diff --git a/configs/stm3210e-eval/README.txt b/configs/stm3210e-eval/README.txt
index e8d634bb98578a24f106df958fe77191cfddf3a5..017af14e5be00dc42a0aeb0efac04760888e43a2 100755
--- a/configs/stm3210e-eval/README.txt
+++ b/configs/stm3210e-eval/README.txt
@@ -457,6 +457,9 @@ STM3210E-EVAL-specific Configuration Options
CONFIG_LCD_BACKLIGHT - Define to support an adjustable backlight
using timer 1. The granularity of the settings is determined
by CONFIG_LCD_MAXPOWER. Requires CONFIG_STM32_TIM1.
+ CONFIG_LCD_RDSHIFT - When reading 16-bit gram data, there appears
+ to be a shift in the returned data. This value fixes the offset.
+ Default 5.
Configurations
==============
diff --git a/configs/stm3210e-eval/src/up_lcd.c b/configs/stm3210e-eval/src/up_lcd.c
index af4e412ce4e7700eeb50e340f93b410ab5006f07..6ce37f390123eefc8f59d41b637d3b4752e37683 100644
--- a/configs/stm3210e-eval/src/up_lcd.c
+++ b/configs/stm3210e-eval/src/up_lcd.c
@@ -121,6 +121,19 @@
# error "PA8 cannot be configured as TIM1 CH1 with full remap"
#endif
+/* When reading 16-bit gram data, there appears to be a 5-bit shift in the returned
+ * data.
+ */
+
+#ifndef CONFIG_LCD_RDSHIFT
+# define CONFIG_LCD_RDSHIFT 5
+#endif
+
+/* Red and green appear to be swapped on read-back as well */
+
+#undef CONFIG_LCD_RDSWAP
+#define CONFIG_LCD_RDSWAP 1
+
/* Define CONFIG_DEBUG_LCD to enable detailed LCD debug output. Verbose debug must
* also be enabled.
*/
@@ -317,7 +330,14 @@ static void stm3210e_writereg(uint8_t regaddr, uint16_t regval);
static uint16_t stm3210e_readreg(uint8_t regaddr);
static inline void stm3210e_gramselect(void);
static inline void stm3210e_writegram(uint16_t rgbval);
-static inline uint16_t stm3210e_readgram(void);
+#if CONFIG_LCD_RDSHIFT > 0
+static inline void stm3210e_readsetup(FAR uint16_t *accum);
+static inline uint16_t stm3210e_readgram(FAR uint16_t *accum);
+#else
+static inline uint16_t stm3210e_readnoshift(void);
+# define stm3210e_readsetup(a,n)
+# define stm3210e_readgram(a,n) stm3210e_readnoshift()
+#endif
static void stm3210e_setcursor(uint16_t col, uint16_t row);
/* LCD Data Transfer Methods */
@@ -486,20 +506,137 @@ static inline void stm3210e_writegram(uint16_t rgbval)
LCD->value = rgbval;
}
+/**************************************************************************************
+ * Name: stm3210e_readsetup
+ *
+ * Description:
+ * Prime the operation by reading one pixel from the GRAM memory
+ *
+ **************************************************************************************/
+
+#if CONFIG_LCD_RDSHIFT > 0
+static inline void stm3210e_readsetup(FAR uint16_t *accum)
+{
+ /* Read the value (GRAM register already selected) */
+
+ *accum = LCD->value;
+}
+#endif
+
/**************************************************************************************
* Name: stm3210e_readgram
*
* Description:
+ * Read one correctly aligned pixel from the GRAM memory
+ *
+ **************************************************************************************/
+
+#if CONFIG_LCD_RDSHIFT > 0
+static inline uint16_t stm3210e_readgram(FAR uint16_t *accum)
+{
+#ifdef CONFIG_LCD_RDSWAP
+ uint16_t red;
+ uint16_t green;
+ uint16_t blue;
+#endif
+
+ /* Read the value (GRAM register already selected) */
+
+ uint16_t next = LCD->value;
+
+ /* Return previous bits 0-10 as bits 6-15 and next data bits 11-15 as bits 0-5
+ *
+ * xxxx xPPP PPPP PPPP
+ * NNNN Nxxx xxxx xxxx
+ *
+ * Assuming that CONFIG_LCD_RDSHIFT == 5
+ */
+
+ uint16_t value = *accum << CONFIG_LCD_RDSHIFT | next >> (16-CONFIG_LCD_RDSHIFT);
+
+ /* Save the value for the next time we are called */
+
+ *accum = next;
+
+ /* Tear the RGB655 apart. Swap read and green */
+
+#ifdef CONFIG_LCD_RDSWAP
+ red = (value << (11-5)) & 0xf800; /* Move bits 5-9 to 11-15 */
+ green = (value >> (10-5)) & 0x07e0; /* Move bits 10-15 to bits 5-10 */
+ blue = value & 0x001f; /* Blue is in the right place */
+
+ /* And put the RGB565 back together */
+
+ value = red | green | blue;
+
+ /* This is wierd... If blue is zero, then red+green values are off by 0x20.
