[display] Refactor to avoid implicit framebuffer allocation.

target/dartuinoP0/memory_lcd.c

 /*
  * Copyright (c) 2015 Gurjant Kalsi <me@gurjantkalsi.com>
  *
  * 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, sublicense, 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 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 NONINFRINGEMENT.
  * 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 <err.h>
 #include <debug.h>
 #include <trace.h>
 #include <rand.h>
+#include <stdlib.h>
+#include <assert.h>
 
 #include <dev/display.h>
 #include <platform/gpio.h>
 #include <target/memory_lcd.h>
 
 #if defined (LCD_LS013B7DH06)
 #include <target/display/LS013B7DH06.h>
 #elif defined (LCD_LS027B7DH01)
 #include <target/display/LS027B7DH01.h>
 #elif defined (LCD_LS013B7DH03)
 #include <target/display/LS013B7DH03.h>
 #endif
 
 #define LOCAL_TRACE 0
 
 SPI_HandleTypeDef SpiHandle;
 
 #define MLCD_WR 0x01  // LCD Write Command
 #define MLCD_CM 0x04  // LCD Clear Memory Command
 #define MLCD_NO 0x00  // LCD No-op command
 
 // 5 bytes used as control bytes, MLCD_BYTES_LINE bytes used to data
 #define MLCD_BUF_SIZE  (MLCD_BYTES_LINE + 5)
 
 #define VCOM_HI 0x02
 #define VCOM_LO 0x00
 
-static uint8_t framebuffer[MLCD_HEIGHT * FB_STRIDE];
+static struct display_framebuffer default_fb;
 static uint8_t vcom_state;
 
 static void chip_select(bool s)
 {
     if (s) {
         gpio_set(GPIO(GPIO_PORT_B, 12), GPIO_PIN_SET);
     } else {
         gpio_set(GPIO(GPIO_PORT_B, 12), GPIO_PIN_RESET);
     }
 }
@@ skipping 41 matching lines @@
 
     vcom_state = VCOM_LO;
 
     lcd_power(true);
 
     mlcd_clear();
 
     return NO_ERROR;
 }
 
-
-
 static void mlcd_flush(uint starty, uint endy)
 {
+    display_present(&default_fb.image, starty, endy);
+}
+
+status_t display_get_framebuffer(struct display_framebuffer *fb)
+{
+    DEBUG_ASSERT(fb);
+    if (!default_fb.image.pixels) {
+        switch (MLCD_FORMAT) {
+            // Use closest match format supported by gfx lib
+            case DISPLAY_FORMAT_RGB_111:
+                default_fb.image.format = IMAGE_FORMAT_RGB_332;
+                default_fb.image.stride = MLCD_WIDTH;
+                default_fb.image.rowbytes = MLCD_WIDTH;
+                break;
+            case DISPLAY_FORMAT_MONO_1:
+                default_fb.image.format = IMAGE_FORMAT_MONO_8;
+                default_fb.image.stride = MLCD_WIDTH;
+                default_fb.image.rowbytes = MLCD_WIDTH;
+                break;
+            default:
+                DEBUG_ASSERT(false);
+                return ERR_NOT_SUPPORTED;
+        }
+        default_fb.image.pixels = malloc(MLCD_HEIGHT *
+            default_fb.image.rowbytes);
+        default_fb.image.width = MLCD_WIDTH;
+        default_fb.image.height = MLCD_HEIGHT;
+        default_fb.flush = mlcd_flush;
+        default_fb.format = MLCD_FORMAT;
+    }
+    *fb = default_fb;
+    return NO_ERROR;
+}
+
+status_t display_present(struct display_image *image, uint starty, uint endy)
+{
+    DEBUG_ASSERT(image);
+    status_t status = NO_ERROR;
     chip_select(true);
 
     static uint8_t localbuf[MLCD_BUF_SIZE];
     uint8_t *bufptr = localbuf;
     uint8_t trailer = 0;
 
     // The first line is preceeded with a write command.
     *bufptr++ = MLCD_WR | vcom_state;
 
     vcom_state = vcom_state == VCOM_HI ? VCOM_LO : VCOM_HI;
 
     // Send the image data.
     for (uint j = starty; j <= endy; ++j) {
         *bufptr++ = (j + 1);
 
-        bufptr += lcd_get_line(framebuffer, j, bufptr);
+        bufptr += lcd_get_line(image, j, bufptr);
 
         // 8 bit trailer per line
         *bufptr++ = trailer;
         if (j == endy) {
             // 16 bit trailer on the last line
             *bufptr++ = trailer;
         }
 
-        if (HAL_SPI_Transmit(&SpiHandle, localbuf, bufptr - localbuf, HAL_MAX_DELAY) != HAL_OK) {
+        if (HAL_SPI_Transmit(&SpiHandle, localbuf, bufptr - localbuf,
+                HAL_MAX_DELAY) != HAL_OK) {
+            status = ERR_GENERIC;
             goto finish;
         }
 
         bufptr = localbuf;
     }
 
 finish:
     chip_select(false);
+
+    return status;
 }
 
 status_t display_get_info(struct display_info *info)
 {
+    DEBUG_ASSERT(info);
     LTRACEF("display_info %p\n", info);
 
-    info->framebuffer = (void *)framebuffer;
-    info->format = FB_FORMAT;
+    info->format = MLCD_FORMAT;
     info->width = MLCD_WIDTH;
     info->height = MLCD_HEIGHT;
-    info->stride = FB_STRIDE;
-    info->flush = mlcd_flush;
 
     return NO_ERROR;
 }