diff options
Diffstat (limited to 'drivers/gpu/drm/rockchip/rockchip_drm_psr.c')
-rw-r--r-- | drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 158 |
1 files changed, 63 insertions, 95 deletions
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index b339ca943139..79d00d861a31 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -20,42 +20,19 @@ #define PSR_FLUSH_TIMEOUT_MS 100 -enum psr_state { - PSR_FLUSH, - PSR_ENABLE, - PSR_DISABLE, -}; - struct psr_drv { struct list_head list; struct drm_encoder *encoder; struct mutex lock; - bool active; - enum psr_state state; + int inhibit_count; + bool enabled; struct delayed_work flush_work; - void (*set)(struct drm_encoder *encoder, bool enable); + int (*set)(struct drm_encoder *encoder, bool enable); }; -static struct psr_drv *find_psr_by_crtc(struct drm_crtc *crtc) -{ - struct rockchip_drm_private *drm_drv = crtc->dev->dev_private; - struct psr_drv *psr; - - mutex_lock(&drm_drv->psr_list_lock); - list_for_each_entry(psr, &drm_drv->psr_list, list) { - if (psr->encoder->crtc == crtc) - goto out; - } - psr = ERR_PTR(-ENODEV); - -out: - mutex_unlock(&drm_drv->psr_list_lock); - return psr; -} - static struct psr_drv *find_psr_by_encoder(struct drm_encoder *encoder) { struct rockchip_drm_private *drm_drv = encoder->dev->dev_private; @@ -73,46 +50,22 @@ out: return psr; } -static void psr_set_state_locked(struct psr_drv *psr, enum psr_state state) +static int psr_set_state_locked(struct psr_drv *psr, bool enable) { - /* - * Allowed finite state machine: - * - * PSR_ENABLE < = = = = = > PSR_FLUSH - * | ^ | - * | | | - * v | | - * PSR_DISABLE < - - - - - - - - - - */ - if (state == psr->state || !psr->active) - return; - - /* Already disabled in flush, change the state, but not the hardware */ - if (state == PSR_DISABLE && psr->state == PSR_FLUSH) { - psr->state = state; - return; - } + int ret; - psr->state = state; + if (psr->inhibit_count > 0) + return -EINVAL; - /* Actually commit the state change to hardware */ - switch (psr->state) { - case PSR_ENABLE: - psr->set(psr->encoder, true); - break; + if (enable == psr->enabled) + return 0; - case PSR_DISABLE: - case PSR_FLUSH: - psr->set(psr->encoder, false); - break; - } -} + ret = psr->set(psr->encoder, enable); + if (ret) + return ret; -static void psr_set_state(struct psr_drv *psr, enum psr_state state) -{ - mutex_lock(&psr->lock); - psr_set_state_locked(psr, state); - mutex_unlock(&psr->lock); + psr->enabled = enable; + return 0; } static void psr_flush_handler(struct work_struct *work) @@ -120,21 +73,24 @@ static void psr_flush_handler(struct work_struct *work) struct psr_drv *psr = container_of(to_delayed_work(work), struct psr_drv, flush_work); - /* If the state has changed since we initiated the flush, do nothing */ mutex_lock(&psr->lock); - if (psr->state == PSR_FLUSH) - psr_set_state_locked(psr, PSR_ENABLE); + psr_set_state_locked(psr, true); mutex_unlock(&psr->lock); } /** - * rockchip_drm_psr_activate - activate PSR on the given pipe + * rockchip_drm_psr_inhibit_put - release PSR inhibit on given encoder * @encoder: encoder to obtain the PSR encoder * + * Decrements PSR inhibit count on given encoder. Should be called only + * for a PSR inhibit count increment done before. If PSR inhibit counter + * reaches zero, PSR flush work is scheduled to make the hardware enter + * PSR mode in PSR_FLUSH_TIMEOUT_MS. + * * Returns: * Zero on success, negative errno on failure. */ -int rockchip_drm_psr_activate(struct drm_encoder *encoder) +int rockchip_drm_psr_inhibit_put(struct drm_encoder *encoder) { struct psr_drv *psr = find_psr_by_encoder(encoder); @@ -142,21 +98,30 @@ int rockchip_drm_psr_activate(struct drm_encoder *encoder) return PTR_ERR(psr); mutex_lock(&psr->lock); - psr->active = true; + --psr->inhibit_count; + WARN_ON(psr->inhibit_count < 0); + if (!psr->inhibit_count) + mod_delayed_work(system_wq, &psr->flush_work, + PSR_FLUSH_TIMEOUT_MS); mutex_unlock(&psr->lock); return 