cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

extcon-max3355.c (3580B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Maxim Integrated MAX3355 USB OTG chip extcon driver
      4 *
      5 * Copyright (C)  2014-2015 Cogent Embedded, Inc.
      6 * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
      7 */
      8
      9#include <linux/extcon-provider.h>
     10#include <linux/gpio/consumer.h>
     11#include <linux/interrupt.h>
     12#include <linux/module.h>
     13#include <linux/mod_devicetable.h>
     14#include <linux/platform_device.h>
     15
     16struct max3355_data {
     17	struct extcon_dev *edev;
     18	struct gpio_desc *id_gpiod;
     19	struct gpio_desc *shdn_gpiod;
     20};
     21
     22static const unsigned int max3355_cable[] = {
     23	EXTCON_USB,
     24	EXTCON_USB_HOST,
     25	EXTCON_NONE,
     26};
     27
     28static irqreturn_t max3355_id_irq(int irq, void *dev_id)
     29{
     30	struct max3355_data *data = dev_id;
     31	int id = gpiod_get_value_cansleep(data->id_gpiod);
     32
     33	if (id) {
     34		/*
     35		 * ID = 1 means USB HOST cable detached.
     36		 * As we don't have event for USB peripheral cable attached,
     37		 * we simulate USB peripheral attach here.
     38		 */
     39		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);
     40		extcon_set_state_sync(data->edev, EXTCON_USB, true);
     41	} else {
     42		/*
     43		 * ID = 0 means USB HOST cable attached.
     44		 * As we don't have event for USB peripheral cable detached,
     45		 * we simulate USB peripheral detach here.
     46		 */
     47		extcon_set_state_sync(data->edev, EXTCON_USB, false);
     48		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);
     49	}
     50
     51	return IRQ_HANDLED;
     52}
     53
     54static int max3355_probe(struct platform_device *pdev)
     55{
     56	struct max3355_data *data;
     57	struct gpio_desc *gpiod;
     58	int irq, err;
     59
     60	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
     61			    GFP_KERNEL);
     62	if (!data)
     63		return -ENOMEM;
     64
     65	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
     66	if (IS_ERR(gpiod)) {
     67		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
     68		return PTR_ERR(gpiod);
     69	}
     70	data->id_gpiod = gpiod;
     71
     72	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
     73	if (IS_ERR(gpiod)) {
     74		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
     75		return PTR_ERR(gpiod);
     76	}
     77	data->shdn_gpiod = gpiod;
     78
     79	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
     80	if (IS_ERR(data->edev)) {
     81		dev_err(&pdev->dev, "failed to allocate extcon device\n");
     82		return PTR_ERR(data->edev);
     83	}
     84
     85	err = devm_extcon_dev_register(&pdev->dev, data->edev);
     86	if (err < 0) {
     87		dev_err(&pdev->dev, "failed to register extcon device\n");
     88		return err;
     89	}
     90
     91	irq = gpiod_to_irq(data->id_gpiod);
     92	if (irq < 0) {
     93		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
     94		return irq;
     95	}
     96
     97	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
     98					IRQF_ONESHOT | IRQF_NO_SUSPEND |
     99					IRQF_TRIGGER_RISING |
    100					IRQF_TRIGGER_FALLING,
    101					pdev->name, data);
    102	if (err < 0) {
    103		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
    104		return err;
    105	}
    106
    107	platform_set_drvdata(pdev, data);
    108
    109	/* Perform initial detection */
    110	max3355_id_irq(irq, data);
    111
    112	return 0;
    113}
    114
    115static int max3355_remove(struct platform_device *pdev)
    116{
    117	struct max3355_data *data = platform_get_drvdata(pdev);
    118
    119	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
    120
    121	return 0;
    122}
    123
    124static const struct of_device_id max3355_match_table[] = {
    125	{ .compatible = "maxim,max3355", },
    126	{ }
    127};
    128MODULE_DEVICE_TABLE(of, max3355_match_table);
    129
    130static struct platform_driver max3355_driver = {
    131	.probe		= max3355_probe,
    132	.remove		= max3355_remove,
    133	.driver		= {
    134		.name	= "extcon-max3355",
    135		.of_match_table = max3355_match_table,
    136	},
    137};
    138
    139module_platform_driver(max3355_driver);
    140
    141MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
    142MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
    143MODULE_LICENSE("GPL v2");