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         /*
  54          * Some platforms have a bug in ACPI GPIO description making IRQ
  55          * GPIO to be output only. Ask the GPIO core to ignore this limit.
  56          */
  57         { "id-gpios", &id_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
  58         { "vbus-gpios", &vbus_gpios, 1 },
  59         { "mux-gpios", &mux_gpios, 1 },
  60         { },
  61 };
  62
  63 static void int3496_do_usb_id(struct work_struct *work)
  64 {
  65         struct int3496_data *data =
  66                 container_of(work, struct int3496_data, work.work);
  67         int id = gpiod_get_value_cansleep(data->gpio_usb_id);
  68
  69         /* id == 1: PERIPHERAL, id == 0: HOST */
  70         dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
  71
  72         /*
  73          * Peripheral: set USB mux to peripheral and disable VBUS
  74          * Host: set USB mux to host and enable VBUS
  75          */
  76         if (!IS_ERR(data->gpio_usb_mux))
  77                 gpiod_direction_output(data->gpio_usb_mux, id);
  78
  79         if (!IS_ERR(data->gpio_vbus_en))
  80                 gpiod_direction_output(data->gpio_vbus_en, !id);
  81
  82         extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
  83 }
  84
  85 static irqreturn_t int3496_thread_isr(int irq, void *priv)
  86 {
  87         struct int3496_data *data = priv;
  88
  89         /* Let the pin settle before processing it */
  90         mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
  91
  92         return IRQ_HANDLED;
  93 }
  94
  95 static int int3496_probe(struct platform_device *pdev)
  96 {
  97         struct device *dev = &pdev->dev;
  98         struct int3496_data *data;
  99         int ret;
 100
 101         ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
 102         if (ret) {
 103                 dev_err(dev, "can't add GPIO ACPI mapping\n");
 104                 return ret;
 105         }
 106
 107         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 108         if (!data)
 109                 return -ENOMEM;
 110
 111         data->dev = dev;
 112         INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
 113
 114         data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
 115         if (IS_ERR(data->gpio_usb_id)) {
 116                 ret = PTR_ERR(data->gpio_usb_id);
 117                 dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
 118                 return ret;
 119         }
 120
 121         data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
 122         if (data->usb_id_irq < 0) {
 123                 dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
 124                 return data->usb_id_irq;
 125         }
 126
 127         data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
 128         if (IS_ERR(data->gpio_vbus_en))
 129                 dev_info(dev, "can't request VBUS EN GPIO\n");
 130
 131         data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
 132         if (IS_ERR(data->gpio_usb_mux))
 133                 dev_info(dev, "can't request USB MUX GPIO\n");
 134
 135         /* register extcon device */
 136         data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
 137         if (IS_ERR(data->edev))
 138                 return -ENOMEM;
 139
 140         ret = devm_extcon_dev_register(dev, data->edev);
 141         if (ret < 0) {
 142                 dev_err(dev, "can't register extcon device: %d\n", ret);
 143                 return ret;
 144         }
 145
 146         ret = devm_request_threaded_irq(dev, data->usb_id_irq,
 147                                         NULL, int3496_thread_isr,
 148                                         IRQF_SHARED | IRQF_ONESHOT |
 149                                         IRQF_TRIGGER_RISING |
 150                                         IRQF_TRIGGER_FALLING,
 151                                         dev_name(dev), data);
 152         if (ret < 0) {
 153                 dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
 154                 return ret;
 155         }
 156
 157         /* process id-pin so that we start with the right status */
 158         queue_delayed_work(system_wq, &data->work, 0);
 159         flush_delayed_work(&data->work);
 160
 161         platform_set_drvdata(pdev, data);
 162
 163         return 0;
 164 }
 165
 166 static int int3496_remove(struct platform_device *pdev)
 167 {
 168         struct int3496_data *data = platform_get_drvdata(pdev);
 169
 170         devm_free_irq(&pdev->dev, data->usb_id_irq, data);
 171         cancel_delayed_work_sync(&data->work);
 172
 173         return 0;
 174 }
 175
 176 static const struct acpi_device_id int3496_acpi_match[] = {
 177         { "INT3496" },
 178         { }
 179 };
 180 MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
 181
 182 static struct platform_driver int3496_driver = {
 183         .driver = {
 184                 .name = "intel-int3496",
 185                 .acpi_match_table = int3496_acpi_match,
 186         },
 187         .probe = int3496_probe,
 188         .remove = int3496_remove,
 189 };
 190
 191 module_platform_driver(int3496_driver);
 192
 193 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 194 MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
 195 MODULE_LICENSE("GPL");