// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
* Author: Yakir Yang <ykk@rock-chips.com>
*/
#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_probe_helper.h>
#include "rockchip_drm_drv.h"
#include "rockchip_drm_psr.h"
#define PSR_FLUSH_TIMEOUT_MS 100
struct psr_drv {
struct list_head list;
struct drm_encoder *encoder;
struct mutex lock;
int inhibit_count;
bool enabled;
struct delayed_work flush_work;
int (*set)(struct drm_encoder *encoder, bool enable);
};
static struct psr_drv *find_psr_by_encoder(struct drm_encoder *encoder)
{
struct rockchip_drm_private *drm_drv = encoder->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 == encoder)
goto out;
}
psr = ERR_PTR(-ENODEV);
out:
mutex_unlock(&drm_drv->psr_list_lock);
return psr;
}
static int psr_set_state_locked(struct psr_drv *psr, bool enable)
{
int ret;
if (psr->inhibit_count > 0)
return -EINVAL;
if (enable == psr->enabled)
return 0;
ret = psr->set(psr->encoder, enable);
if (ret)
return ret;
psr->enabled = enable;
return 0;
}
static void psr_flush_handler(struct work_struct *work)
{
struct psr_drv *psr = container_of(to_delayed_work(work),
struct psr_drv, flush_work);
mutex_lock(&psr->lock);
psr_set_state_locked(psr, true);
mutex_unlock(&psr->lock);
}
/**
* 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_inhibit_put(struct drm_encoder *encoder)
{
struct psr_drv *psr = find_psr_by_encoder(encoder);
if (IS_ERR(psr))
return PTR_ERR(psr);
mutex_lock(&psr->lock);
--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_inhibit_put);
void rockchip_drm_psr_inhibit_get_state(struct drm_atomic_state *state)
{
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
struct drm_encoder *encoder;
u32 encoder_mask = 0;
int i;
for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
encoder_mask |= crtc_state->encoder_mask;
encoder_mask |= crtc->state->encoder_mask;
}
drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
rockchip_drm_psr_inhibit_get(encoder);
}
EXPORT_SYMBOL(rockchip_drm_psr_inhibit_get_state);
void rockchip_drm_psr_inhibit_put_state(struct drm_atomic_state *state)
{
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
struct drm_encoder *encoder;
u32 encoder_mask = 0;
int i;
for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
encoder_mask |= crtc_state->encoder_mask;
encoder_mask |= crtc->state->encoder_mask;
}
drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
rockchip_drm_psr_inhibit_put(encoder);
}
EXPORT_SYMBOL(rockchip_drm_psr_inhibit_put_state);
/**
* 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_inhibit_get(struct drm_encoder *encoder)
{
struct psr_drv *psr = find_psr_by_encoder(encoder);
if (IS_ERR(psr))
return PTR_ERR(psr);
mutex_lock(&psr->lock);
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_inhibit_get);
static void rockchip_drm_do_flush(struct psr_drv *psr)
{
cancel_delayed_work_sync(&psr->flush_work);
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);
}
/**
* rockchip_drm_psr_flush_all - 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_all(struct drm_device *dev)
{
struct rockchip_drm_private *drm_drv = dev->dev_private;
struct psr_drv *psr;
mutex_lock(&drm_drv->psr_list_lock);
list_for_each_entry(psr, &drm_drv->psr_list, list)
rockchip_drm_do_flush(psr);
mutex_unlock(&drm_drv->psr_list_lock);
}
EXPORT_SYMBOL(rockchip_drm_psr_flush_all);
/**
* rockchip_drm_psr_register - register encoder to psr driver
* @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,
int (*psr_set)(struct drm_encoder *, bool enable))
{
struct rockchip_drm_private *drm_drv;
struct psr_drv *psr;
if (!encoder || !psr_set)
return -EINVAL;
drm_drv = encoder->dev->dev_private;
psr = kzalloc(sizeof(struct psr_drv), GFP_KERNEL);
if (!psr)
return -ENOMEM;
INIT_DELAYED_WORK(&psr->flush_work, psr_flush_handler);
mutex_init(&psr->lock);
psr->inhibit_count = 1;
psr->enabled = false;
psr->encoder = encoder;
psr->set = psr_set;
mutex_lock(&drm_drv->psr_list_lock);
list_add_tail(&psr->list, &drm_drv->psr_list);
mutex_unlock(&drm_drv->psr_list_lock);
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
*
* 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.
*/
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_lock);
list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) {
if (psr->encoder == encoder) {
/*
* Any other value would mean that the encoder
* is still in use.
*/
WARN_ON(psr->inhibit_count != 1);
list_del(&psr->list);
kfree(psr);
}
}
mutex_unlock(&drm_drv->psr_list_lock);
}
EXPORT_SYMBOL(rockchip_drm_psr_unregister);
