drivers/hwmon/ams/ams-core.c

   1 /*
   2  * Apple Motion Sensor driver
   3  *
   4  * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
   5  * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/errno.h>
  25 #include <linux/init.h>
  26 #include <asm/pmac_pfunc.h>
  27 #include <asm/of_platform.h>
  28
  29 #include "ams.h"
  30
  31 /* There is only one motion sensor per machine */
  32 struct ams ams_info;
  33
  34 static unsigned int verbose;
  35 module_param(verbose, bool, 0644);
  36 MODULE_PARM_DESC(verbose, "Show free falls and shocks in kernel output");
  37
  38 /* Call with ams_info.lock held! */
  39 void ams_sensors(s8 *x, s8 *y, s8 *z)
  40 {
  41         u32 orient = ams_info.vflag? ams_info.orient1 : ams_info.orient2;
  42
  43         if (orient & 0x80)
  44                 /* X and Y swapped */
  45                 ams_info.get_xyz(y, x, z);
  46         else
  47                 ams_info.get_xyz(x, y, z);
  48
  49         if (orient & 0x04)
  50                 *z = ~(*z);
  51         if (orient & 0x02)
  52                 *y = ~(*y);
  53         if (orient & 0x01)
  54                 *x = ~(*x);
  55 }
  56
  57 static ssize_t ams_show_current(struct device *dev,
  58         struct device_attribute *attr, char *buf)
  59 {
  60         s8 x, y, z;
  61
  62         mutex_lock(&ams_info.lock);
  63         ams_sensors(&x, &y, &z);
  64         mutex_unlock(&ams_info.lock);
  65
  66         return snprintf(buf, PAGE_SIZE, "%d %d %d\n", x, y, z);
  67 }
  68
  69 static DEVICE_ATTR(current, S_IRUGO, ams_show_current, NULL);
  70
  71 static void ams_handle_irq(void *data)
  72 {
  73         enum ams_irq irq = *((enum ams_irq *)data);
  74
  75         spin_lock(&ams_info.irq_lock);
  76
  77         ams_info.worker_irqs |= irq;
  78         schedule_work(&ams_info.worker);
  79
  80         spin_unlock(&ams_info.irq_lock);
  81 }
  82
  83 static enum ams_irq ams_freefall_irq_data = AMS_IRQ_FREEFALL;
  84 static struct pmf_irq_client ams_freefall_client = {
  85         .owner = THIS_MODULE,
  86         .handler = ams_handle_irq,
  87         .data = &ams_freefall_irq_data,
  88 };
  89
  90 static enum ams_irq ams_shock_irq_data = AMS_IRQ_SHOCK;
  91 static struct pmf_irq_client ams_shock_client = {
  92         .owner = THIS_MODULE,
  93         .handler = ams_handle_irq,
  94         .data = &ams_shock_irq_data,
  95 };
  96
  97 /* Once hard disk parking is implemented in the kernel, this function can
  98  * trigger it.
  99  */
 100 static void ams_worker(struct work_struct *work)
 101 {
 102         mutex_lock(&ams_info.lock);
 103
 104         if (ams_info.has_device) {
 105                 unsigned long flags;
 106
 107                 spin_lock_irqsave(&ams_info.irq_lock, flags);
 108
 109                 if (ams_info.worker_irqs & AMS_IRQ_FREEFALL) {
 110                         if (verbose)
 111                                 printk(KERN_INFO "ams: freefall detected!\n");
 112
 113                         ams_info.worker_irqs &= ~AMS_IRQ_FREEFALL;
 114
 115                         /* we must call this with interrupts enabled */
 116                         spin_unlock_irqrestore(&ams_info.irq_lock, flags);
 117                         ams_info.clear_irq(AMS_IRQ_FREEFALL);
 118                         spin_lock_irqsave(&ams_info.irq_lock, flags);
 119                 }
 120
 121                 if (ams_info.worker_irqs & AMS_IRQ_SHOCK) {
 122                         if (verbose)
 123                                 printk(KERN_INFO "ams: shock detected!\n");
 124
 125                         ams_info.worker_irqs &= ~AMS_IRQ_SHOCK;
 126
 127                         /* we must call this with interrupts enabled */
 128                         spin_unlock_irqrestore(&ams_info.irq_lock, flags);
 129                         ams_info.clear_irq(AMS_IRQ_SHOCK);
 130                         spin_lock_irqsave(&ams_info.irq_lock, flags);
 131                 }
 132
 133                 spin_unlock_irqrestore(&ams_info.irq_lock, flags);
 134         }
 135
 136         mutex_unlock(&ams_info.lock);
 137 }
 138
 139 /* Call with ams_info.lock held! */
