nuttx/drivers/lcd/lcd_framebuffer.c

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/****************************************************************************
* drivers/lcd/lcd_framebuffer.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/board.h>
#include <nuttx/kmalloc.h>
#include <nuttx/lcd/lcd.h>
#include <nuttx/video/fb.h>
#ifdef CONFIG_LCD_FRAMEBUFFER
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* At present, only video plane 0 is supported */
#define VIDEO_PLANE 0
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes the LCD framebuffer */
struct lcdfb_dev_s
{
struct fb_vtable_s vtable; /* Must be cast compatible with lcdfb_dev_s */
FAR struct lcdfb_dev_s *flink; /* Supports a singly linked list */
FAR struct lcd_dev_s *lcd; /* Contained LCD device */
FAR uint8_t *fbmem; /* Allocated framebuffer */
FAR struct lcd_planeinfo_s pinfo; /* LCD plane info */
size_t fblen; /* Size of the framebuffer in bytes */
fb_coord_t xres; /* Horizontal resolution in pixel columns */
fb_coord_t yres; /* Vertical resolution in pixel rows */
fb_coord_t stride; /* Width of a row in bytes */
uint8_t display; /* Display number */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Update the LCD when there is a change to the framebuffer */
static int lcdfb_updateearea(FAR struct fb_vtable_s *vtable,
FAR const struct fb_area_s *area);
/* Get information about the video controller configuration and the
* configuration of each color plane.
*/
static int lcdfb_getvideoinfo(FAR struct fb_vtable_s *vtable,
FAR struct fb_videoinfo_s *vinfo);
static int lcdfb_getplaneinfo(FAR struct fb_vtable_s *vtable, int planeno,
FAR struct fb_planeinfo_s *pinfo);
/* The following is provided only if the video hardware supports RGB color
* mapping
*/
#ifdef CONFIG_FB_CMAP
static int lcdfb_getcmap(FAR struct fb_vtable_s *vtable,
FAR struct fb_cmap_s *cmap);
static int lcdfb_putcmap(FAR struct fb_vtable_s *vtable,
FAR const struct fb_cmap_s *cmap);
#endif
/* The following is provided only if the video hardware supports a hardware
* cursor
*/
#ifdef CONFIG_FB_HWCURSOR
static int lcdfb_getcursor(FAR struct fb_vtable_s *vtable,
FAR struct fb_cursorattrib_s *attrib);
static int lcdfb_setcursor(FAR struct fb_vtable_s *vtable,
FAR struct fb_setcursor_s *settings);
#endif
static int lcdfb_setpower(FAR struct fb_vtable_s *vtable, int power);
/****************************************************************************
* Private Data
****************************************************************************/
/* This is a singly linked list that supports look-up of framebuffer state
* using the display number.
*/
static FAR struct lcdfb_dev_s *g_lcdfb;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: lcdfb_find
*
* Description:
* Find the LCD framebuffer state associated with the display.
*
****************************************************************************/
static FAR struct lcdfb_dev_s *lcdfb_find(int display)
{
FAR struct lcdfb_dev_s *priv;
/* Look up the LCD framebuffer state structure for this display.
*
* REVISIT: If many LCD framebuffers are used, then this lookup would be
* a performance issue.
* REVISIT: Semaphore protections is needed if there is concurrent access.
*/
for (priv = g_lcdfb; priv != NULL; priv = priv->flink)
{
if (priv->display == display)
{
return priv;
}
}
return NULL;
}
/****************************************************************************
* Name: lcdfb_updateearea
*
* Description:
* Update the LCD when there is a change to the framebuffer.
