drivers/staging/omapdrm/omap_irq.c

   1 /*
   2  * drivers/staging/omapdrm/omap_irq.c
   3  *
   4  * Copyright (C) 2012 Texas Instruments
   5  * Author: Rob Clark <rob.clark@linaro.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "omap_drv.h"
  21
  22 static DEFINE_SPINLOCK(list_lock);
  23
  24 static void omap_irq_error_handler(struct omap_drm_irq *irq,
  25                 uint32_t irqstatus)
  26 {
  27         DRM_ERROR("errors: %08x\n", irqstatus);
  28 }
  29
  30 /* call with list_lock and dispc runtime held */
  31 static void omap_irq_update(struct drm_device *dev)
  32 {
  33         struct omap_drm_private *priv = dev->dev_private;
  34         struct omap_drm_irq *irq;
  35         uint32_t irqmask = priv->vblank_mask;
  36
  37         BUG_ON(!spin_is_locked(&list_lock));
  38
  39         list_for_each_entry(irq, &priv->irq_list, node)
  40                 irqmask |= irq->irqmask;
  41
  42         DBG("irqmask=%08x", irqmask);
  43
  44         dispc_write_irqenable(irqmask);
  45         dispc_read_irqenable();        /* flush posted write */
  46 }
  47
  48 void omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq)
  49 {
  50         struct omap_drm_private *priv = dev->dev_private;
  51         unsigned long flags;
  52
  53         dispc_runtime_get();
  54         spin_lock_irqsave(&list_lock, flags);
  55
  56         if (!WARN_ON(irq->registered)) {
  57                 irq->registered = true;
  58                 list_add(&irq->node, &priv->irq_list);
  59                 omap_irq_update(dev);
  60         }
  61
  62         spin_unlock_irqrestore(&list_lock, flags);
  63         dispc_runtime_put();
  64 }
  65
  66 void omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq)
  67 {
  68         unsigned long flags;
  69
  70         dispc_runtime_get();
  71         spin_lock_irqsave(&list_lock, flags);
  72
  73         if (!WARN_ON(!irq->registered)) {
  74                 irq->registered = false;
  75                 list_del(&irq->node);
  76                 omap_irq_update(dev);
  77         }
  78
  79         spin_unlock_irqrestore(&list_lock, flags);
  80         dispc_runtime_put();
  81 }
  82
  83 struct omap_irq_wait {
  84         struct omap_drm_irq irq;
  85         int count;
  86 };
  87
  88 static DECLARE_WAIT_QUEUE_HEAD(wait_event);
  89
  90 static void wait_irq(struct omap_drm_irq *irq, uint32_t irqstatus)
  91 {
  92         struct omap_irq_wait *wait =
  93                         container_of(irq, struct omap_irq_wait, irq);
  94         wait->count--;
  95         wake_up_all(&wait_event);
  96 }
  97
  98 struct omap_irq_wait * omap_irq_wait_init(struct drm_device *dev,
  99                 uint32_t irqmask, int count)
 100 {
 101         struct omap_irq_wait *wait = kzalloc(sizeof(*wait), GFP_KERNEL);
 102         wait->irq.irq = wait_irq;
 103         wait->irq.irqmask = irqmask;
 104         wait->count = count;
 105         omap_irq_register(dev, &wait->irq);
 106         return wait;
 107 }
 108
 109 int omap_irq_wait(struct drm_device *dev, struct omap_irq_wait *wait,
 110                 unsigned long timeout)
 111 {
 112         int ret = wait_event_timeout(wait_event, (wait->count <= 0), timeout);
 113         omap_irq_unregister(dev, &wait->irq);
 114         kfree(wait);
 115         if (ret == 0)
 116                 return -1;
 117         return 0;
 118 }
 119
 120 /**
 121  * enable_vblank - enable vblank interrupt events
 122  * @dev: DRM device
 123  * @crtc: which irq to enable
 124  *
 125  * Enable vblank interrupts for @crtc.  If the device doesn't have
 126  * a hardware vblank counter, this routine should be a no-op, since
 127  * interrupts will have to stay on to keep the count accurate.
 128  *
 129  * RETURNS
 130  * Zero on success, appropriate errno if the given @crtc's vblank
 131  * interrupt cannot be enabled.
 132  */
 133 int omap_irq_enable_vblank(struct drm_device *dev, int crtc)
 134 {
 135         struct omap_drm_private *priv = dev->dev_private;
 136         unsigned long flags;
 137
 138         DBG("dev=%p, crtc=%d", dev, crtc);
 139
 140         dispc_runtime_get();
 141         spin_lock_irqsave(&list_lock, flags);
 142         priv->vblank_mask |= pipe2vbl(crtc);
 143         omap_irq_update(dev);
 144         spin_unlock_irqrestore(&list_lock, flags);
 145         dispc_runtime_put();
 146
 147         return 0;
 148 }
 149
 150 /**
 151  * disable_vblank - disable vblank interrupt events
 152  * @dev: DRM device
 153  * @crtc: which irq to enable
 154  *
 155  * Disable vblank interrupts for @crtc.  If the device doesn't have
 156  * a hardware vblank counter, this routine should be a no-op, since
 157  * interrupts will have to stay on to keep the count accurate.
