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
  17 struct max3355_data {
  18         struct extcon_dev *edev;
  19         struct gpio_desc *id_gpiod;
  20         struct gpio_desc *shdn_gpiod;
  21 };
  22
  23 static const unsigned int max3355_cable[] = {
  24         EXTCON_USB,
  25         EXTCON_USB_HOST,
  26         EXTCON_NONE,
  27 };
  28
  29 static 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
  55 static 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
 116 static 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
 125 static const struct of_device_id max3355_match_table[] = {
 126         { .compatible = "maxim,max3355", },
 127         { }
 128 };
 129 MODULE_DEVICE_TABLE(of, max3355_match_table);
 130
 131 static 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
 140 module_platform_driver(max3355_driver);
 141
 142 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
 143 MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
 144 MODULE_LICENSE("GPL v2");