kernel/drivers/input/misc/tps65218-pwrbutton.c

   1 /*
   2  * Texas Instruments' TPS65218 Power Button Input Driver
   3  *
   4  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
   5  * Author: Felipe Balbi <balbi@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  12  * kind, whether express or implied; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/init.h>
  18 #include <linux/input.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mfd/tps65218.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26
  27 struct tps65218_pwrbutton {
  28         struct device *dev;
  29         struct tps65218 *tps;
  30         struct input_dev *idev;
  31 };
  32
  33 static irqreturn_t tps65218_pwr_irq(int irq, void *_pwr)
  34 {
  35         struct tps65218_pwrbutton *pwr = _pwr;
  36         unsigned int reg;
  37         int error;
  38
  39         error = tps65218_reg_read(pwr->tps, TPS65218_REG_STATUS, &reg);
  40         if (error) {
  41                 dev_err(pwr->dev, "can't read register: %d\n", error);
  42                 goto out;
  43         }
  44
  45         if (reg & TPS65218_STATUS_PB_STATE) {
  46                 input_report_key(pwr->idev, KEY_POWER, 1);
  47                 pm_wakeup_event(pwr->dev, 0);
  48         } else {
  49                 input_report_key(pwr->idev, KEY_POWER, 0);
  50         }
  51
  52         input_sync(pwr->idev);
  53
  54 out:
  55         return IRQ_HANDLED;
  56 }
  57
  58 static int tps65218_pwron_probe(struct platform_device *pdev)
  59 {
  60         struct tps65218 *tps = dev_get_drvdata(pdev->dev.parent);
  61         struct device *dev = &pdev->dev;
  62         struct tps65218_pwrbutton *pwr;
  63         struct input_dev *idev;
  64         int error;
  65         int irq;
  66
  67         pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL);
  68         if (!pwr)
  69                 return -ENOMEM;
  70
  71         idev = devm_input_allocate_device(dev);
  72         if (!idev)
  73                 return -ENOMEM;
  74
  75         idev->name = "tps65218_pwrbutton";
  76         idev->phys = "tps65218_pwrbutton/input0";
  77         idev->dev.parent = dev;
  78         idev->id.bustype = BUS_I2C;
  79
  80         input_set_capability(idev, EV_KEY, KEY_POWER);
  81
  82         pwr->tps = tps;
  83         pwr->dev = dev;
  84         pwr->idev = idev;
  85         platform_set_drvdata(pdev, pwr);
  86         device_init_wakeup(dev, true);
  87
  88         irq = platform_get_irq(pdev, 0);
  89         error = devm_request_threaded_irq(dev, irq, NULL, tps65218_pwr_irq,
  90                                           IRQF_TRIGGER_RISING |
  91                                                 IRQF_TRIGGER_FALLING |
  92                                                 IRQF_ONESHOT,
  93                                           "tps65218-pwrbutton", pwr);
  94         if (error) {
  95                 dev_err(dev, "failed to request IRQ #%d: %d\n",
  96                         irq, error);
  97                 return error;
  98         }
  99
 100         error= input_register_device(idev);
 101         if (error) {
 102                 dev_err(dev, "Can't register power button: %d\n", error);
 103                 return error;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static const struct of_device_id of_tps65218_pwr_match[] = {
 110         { .compatible = "ti,tps65218-pwrbutton" },
 111         { },
 112 };
 113 MODULE_DEVICE_TABLE(of, of_tps65218_pwr_match);
 114
 115 static struct platform_driver tps65218_pwron_driver = {
 116         .probe  = tps65218_pwron_probe,
 117         .driver = {
 118                 .name   = "tps65218_pwrbutton",
 119                 .of_match_table = of_tps65218_pwr_match,
 120         },
 121 };
 122 module_platform_driver(tps65218_pwron_driver);
 123
 124 MODULE_DESCRIPTION("TPS65218 Power Button");
 125 MODULE_LICENSE("GPL v2");
 126 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");