kernel/drivers/gpu/drm/omapdrm/omap_irq.c

   1 /*
   2  * drivers/gpu/drm/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         assert_spin_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         spin_lock_irqsave(&list_lock, flags);
  54
  55         if (!WARN_ON(irq->registered)) {
  56                 irq->registered = true;
  57                 list_add(&irq->node, &priv->irq_list);
  58                 omap_irq_update(dev);
  59         }
  60
  61         spin_unlock_irqrestore(&list_lock, flags);
  62 }
  63
  64 void omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq)
  65 {
  66         dispc_runtime_get();
  67
  68         __omap_irq_register(dev, irq);
  69
  70         dispc_runtime_put();
  71 }
  72
  73 void __omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq)
  74 {
  75         unsigned long flags;
  76
  77         spin_lock_irqsave(&list_lock, flags);
  78
  79         if (!WARN_ON(!irq->registered)) {
  80                 irq->registered = false;
  81                 list_del(&irq->node);
  82                 omap_irq_update(dev);
  83         }
  84
  85         spin_unlock_irqrestore(&list_lock, flags);
  86 }
  87
  88 void omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq)
  89 {
  90         dispc_runtime_get();
  91
  92         __omap_irq_unregister(dev, irq);
  93
  94         dispc_runtime_put();
  95 }
  96
  97 struct omap_irq_wait {
  98         struct omap_drm_irq irq;
  99         int count;
 100 };
 101
 102 static DECLARE_WAIT_QUEUE_HEAD(wait_event);
 103
 104 static void wait_irq(struct omap_drm_irq *irq, uint32_t irqstatus)
 105 {
 106         struct omap_irq_wait *wait =
 107                         container_of(irq, struct omap_irq_wait, irq);
 108         wait->count--;
 109         wake_up_all(&wait_event);
 110 }
 111
 112 struct omap_irq_wait * omap_irq_wait_init(struct drm_device *dev,
 113                 uint32_t irqmask, int count)
 114 {
 115         struct omap_irq_wait *wait = kzalloc(sizeof(*wait), GFP_KERNEL);
 116         wait->irq.irq = wait_irq;
 117         wait->irq.irqmask = irqmask;
 118         wait->count = count;
 119         omap_irq_register(dev, &wait->irq);
 120         return wait;
 121 }
 122
 123 int omap_irq_wait(struct drm_device *dev, struct omap_irq_wait *wait,
 124                 unsigned long timeout)
 125 {
 126         int ret = wait_event_timeout(wait_event, (wait->count <= 0), timeout);
 127         omap_irq_unregister(dev, &wait->irq);
 128         kfree(wait);
 129         if (ret == 0)
 130                 return -1;
 131         return 0;
 132 }
 133
 134 /**
 135  * enable_vblank - enable vblank interrupt events
 136  * @dev: DRM device
 137  * @crtc: which irq to enable
 138  *
 139  * Enable vblank interrupts for @crtc.  If the device doesn't have
 140  * a hardware vblank counter, this routine should be a no-op, since
 141  * interrupts will have to stay on to keep the count accurate.
 142  *
 143  * RETURNS
 144  * Zero on success, appropriate errno if the given @crtc's vblank
 145  * interrupt cannot be enabled.
 146  */
 147 int omap_irq_enable_vblank(struct drm_device *dev, int crtc_id)
 148 {
 149         struct omap_drm_private *priv = dev->dev_private;
 150         struct drm_crtc *crtc = priv->crtcs[crtc_id];
 151         unsigned long flags;
 152
 153         DBG("dev=%p, crtc=%d", dev, crtc_id);
 154
 155         dispc_runtime_get();
 156         spin_lock_irqsave(&list_lock, flags);
 157         priv->vblank_mask |= pipe2vbl(crtc);
 158         omap_irq_update(dev);
 159         spin_unlock_irqrestore(&list_lock, flags);
 160         dispc_runtime_put();
 161
 162         return 0;
 163 }
 164
 165 /**
 166  * disable_vblank - disable vblank interrupt events
 167  * @dev: DRM device
 168  * @crtc: which irq to enable
 169  *
 170  * Disable vblank interrupts for @crtc.  If the device doesn't have
 171  * a hardware vblank counter, this routine should be a no-op, since
 172  * interrupts will have to stay on to keep the count accurate.
