linux/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
Pan Bian 8ac9e914a4 media: mtk-mdp: use IS_ERR to check return value of of_clk_get
Function of_clk_get() returns an ERR_PTR on failures. In file
mtk_mdp_commp.c, its return value is checked against NULL. Such checks
cannot prevent from accessing bad memory. This patch replaces the NULL
checks with IS_ERR checks.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-20 08:20:42 -04:00

158 lines
3.7 KiB
C

/*
* Copyright (c) 2016 MediaTek Inc.
* Author: Ming Hsiu Tsai <minghsiu.tsai@mediatek.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License 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.
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <soc/mediatek/smi.h>
#include "mtk_mdp_comp.h"
static const char * const mtk_mdp_comp_stem[MTK_MDP_COMP_TYPE_MAX] = {
"mdp_rdma",
"mdp_rsz",
"mdp_wdma",
"mdp_wrot",
};
struct mtk_mdp_comp_match {
enum mtk_mdp_comp_type type;
int alias_id;
};
static const struct mtk_mdp_comp_match mtk_mdp_matches[MTK_MDP_COMP_ID_MAX] = {
{ MTK_MDP_RDMA, 0 },
{ MTK_MDP_RDMA, 1 },
{ MTK_MDP_RSZ, 0 },
{ MTK_MDP_RSZ, 1 },
{ MTK_MDP_RSZ, 2 },
{ MTK_MDP_WDMA, 0 },
{ MTK_MDP_WROT, 0 },
{ MTK_MDP_WROT, 1 },
};
int mtk_mdp_comp_get_id(struct device *dev, struct device_node *node,
enum mtk_mdp_comp_type comp_type)
{
int id = of_alias_get_id(node, mtk_mdp_comp_stem[comp_type]);
int i;
for (i = 0; i < ARRAY_SIZE(mtk_mdp_matches); i++) {
if (comp_type == mtk_mdp_matches[i].type &&
id == mtk_mdp_matches[i].alias_id)
return i;
}
dev_err(dev, "Failed to get id. type: %d, id: %d\n", comp_type, id);
return -EINVAL;
}
void mtk_mdp_comp_clock_on(struct device *dev, struct mtk_mdp_comp *comp)
{
int i, err;
if (comp->larb_dev) {
err = mtk_smi_larb_get(comp->larb_dev);
if (err)
dev_err(dev,
"failed to get larb, err %d. type:%d id:%d\n",
err, comp->type, comp->id);
}
for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
if (IS_ERR(comp->clk[i]))
continue;
err = clk_prepare_enable(comp->clk[i]);
if (err)
dev_err(dev,
"failed to enable clock, err %d. type:%d id:%d i:%d\n",
err, comp->type, comp->id, i);
}
}
void mtk_mdp_comp_clock_off(struct device *dev, struct mtk_mdp_comp *comp)
{
int i;
for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
if (IS_ERR(comp->clk[i]))
continue;
clk_disable_unprepare(comp->clk[i]);
}
if (comp->larb_dev)
mtk_smi_larb_put(comp->larb_dev);
}
int mtk_mdp_comp_init(struct device *dev, struct device_node *node,
struct mtk_mdp_comp *comp, enum mtk_mdp_comp_id comp_id)
{
struct device_node *larb_node;
struct platform_device *larb_pdev;
int i;
if (comp_id < 0 || comp_id >= MTK_MDP_COMP_ID_MAX) {
dev_err(dev, "Invalid comp_id %d\n", comp_id);
return -EINVAL;
}
comp->dev_node = of_node_get(node);
comp->id = comp_id;
comp->type = mtk_mdp_matches[comp_id].type;
comp->regs = of_iomap(node, 0);
for (i = 0; i < ARRAY_SIZE(comp->clk); i++) {
comp->clk[i] = of_clk_get(node, i);
/* Only RDMA needs two clocks */
if (comp->type != MTK_MDP_RDMA)
break;
}
/* Only DMA capable components need the LARB property */
comp->larb_dev = NULL;
if (comp->type != MTK_MDP_RDMA &&
comp->type != MTK_MDP_WDMA &&
comp->type != MTK_MDP_WROT)
return 0;
larb_node = of_parse_phandle(node, "mediatek,larb", 0);
if (!larb_node) {
dev_err(dev,
"Missing mediadek,larb phandle in %pOF node\n", node);
return -EINVAL;
}
larb_pdev = of_find_device_by_node(larb_node);
if (!larb_pdev) {
dev_warn(dev, "Waiting for larb device %pOF\n", larb_node);
of_node_put(larb_node);
return -EPROBE_DEFER;
}
of_node_put(larb_node);
comp->larb_dev = &larb_pdev->dev;
return 0;
}
void mtk_mdp_comp_deinit(struct device *dev, struct mtk_mdp_comp *comp)
{
of_node_put(comp->dev_node);
}