drivers/input/serio/q40kbd.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (c) 2000-2001 Vojtech Pavlik
   4  *
   5  *  Based on the work of:
   6  *      Richard Zidlicky <Richard.Zidlicky@stud.informatik.uni-erlangen.de>
   7  */
   8
   9 /*
  10  * Q40 PS/2 keyboard controller driver for Linux/m68k
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/serio.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/err.h>
  17 #include <linux/bitops.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/slab.h>
  20
  21 #include <asm/io.h>
  22 #include <linux/uaccess.h>
  23 #include <asm/q40_master.h>
  24 #include <asm/irq.h>
  25 #include <asm/q40ints.h>
  26
  27 #define DRV_NAME        "q40kbd"
  28
  29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  30 MODULE_DESCRIPTION("Q40 PS/2 keyboard controller driver");
  31 MODULE_LICENSE("GPL");
  32 MODULE_ALIAS("platform:" DRV_NAME);
  33
  34 struct q40kbd {
  35         struct serio *port;
  36         spinlock_t lock;
  37 };
  38
  39 static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
  40 {
  41         struct q40kbd *q40kbd = dev_id;
  42
  43         guard(spinlock_irqsave)(&q40kbd->lock);
  44
  45         if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
  46                 serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
  47
  48         master_outb(-1, KEYBOARD_UNLOCK_REG);
  49
  50         return IRQ_HANDLED;
  51 }
  52
  53 /*
  54  * q40kbd_flush() flushes all data that may be in the keyboard buffers
  55  */
  56
  57 static void q40kbd_flush(struct q40kbd *q40kbd)
  58 {
  59         int maxread = 100;
  60
  61         guard(spinlock_irqsave)(&q40kbd->lock);
  62
  63         while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
  64                 master_inb(KEYCODE_REG);
  65 }
  66
  67 static void q40kbd_stop(void)
  68 {
  69         master_outb(0, KEY_IRQ_ENABLE_REG);
  70         master_outb(-1, KEYBOARD_UNLOCK_REG);
  71 }
  72
  73 /*
  74  * q40kbd_open() is called when a port is open by the higher layer.
  75  * It allocates the interrupt and enables in in the chip.
  76  */
  77
  78 static int q40kbd_open(struct serio *port)
  79 {
  80         struct q40kbd *q40kbd = port->port_data;
  81
  82         q40kbd_flush(q40kbd);
  83
  84         /* off we go */
  85         master_outb(-1, KEYBOARD_UNLOCK_REG);
  86         master_outb(1, KEY_IRQ_ENABLE_REG);
  87
  88         return 0;
  89 }
  90
  91 static void q40kbd_close(struct serio *port)
  92 {
  93         struct q40kbd *q40kbd = port->port_data;
  94
  95         q40kbd_stop();
  96         q40kbd_flush(q40kbd);
  97 }
  98
  99 static int q40kbd_probe(struct platform_device *pdev)
 100 {
 101         struct q40kbd *q40kbd;
 102         struct serio *port;
 103         int error;
 104
 105         q40kbd = kzalloc(sizeof(*q40kbd), GFP_KERNEL);
 106         port = kzalloc(sizeof(*port), GFP_KERNEL);
 107         if (!q40kbd || !port) {
 108                 error = -ENOMEM;
 109                 goto err_free_mem;
 110         }
 111
 112         q40kbd->port = port;
 113         spin_lock_init(&q40kbd->lock);
 114
 115         port->id.type = SERIO_8042;
 116         port->open = q40kbd_open;
 117         port->close = q40kbd_close;
 118         port->port_data = q40kbd;
 119         port->dev.parent = &pdev->dev;
 120         strscpy(port->name, "Q40 Kbd Port", sizeof(port->name));
 121         strscpy(port->phys, "Q40", sizeof(port->phys));
 122
 123         q40kbd_stop();
 124
 125         error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
 126                             DRV_NAME, q40kbd);
 127         if (error) {
 128                 dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
 129                 goto err_free_mem;
 130         }
 131
 132         serio_register_port(q40kbd->port);
 133
 134         platform_set_drvdata(pdev, q40kbd);
 135         printk(KERN_INFO "serio: Q40 kbd registered\n");
 136
 137         return 0;
 138
 139 err_free_mem:
 140         kfree(port);
 141         kfree(q40kbd);
 142         return error;
 143 }
 144
 145 static void q40kbd_remove(struct platform_device *pdev)
 146 {
 147         struct q40kbd *q40kbd = platform_get_drvdata(pdev);
 148
 149         /*
 150          * q40kbd_close() will be called as part of unregistering
 151          * and will ensure that IRQ is turned off, so it is safe
 152          * to unregister port first and free IRQ later.
 153          */
 154         serio_unregister_port(q40kbd->port);
 155         free_irq(Q40_IRQ_KEYBOARD, q40kbd);
 156         kfree(q40kbd);
 157 }
 158
 159 static struct platform_driver q40kbd_driver = {
 160         .driver         = {
 161                 .name   = "q40kbd",
 162         },
 163         .remove         = q40kbd_remove,
 164 };
 165
 166 module_platform_driver_probe(q40kbd_driver, q40kbd_probe);