drivers/extcon/extcon-intel-int3496.c

   1 /*
   2  * Intel INT3496 ACPI device extcon driver
   3  *
   4  * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
   5  *
   6  * Based on android x86 kernel code which is:
   7  *
   8  * Copyright (c) 2014, Intel Corporation.
   9  * Author: David Cohen <david.a.cohen@linux.intel.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include <linux/acpi.h>
  22 #include <linux/extcon-provider.h>
  23 #include <linux/gpio.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27
  28 #define INT3496_GPIO_USB_ID     0
  29 #define INT3496_GPIO_VBUS_EN    1
  30 #define INT3496_GPIO_USB_MUX    2
  31 #define DEBOUNCE_TIME           msecs_to_jiffies(50)
  32
  33 struct int3496_data {
  34         struct device *dev;
  35         struct extcon_dev *edev;
  36         struct delayed_work work;
  37         struct gpio_desc *gpio_usb_id;
  38         struct gpio_desc *gpio_vbus_en;
  39         struct gpio_desc *gpio_usb_mux;
  40         int usb_id_irq;
  41 };
  42
  43 static const unsigned int int3496_cable[] = {
  44         EXTCON_USB_HOST,
  45         EXTCON_NONE,
  46 };
  47
  48 static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
  49 static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
  50 static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
  51
  52 static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
  53         { "id-gpios", &id_gpios, 1 },
  54         { "vbus-gpios", &vbus_gpios, 1 },
  55         { "mux-gpios", &mux_gpios, 1 },
  56         { },
  57 };
  58
  59 static void int3496_do_usb_id(struct work_struct *work)
  60 {
  61         struct int3496_data *data =
  62                 container_of(work, struct int3496_data, work.work);
  63         int id = gpiod_get_value_cansleep(data->gpio_usb_id);
  64
  65         /* id == 1: PERIPHERAL, id == 0: HOST */
  66         dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
  67
  68         /*
  69          * Peripheral: set USB mux to peripheral and disable VBUS
  70          * Host: set USB mux to host and enable VBUS
  71          */
  72         if (!IS_ERR(data->gpio_usb_mux))
  73                 gpiod_direction_output(data->gpio_usb_mux, id);
  74
  75         if (!IS_ERR(data->gpio_vbus_en))
  76                 gpiod_direction_output(data->gpio_vbus_en, !id);
  77
  78         extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
  79 }
  80
  81 static irqreturn_t int3496_thread_isr(int irq, void *priv)
  82 {
  83         struct int3496_data *data = priv;
  84
  85         /* Let the pin settle before processing it */
  86         mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
  87
  88         return IRQ_HANDLED;
  89 }
  90
  91 static int int3496_probe(struct platform_device *pdev)
  92 {
  93         struct device *dev = &pdev->dev;
  94         struct int3496_data *data;
  95         int ret;
  96
  97         ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
  98         if (ret) {
  99                 dev_err(dev, "can't add GPIO ACPI mapping\n");
 100                 return ret;
 101         }
 102
 103         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 104         if (!data)
 105                 return -ENOMEM;
 106
 107         data->dev = dev;
 108         INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
 109
 110         data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
 111         if (IS_ERR(data->gpio_usb_id)) {
 112                 ret = PTR_ERR(data->gpio_usb_id);
 113                 dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
 114                 return ret;
 115         } else if (gpiod_get_direction(data->gpio_usb_id) != GPIOF_DIR_IN) {
 116                 dev_warn(dev, FW_BUG "USB ID GPIO not in input mode, fixing\n");
 117                 gpiod_direction_input(data->gpio_usb_id);
 118         }
 119
 120         data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
 121         if (data->usb_id_irq < 0) {
 122                 dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
 123                 return data->usb_id_irq;
 124         }
 125
 126         data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
 127         if (IS_ERR(data->gpio_vbus_en))
 128                 dev_info(dev, "can't request VBUS EN GPIO\n");
 129
 130         data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
 131         if (IS_ERR(data->gpio_usb_mux))
 132                 dev_info(dev, "can't request USB MUX GPIO\n");
 133
 134         /* register extcon device */
 135         data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
 136         if (IS_ERR(data->edev))
 137                 return -ENOMEM;
 138
 139         ret = devm_extcon_dev_register(dev, data->edev);
 140         if (ret < 0) {
 141                 dev_err(dev, "can't register extcon device: %d\n", ret);
 142                 return ret;
 143         }
 144
 145         ret = devm_request_threaded_irq(dev, data->usb_id_irq,
 146                                         NULL, int3496_thread_isr,
 147                                         IRQF_SHARED | IRQF_ONESHOT |
 148                                         IRQF_TRIGGER_RISING |
 149                                         IRQF_TRIGGER_FALLING,
 150                                         dev_name(dev), data);
 151         if (ret < 0) {
 152                 dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
 153                 return ret;
 154         }
 155
 156         /* queue initial processing of id-pin */
 157         queue_delayed_work(system_wq, &data->work, 0);
 158
 159         platform_set_drvdata(pdev, data);
 160
 161         return 0;
 162 }
 163
 164 static int int3496_remove(struct platform_device *pdev)
 165 {
 166         struct int3496_data *data = platform_get_drvdata(pdev);
 167
 168         devm_free_irq(&pdev->dev, data->usb_id_irq, data);
 169         cancel_delayed_work_sync(&data->work);
 170
 171         return 0;
 172 }
 173
 174 static const struct acpi_device_id int3496_acpi_match[] = {
 175         { "INT3496" },
 176         { }
 177 };
 178 MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
 179
 180 static struct platform_driver int3496_driver = {
 181         .driver = {
 182                 .name = "intel-int3496",
 183                 .acpi_match_table = int3496_acpi_match,
 184         },
 185         .probe = int3496_probe,
 186         .remove = int3496_remove,
 187 };
 188
 189 module_platform_driver(int3496_driver);
 190
 191 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 192 MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
 193 MODULE_LICENSE("GPL");