// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Apple Motion Sensor driver
 *
 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
 */

#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);