diff options
Diffstat (limited to 'drivers/extcon/extcon-intel-int3496.c')
| -rw-r--r-- | drivers/extcon/extcon-intel-int3496.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-intel-int3496.c b/drivers/extcon/extcon-intel-int3496.c new file mode 100644 index 000000000000..a3131b036de6 --- /dev/null +++ b/drivers/extcon/extcon-intel-int3496.c @@ -0,0 +1,179 @@ +/* + * Intel INT3496 ACPI device extcon driver + * + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> + * + * Based on android x86 kernel code which is: + * + * Copyright (c) 2014, Intel Corporation. + * Author: David Cohen <david.a.cohen@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/acpi.h> +#include <linux/extcon.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#define INT3496_GPIO_USB_ID 0 +#define INT3496_GPIO_VBUS_EN 1 +#define INT3496_GPIO_USB_MUX 2 +#define DEBOUNCE_TIME msecs_to_jiffies(50) + +struct int3496_data { + struct device *dev; + struct extcon_dev *edev; + struct delayed_work work; + struct gpio_desc *gpio_usb_id; + struct gpio_desc *gpio_vbus_en; + struct gpio_desc *gpio_usb_mux; + int usb_id_irq; +}; + +static const unsigned int int3496_cable[] = { + EXTCON_USB_HOST, + EXTCON_NONE, +}; + +static void int3496_do_usb_id(struct work_struct *work) +{ + struct int3496_data *data = + container_of(work, struct int3496_data, work.work); + int id = gpiod_get_value_cansleep(data->gpio_usb_id); + + /* id == 1: PERIPHERAL, id == 0: HOST */ + dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST"); + + /* + * Peripheral: set USB mux to peripheral and disable VBUS + * Host: set USB mux to host and enable VBUS + */ + if (!IS_ERR(data->gpio_usb_mux)) + gpiod_direction_output(data->gpio_usb_mux, id); + + if (!IS_ERR(data->gpio_vbus_en)) + gpiod_direction_output(data->gpio_vbus_en, !id); + + extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id); +} + +static irqreturn_t int3496_thread_isr(int irq, void *priv) +{ + struct int3496_data *data = priv; + + /* Let the pin settle before processing it */ + mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME); + + return IRQ_HANDLED; +} + +static int int3496_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct int3496_data *data; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = dev; + INIT_DELAYED_WORK(&data->work, int3496_do_usb_id); + + data->gpio_usb_id = devm_gpiod_get_index(dev, "id", + INT3496_GPIO_USB_ID, + GPIOD_IN); + if (IS_ERR(data->gpio_usb_id)) { + ret = PTR_ERR(data->gpio_usb_id); + dev_err(dev, "can't request USB ID GPIO: %d\n", ret); + return ret; + } + + data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id); + if (data->usb_id_irq <= 0) { + dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq); + return -EINVAL; + } + + data->gpio_vbus_en = devm_gpiod_get_index(dev, "vbus en", + INT3496_GPIO_VBUS_EN, + GPIOD_ASIS); + if (IS_ERR(data->gpio_vbus_en)) + dev_info(dev, "can't request VBUS EN GPIO\n"); + + data->gpio_usb_mux = devm_gpiod_get_index(dev, "usb mux", + INT3496_GPIO_USB_MUX, + GPIOD_ASIS); + if (IS_ERR(data->gpio_usb_mux)) + dev_info(dev, "can't request USB MUX GPIO\n"); + + /* register extcon device */ + data->edev = devm_extcon_dev_allocate(dev, int3496_cable); + if (IS_ERR(data->edev)) + return -ENOMEM; + + ret = devm_extcon_dev_register(dev, data->edev); + if (ret < 0) { + dev_err(dev, "can't register extcon device: %d\n", ret); + return ret; + } + + ret = devm_request_threaded_irq(dev, data->usb_id_irq, + NULL, int3496_thread_isr, + IRQF_SHARED | IRQF_ONESHOT | + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING, + dev_name(dev), data); + if (ret < 0) { + dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret); + return ret; + } + + /* queue initial processing of id-pin */ + queue_delayed_work(system_wq, &data->work, 0); + + platform_set_drvdata(pdev, data); + + return 0; +} + +static int int3496_remove(struct platform_device *pdev) +{ + struct int3496_data *data = platform_get_drvdata(pdev); + + devm_free_irq(&pdev->dev, data->usb_id_irq, data); + cancel_delayed_work_sync(&data->work); + + return 0; +} + +static struct acpi_device_id int3496_acpi_match[] = { + { "INT3496" }, + { } +}; +MODULE_DEVICE_TABLE(acpi, int3496_acpi_match); + +static struct platform_driver int3496_driver = { + .driver = { + .name = "intel-int3496", + .acpi_match_table = int3496_acpi_match, + }, + .probe = int3496_probe, + .remove = int3496_remove, +}; + +module_platform_driver(int3496_driver); + +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver"); +MODULE_LICENSE("GPL"); |