+ * Except that both 0x0000 and 0x0020 can map to 0x0000. Need to revisit
+ * this!!!!!!!!!!! I might be misinterpreting some of the data that I have.
+ */
+
+#if 0 /* REVISIT */
+ if (value != 0 && blue == 0)
+ {
+ value += 0x20;
+ }
+#endif
+#endif
+
+ return value;
+}
+#endif
+
+/**************************************************************************************
+ * Name: stm3210e_readnoshift
+ *
+ * Description:
* Read one pixel from the GRAM memory
*
**************************************************************************************/
-static inline uint16_t stm3210e_readgram(void)
+#if CONFIG_LCD_RDSHIFT <= 0
+static inline uint16_t stm3210e_readnoshift(void)
{
- /* Write the value (GRAM register already selected) */
+#ifdef CONFIG_LCD_RDSWAP
+ uint16_t value;
+ uint16_t red;
+ uint16_t green;
+ uint16_t blue;
+
+ /* Read the value (GRAM register already selected) */
+
+ value = LCD->value;
+
+ /* Tear the RGB655 apart. Swap read and green */
+
+ red = (value << (11-5)) & 0xf800; /* Move bits 5-9 to 11-15 */
+ green = (value >> (10-5)) & 0x07e0; /* Move bits 10-15 to bits 5-10 */
+ blue = value & 0x001f; /* Blue is in the right place */
+
+ /* And put the RGB565 back together */
+
+ value = red | green | blue;
+
+ /* This is wierd... If blue is zero, then red+green values are off by 0x20.
+ * Except that both 0x0000 and 0x0020 can map to 0x0000. Need to revisit
+ * this!!!!!!!!!!! I might be misinterpreting some of the data that I have.
+ */
+
+#if 0 /* REVISIT */
+ if (value != 0 && blue == 0)
+ {
+ value += 0x20;
+ }
+#endif
+
+ return value;
+#else
+ /* Read the value (GRAM register already selected) */
return LCD->value;
+#endif
}
+#endif
/**************************************************************************************
* Name: stm3210e_setcursor
@@ -654,6 +791,9 @@ static int stm3210e_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer,
size_t npixels)
{
FAR uint16_t *dest = (FAR uint16_t*)buffer;
+#if CONFIG_LCD_RDSHIFT > 0
+ uint16_t accum;
+#endif
int i;
/* Buffer must be provided and aligned to a 16-bit address boundary */
@@ -677,11 +817,16 @@ static int stm3210e_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer,
/* Then read the GRAM data, auto-decrementing Y */
stm3210e_gramselect();
+
+ /* Prime the pump for unaligned read data */
+
+ stm3210e_readsetup(&accum);
+
for (i = 0; i < npixels; i++)
{
/* Read the next pixel from this position (autoincrements to the next row) */
- *dest++ = stm3210e_readgram();
+ *dest++ = stm3210e_readgram(&accum);
}
#elif defined(CONFIG_LCD_PORTRAIT)
/* Convert coordinates (Swap row and column. This is done implicitly). */
@@ -694,7 +839,8 @@ static int stm3210e_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer,
stm3210e_setcursor(row, col);
stm3210e_gramselect();
- *dest++ = stm3210e_readgram();
+ stm3210e_readsetup(&accum);
+ *dest++ = stm3210e_readgram(&accum);
/* Increment to next column */
@@ -716,7 +862,8 @@ static int stm3210e_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer,
stm3210e_setcursor(row, col);
stm3210e_gramselect();
- *dest++ = stm3210e_readgram();
+ stm3210e_readsetup(&accum);
+ *dest++ = stm3210e_readgram(&accum);
/* Decrement to next column */