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/serio.h>
  14 #include <linux/errno.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioport.h>
  17 #include <linux/device.h>
  18 #include <linux/delay.h>
  19 #include <linux/slab.h>
  20 #include <linux/err.h>
  21 #include <linux/amba/bus.h>
  22 #include <linux/amba/kmi.h>
  23 #include <linux/clk.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/irq.h>
  27
  28 #define KMI_BASE        (kmi->base)
  29
  30 struct amba_kmi_port {
  31         struct serio            *io;
  32         struct clk              *clk;
  33         void __iomem            *base;
  34         unsigned int            irq;
  35         unsigned int            divisor;
  36         unsigned int            open;
  37 };
  38
  39 static irqreturn_t amba_kmi_int(int irq, void *dev_id)
  40 {
  41         struct amba_kmi_port *kmi = dev_id;
  42         unsigned int status = readb(KMIIR);
  43         int handled = IRQ_NONE;
  44
  45         while (status & KMIIR_RXINTR) {
  46                 serio_interrupt(kmi->io, readb(KMIDATA), 0);
  47                 status = readb(KMIIR);
  48                 handled = IRQ_HANDLED;
  49         }
  50
  51         return handled;
  52 }
  53
  54 static int amba_kmi_write(struct serio *io, unsigned char val)
  55 {
  56         struct amba_kmi_port *kmi = io->port_data;
  57         unsigned int timeleft = 10000; /* timeout in 100ms */
  58
  59         while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
  60                 udelay(10);
  61
  62         if (timeleft)
  63                 writeb(val, KMIDATA);
  64
  65         return timeleft ? 0 : SERIO_TIMEOUT;
  66 }
  67
  68 static int amba_kmi_open(struct serio *io)
  69 {
  70         struct amba_kmi_port *kmi = io->port_data;
  71         unsigned int divisor;
  72         int ret;
  73
  74         ret = clk_prepare_enable(kmi->clk);
  75         if (ret)
  76                 goto out;
  77
  78         divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
  79         writeb(divisor, KMICLKDIV);
  80         writeb(KMICR_EN, KMICR);
  81
  82         ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
  83         if (ret) {
  84                 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
  85                 writeb(0, KMICR);
  86                 goto clk_disable;
  87         }
  88
  89         writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
  90
  91         return 0;
  92
  93  clk_disable:
  94         clk_disable_unprepare(kmi->clk);
  95  out:
  96         return ret;
  97 }
  98
  99 static void amba_kmi_close(struct serio *io)
 100 {
 101         struct amba_kmi_port *kmi = io->port_data;
 102
 103         writeb(0, KMICR);
 104
 105         free_irq(kmi->irq, kmi);
 106         clk_disable_unprepare(kmi->clk);
 107 }
 108
 109 static int amba_kmi_probe(struct amba_device *dev,
 110         const struct amba_id *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, resource_size(&dev->res));
 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         serio_unregister_port(kmi->io);
 170         clk_put(kmi->clk);
 171         iounmap(kmi->base);
 172         kfree(kmi);
 173         amba_release_regions(dev);
 174         return 0;
 175 }
 176
 177 static int amba_kmi_resume(struct amba_device *dev)
 178 {
 179         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 180
 181         /* kick the serio layer to rescan this port */
 182         serio_reconnect(kmi->io);
 183
 184         return 0;
 185 }
 186
 187 static struct amba_id amba_kmi_idtable[] = {
 188         {
 189                 .id     = 0x00041050,
 190                 .mask   = 0x000fffff,
 191         },
 192         { 0, 0 }
 193 };
 194
 195 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
 196
 197 static struct amba_driver ambakmi_driver = {
 198         .drv            = {
 199                 .name   = "kmi-pl050",
 200                 .owner  = THIS_MODULE,
 201         },
 202         .id_table       = amba_kmi_idtable,
 203         .probe          = amba_kmi_probe,
 204         .remove         = amba_kmi_remove,
 205         .resume         = amba_kmi_resume,
 206 };
 207
 208 module_amba_driver(ambakmi_driver);
 209
 210 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 211 MODULE_DESCRIPTION("AMBA KMI controller driver");
 212 MODULE_LICENSE("GPL");