--- /dev/null
+/*
+ * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
+ * Author: Yakir Yang <ykk@rock-chips.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+
+#include "rockchip_drm_drv.h"
+#include "rockchip_drm_psr.h"
+
+#define PSR_FLUSH_TIMEOUT msecs_to_jiffies(3000) /* 3 seconds */
+#define PSR_SET_DELAY_TIME msecs_to_jiffies(10)
+
+enum psr_state {
+ PSR_FLUSH,
+ PSR_ENABLE,
+ PSR_DISABLE,
+};
+
+struct psr_drv {
+ struct list_head list;
+ struct drm_encoder *encoder;
+
+ enum psr_state request_state;
+ enum psr_state state;
+
+ struct delayed_work state_work;
+
+ struct timer_list flush_timer;
+
+ void (*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;
+
+ list_for_each_entry(psr, &drm_drv->psr_list, list)
+ if (psr->encoder->crtc == crtc)
+ return psr;
+
+ return ERR_PTR(-ENODEV);
+}
+
+static void psr_state_work(struct work_struct *work)
+{
+ struct psr_drv *psr = container_of(work, typeof(*psr), state_work.work);
+ enum psr_state request_state = psr->request_state;
+
+ /*
+ * Allowed finite state machine:
+ *
+ * PSR_ENABLE < = = = = = > PSR_FLUSH
+ * | ^ |
+ * | | |
+ * v | |
+ * PSR_DISABLE < - - - - - - - - -
+ */
+
+ /* Forbid no state change */
+ if (request_state == psr->state)
+ return;
+
+ /* Forbid DISABLE change to FLUSH */
+ if (request_state == PSR_FLUSH && psr->state == PSR_DISABLE)
+ return;
+
+ /* Allow but no need hardware change, just need assign the state */
+ if (request_state == PSR_DISABLE && psr->state == PSR_FLUSH) {
+ psr->state = request_state;
+ return;
+ }
+
+ /* Only wrote in this work, no need lock protection */
+ psr->state = request_state;
+
+ /* Refact to hardware state change */
+ switch (request_state) {
+ case PSR_ENABLE:
+ psr->set(psr->encoder, true);
+ break;
+
+ case PSR_DISABLE:
+ case PSR_FLUSH:
+ psr->set(psr->encoder, false);
+ break;
+ }
+}
+
+static void psr_set_state(struct psr_drv *psr, enum psr_state state)
+{
+ psr->request_state = state;
+
+ schedule_delayed_work(&psr->state_work, PSR_SET_DELAY_TIME);
+}
+
+static void psr_flush_handler(unsigned long data)
+{
+ struct psr_drv *psr = (struct psr_drv *)data;
+
+ if (!psr)
+ return;
+
+ /* State changed between flush time, then keep it */
+ if (psr->request_state != PSR_FLUSH)
+ return;
+
+ psr_set_state(psr, PSR_ENABLE);
+}
+
+/**
+ * rockchip_drm_psr_enable - enable the encoder PSR which bind to given CRTC
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_enable(struct drm_crtc *crtc)
+{
+ struct psr_drv *psr = find_psr_by_crtc(crtc);
+
+ if (IS_ERR(psr))
+ return PTR_ERR(psr);
+
+ psr_set_state(psr, PSR_ENABLE);
+ return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_enable);
+
+/**
+ * rockchip_drm_psr_disable - disable the encoder PSR which bind to given CRTC
+ * @crtc: CRTC to obtain the PSR encoder
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_psr_disable(struct drm_crtc *crtc)
+{
+ struct psr_drv *psr = find_psr_by_crtc(crtc);
+
+ if (IS_ERR(psr))
+ return PTR_ERR(psr);
+
+ psr_set_state(psr, PSR_DISABLE);
+ return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_disable);
+
+/**
+ * rockchip_drm_psr_flush - force to flush all registered PSR encoders
+ * @dev: drm device
+ *
+ * Disable the PSR function for all registered encoders, and then enable the
+ * PSR function back after PSR_FLUSH_TIMEOUT. If encoder PSR state have been
+ * changed during flush time, then keep the state no change after flush
+ * timeout.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+void rockchip_drm_psr_flush(struct drm_device *dev)
+{
+ struct rockchip_drm_private *drm_drv = dev->dev_private;
+ struct psr_drv *psr;
+
+ list_for_each_entry(psr, &drm_drv->psr_list, list) {
+ if (psr->request_state == PSR_DISABLE)
+ continue;
+
+ mod_timer(&psr->flush_timer,
+ round_jiffies_up(jiffies + PSR_FLUSH_TIMEOUT));
+
+ psr_set_state(psr, PSR_FLUSH);
+ }
+}
+EXPORT_SYMBOL(rockchip_drm_psr_flush);
+
+/**
+ * rockchip_drm_psr_register - register encoder to psr driver
+ * @encoder: encoder that obtain the PSR function
+ * @psr_set: call back to set PSR state
+ *
+ * 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))
+{
+ struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
+ struct psr_drv *psr;
+
+ if (!encoder || !psr_set)
+ return -EINVAL;
+
+ psr = kzalloc(sizeof(struct psr_drv), GFP_KERNEL);
+ if (!psr)
+ return -ENOMEM;
+
+ setup_timer(&psr->flush_timer, psr_flush_handler, (unsigned long)psr);
+
+ INIT_DELAYED_WORK(&psr->state_work, psr_state_work);
+
+ psr->state = PSR_DISABLE;
+ psr->encoder = encoder;
+ psr->set = psr_set;
+
+ mutex_lock(&drm_drv->psr_list_mutex);
+ list_add_tail(&psr->list, &drm_drv->psr_list);
+ mutex_unlock(&drm_drv->psr_list_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_psr_register);
+
+/**
+ * rockchip_drm_psr_unregister - unregister encoder to psr driver
+ * @encoder: encoder that obtain the PSR function
+ * @psr_set: call back to set PSR state
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+void rockchip_drm_psr_unregister(struct drm_encoder *encoder)
+{
+ struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
+ struct psr_drv *psr, *n;
+
+ mutex_lock(&drm_drv->psr_list_mutex);
+ list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) {
+ if (psr->encoder == encoder) {
+ del_timer(&psr->flush_timer);
+ list_del(&psr->list);
+ kfree(psr);
+ }
+ }
+ mutex_unlock(&drm_drv->psr_list_mutex);
+}
+EXPORT_SYMBOL(rockchip_drm_psr_unregister);
projects / cascardo / linux.git / commitdiff