drivers/gpu/drm/rockchip/rockchip_drm_psr.c

   1 /*
   2  * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
   3  * Author: Yakir Yang <ykk@rock-chips.com>
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <drm/drmP.h>
  16 #include <drm/drm_crtc_helper.h>
  17
  18 #include "rockchip_drm_drv.h"
  19 #include "rockchip_drm_psr.h"
  20
  21 #define PSR_FLUSH_TIMEOUT       msecs_to_jiffies(100)
  22
  23 enum psr_state {
  24         PSR_FLUSH,
  25         PSR_ENABLE,
  26         PSR_DISABLE,
  27 };
  28
  29 struct psr_drv {
  30         struct list_head        list;
  31         struct drm_encoder      *encoder;
  32
  33         spinlock_t              lock;
  34         bool                    active;
  35         enum psr_state          state;
  36
  37         struct timer_list       flush_timer;
  38
  39         void (*set)(struct drm_encoder *encoder, bool enable);
  40 };
  41
  42 static struct psr_drv *find_psr_by_crtc(struct drm_crtc *crtc)
  43 {
  44         struct rockchip_drm_private *drm_drv = crtc->dev->dev_private;
  45         struct psr_drv *psr;
  46         unsigned long flags;
  47
  48         spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
  49         list_for_each_entry(psr, &drm_drv->psr_list, list) {
  50                 if (psr->encoder->crtc == crtc)
  51                         goto out;
  52         }
  53         psr = ERR_PTR(-ENODEV);
  54
  55 out:
  56         spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
  57         return psr;
  58 }
  59
  60 static void psr_set_state_locked(struct psr_drv *psr, enum psr_state state)
  61 {
  62         /*
  63          * Allowed finite state machine:
  64          *
  65          *   PSR_ENABLE  < = = = = = >  PSR_FLUSH
  66          *       | ^                        |
  67          *       | |                        |
  68          *       v |                        |
  69          *   PSR_DISABLE < - - - - - - - - -
  70          */
  71         if (state == psr->state || !psr->active)
  72                 return;
  73
  74         /* Already disabled in flush, change the state, but not the hardware */
  75         if (state == PSR_DISABLE && psr->state == PSR_FLUSH) {
  76                 psr->state = state;
  77                 return;
  78         }
  79
  80         psr->state = state;
  81
  82         /* Actually commit the state change to hardware */
  83         switch (psr->state) {
  84         case PSR_ENABLE:
  85                 psr->set(psr->encoder, true);
  86                 break;
  87
  88         case PSR_DISABLE:
  89         case PSR_FLUSH:
  90                 psr->set(psr->encoder, false);
  91                 break;
  92         }
  93 }
  94
  95 static void psr_set_state(struct psr_drv *psr, enum psr_state state)
  96 {
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&psr->lock, flags);
 100         psr_set_state_locked(psr, state);
 101         spin_unlock_irqrestore(&psr->lock, flags);
 102 }
 103
 104 static void psr_flush_handler(unsigned long data)
 105 {
 106         struct psr_drv *psr = (struct psr_drv *)data;
 107         unsigned long flags;
 108
 109         /* If the state has changed since we initiated the flush, do nothing */
 110         spin_lock_irqsave(&psr->lock, flags);
 111         if (psr->state == PSR_FLUSH)
 112                 psr_set_state_locked(psr, PSR_ENABLE);
 113         spin_unlock_irqrestore(&psr->lock, flags);
 114 }
 115
 116 /**
 117  * rockchip_drm_psr_activate - activate PSR on the given pipe
 118  * @crtc: CRTC to obtain the PSR encoder
 119  *
 120  * Returns:
 121  * Zero on success, negative errno on failure.
 122  */
 123 int rockchip_drm_psr_activate(struct drm_crtc *crtc)
 124 {
 125         struct psr_drv *psr = find_psr_by_crtc(crtc);
 126         unsigned long flags;
 127
 128         if (IS_ERR(psr))
 129                 return PTR_ERR(psr);
 130
 131         spin_lock_irqsave(&psr->lock, flags);
 132         psr->active = true;
 133         spin_unlock_irqrestore(&psr->lock, flags);
 134
 135         return 0;
 136 }
 137 EXPORT_SYMBOL(rockchip_drm_psr_activate);
 138
 139 /**
 140  * rockchip_drm_psr_deactivate - deactivate PSR on the given pipe
 141  * @crtc: CRTC to obtain the PSR encoder
 142  *
 143  * Returns:
 144  * Zero on success, negative errno on failure.
