drivers/input/joystick/rpisense-js.c

   1 /*
   2  * Raspberry Pi Sense HAT joystick driver
   3  * http://raspberrypi.org
   4  *
   5  * Copyright (C) 2015 Raspberry Pi
   6  *
   7  * Author: Serge Schneider
   8  *
   9  *  This program is free software; you can redistribute  it and/or modify it
  10  *  under  the terms of  the GNU General  Public License as published by the
  11  *  Free Software Foundation;  either version 2 of the  License, or (at your
  12  *  option) any later version.
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17
  18 #include <linux/mfd/rpisense/joystick.h>
  19 #include <linux/mfd/rpisense/core.h>
  20
  21 static struct rpisense *rpisense;
  22 static unsigned char keymap[5] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
  23
  24 static void keys_work_fn(struct work_struct *work)
  25 {
  26         int i;
  27         static s32 prev_keys;
  28         struct rpisense_js *rpisense_js = &rpisense->joystick;
  29         s32 keys = rpisense_reg_read(rpisense, RPISENSE_KEYS);
  30         s32 changes = keys ^ prev_keys;
  31
  32         prev_keys = keys;
  33         for (i = 0; i < 5; i++) {
  34                 if (changes & 1) {
  35                         input_report_key(rpisense_js->keys_dev,
  36                                          keymap[i], keys & 1);
  37                 }
  38                 changes >>= 1;
  39                 keys >>= 1;
  40         }
  41         input_sync(rpisense_js->keys_dev);
  42 }
  43
  44 static irqreturn_t keys_irq_handler(int irq, void *pdev)
  45 {
  46         struct rpisense_js *rpisense_js = &rpisense->joystick;
  47
  48         schedule_work(&rpisense_js->keys_work_s);
  49         return IRQ_HANDLED;
  50 }
  51
  52 static int rpisense_js_probe(struct platform_device *pdev)
  53 {
  54         int ret;
  55         int i;
  56         struct rpisense_js *rpisense_js;
  57
  58         rpisense = rpisense_get_dev();
  59         rpisense_js = &rpisense->joystick;
  60
  61         INIT_WORK(&rpisense_js->keys_work_s, keys_work_fn);
  62
  63         rpisense_js->keys_dev = input_allocate_device();
  64         if (!rpisense_js->keys_dev) {
  65                 dev_err(&pdev->dev, "Could not allocate input device.\n");
  66                 return -ENOMEM;
  67         }
  68
  69         rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY);
  70         for (i = 0; i < ARRAY_SIZE(keymap); i++) {
  71                 set_bit(keymap[i],
  72                         rpisense_js->keys_dev->keybit);
  73         }
  74
  75         rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
  76         rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
  77         rpisense_js->keys_dev->id.bustype = BUS_I2C;
  78         rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
  79         rpisense_js->keys_dev->keycode = keymap;
  80         rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
  81         rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
  82
  83         ret = input_register_device(rpisense_js->keys_dev);
  84         if (ret) {
  85                 dev_err(&pdev->dev, "Could not register input device.\n");
  86                 goto err_keys_alloc;
  87         }
  88
  89         ret = gpiod_direction_input(rpisense_js->keys_desc);
  90         if (ret) {
  91                 dev_err(&pdev->dev, "Could not set keys-int direction.\n");
  92                 goto err_keys_reg;
  93         }
  94
  95         rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
  96         if (rpisense_js->keys_irq < 0) {
  97                 dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
  98                 ret = rpisense_js->keys_irq;
  99                 goto err_keys_reg;
 100         }
 101
 102         ret = devm_request_irq(&pdev->dev, rpisense_js->keys_irq,
 103                                keys_irq_handler, IRQF_TRIGGER_RISING,
 104                                "keys", &pdev->dev);
 105         if (ret) {
 106                 dev_err(&pdev->dev, "IRQ request failed.\n");
 107                 goto err_keys_reg;
 108         }
 109         return 0;
 110 err_keys_reg:
 111         input_unregister_device(rpisense_js->keys_dev);
 112 err_keys_alloc:
 113         input_free_device(rpisense_js->keys_dev);
 114         return ret;
 115 }
 116
 117 static int rpisense_js_remove(struct platform_device *pdev)
 118 {
 119         struct rpisense_js *rpisense_js = &rpisense->joystick;
 120
 121         input_unregister_device(rpisense_js->keys_dev);
 122         input_free_device(rpisense_js->keys_dev);
 123         return 0;
 124 }
 125
 126 #ifdef CONFIG_OF
 127 static const struct of_device_id rpisense_js_id[] = {
 128         { .compatible = "rpi,rpi-sense-js" },
 129         { },
 130 };
 131 MODULE_DEVICE_TABLE(of, rpisense_js_id);
 132 #endif
 133
 134 static struct platform_device_id rpisense_js_device_id[] = {
 135         { .name = "rpi-sense-js" },
 136         { },
 137 };
 138 MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
 139
 140 static struct platform_driver rpisense_js_driver = {
 141         .probe = rpisense_js_probe,
 142         .remove = rpisense_js_remove,
 143         .driver = {
 144                 .name = "rpi-sense-js",
 145                 .owner = THIS_MODULE,
 146         },
 147 };
 148
 149 module_platform_driver(rpisense_js_driver);
 150
 151 MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
 152 MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
 153 MODULE_LICENSE("GPL");