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/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
  16 struct max3355_data {
  17         struct extcon_dev *edev;
  18         struct gpio_desc *id_gpiod;
  19         struct gpio_desc *shdn_gpiod;
  20 };
  21
  22 static const unsigned int max3355_cable[] = {
  23         EXTCON_USB,
  24         EXTCON_USB_HOST,
  25         EXTCON_NONE,
  26 };
  27
  28 static 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
  54 static 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
 115 static void 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
 122 static const struct of_device_id max3355_match_table[] = {
 123         { .compatible = "maxim,max3355", },
 124         { }
 125 };
 126 MODULE_DEVICE_TABLE(of, max3355_match_table);
 127
 128 static struct platform_driver max3355_driver = {
 129         .probe          = max3355_probe,
 130         .remove_new     = max3355_remove,
 131         .driver         = {
 132                 .name   = "extcon-max3355",
 133                 .of_match_table = max3355_match_table,
 134         },
 135 };
 136
 137 module_platform_driver(max3355_driver);
 138
 139 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
 140 MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
 141 MODULE_LICENSE("GPL v2");