LXR linux/drivers/extcon/extcon-max3355.c

   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.h>
  11#include <linux/gpio/consumer.h>
  12#include <linux/interrupt.h>
  13#include <linux/module.h>
  14#include <linux/mod_devicetable.h>
  15#include <linux/platform_device.h>
  16
  17struct max3355_data {
  18        struct extcon_dev *edev;
  19        struct gpio_desc *id_gpiod;
  20        struct gpio_desc *shdn_gpiod;
  21};
  22
  23static const unsigned int max3355_cable[] = {
  24        EXTCON_USB,
  25        EXTCON_USB_HOST,
  26        EXTCON_NONE,
  27};
  28
  29static irqreturn_t max3355_id_irq(int irq, void *dev_id)
  30{
  31        struct max3355_data *data = dev_id;
  32        int id = gpiod_get_value_cansleep(data->id_gpiod);
  33
  34        if (id) {
  35                /*
  36                 * ID = 1 means USB HOST cable detached.
  37                 * As we don't have event for USB peripheral cable attached,
  38                 * we simulate USB peripheral attach here.
  39                 */
  40                extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);
  41                extcon_set_state_sync(data->edev, EXTCON_USB, true);
  42        } else {
  43                /*
  44                 * ID = 0 means USB HOST cable attached.
  45                 * As we don't have event for USB peripheral cable detached,
  46                 * we simulate USB peripheral detach here.
  47                 */
  48                extcon_set_state_sync(data->edev, EXTCON_USB, false);
  49                extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);
  50        }
  51
  52        return IRQ_HANDLED;
  53}
  54
  55static int max3355_probe(struct platform_device *pdev)
  56{
  57        struct max3355_data *data;
  58        struct gpio_desc *gpiod;
  59        int irq, err;
  60
  61        data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
  62                            GFP_KERNEL);
  63        if (!data)
  64                return -ENOMEM;
  65
  66        gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
  67        if (IS_ERR(gpiod)) {
  68                dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
  69                return PTR_ERR(gpiod);
  70        }
  71        data->id_gpiod = gpiod;
  72
  73        gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
  74        if (IS_ERR(gpiod)) {
  75                dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
  76                return PTR_ERR(gpiod);
  77        }
  78        data->shdn_gpiod = gpiod;
  79
  80        data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
  81        if (IS_ERR(data->edev)) {
  82                dev_err(&pdev->dev, "failed to allocate extcon device\n");
  83                return PTR_ERR(data->edev);
  84        }
  85
  86        err = devm_extcon_dev_register(&pdev->dev, data->edev);
  87        if (err < 0) {
  88                dev_err(&pdev->dev, "failed to register extcon device\n");
  89                return err;
  90        }
  91
  92        irq = gpiod_to_irq(data->id_gpiod);
  93        if (irq < 0) {
  94                dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
  95                return irq;
  96        }
  97
  98        err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
  99                                        IRQF_ONESHOT | IRQF_NO_SUSPEND |
 100                                        IRQF_TRIGGER_RISING |
 101                                        IRQF_TRIGGER_FALLING,
 102                                        pdev->name, data);
 103        if (err < 0) {
 104                dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
 105                return err;
 106        }
 107
 108        platform_set_drvdata(pdev, data);
 109
 110        /* Perform initial detection */
 111        max3355_id_irq(irq, data);
 112
 113        return 0;
 114}
 115
 116static int max3355_remove(struct platform_device *pdev)
 117{
 118        struct max3355_data *data = platform_get_drvdata(pdev);
 119
 120        gpiod_set_value_cansleep(data->shdn_gpiod, 0);
 121
 122        return 0;
 123}
 124
 125static const struct of_device_id max3355_match_table[] = {
 126        { .compatible = "maxim,max3355", },
 127        { }
 128};
 129MODULE_DEVICE_TABLE(of, max3355_match_table);
 130
 131static struct platform_driver max3355_driver = {
 132        .probe          = max3355_probe,
 133        .remove         = max3355_remove,
 134        .driver         = {
 135                .name   = "extcon-max3355",
 136                .of_match_table = max3355_match_table,
 137        },
 138};
 139
 140module_platform_driver(max3355_driver);
 141
 142MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
 143MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
 144MODULE_LICENSE("GPL v2");
 145