 145  */
 146 int rockchip_drm_psr_deactivate(struct drm_crtc *crtc)
 147 {
 148         struct psr_drv *psr = find_psr_by_crtc(crtc);
 149         unsigned long flags;
 150
 151         if (IS_ERR(psr))
 152                 return PTR_ERR(psr);
 153
 154         spin_lock_irqsave(&psr->lock, flags);
 155         psr->active = false;
 156         spin_unlock_irqrestore(&psr->lock, flags);
 157         del_timer_sync(&psr->flush_timer);
 158
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(rockchip_drm_psr_deactivate);
 162
 163 static void rockchip_drm_do_flush(struct psr_drv *psr)
 164 {
 165         mod_timer(&psr->flush_timer,
 166                   round_jiffies_up(jiffies + PSR_FLUSH_TIMEOUT));
 167         psr_set_state(psr, PSR_FLUSH);
 168 }
 169
 170 /**
 171  * rockchip_drm_psr_flush - flush a single pipe
 172  * @crtc: CRTC of the pipe to flush
 173  *
 174  * Returns:
 175  * 0 on success, -errno on fail
 176  */
 177 int rockchip_drm_psr_flush(struct drm_crtc *crtc)
 178 {
 179         struct psr_drv *psr = find_psr_by_crtc(crtc);
 180         if (IS_ERR(psr))
 181                 return PTR_ERR(psr);
 182
 183         rockchip_drm_do_flush(psr);
 184         return 0;
 185 }
 186 EXPORT_SYMBOL(rockchip_drm_psr_flush);
 187
 188 /**
 189  * rockchip_drm_psr_flush_all - force to flush all registered PSR encoders
 190  * @dev: drm device
 191  *
 192  * Disable the PSR function for all registered encoders, and then enable the
 193  * PSR function back after PSR_FLUSH_TIMEOUT. If encoder PSR state have been
 194  * changed during flush time, then keep the state no change after flush
 195  * timeout.
 196  *
 197  * Returns:
 198  * Zero on success, negative errno on failure.
 199  */
 200 void rockchip_drm_psr_flush_all(struct drm_device *dev)
 201 {
 202         struct rockchip_drm_private *drm_drv = dev->dev_private;
 203         struct psr_drv *psr;
 204         unsigned long flags;
 205
 206         spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
 207         list_for_each_entry(psr, &drm_drv->psr_list, list)
 208                 rockchip_drm_do_flush(psr);
 209         spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
 210 }
 211 EXPORT_SYMBOL(rockchip_drm_psr_flush_all);
 212
 213 /**
 214  * rockchip_drm_psr_register - register encoder to psr driver
 215  * @encoder: encoder that obtain the PSR function
 216  * @psr_set: call back to set PSR state
 217  *
 218  * Returns:
 219  * Zero on success, negative errno on failure.
 220  */
 221 int rockchip_drm_psr_register(struct drm_encoder *encoder,
 222                         void (*psr_set)(struct drm_encoder *, bool enable))
 223 {
 224         struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
 225         struct psr_drv *psr;
 226         unsigned long flags;
 227
 228         if (!encoder || !psr_set)
 229                 return -EINVAL;
 230
 231         psr = kzalloc(sizeof(struct psr_drv), GFP_KERNEL);
 232         if (!psr)
 233                 return -ENOMEM;
 234
 235         setup_timer(&psr->flush_timer, psr_flush_handler, (unsigned long)psr);
 236         spin_lock_init(&psr->lock);
 237
 238         psr->active = true;
 239         psr->state = PSR_DISABLE;
 240         psr->encoder = encoder;
 241         psr->set = psr_set;
 242
 243         spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
 244         list_add_tail(&psr->list, &drm_drv->psr_list);
 245         spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
 246
 247         return 0;
 248 }
 249 EXPORT_SYMBOL(rockchip_drm_psr_register);
 250
 251 /**
 252  * rockchip_drm_psr_unregister - unregister encoder to psr driver
 253  * @encoder: encoder that obtain the PSR function
 254  * @psr_set: call back to set PSR state
 255  *
 256  * Returns:
 257  * Zero on success, negative errno on failure.
 258  */
 259 void rockchip_drm_psr_unregister(struct drm_encoder *encoder)
 260 {
 261         struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
 262         struct psr_drv *psr, *n;
 263         unsigned long flags;
 264
 265         spin_lock_irqsave(&drm_drv->psr_list_lock, flags);
 266         list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) {
 267                 if (psr->encoder == encoder) {
 268                         del_timer(&psr->flush_timer);
 269                         list_del(&psr->list);
 270                         kfree(psr);
 271                 }
 272         }
 273         spin_unlock_irqrestore(&drm_drv->psr_list_lock, flags);
 274 }
 275 EXPORT_SYMBOL(rockchip_drm_psr_unregister);