*
****************************************************************************/
static int lcdfb_updateearea(FAR struct fb_vtable_s *vtable,
FAR const struct fb_area_s *area)
{
FAR struct lcdfb_dev_s *priv = (FAR struct lcdfb_dev_s *)vtable;
FAR struct lcd_planeinfo_s *pinfo = &priv->pinfo;
FAR uint8_t *run = priv->fbmem;
fb_coord_t row;
fb_coord_t startx = 0;
fb_coord_t endx = priv->xres - 1;
fb_coord_t width = priv->xres;
fb_coord_t starty = 0;
fb_coord_t endy = priv->yres - 1;
int ret;
if (area != NULL)
{
/* Clip to fit in the framebuffer */
startx = area->x;
if (startx < 0)
{
startx = 0;
}
endx = startx + area->w - 1;
if (endx >= priv->xres)
{
endx = priv->xres - 1;
}
starty = area->y;
if (starty < 0)
{
starty = 0;
}
endy = starty + area->h - 1;
if (endy >= priv->yres)
{
endy = priv->yres - 1;
}
/* If the display uses a value of BPP < 8, then we may have to extend
* the rectangle on the left so that it is byte aligned. Works for
* BPP={1,2,4}
*/
if (pinfo->bpp < 8)
{
unsigned int pixperbyte = 8 / pinfo->bpp;
startx &= ~(pixperbyte - 1);
}
Framebuffer's callback buffer starts from the area being drawn. The commit 664d45dcbace03a879017aa99566592be31f4308 updated the behavior of the framebuffer's putarea callback enabling it to be used to draw a particular area of the display. Previously, putarea was only used to draw the entire area of the display. Any different area was drawn, row by row, by putrun. Also, before checking for which callback to call, the framebuffer driver adjusted the buffer reference that was going to be used for calling the driver's callback to point to the init of the relevant data. After that commit, the framebuffer's buffer reference passed to the driver's putarea now contains the data to draw the entire display. Unlike the previous version of that implementation, only the putrun's callback buffer was being referenced from the address that contains the data that actually is being drawn. This commit fixes it by adjusting the reference for the run buffer passed to the putrun/putarea callback. It always starts from the beginning of the relevant data that is actually being drawn. That is necessary because lcddev (which uses the same LCD display driver callbacks) actually don't allocate a buffer containing the data to draw the whole display, so the same putarea implementation of the LCD drivers would'n be able to work for both lcddev and framebuffer. Also it's necessary to pass the stride argument to the LCD drivers in order to enable them to do partial writes by calculating the buffer offset while sending row-by-row. The stride is equal the width multiplied by the bytes per pixel (may add some padding) for framebuffer and is equal to the lenght of the row being drawn (multiplied by the same BPP) for lcddev. Why this approach? Other possible approaches would be: 1) modify lcddev driver to translate received buffer data to a buffer similar to the framebuffer. That wouldn't be efficient considering memory allocation. 2) Create a new callback function. While possible, it'd be confusing to create a different callback to draw the whole screen and another to draw only an area of the screen. Also, these callbacks would differ themselves only from the way the buffer is filled. 3) Simply reverting 664d45dcbace03a879017aa99566592be31f4308 would break the usage of the putarea callback to draw an area of the display, which would also be inefficient. This approach is based on the Zephyr's implementation of the ST7789 driver: the buffer starts from the beginiing of the region that would be drawn. The display device driver's putarea implementation should check if the operation refers to a full screen/full row and implement (if possible) a single operation to send the data to be drawn more efficiently. Finally, this approach requires that the drivers which implement the putarea callback and expects the entire framebuffer buffer to be modified. They don't need to calculate where the data begins as the new buffer represents the data from the address that is actually being drawn. This includes adjusting the LCD drivers GC9A01 and ST7789 and the driver for APA102-based LED matrix display.
2022-08-08 15:07:47 +02:00
/* Get the starting position in the framebuffer */
run = priv->fbmem + starty * priv->stride;
run += (startx * pinfo->bpp + 7) >> 3;
}
if (pinfo->putarea != NULL)
{
/* Each Driver's callback function putarea may be optimized by checking
* if it is a full screen/full row mode or not.
* In case of full screen/row mode the memory layout of drivers memory
* and data provided to putarea function may be (or not, it depends of
* display and driver implementation) identical.
* Identical memory layout let us to use:
* - memcopy (if there is shadow buffer in driver implementation)
* - apply DMA channel to transfer data to driver memory.
