ams-pmu.c

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/*
 * Apple Motion Sensor driver (PMU variant)
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/adb.h>
#include <linux/pmu.h>

#include "ams.h"

/* Attitude */
#define AMS_X           0x00
#define AMS_Y           0x01
#define AMS_Z           0x02

/* Not exactly known, maybe chip vendor */
#define AMS_VENDOR      0x03

/* Freefall registers */
#define AMS_FF_CLEAR        0x04
#define AMS_FF_ENABLE       0x05
#define AMS_FF_LOW_LIMIT    0x06
#define AMS_FF_DEBOUNCE     0x07

/* Shock registers */
#define AMS_SHOCK_CLEAR     0x08
#define AMS_SHOCK_ENABLE    0x09
#define AMS_SHOCK_HIGH_LIMIT    0x0a
#define AMS_SHOCK_DEBOUNCE  0x0b

/* Global interrupt and power control register */
#define AMS_CONTROL     0x0c

static u8 ams_pmu_cmd;

static void ams_pmu_req_complete(struct adb_request *req)
{
    complete((struct completion *)req->arg);
}

/* Only call this function from task context */
static void ams_pmu_set_register(u8 reg, u8 value)
{
    static struct adb_request req;
    DECLARE_COMPLETION(req_complete);

    req.arg = &req_complete;
    if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
        return;

    wait_for_completion(&req_complete);
}

/* Only call this function from task context */
static u8 ams_pmu_get_register(u8 reg)
{
    static struct adb_request req;
    DECLARE_COMPLETION(req_complete);

    req.arg = &req_complete;
    if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
        return 0;

    wait_for_completion(&req_complete);

    if (req.reply_len > 0)
        return req.reply[0];
    else
        return 0;
}

/* Enables or disables the specified interrupts */
static void ams_pmu_set_irq(enum ams_irq reg, char enable)
{
    if (reg & AMS_IRQ_FREEFALL) {
        u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
        if (enable)
            val |= 0x80;
        else
            val &= ~0x80;
        ams_pmu_set_register(AMS_FF_ENABLE, val);
    }

    if (reg & AMS_IRQ_SHOCK) {
        u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
        if (enable)
            val |= 0x80;
        else
            val &= ~0x80;
        ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
    }

    if (reg & AMS_IRQ_GLOBAL) {
        u8 val = ams_pmu_get_register(AMS_CONTROL);
        if (enable)
            val |= 0x80;
        else
            val &= ~0x80;
        ams_pmu_set_register(AMS_CONTROL, val);
    }
}

static void ams_pmu_clear_irq(enum ams_irq reg)
{
    if (reg & AMS_IRQ_FREEFALL)
        ams_pmu_set_register(AMS_FF_CLEAR, 0x00);

    if (reg & AMS_IRQ_SHOCK)
        ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
}

static u8 ams_pmu_get_vendor(void)
{
    return ams_pmu_get_register(AMS_VENDOR);
}

static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
{
    *x = ams_pmu_get_register(AMS_X);
    *y = ams_pmu_get_register(AMS_Y);
    *z = ams_pmu_get_register(AMS_Z);
}

static void ams_pmu_exit(void)
{
    ams_sensor_detach();

    /* Disable interrupts */
    ams_pmu_set_irq(AMS_IRQ_ALL, 0);

    /* Clear interrupts */
    ams_pmu_clear_irq(AMS_IRQ_ALL);

    ams_info.has_device = 0;

    printk(KERN_INFO "ams: Unloading\n");
}

int __init ams_pmu_init(struct device_node *np)
{
    const u32 *prop;
    int result;

    /* Set implementation stuff */
    ams_info.of_node = np;
    ams_info.exit = ams_pmu_exit;
    ams_info.get_vendor = ams_pmu_get_vendor;
    ams_info.get_xyz = ams_pmu_get_xyz;
    ams_info.clear_irq = ams_pmu_clear_irq;
    ams_info.bustype = BUS_HOST;

    /* Get PMU command, should be 0x4e, but we can never know */
    prop = of_get_property(ams_info.of_node, "reg", NULL);
    if (!prop)
        return -ENODEV;

    ams_pmu_cmd = ((*prop) >> 8) & 0xff;

    /* Disable interrupts */
    ams_pmu_set_irq(AMS_IRQ_ALL, 0);

    /* Clear interrupts */
    ams_pmu_clear_irq(AMS_IRQ_ALL);

    result = ams_sensor_attach();
    if (result < 0)
        return result;

    /* Set default values */
    ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
    ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
    ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);

    ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
    ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
    ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);

    ams_pmu_set_register(AMS_CONTROL, 0x4f);

    /* Clear interrupts */
    ams_pmu_clear_irq(AMS_IRQ_ALL);

    ams_info.has_device = 1;

    /* Enable interrupts */
    ams_pmu_set_irq(AMS_IRQ_ALL, 1);

    printk(KERN_INFO "ams: Found PMU based motion sensor\n");

    return 0;
}