LXR linux/drivers/macintosh/ams/ams-pmu.c

   1/*
   2 * Apple Motion Sensor driver (PMU variant)
   3 *
   4 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/types.h>
  14#include <linux/errno.h>
  15#include <linux/init.h>
  16#include <linux/adb.h>
  17#include <linux/pmu.h>
  18
  19#include "ams.h"
  20
  21/* Attitude */
  22#define AMS_X                   0x00
  23#define AMS_Y                   0x01
  24#define AMS_Z                   0x02
  25
  26/* Not exactly known, maybe chip vendor */
  27#define AMS_VENDOR              0x03
  28
  29/* Freefall registers */
  30#define AMS_FF_CLEAR            0x04
  31#define AMS_FF_ENABLE           0x05
  32#define AMS_FF_LOW_LIMIT        0x06
  33#define AMS_FF_DEBOUNCE         0x07
  34
  35/* Shock registers */
  36#define AMS_SHOCK_CLEAR         0x08
  37#define AMS_SHOCK_ENABLE        0x09
  38#define AMS_SHOCK_HIGH_LIMIT    0x0a
  39#define AMS_SHOCK_DEBOUNCE      0x0b
  40
  41/* Global interrupt and power control register */
  42#define AMS_CONTROL             0x0c
  43
  44static u8 ams_pmu_cmd;
  45
  46static void ams_pmu_req_complete(struct adb_request *req)
  47{
  48        complete((struct completion *)req->arg);
  49}
  50
  51/* Only call this function from task context */
  52static void ams_pmu_set_register(u8 reg, u8 value)
  53{
  54        static struct adb_request req;
  55        DECLARE_COMPLETION(req_complete);
  56
  57        req.arg = &req_complete;
  58        if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
  59                return;
  60
  61        wait_for_completion(&req_complete);
  62}
  63
  64/* Only call this function from task context */
  65static u8 ams_pmu_get_register(u8 reg)
  66{
  67        static struct adb_request req;
  68        DECLARE_COMPLETION(req_complete);
  69
  70        req.arg = &req_complete;
  71        if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
  72                return 0;
  73
  74        wait_for_completion(&req_complete);
  75
  76        if (req.reply_len > 0)
  77                return req.reply[0];
  78        else
  79                return 0;
  80}
  81
  82/* Enables or disables the specified interrupts */
  83static void ams_pmu_set_irq(enum ams_irq reg, char enable)
  84{
  85        if (reg & AMS_IRQ_FREEFALL) {
  86                u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
  87                if (enable)
  88                        val |= 0x80;
  89                else
  90                        val &= ~0x80;
  91                ams_pmu_set_register(AMS_FF_ENABLE, val);
  92        }
  93
  94        if (reg & AMS_IRQ_SHOCK) {
  95                u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
  96                if (enable)
  97                        val |= 0x80;
  98                else
  99                        val &= ~0x80;
 100                ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
 101        }
 102
 103        if (reg & AMS_IRQ_GLOBAL) {
 104                u8 val = ams_pmu_get_register(AMS_CONTROL);
 105                if (enable)
 106                        val |= 0x80;
 107                else
 108                        val &= ~0x80;
 109                ams_pmu_set_register(AMS_CONTROL, val);
 110        }
 111}
 112
 113static void ams_pmu_clear_irq(enum ams_irq reg)
 114{
 115        if (reg & AMS_IRQ_FREEFALL)
 116                ams_pmu_set_register(AMS_FF_CLEAR, 0x00);
 117
 118        if (reg & AMS_IRQ_SHOCK)
 119                ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
 120}
 121
 122static u8 ams_pmu_get_vendor(void)
 123{
 124        return ams_pmu_get_register(AMS_VENDOR);
 125}
 126
 127static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
 128{
 129        *x = ams_pmu_get_register(AMS_X);
 130        *y = ams_pmu_get_register(AMS_Y);
 131        *z = ams_pmu_get_register(AMS_Z);
 132}
 133
 134static void ams_pmu_exit(void)
 135{
 136        ams_sensor_detach();
 137
 138        /* Disable interrupts */
 139        ams_pmu_set_irq(AMS_IRQ_ALL, 0);
 140
 141        /* Clear interrupts */
 142        ams_pmu_clear_irq(AMS_IRQ_ALL);
 143
 144        ams_info.has_device = 0;
 145
 146        printk(KERN_INFO "ams: Unloading\n");
 147}
 148
 149int __init ams_pmu_init(struct device_node *np)
 150{
 151        const u32 *prop;
 152        int result;
 153
 154        /* Set implementation stuff */
 155        ams_info.of_node = np;
 156        ams_info.exit = ams_pmu_exit;
 157        ams_info.get_vendor = ams_pmu_get_vendor;
 158        ams_info.get_xyz = ams_pmu_get_xyz;
 159        ams_info.clear_irq = ams_pmu_clear_irq;
 160        ams_info.bustype = BUS_HOST;
 161
 162        /* Get PMU command, should be 0x4e, but we can never know */
 163        prop = of_get_property(ams_info.of_node, "reg", NULL);
 164        if (!prop)
 165                return -ENODEV;
 166
 167        ams_pmu_cmd = ((*prop) >> 8) & 0xff;
 168
 169        /* Disable interrupts */
 170        ams_pmu_set_irq(AMS_IRQ_ALL, 0);
 171
 172        /* Clear interrupts */
 173        ams_pmu_clear_irq(AMS_IRQ_ALL);
 174
 175        result = ams_sensor_attach();
 176        if (result < 0)
 177                return result;
 178
 179        /* Set default values */
 180        ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
 181        ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
 182        ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);
 183
 184        ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
 185        ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
 186        ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);
 187
 188        ams_pmu_set_register(AMS_CONTROL, 0x4f);
 189
 190        /* Clear interrupts */
 191        ams_pmu_clear_irq(AMS_IRQ_ALL);
 192
 193        ams_info.has_device = 1;
 194
 195        /* Enable interrupts */
 196        ams_pmu_set_irq(AMS_IRQ_ALL, 1);
 197
 198        printk(KERN_INFO "ams: Found PMU based motion sensor\n");
 199
 200        return 0;
 201}
 202