OpenCloudOS-Kernel/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_blk.c

156 lines
3.7 KiB
C

/* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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.
*/
#define pr_fmt(fmt) "[drm:%s:%d] " fmt, __func__, __LINE__
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include "dpu_hw_mdss.h"
#include "dpu_hw_blk.h"
/* Serialization lock for dpu_hw_blk_list */
static DEFINE_MUTEX(dpu_hw_blk_lock);
/* List of all hw block objects */
static LIST_HEAD(dpu_hw_blk_list);
/**
* dpu_hw_blk_init - initialize hw block object
* @type: hw block type - enum dpu_hw_blk_type
* @id: instance id of the hw block
* @ops: Pointer to block operations
* return: 0 if success; error code otherwise
*/
int dpu_hw_blk_init(struct dpu_hw_blk *hw_blk, u32 type, int id,
struct dpu_hw_blk_ops *ops)
{
if (!hw_blk) {
pr_err("invalid parameters\n");
return -EINVAL;
}
INIT_LIST_HEAD(&hw_blk->list);
hw_blk->type = type;
hw_blk->id = id;
atomic_set(&hw_blk->refcount, 0);
if (ops)
hw_blk->ops = *ops;
mutex_lock(&dpu_hw_blk_lock);
list_add(&hw_blk->list, &dpu_hw_blk_list);
mutex_unlock(&dpu_hw_blk_lock);
return 0;
}
/**
* dpu_hw_blk_destroy - destroy hw block object.
* @hw_blk: pointer to hw block object
* return: none
*/
void dpu_hw_blk_destroy(struct dpu_hw_blk *hw_blk)
{
if (!hw_blk) {
pr_err("invalid parameters\n");
return;
}
if (atomic_read(&hw_blk->refcount))
pr_err("hw_blk:%d.%d invalid refcount\n", hw_blk->type,
hw_blk->id);
mutex_lock(&dpu_hw_blk_lock);
list_del(&hw_blk->list);
mutex_unlock(&dpu_hw_blk_lock);
}
/**
* dpu_hw_blk_get - get hw_blk from free pool
* @hw_blk: if specified, increment reference count only
* @type: if hw_blk is not specified, allocate the next available of this type
* @id: if specified (>= 0), allocate the given instance of the above type
* return: pointer to hw block object
*/
struct dpu_hw_blk *dpu_hw_blk_get(struct dpu_hw_blk *hw_blk, u32 type, int id)
{
struct dpu_hw_blk *curr;
int rc, refcount;
if (!hw_blk) {
mutex_lock(&dpu_hw_blk_lock);
list_for_each_entry(curr, &dpu_hw_blk_list, list) {
if ((curr->type != type) ||
(id >= 0 && curr->id != id) ||
(id < 0 &&
atomic_read(&curr->refcount)))
continue;
hw_blk = curr;
break;
}
mutex_unlock(&dpu_hw_blk_lock);
}
if (!hw_blk) {
pr_debug("no hw_blk:%d\n", type);
return NULL;
}
refcount = atomic_inc_return(&hw_blk->refcount);
if (refcount == 1 && hw_blk->ops.start) {
rc = hw_blk->ops.start(hw_blk);
if (rc) {
pr_err("failed to start hw_blk:%d rc:%d\n", type, rc);
goto error_start;
}
}
pr_debug("hw_blk:%d.%d refcount:%d\n", hw_blk->type,
hw_blk->id, refcount);
return hw_blk;
error_start:
dpu_hw_blk_put(hw_blk);
return ERR_PTR(rc);
}
/**
* dpu_hw_blk_put - put hw_blk to free pool if decremented refcount is zero
* @hw_blk: hw block to be freed
* @free_blk: function to be called when reference count goes to zero
*/
void dpu_hw_blk_put(struct dpu_hw_blk *hw_blk)
{
if (!hw_blk) {
pr_err("invalid parameters\n");
return;
}
pr_debug("hw_blk:%d.%d refcount:%d\n", hw_blk->type, hw_blk->id,
atomic_read(&hw_blk->refcount));
if (!atomic_read(&hw_blk->refcount)) {
pr_err("hw_blk:%d.%d invalid put\n", hw_blk->type, hw_blk->id);
return;
}
if (atomic_dec_return(&hw_blk->refcount))
return;
if (hw_blk->ops.stop)
hw_blk->ops.stop(hw_blk);
}