drivers/input/misc/cpcap-pwrbutton.c

   1 /**
   2  * CPCAP Power Button Input Driver
   3  *
   4  * Copyright (C) 2017 Sebastian Reichel <sre@kernel.org>
   5  *
   6  * This file is subject to the terms and conditions of the GNU General
   7  * Public License. See the file "COPYING" in the main directory of this
   8  * archive for more details.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/errno.h>
  20 #include <linux/input.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/regmap.h>
  23 #include <linux/of.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/mfd/motorola-cpcap.h>
  26
  27 #define CPCAP_IRQ_ON 23
  28 #define CPCAP_IRQ_ON_BITMASK (1 << (CPCAP_IRQ_ON % 16))
  29
  30 struct cpcap_power_button {
  31         struct regmap *regmap;
  32         struct input_dev *idev;
  33         struct device *dev;
  34 };
  35
  36 static irqreturn_t powerbutton_irq(int irq, void *_button)
  37 {
  38         struct cpcap_power_button *button = _button;
  39         int val;
  40
  41         val = cpcap_sense_virq(button->regmap, irq);
  42         if (val < 0) {
  43                 dev_err(button->dev, "irq read failed: %d", val);
  44                 return IRQ_HANDLED;
  45         }
  46
  47         pm_wakeup_event(button->dev, 0);
  48         input_report_key(button->idev, KEY_POWER, val);
  49         input_sync(button->idev);
  50
  51         return IRQ_HANDLED;
  52 }
  53
  54 static int cpcap_power_button_probe(struct platform_device *pdev)
  55 {
  56         struct cpcap_power_button *button;
  57         int irq;
  58         int err;
  59
  60         irq = platform_get_irq(pdev, 0);
  61         if (irq < 0)
  62                 return irq;
  63
  64         button = devm_kmalloc(&pdev->dev, sizeof(*button), GFP_KERNEL);
  65         if (!button)
  66                 return -ENOMEM;
  67
  68         button->idev = devm_input_allocate_device(&pdev->dev);
  69         if (!button->idev)
  70                 return -ENOMEM;
  71
  72         button->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  73         if (!button->regmap)
  74                 return -ENODEV;
  75
  76         button->dev = &pdev->dev;
  77
  78         button->idev->name = "cpcap-pwrbutton";
  79         button->idev->phys = "cpcap-pwrbutton/input0";
  80         input_set_capability(button->idev, EV_KEY, KEY_POWER);
  81
  82         err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  83                 powerbutton_irq, IRQF_ONESHOT, "cpcap_pwrbutton", button);
  84         if (err < 0) {
  85                 dev_err(&pdev->dev, "IRQ request failed: %d\n", err);
  86                 return err;
  87         }
  88
  89         err = input_register_device(button->idev);
  90         if (err) {
  91                 dev_err(&pdev->dev, "Input register failed: %d\n", err);
  92                 return err;
  93         }
  94
  95         device_init_wakeup(&pdev->dev, true);
  96
  97         return 0;
  98 }
  99
 100 #ifdef CONFIG_OF
 101 static const struct of_device_id cpcap_pwrbutton_dt_match_table[] = {
 102         { .compatible = "motorola,cpcap-pwrbutton" },
 103         {},
 104 };
 105 MODULE_DEVICE_TABLE(of, cpcap_pwrbutton_dt_match_table);
 106 #endif
 107
 108 static struct platform_driver cpcap_power_button_driver = {
 109         .probe          = cpcap_power_button_probe,
 110         .driver         = {
 111                 .name   = "cpcap-pwrbutton",
 112                 .of_match_table = of_match_ptr(cpcap_pwrbutton_dt_match_table),
 113         },
 114 };
 115 module_platform_driver(cpcap_power_button_driver);
 116
 117 MODULE_ALIAS("platform:cpcap-pwrbutton");
 118 MODULE_DESCRIPTION("CPCAP Power Button");
 119 MODULE_LICENSE("GPL");
 120 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");