*/
Framebuffer's callback buffer starts from the area being drawn. The commit 664d45dcbace03a879017aa99566592be31f4308 updated the behavior of the framebuffer's putarea callback enabling it to be used to draw a particular area of the display. Previously, putarea was only used to draw the entire area of the display. Any different area was drawn, row by row, by putrun. Also, before checking for which callback to call, the framebuffer driver adjusted the buffer reference that was going to be used for calling the driver's callback to point to the init of the relevant data. After that commit, the framebuffer's buffer reference passed to the driver's putarea now contains the data to draw the entire display. Unlike the previous version of that implementation, only the putrun's callback buffer was being referenced from the address that contains the data that actually is being drawn. This commit fixes it by adjusting the reference for the run buffer passed to the putrun/putarea callback. It always starts from the beginning of the relevant data that is actually being drawn. That is necessary because lcddev (which uses the same LCD display driver callbacks) actually don't allocate a buffer containing the data to draw the whole display, so the same putarea implementation of the LCD drivers would'n be able to work for both lcddev and framebuffer. Also it's necessary to pass the stride argument to the LCD drivers in order to enable them to do partial writes by calculating the buffer offset while sending row-by-row. The stride is equal the width multiplied by the bytes per pixel (may add some padding) for framebuffer and is equal to the lenght of the row being drawn (multiplied by the same BPP) for lcddev. Why this approach? Other possible approaches would be: 1) modify lcddev driver to translate received buffer data to a buffer similar to the framebuffer. That wouldn't be efficient considering memory allocation. 2) Create a new callback function. While possible, it'd be confusing to create a different callback to draw the whole screen and another to draw only an area of the screen. Also, these callbacks would differ themselves only from the way the buffer is filled. 3) Simply reverting 664d45dcbace03a879017aa99566592be31f4308 would break the usage of the putarea callback to draw an area of the display, which would also be inefficient. This approach is based on the Zephyr's implementation of the ST7789 driver: the buffer starts from the beginiing of the region that would be drawn. The display device driver's putarea implementation should check if the operation refers to a full screen/full row and implement (if possible) a single operation to send the data to be drawn more efficiently. Finally, this approach requires that the drivers which implement the putarea callback and expects the entire framebuffer buffer to be modified. They don't need to calculate where the data begins as the new buffer represents the data from the address that is actually being drawn. This includes adjusting the LCD drivers GC9A01 and ST7789 and the driver for APA102-based LED matrix display.
2022-08-08 15:07:47 +02:00
ret = pinfo->putarea(pinfo->dev, starty, endy, startx, endx,
run, priv->stride);
if (ret < 0)
{
lcderr("Failed to update area");
return ret;
}
}
else
{
width = endx - startx + 1;
for (row = starty; row <= endy; row++)
{
ret = pinfo->putrun(pinfo->dev, row, startx, run, width);
if (ret < 0)
{
lcderr("Failed to update row");
return ret;
}
run += priv->stride;
}
}
if (pinfo->redraw != NULL)
{
pinfo->redraw(pinfo->dev);
}
return OK;
}
/****************************************************************************
* Name: lcdfb_getvideoinfo
****************************************************************************/
static int lcdfb_getvideoinfo(FAR struct fb_vtable_s *vtable,
FAR struct fb_videoinfo_s *vinfo)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
int ret = -EINVAL;
lcdinfo("vtable=%p vinfo=%p\n", vtable, vinfo);
