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

   1/*
   2 * Maxim Integrated MAX3355 USB OTG chip extcon driver
   3 *
   4 * Copyright (C)  2014-2015 Cogent Embedded, Inc.
   5 * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
   6 *
   7 * This software is licensed under the terms of the GNU General Public
   8 * License version 2, as published by the Free Software Foundation, and
   9 * may be copied, distributed, and modified under those terms.
  10 */
  11
  12#include <linux/extcon-provider.h>
  13#include <linux/gpio.h>
  14#include <linux/gpio/consumer.h>
  15#include <linux/interrupt.h>
  16#include <linux/module.h>
  17#include <linux/platform_device.h>
  18
  19struct max3355_data {
  20        struct extcon_dev *edev;
  21        struct gpio_desc *id_gpiod;
  22        struct gpio_desc *shdn_gpiod;
  23};
  24
  25static const unsigned int max3355_cable[] = {
  26        EXTCON_USB,
  27        EXTCON_USB_HOST,
  28        EXTCON_NONE,
  29};
  30
  31static irqreturn_t max3355_id_irq(int irq, void *dev_id)
  32{
  33        struct max3355_data *data = dev_id;
  34        int id = gpiod_get_value_cansleep(data->id_gpiod);
  35
  36        if (id) {
  37                /*
  38                 * ID = 1 means USB HOST cable detached.
  39                 * As we don't have event for USB peripheral cable attached,
  40                 * we simulate USB peripheral attach here.
  41                 */
  42                extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);
  43                extcon_set_state_sync(data->edev, EXTCON_USB, true);
  44        } else {
  45                /*
  46                 * ID = 0 means USB HOST cable attached.
  47                 * As we don't have event for USB peripheral cable detached,
  48                 * we simulate USB peripheral detach here.
  49                 */
  50                extcon_set_state_sync(data->edev, EXTCON_USB, false);
  51                extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);
  52        }
  53
  54        return IRQ_HANDLED;
  55}
  56
  57static int max3355_probe(struct platform_device *pdev)
  58{
  59        struct max3355_data *data;
  60        struct gpio_desc *gpiod;
  61        int irq, err;
  62
  63        data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
  64                            GFP_KERNEL);
  65        if (!data)
  66                return -ENOMEM;
  67
  68        gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
  69        if (IS_ERR(gpiod)) {
  70                dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
  71                return PTR_ERR(gpiod);
  72        }
  73        data->id_gpiod = gpiod;
  74
  75        gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
  76        if (IS_ERR(gpiod)) {
  77                dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
  78                return PTR_ERR(gpiod);
  79        }
  80        data->shdn_gpiod = gpiod;
  81
  82        data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
  83        if (IS_ERR(data->edev)) {
  84                dev_err(&pdev->dev, "failed to allocate extcon device\n");
  85                return PTR_ERR(data->edev);
  86        }
  87
  88        err = devm_extcon_dev_register(&pdev->dev, data->edev);
  89        if (err < 0) {
  90                dev_err(&pdev->dev, "failed to register extcon device\n");
  91                return err;
  92        }
  93
  94        irq = gpiod_to_irq(data->id_gpiod);
  95        if (irq < 0) {
  96                dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
  97                return irq;
  98        }
  99
 100        err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
 101                                        IRQF_ONESHOT | IRQF_NO_SUSPEND |
 102                                        IRQF_TRIGGER_RISING |
 103                                        IRQF_TRIGGER_FALLING,
 104                                        pdev->name, data);
 105        if (err < 0) {
 106                dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
 107                return err;
 108        }
 109
 110        platform_set_drvdata(pdev, data);
 111
 112        /* Perform initial detection */
 113        max3355_id_irq(irq, data);
 114
 115        return 0;
 116}
 117
 118static int max3355_remove(struct platform_device *pdev)
 119{
 120        struct max3355_data *data = platform_get_drvdata(pdev);
 121
 122        gpiod_set_value_cansleep(data->shdn_gpiod, 0);
 123
 124        return 0;
 125}
 126
 127static const struct of_device_id max3355_match_table[] = {
 128        { .compatible = "maxim,max3355", },
 129        { }
 130};
 131MODULE_DEVICE_TABLE(of, max3355_match_table);
 132
 133static struct platform_driver max3355_driver = {
 134        .probe          = max3355_probe,
 135        .remove         = max3355_remove,
 136        .driver         = {
 137                .name   = "extcon-max3355",
 138                .of_match_table = max3355_match_table,
 139        },
 140};
 141
 142module_platform_driver(max3355_driver);
 143
 144MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
 145MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
 146MODULE_LICENSE("GPL v2");
 147