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ambakmi.c

/*
 *  linux/drivers/input/serio/ambakmi.c
 *
 *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
 *  Copyright (C) 2002 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/kmi.h>
#include <linux/clk.h>

#include <asm/io.h>
#include <asm/irq.h>

#define KMI_BASE  (kmi->base)

struct amba_kmi_port {
      struct serio            *io;
      struct clk        *clk;
      void __iomem            *base;
      unsigned int            irq;
      unsigned int            divisor;
      unsigned int            open;
};

static irqreturn_t amba_kmi_int(int irq, void *dev_id)
{
      struct amba_kmi_port *kmi = dev_id;
      unsigned int status = readb(KMIIR);
      int handled = IRQ_NONE;

      while (status & KMIIR_RXINTR) {
            serio_interrupt(kmi->io, readb(KMIDATA), 0);
            status = readb(KMIIR);
            handled = IRQ_HANDLED;
      }

      return handled;
}

static int amba_kmi_write(struct serio *io, unsigned char val)
{
      struct amba_kmi_port *kmi = io->port_data;
      unsigned int timeleft = 10000; /* timeout in 100ms */

      while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && timeleft--)
            udelay(10);

      if (timeleft)
            writeb(val, KMIDATA);

      return timeleft ? 0 : SERIO_TIMEOUT;
}

static int amba_kmi_open(struct serio *io)
{
      struct amba_kmi_port *kmi = io->port_data;
      unsigned int divisor;
      int ret;

      ret = clk_enable(kmi->clk);
      if (ret)
            goto out;

      divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
      writeb(divisor, KMICLKDIV);
      writeb(KMICR_EN, KMICR);

      ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
      if (ret) {
            printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
            writeb(0, KMICR);
            goto clk_disable;
      }

      writeb(KMICR_EN | KMICR_RXINTREN, KMICR);

      return 0;

 clk_disable:
      clk_disable(kmi->clk);
 out:
      return ret;
}

static void amba_kmi_close(struct serio *io)
{
      struct amba_kmi_port *kmi = io->port_data;

      writeb(0, KMICR);

      free_irq(kmi->irq, kmi);
      clk_disable(kmi->clk);
}

static int amba_kmi_probe(struct amba_device *dev, void *id)
{
      struct amba_kmi_port *kmi;
      struct serio *io;
      int ret;

      ret = amba_request_regions(dev, NULL);
      if (ret)
            return ret;

      kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
      io = kzalloc(sizeof(struct serio), GFP_KERNEL);
      if (!kmi || !io) {
            ret = -ENOMEM;
            goto out;
      }


      io->id.type = SERIO_8042;
      io->write   = amba_kmi_write;
      io->open    = amba_kmi_open;
      io->close   = amba_kmi_close;
      strlcpy(io->name, dev->dev.bus_id, sizeof(io->name));
      strlcpy(io->phys, dev->dev.bus_id, sizeof(io->phys));
      io->port_data     = kmi;
      io->dev.parent    = &dev->dev;

      kmi->io     = io;
      kmi->base   = ioremap(dev->res.start, KMI_SIZE);
      if (!kmi->base) {
            ret = -ENOMEM;
            goto out;
      }

      kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
      if (IS_ERR(kmi->clk)) {
            ret = PTR_ERR(kmi->clk);
            goto unmap;
      }

      kmi->irq = dev->irq[0];
      amba_set_drvdata(dev, kmi);

      serio_register_port(kmi->io);
      return 0;

 unmap:
      iounmap(kmi->base);
 out:
      kfree(kmi);
      kfree(io);
      amba_release_regions(dev);
      return ret;
}

static int amba_kmi_remove(struct amba_device *dev)
{
      struct amba_kmi_port *kmi = amba_get_drvdata(dev);

      amba_set_drvdata(dev, NULL);

      serio_unregister_port(kmi->io);
      clk_put(kmi->clk);
      iounmap(kmi->base);
      kfree(kmi);
      amba_release_regions(dev);
      return 0;
}

static int amba_kmi_resume(struct amba_device *dev)
{
      struct amba_kmi_port *kmi = amba_get_drvdata(dev);

      /* kick the serio layer to rescan this port */
      serio_reconnect(kmi->io);

      return 0;
}

static struct amba_id amba_kmi_idtable[] = {
      {
            .id   = 0x00041050,
            .mask = 0x000fffff,
      },
      { 0, 0 }
};

static struct amba_driver ambakmi_driver = {
      .drv        = {
            .name = "kmi-pl050",
      },
      .id_table   = amba_kmi_idtable,
      .probe            = amba_kmi_probe,
      .remove           = amba_kmi_remove,
      .resume           = amba_kmi_resume,
};

static int __init amba_kmi_init(void)
{
      return amba_driver_register(&ambakmi_driver);
}

static void __exit amba_kmi_exit(void)
{
      amba_driver_unregister(&ambakmi_driver);
}

module_init(amba_kmi_init);
module_exit(amba_kmi_exit);

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("AMBA KMI controller driver");
MODULE_LICENSE("GPL");

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