DEBUGASSERT(vtable != NULL && vinfo != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && vinfo != NULL)
{
/* Get the video info from the contained LCD */
lcd = priv->lcd;
DEBUGASSERT(lcd->getvideoinfo != NULL);
ret = lcd->getvideoinfo(lcd, vinfo);
if (ret < 0)
{
lcderr("ERROR: LCD getvideoinfo() failed: %d\n", ret);
}
}
return ret;
}
/****************************************************************************
* Name: lcdfb_getplaneinfo
****************************************************************************/
static int lcdfb_getplaneinfo(FAR struct fb_vtable_s *vtable, int planeno,
FAR struct fb_planeinfo_s *pinfo)
{
FAR struct lcdfb_dev_s *priv;
int ret = -EINVAL;
lcdinfo("vtable=%p planeno=%d pinfo=%p\n", vtable, planeno, pinfo);
DEBUGASSERT(vtable != NULL && planeno == VIDEO_PLANE && pinfo != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && planeno == VIDEO_PLANE && pinfo != NULL)
{
/* Return the plane info */
pinfo->fbmem = priv->fbmem;
pinfo->fblen = priv->fblen;
pinfo->stride = priv->stride;
pinfo->display = priv->display;
pinfo->bpp = priv->pinfo.bpp;
ret = OK;
}
return ret;
}
/****************************************************************************
* Name: lcdfb_getcmap
****************************************************************************/
#ifdef CONFIG_FB_CMAP
static int lcdfb_getcmap(FAR struct fb_vtable_s *vtable,
FAR struct fb_cmap_s *cmap)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
int ret = -EINVAL;
lcdinfo("vtable=%p cmap=%p\n", vtable, cmap);
DEBUGASSERT(vtable != NULL && cmap != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && cmap != NULL)
{
/* Get the color map from the contained LCD */
lcd = priv->lcd
DEBUGASSERT(lcd->getcmap != NULL);
ret = lcd->getcmap(lcd, cmap);
if (ret < 0)
{
lcderr("ERROR: LCD getcmap() failed: %d\n", ret);
}
}
return ret;
}
#endif
/****************************************************************************
* Name: lcdfb_putcmap
****************************************************************************/
#ifdef CONFIG_FB_CMAP
static int lcdfb_putcmap(FAR struct fb_vtable_s *vtable,
FAR const struct fb_cmap_s *cmap)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
int ret = -EINVAL;
lcdinfo("vtable=%p cmap=%p\n", vtable, cmap);
DEBUGASSERT(vtable != NULL && cmap != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && cmap != NULL)
{
/* Set the color map to the contained LCD */
lcd = priv->lcd
DEBUGASSERT(lcd->putcmap != NULL);
ret = lcd->putcmap(lcd, cmap);
if (ret < 0)
{
lcderr("ERROR: LCD putcmap() failed: %d\n", ret);
}
}
return ret;
}
#endif
/****************************************************************************
* Name: lcdfb_getcursor
****************************************************************************/
#ifdef CONFIG_FB_HWCURSOR
static int lcdfb_getcursor(FAR struct fb_vtable_s *vtable,
FAR struct fb_cursorattrib_s *attrib)
{
lcdinfo("vtable=%p attrib=%p\n", vtable, attrib);
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
int ret = -EINVAL;
lcdinfo("vtable=%p attrib=%p\n", vtable, attrib);
DEBUGASSERT(vtable != NULL && attrib != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && attrib != NULL)
{
/* Get the cursor info from the contained LCD */
lcd = priv->lcd
DEBUGASSERT(lcd->getcursor != NULL);
ret = lcd->getcursor(lcd, attrib);
if (ret < 0)
{
lcderr("ERROR: LCD getcursor() failed: %d\n", ret);
}
}
return ret;
}
#endif
/****************************************************************************
* Name: lcdfb_setcursor
****************************************************************************/
#ifdef CONFIG_FB_HWCURSOR
static int lcdfb_setcursor(FAR struct fb_vtable_s *vtable,
FAR struct fb_setcursor_s *settings)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
int ret = -EINVAL;
lcdinfo("vtable=%p settings=%p\n", vtable, settings);
DEBUGASSERT(vtable != NULL && settings != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL && settings != NULL)
{
