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 /*
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/serio.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/err.h>
  20 #include <linux/bitops.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23
  24 #include <asm/io.h>
  25 #include <linux/uaccess.h>
  26 #include <asm/q40_master.h>
  27 #include <asm/irq.h>
  28 #include <asm/q40ints.h>
  29
  30 #define DRV_NAME        "q40kbd"
  31
  32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  33 MODULE_DESCRIPTION("Q40 PS/2 keyboard controller driver");
  34 MODULE_LICENSE("GPL");
  35 MODULE_ALIAS("platform:" DRV_NAME);
  36
  37 struct q40kbd {
  38         struct serio *port;
  39         spinlock_t lock;
  40 };
  41
  42 static irqreturn_t q40kbd_interrupt(int irq, void *dev_id)
  43 {
  44         struct q40kbd *q40kbd = dev_id;
  45         unsigned long flags;
  46
  47         spin_lock_irqsave(&q40kbd->lock, flags);
  48
  49         if (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG))
  50                 serio_interrupt(q40kbd->port, master_inb(KEYCODE_REG), 0);
  51
  52         master_outb(-1, KEYBOARD_UNLOCK_REG);
  53
  54         spin_unlock_irqrestore(&q40kbd->lock, flags);
  55
  56         return IRQ_HANDLED;
  57 }
  58
  59 /*
  60  * q40kbd_flush() flushes all data that may be in the keyboard buffers
  61  */
  62
  63 static void q40kbd_flush(struct q40kbd *q40kbd)
  64 {
  65         int maxread = 100;
  66         unsigned long flags;
  67
  68         spin_lock_irqsave(&q40kbd->lock, flags);
  69
  70         while (maxread-- && (Q40_IRQ_KEYB_MASK & master_inb(INTERRUPT_REG)))
  71                 master_inb(KEYCODE_REG);
  72
  73         spin_unlock_irqrestore(&q40kbd->lock, flags);
  74 }
  75
  76 static void q40kbd_stop(void)
  77 {
  78         master_outb(0, KEY_IRQ_ENABLE_REG);
  79         master_outb(-1, KEYBOARD_UNLOCK_REG);
  80 }
  81
  82 /*
  83  * q40kbd_open() is called when a port is open by the higher layer.
  84  * It allocates the interrupt and enables in in the chip.
  85  */
  86
  87 static int q40kbd_open(struct serio *port)
  88 {
  89         struct q40kbd *q40kbd = port->port_data;
  90
  91         q40kbd_flush(q40kbd);
  92
  93         /* off we go */
  94         master_outb(-1, KEYBOARD_UNLOCK_REG);
  95         master_outb(1, KEY_IRQ_ENABLE_REG);
  96
  97         return 0;
  98 }
  99
 100 static void q40kbd_close(struct serio *port)
 101 {
 102         struct q40kbd *q40kbd = port->port_data;
 103
 104         q40kbd_stop();
 105         q40kbd_flush(q40kbd);
 106 }
 107
 108 static int q40kbd_probe(struct platform_device *pdev)
 109 {
 110         struct q40kbd *q40kbd;
 111         struct serio *port;
 112         int error;
 113
 114         q40kbd = kzalloc(sizeof(struct q40kbd), GFP_KERNEL);
 115         port = kzalloc(sizeof(struct serio), GFP_KERNEL);
 116         if (!q40kbd || !port) {
 117                 error = -ENOMEM;
 118                 goto err_free_mem;
 119         }
 120
 121         q40kbd->port = port;
 122         spin_lock_init(&q40kbd->lock);
 123
 124         port->id.type = SERIO_8042;
 125         port->open = q40kbd_open;
 126         port->close = q40kbd_close;
 127         port->port_data = q40kbd;
 128         port->dev.parent = &pdev->dev;
 129         strlcpy(port->name, "Q40 Kbd Port", sizeof(port->name));
 130         strlcpy(port->phys, "Q40", sizeof(port->phys));
 131
 132         q40kbd_stop();
 133
 134         error = request_irq(Q40_IRQ_KEYBOARD, q40kbd_interrupt, 0,
 135                             DRV_NAME, q40kbd);
 136         if (error) {
 137                 dev_err(&pdev->dev, "Can't get irq %d.\n", Q40_IRQ_KEYBOARD);
 138                 goto err_free_mem;
 139         }
 140
 141         serio_register_port(q40kbd->port);
 142
 143         platform_set_drvdata(pdev, q40kbd);
 144         printk(KERN_INFO "serio: Q40 kbd registered\n");
 145
 146         return 0;
 147
 148 err_free_mem:
 149         kfree(port);
 150         kfree(q40kbd);
 151         return error;
 152 }
 153
 154 static int q40kbd_remove(struct platform_device *pdev)
 155 {
 156         struct q40kbd *q40kbd = platform_get_drvdata(pdev);
 157
 158         /*
 159          * q40kbd_close() will be called as part of unregistering
 160          * and will ensure that IRQ is turned off, so it is safe
 161          * to unregister port first and free IRQ later.
 162          */
 163         serio_unregister_port(q40kbd->port);
 164         free_irq(Q40_IRQ_KEYBOARD, q40kbd);
 165         kfree(q40kbd);
 166
 167         return 0;
 168 }
 169
 170 static struct platform_driver q40kbd_driver = {
 171         .driver         = {
 172                 .name   = "q40kbd",
 173         },
 174         .remove         = q40kbd_remove,
 175 };
 176
 177 module_platform_driver_probe(q40kbd_driver, q40kbd_probe);