 173  */
 174 void omap_irq_disable_vblank(struct drm_device *dev, int crtc_id)
 175 {
 176         struct omap_drm_private *priv = dev->dev_private;
 177         struct drm_crtc *crtc = priv->crtcs[crtc_id];
 178         unsigned long flags;
 179
 180         DBG("dev=%p, crtc=%d", dev, crtc_id);
 181
 182         dispc_runtime_get();
 183         spin_lock_irqsave(&list_lock, flags);
 184         priv->vblank_mask &= ~pipe2vbl(crtc);
 185         omap_irq_update(dev);
 186         spin_unlock_irqrestore(&list_lock, flags);
 187         dispc_runtime_put();
 188 }
 189
 190 irqreturn_t omap_irq_handler(int irq, void *arg)
 191 {
 192         struct drm_device *dev = (struct drm_device *) arg;
 193         struct omap_drm_private *priv = dev->dev_private;
 194         struct omap_drm_irq *handler, *n;
 195         unsigned long flags;
 196         unsigned int id;
 197         u32 irqstatus;
 198
 199         irqstatus = dispc_read_irqstatus();
 200         dispc_clear_irqstatus(irqstatus);
 201         dispc_read_irqstatus();        /* flush posted write */
 202
 203         VERB("irqs: %08x", irqstatus);
 204
 205         for (id = 0; id < priv->num_crtcs; id++) {
 206                 struct drm_crtc *crtc = priv->crtcs[id];
 207
 208                 if (irqstatus & pipe2vbl(crtc))
 209                         drm_handle_vblank(dev, id);
 210         }
 211
 212         spin_lock_irqsave(&list_lock, flags);
 213         list_for_each_entry_safe(handler, n, &priv->irq_list, node) {
 214                 if (handler->irqmask & irqstatus) {
 215                         spin_unlock_irqrestore(&list_lock, flags);
 216                         handler->irq(handler, handler->irqmask & irqstatus);
 217                         spin_lock_irqsave(&list_lock, flags);
 218                 }
 219         }
 220         spin_unlock_irqrestore(&list_lock, flags);
 221
 222         return IRQ_HANDLED;
 223 }
 224
 225 void omap_irq_preinstall(struct drm_device *dev)
 226 {
 227         DBG("dev=%p", dev);
 228         dispc_runtime_get();
 229         dispc_clear_irqstatus(0xffffffff);
 230         dispc_runtime_put();
 231 }
 232
 233 int omap_irq_postinstall(struct drm_device *dev)
 234 {
 235         struct omap_drm_private *priv = dev->dev_private;
 236         struct omap_drm_irq *error_handler = &priv->error_handler;
 237
 238         DBG("dev=%p", dev);
 239
 240         INIT_LIST_HEAD(&priv->irq_list);
 241
 242         error_handler->irq = omap_irq_error_handler;
 243         error_handler->irqmask = DISPC_IRQ_OCP_ERR;
 244
 245         /* for now ignore DISPC_IRQ_SYNC_LOST_DIGIT.. really I think
 246          * we just need to ignore it while enabling tv-out
 247          */
 248         error_handler->irqmask &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
 249
 250         omap_irq_register(dev, error_handler);
 251
 252         return 0;
 253 }
 254
 255 void omap_irq_uninstall(struct drm_device *dev)
 256 {
 257         DBG("dev=%p", dev);
 258         // TODO prolly need to call drm_irq_uninstall() somewhere too
 259 }
 260
 261 /*
 262  * We need a special version, instead of just using drm_irq_install(),
 263  * because we need to register the irq via omapdss.  Once omapdss and
 264  * omapdrm are merged together we can assign the dispc hwmod data to
 265  * ourselves and drop these and just use drm_irq_{install,uninstall}()
 266  */
 267
 268 int omap_drm_irq_install(struct drm_device *dev)
 269 {
 270         int ret;
 271
 272         mutex_lock(&dev->struct_mutex);
 273
 274         if (dev->irq_enabled) {
 275                 mutex_unlock(&dev->struct_mutex);
 276                 return -EBUSY;
 277         }
 278         dev->irq_enabled = true;
 279         mutex_unlock(&dev->struct_mutex);
 280
 281         /* Before installing handler */
 282         if (dev->driver->irq_preinstall)
 283                 dev->driver->irq_preinstall(dev);
 284
 285         ret = dispc_request_irq(dev->driver->irq_handler, dev);
 286
 287         if (ret < 0) {
 288                 mutex_lock(&dev->struct_mutex);
 289                 dev->irq_enabled = false;
 290                 mutex_unlock(&dev->struct_mutex);
 291                 return ret;
 292         }
 293
 294         /* After installing handler */
 295         if (dev->driver->irq_postinstall)
 296                 ret = dev->driver->irq_postinstall(dev);
 297
 298         if (ret < 0) {
 299                 mutex_lock(&dev->struct_mutex);
 300                 dev->irq_enabled = false;
 301                 mutex_unlock(&dev->struct_mutex);
 302                 dispc_free_irq(dev);
 303         }
 304
 305         return ret;
 306 }
 307
 308 int omap_drm_irq_uninstall(struct drm_device *dev)
 309 {
 310         unsigned long irqflags;
 311         bool irq_enabled;
 312         int i;
 313
 314         mutex_lock(&dev->struct_mutex);
 315         irq_enabled = dev->irq_enabled;
 316         dev->irq_enabled = false;
 317         mutex_unlock(&dev->struct_mutex);
 318
 319         /*
 320          * Wake up any waiters so they don't hang.
 321          */
 322         if (dev->num_crtcs) {
 323                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 324                 for (i = 0; i < dev->num_crtcs; i++) {
 325                         wake_up(&dev->vblank[i].queue);
 326                         dev->vblank[i].enabled = false;
 327                         dev->vblank[i].last =
 328                                 dev->driver->get_vblank_counter(dev, i);
 329                 }
 330                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 331         }
 332
 333         if (!irq_enabled)
 334                 return -EINVAL;
 335
 336         if (dev->driver->irq_uninstall)
 337                 dev->driver->irq_uninstall(dev);
 338
 339         dispc_free_irq(dev);
 340
 341         return 0;
 342 }