/* Set the cursor info to the contained LCD */
lcd = priv->lcd
DEBUGASSERT(lcd->setcursor != NULL);
ret = lcd->setcursor(lcd, settings);
if (ret < 0)
{
lcderr("ERROR: LCD setcursor() failed: %d\n", ret);
}
}
return ret;
}
#endif
/****************************************************************************
* Name: lcdfb_setpower
****************************************************************************/
static int lcdfb_setpower(FAR struct fb_vtable_s *vtable, int power)
{
int ret = -EINVAL;
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
DEBUGASSERT(vtable != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL)
{
lcd = priv->lcd;
DEBUGASSERT(lcd->setpower != NULL);
ret = lcd->setpower(lcd, power);
if (ret < 0)
{
lcderr("ERROR: LCD setpower() failed: %d\n", ret);
}
}
return ret;
}
/****************************************************************************
* Name: lcdfb_ioctl
****************************************************************************/
static int lcdfb_ioctl(FAR struct fb_vtable_s *vtable,
int cmd, unsigned long arg)
{
int ret = -EINVAL;
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
DEBUGASSERT(vtable != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL)
{
lcd = priv->lcd;
if (lcd->ioctl)
{
ret = lcd->ioctl(lcd, cmd, arg);
}
else
{
ret = -ENOTTY;
}
}
return ret;
}
/****************************************************************************
* Name: lcdfb_open
****************************************************************************/
static int lcdfb_open(FAR struct fb_vtable_s *vtable)
{
int ret = OK;
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
DEBUGASSERT(vtable != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL)
{
lcd = priv->lcd;
if (lcd->open)
{
ret = lcd->open(lcd);
}
}
return ret;
}
/****************************************************************************
* Name: lcdfb_close
****************************************************************************/
static int lcdfb_close(FAR struct fb_vtable_s *vtable)
{
int ret = OK;
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
DEBUGASSERT(vtable != NULL);
priv = (FAR struct lcdfb_dev_s *)vtable;
if (priv != NULL)
{
lcd = priv->lcd;
if (lcd->close)
{
ret = lcd->close(lcd);
}
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_fbinitialize
*
* Description:
* Initialize the framebuffer video hardware associated with the display.
*
* Input Parameters:
* display - In the case of hardware with multiple displays, this
* specifies the display. Normally this is zero.
*
* Returned Value:
* Zero is returned on success; a negated errno value is returned on any
* failure.
*
****************************************************************************/
int up_fbinitialize(int display)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcd_dev_s *lcd;
struct fb_videoinfo_s vinfo;
struct fb_area_s area;
int ret;
lcdinfo("display=%d\n", display);
DEBUGASSERT((unsigned)display < UINT8_MAX);
/* Allocate the framebuffer state structure */
priv = kmm_zalloc(sizeof(struct lcdfb_dev_s));
if (priv == NULL)
{
lcderr("ERROR: Failed to allocate state structure\n");
return -ENOMEM;
}
/* Initialize the LCD-independent fields of the state structure */
priv->display = display;
priv->vtable.getvideoinfo = lcdfb_getvideoinfo,
priv->vtable.getplaneinfo = lcdfb_getplaneinfo,
#ifdef CONFIG_FB_CMAP
priv->vtable.getcmap = lcdfb_getcmap,
priv->vtable.putcmap = lcdfb_putcmap,
#endif
#ifdef CONFIG_FB_HWCURSOR
priv->vtable.getcursor = lcdfb_getcursor,
priv->vtable.setcursor = lcdfb_setcursor,
#endif
priv->vtable.updatearea = lcdfb_updateearea,
priv->vtable.setpower = lcdfb_setpower,
priv->vtable.ioctl = lcdfb_ioctl,
priv->vtable.open = lcdfb_open,
priv->vtable.close = lcdfb_close,
#ifdef CONFIG_LCD_EXTERNINIT
/* Use external graphics driver initialization */
lcd = board_graphics_setup(display);
if (lcd == NULL)
{
gerr("ERROR: board_graphics_setup failed, devno=%d\n", display);
ret = -ENODEV;
goto errout_with_state;
