linux_dsm_epyc7002/drivers/gpu/drm/exynos/exynos_drm_dpi.c
Tomasz Figa aaa51b13ff drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings
If there is no panel node in DT and instead display timings are provided
directly in FIMD node, there is no panel object created and ctx->panel
becomes NULL. However during Exynos DRM initialization
drm_helper_hpd_irq_event() is called, which in turns calls
exynos_dpi_detect(), which dereferences ctx->panel without a check,
causing a NULL pointer derefrence.

This patch fixes the issue by adding necessary NULL pointer check.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
2014-06-24 11:11:54 +09:00

348 lines
7.4 KiB
C

/*
* Exynos DRM Parallel output support.
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd
*
* Contacts: Andrzej Hajda <a.hajda@samsung.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.
*/
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_panel.h>
#include <linux/regulator/consumer.h>
#include <video/of_videomode.h>
#include <video/videomode.h>
#include "exynos_drm_drv.h"
struct exynos_dpi {
struct device *dev;
struct device_node *panel_node;
struct drm_panel *panel;
struct drm_connector connector;
struct drm_encoder *encoder;
struct videomode *vm;
int dpms_mode;
};
#define connector_to_dpi(c) container_of(c, struct exynos_dpi, connector)
static enum drm_connector_status
exynos_dpi_detect(struct drm_connector *connector, bool force)
{
struct exynos_dpi *ctx = connector_to_dpi(connector);
if (ctx->panel && !ctx->panel->connector)
drm_panel_attach(ctx->panel, &ctx->connector);
return connector_status_connected;
}
static void exynos_dpi_connector_destroy(struct drm_connector *connector)
{
drm_sysfs_connector_remove(connector);
drm_connector_cleanup(connector);
}
static struct drm_connector_funcs exynos_dpi_connector_funcs = {
.dpms = drm_helper_connector_dpms,
.detect = exynos_dpi_detect,
.fill_modes = drm_helper_probe_single_connector_modes,
.destroy = exynos_dpi_connector_destroy,
};
static int exynos_dpi_get_modes(struct drm_connector *connector)
{
struct exynos_dpi *ctx = connector_to_dpi(connector);
/* fimd timings gets precedence over panel modes */
if (ctx->vm) {
struct drm_display_mode *mode;
mode = drm_mode_create(connector->dev);
if (!mode) {
DRM_ERROR("failed to create a new display mode\n");
return 0;
}
drm_display_mode_from_videomode(ctx->vm, mode);
mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
drm_mode_probed_add(connector, mode);
return 1;
}
if (ctx->panel)
return ctx->panel->funcs->get_modes(ctx->panel);
return 0;
}
static struct drm_encoder *
exynos_dpi_best_encoder(struct drm_connector *connector)
{
struct exynos_dpi *ctx = connector_to_dpi(connector);
return ctx->encoder;
}
static struct drm_connector_helper_funcs exynos_dpi_connector_helper_funcs = {
.get_modes = exynos_dpi_get_modes,
.best_encoder = exynos_dpi_best_encoder,
};
static int exynos_dpi_create_connector(struct exynos_drm_display *display,
struct drm_encoder *encoder)
{
struct exynos_dpi *ctx = display->ctx;
struct drm_connector *connector = &ctx->connector;
int ret;
ctx->encoder = encoder;
connector->polled = DRM_CONNECTOR_POLL_HPD;
ret = drm_connector_init(encoder->dev, connector,
&exynos_dpi_connector_funcs,
DRM_MODE_CONNECTOR_VGA);
if (ret) {
DRM_ERROR("failed to initialize connector with drm\n");
return ret;
}
drm_connector_helper_add(connector, &exynos_dpi_connector_helper_funcs);
drm_sysfs_connector_add(connector);
drm_mode_connector_attach_encoder(connector, encoder);
return 0;
}
static void exynos_dpi_poweron(struct exynos_dpi *ctx)
{
if (ctx->panel)
drm_panel_enable(ctx->panel);
}
static void exynos_dpi_poweroff(struct exynos_dpi *ctx)
{
if (ctx->panel)
drm_panel_disable(ctx->panel);
}
static void exynos_dpi_dpms(struct exynos_drm_display *display, int mode)
{
struct exynos_dpi *ctx = display->ctx;
switch (mode) {
case DRM_MODE_DPMS_ON:
