ams-core.c

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/*
 * Apple Motion Sensor driver
 *
 * Copyright (C) 2005 Stelian Pop ([email protected])
 * Copyright (C) 2006 Michael Hanselmann ([email protected])
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/of_platform.h>
#include <asm/pmac_pfunc.h>

#include "ams.h"

/* There is only one motion sensor per machine */
struct ams ams_info;

static bool verbose;
module_param(verbose, bool, 0644);
MODULE_PARM_DESC(verbose, "Show free falls and shocks in kernel output");

/* Call with ams_info.lock held! */
void ams_sensors(s8 *x, s8 *y, s8 *z)
{
    u32 orient = ams_info.vflag? ams_info.orient1 : ams_info.orient2;

    if (orient & 0x80)
        /* X and Y swapped */
        ams_info.get_xyz(y, x, z);
    else
        ams_info.get_xyz(x, y, z);

    if (orient & 0x04)
        *z = ~(*z);
    if (orient & 0x02)
        *y = ~(*y);
    if (orient & 0x01)
        *x = ~(*x);
}

static ssize_t ams_show_current(struct device *dev,
    struct device_attribute *attr, char *buf)
{
    s8 x, y, z;

    mutex_lock(&ams_info.lock);
    ams_sensors(&x, &y, &z);
    mutex_unlock(&ams_info.lock);

    return snprintf(buf, PAGE_SIZE, "%d %d %d\n", x, y, z);
}

static DEVICE_ATTR(current, S_IRUGO, ams_show_current, NULL);

static void ams_handle_irq(void *data)
{
    enum ams_irq irq = *((enum ams_irq *)data);

    spin_lock(&ams_info.irq_lock);

    ams_info.worker_irqs |= irq;
    schedule_work(&ams_info.worker);

    spin_unlock(&ams_info.irq_lock);
}

static enum ams_irq ams_freefall_irq_data = AMS_IRQ_FREEFALL;
static struct pmf_irq_client ams_freefall_client = {
    .owner = THIS_MODULE,
    .handler = ams_handle_irq,
    .data = &ams_freefall_irq_data,
};

static enum ams_irq ams_shock_irq_data = AMS_IRQ_SHOCK;
static struct pmf_irq_client ams_shock_client = {
    .owner = THIS_MODULE,
    .handler = ams_handle_irq,
    .data = &ams_shock_irq_data,
};

/* Once hard disk parking is implemented in the kernel, this function can
 * trigger it.
 */
static void ams_worker(struct work_struct *work)
{
    unsigned long flags;
    u8 irqs_to_clear;

    mutex_lock(&ams_info.lock);

    spin_lock_irqsave(&ams_info.irq_lock, flags);
    irqs_to_clear = ams_info.worker_irqs;

    if (ams_info.worker_irqs & AMS_IRQ_FREEFALL) {
        if (verbose)
            printk(KERN_INFO "ams: freefall detected!\n");

        ams_info.worker_irqs &= ~AMS_IRQ_FREEFALL;
    }

    if (ams_info.worker_irqs & AMS_IRQ_SHOCK) {
        if (verbose)
            printk(KERN_INFO "ams: shock detected!\n");

        ams_info.worker_irqs &= ~AMS_IRQ_SHOCK;
    }

    spin_unlock_irqrestore(&ams_info.irq_lock, flags);

    ams_info.clear_irq(irqs_to_clear);

    mutex_unlock(&ams_info.lock);
}

/* Call with ams_info.lock held! */
int ams_sensor_attach(void)
{
    int result;
    const u32 *prop;

    /* Get orientation */
    prop = of_get_property(ams_info.of_node, "orientation", NULL);
    if (!prop)
        return -ENODEV;
    ams_info.orient1 = *prop;
    ams_info.orient2 = *(prop + 1);

    /* Register freefall interrupt handler */
    result = pmf_register_irq_client(ams_info.of_node,
            "accel-int-1",
            &ams_freefall_client);
    if (result < 0)
        return -ENODEV;

    /* Reset saved irqs */
    ams_info.worker_irqs = 0;

    /* Register shock interrupt handler */
    result = pmf_register_irq_client(ams_info.of_node,
            "accel-int-2",
            &ams_shock_client);
    if (result < 0)
        goto release_freefall;

    /* Create device */
    ams_info.of_dev = of_platform_device_create(ams_info.of_node, "ams", NULL);
    if (!ams_info.of_dev) {
        result = -ENODEV;
        goto release_shock;
    }

    /* Create attributes */
    result = device_create_file(&ams_info.of_dev->dev, &dev_attr_current);
    if (result)
        goto release_of;

    ams_info.vflag = !!(ams_info.get_vendor() & 0x10);

    /* Init input device */
    result = ams_input_init();
    if (result)
        goto release_device_file;

    return result;
release_device_file:
    device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
release_of:
    of_device_unregister(ams_info.of_dev);
release_shock:
    pmf_unregister_irq_client(&ams_shock_client);
release_freefall:
    pmf_unregister_irq_client(&ams_freefall_client);
    return result;
}

int __init ams_init(void)
{
    struct device_node *np;

    spin_lock_init(&ams_info.irq_lock);
    mutex_init(&ams_info.lock);
    INIT_WORK(&ams_info.worker, ams_worker);

#ifdef CONFIG_SENSORS_AMS_I2C
    np = of_find_node_by_name(NULL, "accelerometer");
    if (np && of_device_is_compatible(np, "AAPL,accelerometer_1"))
        /* Found I2C motion sensor */
        return ams_i2c_init(np);
#endif

#ifdef CONFIG_SENSORS_AMS_PMU
    np = of_find_node_by_name(NULL, "sms");
    if (np && of_device_is_compatible(np, "sms"))
        /* Found PMU motion sensor */
        return ams_pmu_init(np);
#endif
    return -ENODEV;
}

void ams_sensor_detach(void)
{
    /* Remove input device */
    ams_input_exit();

    /* Remove attributes */
    device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);

    /* Flush interrupt worker
     *
     * We do this after ams_info.exit(), because an interrupt might
     * have arrived before disabling them.
     */
    flush_work(&ams_info.worker);

    /* Remove device */
    of_device_unregister(ams_info.of_dev);

    /* Remove handler */
    pmf_unregister_irq_client(&ams_shock_client);
    pmf_unregister_irq_client(&ams_freefall_client);
}

static void __exit ams_exit(void)
{
    /* Shut down implementation */
    ams_info.exit();
}

MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
MODULE_DESCRIPTION("Apple Motion Sensor driver");
MODULE_LICENSE("GPL");

module_init(ams_init);
module_exit(ams_exit);