/*
* Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sub license,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/module.h>
#include <drm/drm_crtc.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
static DEFINE_MUTEX(panel_lock);
static LIST_HEAD(panel_list);
/**
* DOC: drm panel
*
* The DRM panel helpers allow drivers to register panel objects with a
* central registry and provide functions to retrieve those panels in display
* drivers.
*
* For easy integration into drivers using the &drm_bridge infrastructure please
* take look at drm_panel_bridge_add() and devm_drm_panel_bridge_add().
*/
/**
* drm_panel_init - initialize a panel
* @panel: DRM panel
* @dev: parent device of the panel
* @funcs: panel operations
* @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
* the panel interface
*
* Initialize the panel structure for subsequent registration with
* drm_panel_add().
*/
void drm_panel_init(struct drm_panel *panel, struct device *dev,
const struct drm_panel_funcs *funcs, int connector_type)
{
INIT_LIST_HEAD(&panel->list);
INIT_LIST_HEAD(&panel->followers);
mutex_init(&panel->follower_lock);
panel->dev = dev;
panel->funcs = funcs;
panel->connector_type = connector_type;
}
EXPORT_SYMBOL(drm_panel_init);
/**
* drm_panel_add - add a panel to the global registry
* @panel: panel to add
*
* Add a panel to the global registry so that it can be looked up by display
* drivers.
*/
void drm_panel_add(struct drm_panel *panel)
{
mutex_lock(&panel_lock);
list_add_tail(&panel->list, &panel_list);
mutex_unlock(&panel_lock);
}
EXPORT_SYMBOL(drm_panel_add);
/**
* drm_panel_remove - remove a panel from the global registry
* @panel: DRM panel
*
* Removes a panel from the global registry.
*/
void drm_panel_remove(struct drm_panel *panel)
{
mutex_lock(&panel_lock);
list_del_init(&panel->list);
mutex_unlock(&panel_lock);
}
EXPORT_SYMBOL(drm_panel_remove);
/**
* drm_panel_prepare - power on a panel
* @panel: DRM panel
*
* Calling this function will enable power and deassert any reset signals to
* the panel. After this has completed it is possible to communicate with any
* integrated circuitry via a command bus.
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_panel_prepare(struct drm_panel *panel)
{
struct drm_panel_follower *follower;
int ret;
if (!panel)
return -EINVAL;
if (panel->prepared) {
dev_warn(panel->dev, "Skipping prepare of already prepared panel\n");
return 0;
}
mutex_lock(&panel->follower_lock);
if (panel->funcs && panel->funcs->prepare) {
ret = panel->funcs->prepare(panel);
if (ret < 0)
goto exit;
}
panel->prepared = true;
list_for_each_entry(follower, &panel->followers, list) {
ret = follower->funcs->panel_prepared(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
follower->funcs->panel_prepared, ret);
}
ret = 0;
exit:
mutex_unlock(&panel->follower_lock);
return ret;
}
EXPORT_SYMBOL(drm_panel_prepare);
/**
* drm_panel_unprepare - power off a panel
* @panel: DRM panel
*
* Calling this function will completely power off a panel (assert the panel's
* reset, turn off power supplies, ...). After this function has completed, it
* is usually no longer possible to communicate with the panel until another
* call to drm_panel_prepare().
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_panel_unprepare(struct drm_panel *panel)
{
struct drm_panel_follower *follower;
int ret;
if (!panel)
return -EINVAL;
/*
* If you are seeing the warning below it likely means one of two things:
* - Your panel driver incorrectly calls drm_panel_unprepare() in its
* shutdown routine. You should delete this.
* - You are using panel-edp or panel-simple and your DRM modeset
* driver's shutdown() callback happened after the panel's shutdown().
* In this case the warning is harmless though ideally you should
* figure out how to reverse the order of the shutdown() callbacks.
*/
if (!panel->prepared) {
dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n");
return 0;
}
mutex_lock(&panel->follower_lock);
list_for_each_entry(follower, &panel->followers, list) {
ret = follower->funcs->panel_unpreparing(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
follower->funcs->panel_unpreparing, ret);
}
if (panel->funcs && panel->funcs->unprepare) {
ret = panel->funcs->unprepare(panel);
if (ret < 0)
goto exit;
}
panel->prepared = false;
ret = 0;
exit:
mutex_unlock(&panel->follower_lock);
return ret;
}
EXPORT_SYMBOL(drm_panel_unprepare);
/**
* drm_panel_enable - enable a panel
* @panel: DRM panel
*
* Calling this function will cause the panel display drivers to be turned on
* and the backlight to be enabled. Content will be visible on screen after
* this call completes.