 140 int ams_sensor_attach(void)
 141 {
 142         int result;
 143         const u32 *prop;
 144
 145         /* Get orientation */
 146         prop = of_get_property(ams_info.of_node, "orientation", NULL);
 147         if (!prop)
 148                 return -ENODEV;
 149         ams_info.orient1 = *prop;
 150         ams_info.orient2 = *(prop + 1);
 151
 152         /* Register freefall interrupt handler */
 153         result = pmf_register_irq_client(ams_info.of_node,
 154                         "accel-int-1",
 155                         &ams_freefall_client);
 156         if (result < 0)
 157                 return -ENODEV;
 158
 159         /* Reset saved irqs */
 160         ams_info.worker_irqs = 0;
 161
 162         /* Register shock interrupt handler */
 163         result = pmf_register_irq_client(ams_info.of_node,
 164                         "accel-int-2",
 165                         &ams_shock_client);
 166         if (result < 0)
 167                 goto release_freefall;
 168
 169         /* Create device */
 170         ams_info.of_dev = of_platform_device_create(ams_info.of_node, "ams", NULL);
 171         if (!ams_info.of_dev) {
 172                 result = -ENODEV;
 173                 goto release_shock;
 174         }
 175
 176         /* Create attributes */
 177         result = device_create_file(&ams_info.of_dev->dev, &dev_attr_current);
 178         if (result)
 179                 goto release_of;
 180
 181         ams_info.vflag = !!(ams_info.get_vendor() & 0x10);
 182
 183         /* Init input device */
 184         result = ams_input_init();
 185         if (result)
 186                 goto release_device_file;
 187
 188         return result;
 189 release_device_file:
 190         device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
 191 release_of:
 192         of_device_unregister(ams_info.of_dev);
 193 release_shock:
 194         pmf_unregister_irq_client(&ams_shock_client);
 195 release_freefall:
 196         pmf_unregister_irq_client(&ams_freefall_client);
 197         return result;
 198 }
 199
 200 int __init ams_init(void)
 201 {
 202         struct device_node *np;
 203
 204         spin_lock_init(&ams_info.irq_lock);
 205         mutex_init(&ams_info.lock);
 206         INIT_WORK(&ams_info.worker, ams_worker);
 207
 208 #ifdef CONFIG_SENSORS_AMS_I2C
 209         np = of_find_node_by_name(NULL, "accelerometer");
 210         if (np && of_device_is_compatible(np, "AAPL,accelerometer_1"))
 211                 /* Found I2C motion sensor */
 212                 return ams_i2c_init(np);
 213 #endif
 214
 215 #ifdef CONFIG_SENSORS_AMS_PMU
 216         np = of_find_node_by_name(NULL, "sms");
 217         if (np && of_device_is_compatible(np, "sms"))
 218                 /* Found PMU motion sensor */
 219                 return ams_pmu_init(np);
 220 #endif
 221         return -ENODEV;
 222 }
 223
 224 void ams_exit(void)
 225 {
 226         mutex_lock(&ams_info.lock);
 227
 228         if (ams_info.has_device) {
 229                 /* Remove input device */
 230                 ams_input_exit();
 231
 232                 /* Shut down implementation */
 233                 ams_info.exit();
 234
 235                 /* Flush interrupt worker
 236                  *
 237                  * We do this after ams_info.exit(), because an interrupt might
 238                  * have arrived before disabling them.
 239                  */
 240                 flush_scheduled_work();
 241
 242                 /* Remove attributes */
 243                 device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
 244
 245                 /* Remove device */
 246                 of_device_unregister(ams_info.of_dev);
 247
 248                 /* Remove handler */
 249                 pmf_unregister_irq_client(&ams_shock_client);
 250                 pmf_unregister_irq_client(&ams_freefall_client);
 251         }
 252
 253         mutex_unlock(&ams_info.lock);
 254 }
 255
 256 MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
 257 MODULE_DESCRIPTION("Apple Motion Sensor driver");
 258 MODULE_LICENSE("GPL");
 259
 260 module_init(ams_init);
 261 module_exit(ams_exit);