}
#else
/* Initialize the LCD device */
ret = board_lcd_initialize();
if (ret < 0)
{
lcderr("ERROR: board_lcd_initialize() failed: %d\n", ret);
goto errout_with_state;
}
/* Get the device instance */
lcd = board_lcd_getdev(display);
if (lcd == NULL)
{
lcderr("ERROR: board_lcd_getdev failed, devno=%d\n", display);
ret = -ENODEV;
goto errout_with_lcd;
}
#endif
priv->lcd = lcd;
/* Initialize the LCD-dependent fields of the state structure */
DEBUGASSERT(lcd->getvideoinfo != NULL);
ret = lcd->getvideoinfo(lcd, &vinfo);
if (ret < 0)
{
lcderr("ERROR: LCD getvideoinfo() failed: %d\n", ret);
goto errout_with_lcd;
}
priv->xres = vinfo.xres;
priv->yres = vinfo.yres;
DEBUGASSERT(lcd->getplaneinfo != NULL);
ret = lcd->getplaneinfo(lcd, VIDEO_PLANE, &priv->pinfo);
if (ret < 0)
{
lcderr("ERROR: LCD getplaneinfo() failed: %d\n", ret);
goto errout_with_lcd;
}
/* Allocate (and clear) the framebuffer */
priv->stride = ((size_t)priv->xres * priv->pinfo.bpp + 7) >> 3;
priv->fblen = priv->stride * priv->yres;
priv->fbmem = kmm_zalloc(priv->fblen);
if (priv->fbmem == NULL)
{
lcderr("ERROR: Failed to allocate frame buffer memory\n");
ret = -ENOMEM;
goto errout_with_lcd;
}
/* Add the state structure to the list of framebuffer interfaces */
priv->flink = g_lcdfb;
g_lcdfb = priv;
/* Write the entire framebuffer to the LCD */
area.x = 0;
area.y = 0;
area.w = priv->xres;
area.h = priv->yres;
ret = lcdfb_updateearea(&priv->vtable, &area);
if (ret < 0)
{
lcderr("FB update failed: %d\n", ret);
}
/* Turn the LCD on at 75% power */
priv->lcd->setpower(priv->lcd, ((3*CONFIG_LCD_MAXPOWER + 3) / 4));
return OK;
errout_with_lcd:
#ifndef CONFIG_LCD_EXTERNINIT
board_lcd_uninitialize();
#endif
errout_with_state:
kmm_free(priv);
return ret;
}
/****************************************************************************
* Name: up_fbgetvplane
*
* Description:
* Return a a reference to the framebuffer object for the specified video
* plane of the specified plane. Many OSDs support multiple planes of
* video.
*
* Input Parameters:
* display - In the case of hardware with multiple displays, this
* specifies the display. Normally this is zero.
* vplane - Identifies the plane being queried.
*
* Returned Value:
* A non-NULL pointer to the frame buffer access structure is returned on
* success; NULL is returned on any failure.
*
****************************************************************************/
FAR struct fb_vtable_s *up_fbgetvplane(int display, int vplane)
{
FAR struct lcdfb_dev_s *priv;
lcdinfo("display=%d vplane=%d\n", display, vplane);
DEBUGASSERT(vplane == VIDEO_PLANE);
/* Look up the LCD framebuffer state structure for this display. */
priv = lcdfb_find(display);
if (priv == NULL)
{
lcderr("ERROR: lcd_find(%d) failed\n", display);
return NULL;
}
return &priv->vtable;
}
/****************************************************************************
* Name: up_fbuninitialize
*
* Description:
* Uninitialize the framebuffer support for the specified display.
*
* Input Parameters:
* display - In the case of hardware with multiple displays, this
* specifies the display. Normally this is zero.
*
* Returned Value:
* None
*
****************************************************************************/
void up_fbuninitialize(int display)
{
FAR struct lcdfb_dev_s *priv;
FAR struct lcdfb_dev_s *prev;
/* Find the LCD framebuffer state associated with this display.
* REVISIT: Semaphore protections is needed if there is concurrent access.
*/
for (prev = NULL, priv = g_lcdfb;
priv != NULL;
prev = priv, priv = priv->flink)
{
if (priv->display == display)
{
/* Remove the state structure from the list */
if (prev != NULL)
{
prev->flink = priv->flink;
}
else
{
g_lcdfb = priv->flink;
}
#ifndef CONFIG_LCD_EXTERNINIT
/* Uninitialize the LCD */
board_lcd_uninitialize();
#endif
/* Free the frame buffer allocation */
kmm_free(priv->fbmem);
/* Free the state structure allocation */
kmm_free(priv);
break;
}
}
}
#endif /* CONFIG_LCD_FRAMEBUFFER */