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_panel_enable(struct drm_panel *panel)
{
int ret;
if (!panel)
return -EINVAL;
if (panel->enabled) {
dev_warn(panel->dev, "Skipping enable of already enabled panel\n");
return 0;
}
if (panel->funcs && panel->funcs->enable) {
ret = panel->funcs->enable(panel);
if (ret < 0)
return ret;
}
panel->enabled = true;
ret = backlight_enable(panel->backlight);
if (ret < 0)
DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",
ret);
return 0;
}
EXPORT_SYMBOL(drm_panel_enable);
/**
* drm_panel_disable - disable a panel
* @panel: DRM panel
*
* This will typically turn off the panel's backlight or disable the display
* drivers. For smart panels it should still be possible to communicate with
* the integrated circuitry via any command bus after this call.
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_panel_disable(struct drm_panel *panel)
{
int ret;
if (!panel)
return -EINVAL;
/*
* If you are seeing the warning below it likely means one of two things:
* - Your panel driver incorrectly calls drm_panel_disable() in its
* shutdown routine. You should delete this.
* - You are using panel-edp or panel-simple and your DRM modeset
* driver's shutdown() callback happened after the panel's shutdown().
* In this case the warning is harmless though ideally you should
* figure out how to reverse the order of the shutdown() callbacks.
*/
if (!panel->enabled) {
dev_warn(panel->dev, "Skipping disable of already disabled panel\n");
return 0;
}
ret = backlight_disable(panel->backlight);
if (ret < 0)
DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
ret);
if (panel->funcs && panel->funcs->disable) {
ret = panel->funcs->disable(panel);
if (ret < 0)
return ret;
}
panel->enabled = false;
return 0;
}
EXPORT_SYMBOL(drm_panel_disable);
/**
* drm_panel_get_modes - probe the available display modes of a panel
* @panel: DRM panel
* @connector: DRM connector
*
* The modes probed from the panel are automatically added to the connector
* that the panel is attached to.
*
* Return: The number of modes available from the panel on success, or 0 on
* failure (no modes).
*/
int drm_panel_get_modes(struct drm_panel *panel,
struct drm_connector *connector)
{
if (!panel)
return 0;
if (panel->funcs && panel->funcs->get_modes) {
int num;
num = panel->funcs->get_modes(panel, connector);
if (num > 0)
return num;
}
return 0;
}
EXPORT_SYMBOL(drm_panel_get_modes);
#ifdef CONFIG_OF
/**
* of_drm_find_panel - look up a panel using a device tree node
* @np: device tree node of the panel
*
* Searches the set of registered panels for one that matches the given device
* tree node. If a matching panel is found, return a pointer to it.
*
* Return: A pointer to the panel registered for the specified device tree
* node or an ERR_PTR() if no panel matching the device tree node can be found.
*
* Possible error codes returned by this function:
*
* - EPROBE_DEFER: the panel device has not been probed yet, and the caller
* should retry later
* - ENODEV: the device is not available (status != "okay" or "ok")
*/
struct drm_panel *of_drm_find_panel(const struct device_node *np)
{
struct drm_panel *panel;
if (!of_device_is_available(np))
return ERR_PTR(-ENODEV);
mutex_lock(&panel_lock);
list_for_each_entry(panel, &panel_list, list) {
if (panel->dev->of_node == np) {
mutex_unlock(&panel_lock);
return panel;
}
}
mutex_unlock(&panel_lock);
return ERR_PTR(-EPROBE_DEFER);
}
EXPORT_SYMBOL(of_drm_find_panel);
/**
* of_drm_get_panel_orientation - look up the orientation of the panel through
* the "rotation" binding from a device tree node
* @np: device tree node of the panel
* @orientation: orientation enum to be filled in
*
* Looks up the rotation of a panel in the device tree. The orientation of the
* panel is expressed as a property name "rotation" in the device tree. The
* rotation in the device tree is counter clockwise.
*
* Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
* rotation property doesn't exist. Return a negative error code on failure.
*/
int of_drm_get_panel_orientation(const struct device_node *np,
enum drm_panel_orientation *orientation)
{
int rotation, ret;
ret = of_property_read_u32(np, "rotation", &rotation);
if (ret == -EINVAL) {
/* Don't return an error if there's no rotation property. */
*orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
return 0;
}
if (ret < 0)
return ret;
if (rotation == 0)
*orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL;
else if (rotation == 90)
*orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP;
else if (rotation == 180)
*orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP;
else if (rotation == 270)
*orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP;
else
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(of_drm_get_panel_orientation);
#endif
/**
* drm_is_panel_follower() - Check if the device is a panel follower
* @dev: The 'struct device' to check
*
* This checks to see if a device needs to be power sequenced together with
* a panel using the panel follower API.
* At the moment panels can only be followed on device tree enabled systems.
* The "panel" property of the follower points to the panel to be followed.
*
* Return: true if we should be power sequenced with a panel; false otherwise.
