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
  23 #include <asm/io.h>
  24 #include <asm/irq.h>
  25 #include <asm/hardware/amba.h>
  26 #include <asm/hardware/amba_kmi.h>
  27 #include <asm/hardware/clock.h>
  28
  29 #define KMI_BASE        (kmi->base)
  30
  31 struct amba_kmi_port {
  32         struct serio            *io;
  33         struct clk              *clk;
  34         unsigned char           *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, struct pt_regs *regs)
  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, regs);
  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_use(kmi->clk);
  76         if (ret)
  77                 goto out;
  78
  79         ret = clk_enable(kmi->clk);
  80         if (ret)
  81                 goto clk_unuse;
  82
  83         divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
  84         writeb(divisor, KMICLKDIV);
  85         writeb(KMICR_EN, KMICR);
  86
  87         ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
  88         if (ret) {
  89                 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
  90                 writeb(0, KMICR);
  91                 goto clk_disable;
  92         }
  93
  94         writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
  95
  96         return 0;
  97
  98  clk_disable:
  99         clk_disable(kmi->clk);
 100  clk_unuse:
 101         clk_unuse(kmi->clk);
 102  out:
 103         return ret;
 104 }
 105
 106 static void amba_kmi_close(struct serio *io)
 107 {
 108         struct amba_kmi_port *kmi = io->port_data;
 109
 110         writeb(0, KMICR);
 111
 112         free_irq(kmi->irq, kmi);
 113         clk_disable(kmi->clk);
 114         clk_unuse(kmi->clk);
 115 }
 116
 117 static int amba_kmi_probe(struct amba_device *dev, void *id)
 118 {
 119         struct amba_kmi_port *kmi;
 120         struct serio *io;
 121         int ret;
 122
 123         ret = amba_request_regions(dev, NULL);
 124         if (ret)
 125                 return ret;
 126
 127         kmi = kmalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
 128         io = kmalloc(sizeof(struct serio), GFP_KERNEL);
 129         if (!kmi || !io) {
 130                 ret = -ENOMEM;
 131                 goto out;
 132         }
 133
 134         memset(kmi, 0, sizeof(struct amba_kmi_port));
 135         memset(io, 0, sizeof(struct serio));
 136
 137         io->type        = SERIO_8042;
 138         io->write       = amba_kmi_write;
 139         io->open        = amba_kmi_open;
 140         io->close       = amba_kmi_close;
 141         strlcpy(io->name, dev->dev.bus_id, sizeof(io->name));
 142         strlcpy(io->phys, dev->dev.bus_id, sizeof(io->phys));
 143         io->port_data   = kmi;
 144         io->dev.parent  = &dev->dev;
 145
 146         kmi->io         = io;
 147         kmi->base       = ioremap(dev->res.start, KMI_SIZE);
 148         if (!kmi->base) {
 149                 ret = -ENOMEM;
 150                 goto out;
 151         }
 152
 153         kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
 154         if (IS_ERR(kmi->clk)) {
 155                 ret = PTR_ERR(kmi->clk);
 156                 goto unmap;
 157         }
 158
 159         kmi->irq = dev->irq[0];
 160         amba_set_drvdata(dev, kmi);
 161
 162         serio_register_port(kmi->io);
 163         return 0;
 164
 165  unmap:
 166         iounmap(kmi->base);
 167  out:
 168         kfree(kmi);
 169         kfree(io);
 170         amba_release_regions(dev);
 171         return ret;
 172 }
 173
 174 static int amba_kmi_remove(struct amba_device *dev)
 175 {
 176         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 177
 178         amba_set_drvdata(dev, NULL);
 179
 180         serio_unregister_port(kmi->io);
 181         clk_put(kmi->clk);
 182         iounmap(kmi->base);
 183         kfree(kmi);
 184         amba_release_regions(dev);
 185         return 0;
 186 }
 187
 188 static int amba_kmi_resume(struct amba_device *dev)
 189 {
 190         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 191
 192         /* kick the serio layer to rescan this port */
 193         serio_reconnect(kmi->io);
 194
 195         return 0;
 196 }
 197
 198 static struct amba_id amba_kmi_idtable[] = {
 199         {
 200                 .id     = 0x00041050,
 201                 .mask   = 0x000fffff,
 202         },
 203         { 0, 0 }
 204 };
 205
 206 static struct amba_driver ambakmi_driver = {
 207         .drv            = {
 208                 .name   = "kmi-pl050",
 209         },
 210         .id_table       = amba_kmi_idtable,
 211         .probe          = amba_kmi_probe,
 212         .remove         = amba_kmi_remove,
 213         .resume         = amba_kmi_resume,
 214 };
 215
 216 static int __init amba_kmi_init(void)
 217 {
 218         return amba_driver_register(&ambakmi_driver);
 219 }
 220
 221 static void __exit amba_kmi_exit(void)
 222 {
 223         amba_driver_unregister(&ambakmi_driver);
 224 }
 225
 226 module_init(amba_kmi_init);
 227 module_exit(amba_kmi_exit);
 228
 229 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 230 MODULE_DESCRIPTION("AMBA KMI controller driver");
 231 MODULE_LICENSE("GPL");