drivers/input/serio/ambakmi.c

   1 /*
   2  *  linux/drivers/input/serio/ambakmi.c
   3  *
   4  *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
   5  *  Copyright (C) 2002 Russell King.
   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 as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/serio.h>
  15 #include <linux/errno.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ioport.h>
  18 #include <linux/device.h>
  19 #include <linux/delay.h>
  20 #include <linux/slab.h>
  21 #include <linux/err.h>
  22 #include <linux/amba/bus.h>
  23 #include <linux/amba/kmi.h>
  24 #include <linux/clk.h>
  25
  26 #include <asm/io.h>
  27 #include <asm/irq.h>
  28
  29 #define KMI_BASE        (kmi->base)
  30
  31 struct amba_kmi_port {
  32         struct serio            *io;
  33         struct clk              *clk;
  34         void __iomem            *base;
  35         unsigned int            irq;
  36         unsigned int            divisor;
  37         unsigned int            open;
  38 };
  39
  40 static irqreturn_t amba_kmi_int(int irq, void *dev_id)
  41 {
  42         struct amba_kmi_port *kmi = dev_id;
  43         unsigned int status = readb(KMIIR);
  44         int handled = IRQ_NONE;
  45
  46         while (status & KMIIR_RXINTR) {
  47                 serio_interrupt(kmi->io, readb(KMIDATA), 0);
  48                 status = readb(KMIIR);
  49                 handled = IRQ_HANDLED;
  50         }
  51
  52         return handled;
  53 }
  54
  55 static int amba_kmi_write(struct serio *io, unsigned char val)
  56 {
  57         struct amba_kmi_port *kmi = io->port_data;
  58         unsigned int timeleft = 10000; /* timeout in 100ms */
  59
  60         while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
  61                 udelay(10);
  62
  63         if (timeleft)
  64                 writeb(val, KMIDATA);
  65
  66         return timeleft ? 0 : SERIO_TIMEOUT;
  67 }
  68
  69 static int amba_kmi_open(struct serio *io)
  70 {
  71         struct amba_kmi_port *kmi = io->port_data;
  72         unsigned int divisor;
  73         int ret;
  74
  75         ret = clk_enable(kmi->clk);
  76         if (ret)
  77                 goto out;
  78
  79         divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
  80         writeb(divisor, KMICLKDIV);
  81         writeb(KMICR_EN, KMICR);
  82
  83         ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
  84         if (ret) {
  85                 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
  86                 writeb(0, KMICR);
  87                 goto clk_disable;
  88         }
  89
  90         writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
  91
  92         return 0;
  93
  94  clk_disable:
  95         clk_disable(kmi->clk);
  96  out:
  97         return ret;
  98 }
  99
 100 static void amba_kmi_close(struct serio *io)
 101 {
 102         struct amba_kmi_port *kmi = io->port_data;
 103
 104         writeb(0, KMICR);
 105
 106         free_irq(kmi->irq, kmi);
 107         clk_disable(kmi->clk);
 108 }
 109
 110 static int amba_kmi_probe(struct amba_device *dev, void *id)
 111 {
 112         struct amba_kmi_port *kmi;
 113         struct serio *io;
 114         int ret;
 115
 116         ret = amba_request_regions(dev, NULL);
 117         if (ret)
 118                 return ret;
 119
 120         kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
 121         io = kzalloc(sizeof(struct serio), GFP_KERNEL);
 122         if (!kmi || !io) {
 123                 ret = -ENOMEM;
 124                 goto out;
 125         }
 126
 127
 128         io->id.type     = SERIO_8042;
 129         io->write       = amba_kmi_write;
 130         io->open        = amba_kmi_open;
 131         io->close       = amba_kmi_close;
 132         strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
 133         strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
 134         io->port_data   = kmi;
 135         io->dev.parent  = &dev->dev;
 136
 137         kmi->io         = io;
 138         kmi->base       = ioremap(dev->res.start, KMI_SIZE);
 139         if (!kmi->base) {
 140                 ret = -ENOMEM;
 141                 goto out;
 142         }
 143
 144         kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
 145         if (IS_ERR(kmi->clk)) {
 146                 ret = PTR_ERR(kmi->clk);
 147                 goto unmap;
 148         }
 149
 150         kmi->irq = dev->irq[0];
 151         amba_set_drvdata(dev, kmi);
 152
 153         serio_register_port(kmi->io);
 154         return 0;
 155
 156  unmap:
 157         iounmap(kmi->base);
 158  out:
 159         kfree(kmi);
 160         kfree(io);
 161         amba_release_regions(dev);
 162         return ret;
 163 }
 164
 165 static int amba_kmi_remove(struct amba_device *dev)
 166 {
 167         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 168
 169         amba_set_drvdata(dev, NULL);
 170
 171         serio_unregister_port(kmi->io);
 172         clk_put(kmi->clk);
 173         iounmap(kmi->base);
 174         kfree(kmi);
 175         amba_release_regions(dev);
 176         return 0;
 177 }
 178
 179 static int amba_kmi_resume(struct amba_device *dev)
 180 {
 181         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 182
 183         /* kick the serio layer to rescan this port */
 184         serio_reconnect(kmi->io);
 185
 186         return 0;
 187 }
 188
 189 static struct amba_id amba_kmi_idtable[] = {
 190         {
 191                 .id     = 0x00041050,
 192                 .mask   = 0x000fffff,
 193         },
 194         { 0, 0 }
 195 };
 196
 197 static struct amba_driver ambakmi_driver = {
 198         .drv            = {
 199                 .name   = "kmi-pl050",
 200         },
 201         .id_table       = amba_kmi_idtable,
 202         .probe          = amba_kmi_probe,
 203         .remove         = amba_kmi_remove,
 204         .resume         = amba_kmi_resume,
 205 };
 206
 207 static int __init amba_kmi_init(void)
 208 {
 209         return amba_driver_register(&ambakmi_driver);
 210 }
 211
 212 static void __exit amba_kmi_exit(void)
 213 {
 214         amba_driver_unregister(&ambakmi_driver);
 215 }
 216
 217 module_init(amba_kmi_init);
 218 module_exit(amba_kmi_exit);
 219
 220 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 221 MODULE_DESCRIPTION("AMBA KMI controller driver");
 222 MODULE_LICENSE("GPL");