linux/drivers/extcon/extcon-intel-int3496.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Intel INT3496 ACPI device extcon driver
   4 *
   5 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
   6 *
   7 * Based on android x86 kernel code which is:
   8 *
   9 * Copyright (c) 2014, Intel Corporation.
  10 * Author: David Cohen <david.a.cohen@linux.intel.com>
  11 */
  12
  13#include <linux/acpi.h>
  14#include <linux/extcon-provider.h>
  15#include <linux/gpio/consumer.h>
  16#include <linux/interrupt.h>
  17#include <linux/module.h>
  18#include <linux/platform_device.h>
  19
  20#define INT3496_GPIO_USB_ID     0
  21#define INT3496_GPIO_VBUS_EN    1
  22#define INT3496_GPIO_USB_MUX    2
  23#define DEBOUNCE_TIME           msecs_to_jiffies(50)
  24
  25struct int3496_data {
  26        struct device *dev;
  27        struct extcon_dev *edev;
  28        struct delayed_work work;
  29        struct gpio_desc *gpio_usb_id;
  30        struct gpio_desc *gpio_vbus_en;
  31        struct gpio_desc *gpio_usb_mux;
  32        int usb_id_irq;
  33};
  34
  35static const unsigned int int3496_cable[] = {
  36        EXTCON_USB_HOST,
  37        EXTCON_NONE,
  38};
  39
  40static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
  41static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
  42static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
  43
  44static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
  45        /*
  46         * Some platforms have a bug in ACPI GPIO description making IRQ
  47         * GPIO to be output only. Ask the GPIO core to ignore this limit.
  48         */
  49        { "id-gpios", &id_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
  50        { "vbus-gpios", &vbus_gpios, 1 },
  51        { "mux-gpios", &mux_gpios, 1 },
  52        { },
  53};
  54
  55static void int3496_do_usb_id(struct work_struct *work)
  56{
  57        struct int3496_data *data =
  58                container_of(work, struct int3496_data, work.work);
  59        int id = gpiod_get_value_cansleep(data->gpio_usb_id);
  60
  61        /* id == 1: PERIPHERAL, id == 0: HOST */
  62        dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
  63
  64        /*
  65         * Peripheral: set USB mux to peripheral and disable VBUS
  66         * Host: set USB mux to host and enable VBUS
  67         */
  68        if (!IS_ERR(data->gpio_usb_mux))
  69                gpiod_direction_output(data->gpio_usb_mux, id);
  70
  71        if (!IS_ERR(data->gpio_vbus_en))
  72                gpiod_direction_output(data->gpio_vbus_en, !id);
  73
  74        extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
  75}
  76
  77static irqreturn_t int3496_thread_isr(int irq, void *priv)
  78{
  79        struct int3496_data *data = priv;
  80
  81        /* Let the pin settle before processing it */
  82        mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
  83
  84        return IRQ_HANDLED;
  85}
  86
  87static int int3496_probe(struct platform_device *pdev)
  88{
  89        struct device *dev = &pdev->dev;
  90        struct int3496_data *data;
  91        int ret;
  92
  93        ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
  94        if (ret) {
  95                dev_err(dev, "can't add GPIO ACPI mapping\n");
  96                return ret;
  97        }
  98
  99        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 100        if (!data)
 101                return -ENOMEM;
 102
 103        data->dev = dev;
 104        INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
 105
 106        data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
 107        if (IS_ERR(data->gpio_usb_id)) {
 108                ret = PTR_ERR(data->gpio_usb_id);
 109                dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
 110                return ret;
 111        }
 112
 113        data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
 114        if (data->usb_id_irq < 0) {
 115                dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
 116                return data->usb_id_irq;
 117        }
 118
 119        data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
 120        if (IS_ERR(data->gpio_vbus_en))
 121                dev_info(dev, "can't request VBUS EN GPIO\n");
 122
 123        data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
 124        if (IS_ERR(data->gpio_usb_mux))
 125                dev_info(dev, "can't request USB MUX GPIO\n");
 126
 127        /* register extcon device */
 128        data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
 129        if (IS_ERR(data->edev))
 130                return -ENOMEM;
 131
 132        ret = devm_extcon_dev_register(dev, data->edev);
 133        if (ret < 0) {
 134                dev_err(dev, "can't register extcon device: %d\n", ret);
 135                return ret;
 136        }
 137
 138        ret = devm_request_threaded_irq(dev, data->usb_id_irq,
 139                                        NULL, int3496_thread_isr,
 140                                        IRQF_SHARED | IRQF_ONESHOT |
 141                                        IRQF_TRIGGER_RISING |
 142                                        IRQF_TRIGGER_FALLING,
 143                                        dev_name(dev), data);
 144        if (ret < 0) {
 145                dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
 146                return ret;
 147        }
 148
 149        /* process id-pin so that we start with the right status */
 150        queue_delayed_work(system_wq, &data->work, 0);
 151        flush_delayed_work(&data->work);
 152
 153        platform_set_drvdata(pdev, data);
 154
 155        return 0;
 156}
 157
 158static int int3496_remove(struct platform_device *pdev)
 159{
 160        struct int3496_data *data = platform_get_drvdata(pdev);
 161
 162        devm_free_irq(&pdev->dev, data->usb_id_irq, data);
 163        cancel_delayed_work_sync(&data->work);
 164
 165        return 0;
 166}
 167
 168static const struct acpi_device_id int3496_acpi_match[] = {
 169        { "INT3496" },
 170        { }
 171};
 172MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
 173
 174static struct platform_driver int3496_driver = {
 175        .driver = {
 176                .name = "intel-int3496",
 177                .acpi_match_table = int3496_acpi_match,
 178        },
 179        .probe = int3496_probe,
 180        .remove = int3496_remove,
 181};
 182
 183module_platform_driver(int3496_driver);
 184
 185MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 186MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
 187MODULE_LICENSE("GPL v2");
 188