*/
bool drm_is_panel_follower(struct device *dev)
{
/*
* The "panel" property is actually a phandle, but for simplicity we
* don't bother trying to parse it here. We just need to know if the
* property is there.
*/
return of_property_read_bool(dev->of_node, "panel");
}
EXPORT_SYMBOL(drm_is_panel_follower);
/**
* drm_panel_add_follower() - Register something to follow panel state.
* @follower_dev: The 'struct device' for the follower.
* @follower: The panel follower descriptor for the follower.
*
* A panel follower is called right after preparing the panel and right before
* unpreparing the panel. It's primary intention is to power on an associated
* touchscreen, though it could be used for any similar devices. Multiple
* devices are allowed the follow the same panel.
*
* If a follower is added to a panel that's already been turned on, the
* follower's prepare callback is called right away.
*
* At the moment panels can only be followed on device tree enabled systems.
* The "panel" property of the follower points to the panel to be followed.
*
* Return: 0 or an error code. Note that -ENODEV means that we detected that
* follower_dev is not actually following a panel. The caller may
* choose to ignore this return value if following a panel is optional.
*/
int drm_panel_add_follower(struct device *follower_dev,
struct drm_panel_follower *follower)
{
struct device_node *panel_np;
struct drm_panel *panel;
int ret;
panel_np = of_parse_phandle(follower_dev->of_node, "panel", 0);
if (!panel_np)
return -ENODEV;
panel = of_drm_find_panel(panel_np);
of_node_put(panel_np);
if (IS_ERR(panel))
return PTR_ERR(panel);
get_device(panel->dev);
follower->panel = panel;
mutex_lock(&panel->follower_lock);
list_add_tail(&follower->list, &panel->followers);
if (panel->prepared) {
ret = follower->funcs->panel_prepared(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
follower->funcs->panel_prepared, ret);
}
mutex_unlock(&panel->follower_lock);
return 0;
}
EXPORT_SYMBOL(drm_panel_add_follower);
/**
* drm_panel_remove_follower() - Reverse drm_panel_add_follower().
* @follower: The panel follower descriptor for the follower.
*
* Undo drm_panel_add_follower(). This includes calling the follower's
* unprepare function if we're removed from a panel that's currently prepared.
*
* Return: 0 or an error code.
*/
void drm_panel_remove_follower(struct drm_panel_follower *follower)
{
struct drm_panel *panel = follower->panel;
int ret;
mutex_lock(&panel->follower_lock);
if (panel->prepared) {
ret = follower->funcs->panel_unpreparing(follower);
if (ret < 0)
dev_info(panel->dev, "%ps failed: %d\n",
follower->funcs->panel_unpreparing, ret);
}
list_del_init(&follower->list);
mutex_unlock(&panel->follower_lock);
put_device(panel->dev);
}
EXPORT_SYMBOL(drm_panel_remove_follower);
static void drm_panel_remove_follower_void(void *follower)
{
drm_panel_remove_follower(follower);
}
/**
* devm_drm_panel_add_follower() - devm version of drm_panel_add_follower()
* @follower_dev: The 'struct device' for the follower.
* @follower: The panel follower descriptor for the follower.
*
* Handles calling drm_panel_remove_follower() using devm on the follower_dev.
*
* Return: 0 or an error code.
*/
int devm_drm_panel_add_follower(struct device *follower_dev,
struct drm_panel_follower *follower)
{
int ret;
ret = drm_panel_add_follower(follower_dev, follower);
if (ret)
return ret;
return devm_add_action_or_reset(follower_dev,
drm_panel_remove_follower_void, follower);
}
EXPORT_SYMBOL(devm_drm_panel_add_follower);
#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
/**
* drm_panel_of_backlight - use backlight device node for backlight
* @panel: DRM panel
*
* Use this function to enable backlight handling if your panel
* uses device tree and has a backlight phandle.
*
* When the panel is enabled backlight will be enabled after a
* successful call to &drm_panel_funcs.enable()
*
* When the panel is disabled backlight will be disabled before the
* call to &drm_panel_funcs.disable().
*
* A typical implementation for a panel driver supporting device tree
* will call this function at probe time. Backlight will then be handled
* transparently without requiring any intervention from the driver.
* drm_panel_of_backlight() must be called after the call to drm_panel_init().
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_panel_of_backlight(struct drm_panel *panel)
{
struct backlight_device *backlight;
if (!panel || !panel->dev)
return -EINVAL;
backlight = devm_of_find_backlight(panel->dev);
if (IS_ERR(backlight))
return PTR_ERR(backlight);
panel->backlight = backlight;
return 0;
}
EXPORT_SYMBOL(drm_panel_of_backlight);
#endif
MODULE_AUTHOR("Thierry Reding <[email protected]>");
MODULE_DESCRIPTION("DRM panel infrastructure");
MODULE_LICENSE("GPL and additional rights");
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