0; } -EXPORT_SYMBOL(rockchip_drm_psr_activate); +EXPORT_SYMBOL(rockchip_drm_psr_inhibit_put); /** - * rockchip_drm_psr_deactivate - deactivate PSR on the given pipe + * rockchip_drm_psr_inhibit_get - acquire PSR inhibit on given encoder * @encoder: encoder to obtain the PSR encoder * + * Increments PSR inhibit count on given encoder. This function guarantees + * that after it returns PSR is turned off on given encoder and no PSR-related + * hardware state change occurs at least until a matching call to + * rockchip_drm_psr_inhibit_put() is done. + * * Returns: * Zero on success, negative errno on failure. */ -int rockchip_drm_psr_deactivate(struct drm_encoder *encoder) +int rockchip_drm_psr_inhibit_get(struct drm_encoder *encoder) { struct psr_drv *psr = find_psr_by_encoder(encoder); @@ -164,37 +129,25 @@ int rockchip_drm_psr_deactivate(struct drm_encoder *encoder) return PTR_ERR(psr); mutex_lock(&psr->lock); - psr->active = false; + psr_set_state_locked(psr, false); + ++psr->inhibit_count; mutex_unlock(&psr->lock); cancel_delayed_work_sync(&psr->flush_work); return 0; } -EXPORT_SYMBOL(rockchip_drm_psr_deactivate); +EXPORT_SYMBOL(rockchip_drm_psr_inhibit_get); static void rockchip_drm_do_flush(struct psr_drv *psr) { - psr_set_state(psr, PSR_FLUSH); - mod_delayed_work(system_wq, &psr->flush_work, PSR_FLUSH_TIMEOUT_MS); -} - -/** - * rockchip_drm_psr_flush - flush a single pipe - * @crtc: CRTC of the pipe to flush - * - * Returns: - * 0 on success, -errno on fail - */ -int rockchip_drm_psr_flush(struct drm_crtc *crtc) -{ - struct psr_drv *psr = find_psr_by_crtc(crtc); - if (IS_ERR(psr)) - return PTR_ERR(psr); + cancel_delayed_work_sync(&psr->flush_work); - rockchip_drm_do_flush(psr); - return 0; + mutex_lock(&psr->lock); + if (!psr_set_state_locked(psr, false)) + mod_delayed_work(system_wq, &psr->flush_work, + PSR_FLUSH_TIMEOUT_MS); + mutex_unlock(&psr->lock); } -EXPORT_SYMBOL(rockchip_drm_psr_flush); /** * rockchip_drm_psr_flush_all - force to flush all registered PSR encoders @@ -225,11 +178,16 @@ EXPORT_SYMBOL(rockchip_drm_psr_flush_all); * @encoder: encoder that obtain the PSR function * @psr_set: call back to set PSR state * + * The function returns with PSR inhibit counter initialized with one + * and the caller (typically encoder driver) needs to call + * rockchip_drm_psr_inhibit_put() when it becomes ready to accept PSR + * enable request. + * * Returns: * Zero on success, negative errno on failure. */ int rockchip_drm_psr_register(struct drm_encoder *encoder, - void (*psr_set)(struct drm_encoder *, bool enable)) + int (*psr_set)(struct drm_encoder *, bool enable)) { struct rockchip_drm_private *drm_drv = encoder->dev->dev_private; struct psr_drv *psr; @@ -244,8 +202,8 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder, INIT_DELAYED_WORK(&psr->flush_work, psr_flush_handler); mutex_init(&psr->lock); - psr->active = true; - psr->state = PSR_DISABLE; + psr->inhibit_count = 1; + psr->enabled = false; psr->encoder = encoder; psr->set = psr_set; @@ -262,6 +220,11 @@ EXPORT_SYMBOL(rockchip_drm_psr_register); * @encoder: encoder that obtain the PSR function * @psr_set: call back to set PSR state * + * It is expected that the PSR inhibit counter is 1 when this function is + * called, which corresponds to a state when related encoder has been + * disconnected from any CRTCs and its driver called + * rockchip_drm_psr_inhibit_get() to stop the PSR logic. + * * Returns: * Zero on success, negative errno on failure. */ @@ -273,7 +236,12 @@ void rockchip_drm_psr_unregister(struct drm_encoder *encoder) mutex_lock(&drm_drv->psr_list_lock); list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) { if (psr->encoder == encoder) { - cancel_delayed_work_sync(&psr->flush_work); + /* + * Any other value would mean that the encoder + * is still in use. + */ + WARN_ON(psr->inhibit_count != 1); + list_del(&psr->list); kfree(psr); } |