 158  */
 159 void omap_irq_disable_vblank(struct drm_device *dev, int crtc)
 160 {
 161         struct omap_drm_private *priv = dev->dev_private;
 162         unsigned long flags;
 163
 164         DBG("dev=%p, crtc=%d", dev, crtc);
 165
 166         dispc_runtime_get();
 167         spin_lock_irqsave(&list_lock, flags);
 168         priv->vblank_mask &= ~pipe2vbl(crtc);
 169         omap_irq_update(dev);
 170         spin_unlock_irqrestore(&list_lock, flags);
 171         dispc_runtime_put();
 172 }
 173
 174 irqreturn_t omap_irq_handler(DRM_IRQ_ARGS)
 175 {
 176         struct drm_device *dev = (struct drm_device *) arg;
 177         struct omap_drm_private *priv = dev->dev_private;
 178         struct omap_drm_irq *handler, *n;
 179         unsigned long flags;
 180         unsigned int id;
 181         u32 irqstatus;
 182
 183         irqstatus = dispc_read_irqstatus();
 184         dispc_clear_irqstatus(irqstatus);
 185         dispc_read_irqstatus();        /* flush posted write */
 186
 187         VERB("irqs: %08x", irqstatus);
 188
 189         for (id = 0; id < priv->num_crtcs; id++)
 190                 if (irqstatus & pipe2vbl(id))
 191                         drm_handle_vblank(dev, id);
 192
 193         spin_lock_irqsave(&list_lock, flags);
 194         list_for_each_entry_safe(handler, n, &priv->irq_list, node) {
 195                 if (handler->irqmask & irqstatus) {
 196                         spin_unlock_irqrestore(&list_lock, flags);
 197                         handler->irq(handler, handler->irqmask & irqstatus);
 198                         spin_lock_irqsave(&list_lock, flags);
 199                 }
 200         }
 201         spin_unlock_irqrestore(&list_lock, flags);
 202
 203         return IRQ_HANDLED;
 204 }
 205
 206 void omap_irq_preinstall(struct drm_device *dev)
 207 {
 208         DBG("dev=%p", dev);
 209         dispc_runtime_get();
 210         dispc_clear_irqstatus(0xffffffff);
 211         dispc_runtime_put();
 212 }
 213
 214 int omap_irq_postinstall(struct drm_device *dev)
 215 {
 216         struct omap_drm_private *priv = dev->dev_private;
 217         struct omap_drm_irq *error_handler = &priv->error_handler;
 218
 219         DBG("dev=%p", dev);
 220
 221         INIT_LIST_HEAD(&priv->irq_list);
 222
 223         error_handler->irq = omap_irq_error_handler;
 224         error_handler->irqmask = DISPC_IRQ_OCP_ERR;
 225
 226         /* for now ignore DISPC_IRQ_SYNC_LOST_DIGIT.. really I think
 227          * we just need to ignore it while enabling tv-out
 228          */
 229         error_handler->irqmask &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
 230
 231         omap_irq_register(dev, error_handler);
 232
 233         return 0;
 234 }
 235
 236 void omap_irq_uninstall(struct drm_device *dev)
 237 {
 238         DBG("dev=%p", dev);
 239         // TODO prolly need to call drm_irq_uninstall() somewhere too
 240 }
 241
 242 /*
 243  * We need a special version, instead of just using drm_irq_install(),
 244  * because we need to register the irq via omapdss.  Once omapdss and
 245  * omapdrm are merged together we can assign the dispc hwmod data to
 246  * ourselves and drop these and just use drm_irq_{install,uninstall}()
 247  */
 248
 249 int omap_drm_irq_install(struct drm_device *dev)
 250 {
 251         int ret;
 252
 253         mutex_lock(&dev->struct_mutex);
 254
 255         if (dev->irq_enabled) {
 256                 mutex_unlock(&dev->struct_mutex);
 257                 return -EBUSY;
 258         }
 259         dev->irq_enabled = 1;
 260         mutex_unlock(&dev->struct_mutex);
 261
 262         /* Before installing handler */
 263         if (dev->driver->irq_preinstall)
 264                 dev->driver->irq_preinstall(dev);
 265
 266         ret = dispc_request_irq(dev->driver->irq_handler, dev);
 267
 268         if (ret < 0) {
 269                 mutex_lock(&dev->struct_mutex);
 270                 dev->irq_enabled = 0;
 271                 mutex_unlock(&dev->struct_mutex);
 272                 return ret;
 273         }
 274
 275         /* After installing handler */
 276         if (dev->driver->irq_postinstall)
 277                 ret = dev->driver->irq_postinstall(dev);
 278
 279         if (ret < 0) {
 280                 mutex_lock(&dev->struct_mutex);
 281                 dev->irq_enabled = 0;
 282                 mutex_unlock(&dev->struct_mutex);
 283                 dispc_free_irq(dev);
 284         }
 285
 286         return ret;
 287 }
 288
 289 int omap_drm_irq_uninstall(struct drm_device *dev)
 290 {
 291         unsigned long irqflags;
 292         int irq_enabled, i;
 293
 294         mutex_lock(&dev->struct_mutex);
 295         irq_enabled = dev->irq_enabled;
 296         dev->irq_enabled = 0;
 297         mutex_unlock(&dev->struct_mutex);
 298
 299         /*
 300          * Wake up any waiters so they don't hang.
 301          */
 302         if (dev->num_crtcs) {
 303                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 304                 for (i = 0; i < dev->num_crtcs; i++) {
 305                         DRM_WAKEUP(&dev->vbl_queue[i]);
 306                         dev->vblank_enabled[i] = 0;
 307                         dev->last_vblank[i] =
 308                                 dev->driver->get_vblank_counter(dev, i);
 309                 }
 310                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 311         }
 312
 313         if (!irq_enabled)
 314                 return -EINVAL;
 315
 316         if (dev->driver->irq_uninstall)
 317                 dev->driver->irq_uninstall(dev);
 318
 319         dispc_free_irq(dev);
 320
 321         return 0;
 322 }