejun Zhu { 156042e1c79SJin Yao struct device *dev = &pdev->dev; 157042e1c79SJin Yao const struct acpi_device_id *id; 158042e1c79SJin Yao struct soc_button_info *button_info; 15961cd4822SLejun Zhu struct soc_button_data *priv; 16061cd4822SLejun Zhu struct platform_device *pd; 16161cd4822SLejun Zhu int i; 16261cd4822SLejun Zhu int error; 16361cd4822SLejun Zhu 164042e1c79SJin Yao id = acpi_match_device(dev->driver->acpi_match_table, dev); 165042e1c79SJin Yao if (!id) 166042e1c79SJin Yao return -ENODEV; 167042e1c79SJin Yao 168042e1c79SJin Yao button_info = (struct soc_button_info *)id->driver_data; 169042e1c79SJin Yao 170a01cd170SHans de Goede if (gpiod_count(dev, NULL) <= 0) { 171aa45590aSGuenter Roeck dev_dbg(dev, "no GPIO attached, ignoring...\n"); 1723d5a9437SBenjamin Tissoires return -ENODEV; 1733d5a9437SBenjamin Tissoires } 1743d5a9437SBenjamin Tissoires 175aa45590aSGuenter Roeck priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 17661cd4822SLejun Zhu if (!priv) 17761cd4822SLejun Zhu return -ENOMEM; 17861cd4822SLejun Zhu 179042e1c79SJin Yao platform_set_drvdata(pdev, priv); 18061cd4822SLejun Zhu 18161cd4822SLejun Zhu for (i = 0; i < BUTTON_TYPES; i++) { 18261cd4822SLejun Zhu pd = soc_button_device_create(pdev, button_info, i == 0); 18361cd4822SLejun Zhu if (IS_ERR(pd)) { 18461cd4822SLejun Zhu error = PTR_ERR(pd); 18561cd4822SLejun Zhu if (error != -ENODEV) { 18661cd4822SLejun Zhu soc_button_remove(pdev); 18761cd4822SLejun Zhu return error; 18861cd4822SLejun Zhu } 1897740fc52SLejun Zhu continue; 19061cd4822SLejun Zhu } 19161cd4822SLejun Zhu 19261cd4822SLejun Zhu priv->children[i] = pd; 19361cd4822SLejun Zhu } 19461cd4822SLejun Zhu 19561cd4822SLejun Zhu if (!priv->children[0] && !priv->children[1]) 19661cd4822SLejun Zhu return -ENODEV; 19761cd4822SLejun Zhu 19861cd4822SLejun Zhu return 0; 19961cd4822SLejun Zhu } 20061cd4822SLejun Zhu 2017283b47dSHans de Goede /* 2027283b47dSHans de Goede * Definition of buttons on the tablet. The ACPI index of each button 2037283b47dSHans de Goede * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC 2047283b47dSHans de Goede * Platforms" 2057283b47dSHans de Goede */ 20661cd4822SLejun Zhu static struct soc_button_info soc_button_PNP0C40[] = { 20761cd4822SLejun Zhu { "power", 0, EV_KEY, KEY_POWER, false, true }, 208791738beSBastien Nocera { "home", 1, EV_KEY, KEY_LEFTMETA, false, true }, 20961cd4822SLejun Zhu { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false }, 21061cd4822SLejun Zhu { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false }, 21161cd4822SLejun Zhu { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false }, 21261cd4822SLejun Zhu { } 21361cd4822SLejun Zhu }; 21461cd4822SLejun Zhu 215042e1c79SJin Yao static const struct acpi_device_id soc_button_acpi_match[] = { 216042e1c79SJin Yao { "PNP0C40", (unsigned long)soc_button_PNP0C40 }, 217042e1c79SJin Yao { } 21861cd4822SLejun Zhu }; 21961cd4822SLejun Zhu 220042e1c79SJin Yao MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); 221042e1c79SJin Yao 222042e1c79SJin Yao static struct platform_driver soc_button_driver = { 223042e1c79SJin Yao .probe = soc_button_probe, 22461cd4822SLejun Zhu .remove = soc_button_remove, 225042e1c79SJin Yao .driver = { 226042e1c79SJin Yao .name = KBUILD_MODNAME, 227042e1c79SJin Yao .acpi_match_table = ACPI_PTR(soc_button_acpi_match), 228042e1c79SJin Yao }, 22961cd4822SLejun Zhu }; 230042e1c79SJin Yao module_platform_driver(soc_button_driver); 23161cd4822SLejun Zhu 23261cd4822SLejun Zhu MODULE_LICENSE("GPL"); 233