if (ctx->dpms_mode != DRM_MODE_DPMS_ON)
exynos_dpi_poweron(ctx);
break;
case DRM_MODE_DPMS_STANDBY:
case DRM_MODE_DPMS_SUSPEND:
case DRM_MODE_DPMS_OFF:
if (ctx->dpms_mode == DRM_MODE_DPMS_ON)
exynos_dpi_poweroff(ctx);
break;
default:
break;
}
ctx->dpms_mode = mode;
}
static struct exynos_drm_display_ops exynos_dpi_display_ops = {
.create_connector = exynos_dpi_create_connector,
.dpms = exynos_dpi_dpms
};
static struct exynos_drm_display exynos_dpi_display = {
.type = EXYNOS_DISPLAY_TYPE_LCD,
.ops = &exynos_dpi_display_ops,
};
/* of_* functions will be removed after merge of of_graph patches */
static struct device_node *
of_get_child_by_name_reg(struct device_node *parent, const char *name, u32 reg)
{
struct device_node *np;
for_each_child_of_node(parent, np) {
u32 r;
if (!np->name || of_node_cmp(np->name, name))
continue;
if (of_property_read_u32(np, "reg", &r) < 0)
r = 0;
if (reg == r)
break;
}
return np;
}
static struct device_node *of_graph_get_port_by_reg(struct device_node *parent,
u32 reg)
{
struct device_node *ports, *port;
ports = of_get_child_by_name(parent, "ports");
if (ports)
parent = ports;
port = of_get_child_by_name_reg(parent, "port", reg);
of_node_put(ports);
return port;
}
static struct device_node *
of_graph_get_endpoint_by_reg(struct device_node *port, u32 reg)
{
return of_get_child_by_name_reg(port, "endpoint", reg);
}
static struct device_node *
of_graph_get_remote_port_parent(const struct device_node *node)
{
struct device_node *np;
unsigned int depth;
np = of_parse_phandle(node, "remote-endpoint", 0);
/* Walk 3 levels up only if there is 'ports' node. */
for (depth = 3; depth && np; depth--) {
np = of_get_next_parent(np);
if (depth == 2 && of_node_cmp(np->name, "ports"))
break;
}
return np;
}
enum {
FIMD_PORT_IN0,
FIMD_PORT_IN1,
FIMD_PORT_IN2,
FIMD_PORT_RGB,
FIMD_PORT_WRB,
};
static struct device_node *exynos_dpi_of_find_panel_node(struct device *dev)
{
struct device_node *np, *ep;
np = of_graph_get_port_by_reg(dev->of_node, FIMD_PORT_RGB);
if (!np)
return NULL;
ep = of_graph_get_endpoint_by_reg(np, 0);
of_node_put(np);
if (!ep)
return NULL;
np = of_graph_get_remote_port_parent(ep);
of_node_put(ep);
return np;
}
static int exynos_dpi_parse_dt(struct exynos_dpi *ctx)
{
struct device *dev = ctx->dev;
struct device_node *dn = dev->of_node;
struct device_node *np;
ctx->panel_node = exynos_dpi_of_find_panel_node(dev);
np = of_get_child_by_name(dn, "display-timings");
if (np) {
struct videomode *vm;
int ret;
of_node_put(np);
vm = devm_kzalloc(dev, sizeof(*ctx->vm), GFP_KERNEL);
if (!vm)
return -ENOMEM;
ret = of_get_videomode(dn, vm, 0);
if (ret < 0) {
devm_kfree(dev, vm);
return ret;
}
ctx->vm = vm;
return 0;
}
if (!ctx->panel_node)
return -EINVAL;
return 0;
}
struct exynos_drm_display *exynos_dpi_probe(struct device *dev)
{
struct exynos_dpi *ctx;
int ret;
ret = exynos_drm_component_add(dev,
EXYNOS_DEVICE_TYPE_CONNECTOR,
exynos_dpi_display.type);
if (ret)
return ERR_PTR(ret);
ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
goto err_del_component;
ctx->dev = dev;
exynos_dpi_display.ctx = ctx;
ctx->dpms_mode = DRM_MODE_DPMS_OFF;
ret = exynos_dpi_parse_dt(ctx);
if (ret < 0) {
devm_kfree(dev, ctx);
goto err_del_component;
}
if (ctx->panel_node) {
ctx->panel = of_drm_find_panel(ctx->panel_node);
if (!ctx->panel) {
exynos_drm_component_del(dev,
EXYNOS_DEVICE_TYPE_CONNECTOR);
return ERR_PTR(-EPROBE_DEFER);
}
}
return &exynos_dpi_display;
err_del_component:
exynos_drm_component_del(dev, EXYNOS_DEVICE_TYPE_CONNECTOR);
return NULL;
}
int exynos_dpi_remove(struct device *dev)
{
struct drm_encoder *encoder = exynos_dpi_display.encoder;
struct exynos_dpi *ctx = exynos_dpi_display.ctx;
exynos_dpi_dpms(&exynos_dpi_display, DRM_MODE_DPMS_OFF);
encoder->funcs->destroy(encoder);
drm_connector_cleanup(&ctx->connector);
exynos_drm_component_del(dev, EXYNOS_DEVICE_TYPE_CONNECTOR);
return 0;
}