static void lcd_writech(uint8_t ch, uint8_t row, uint8_t column)
{
uint8_t addr;
/* Set the cursor position. Internally, the HD44780U supports a display
* size of up to 2x40 addressed as follows:
*
* Column 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ... 39
* Row 0 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ... 27
* Ro1 1 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f ... 67
*/
addr = column;
if (row > 0)
{
addr |= HD4478OU_DDRAM_ROW1;
}
lcd_wrcommand(HD4478OU_DDRAM_AD(addr));
/* And write the character here */
lcd_wrdata(ch);
}
int up_lcd1602_initialize(void)
{
uint32_t regval;
int ret = OK;
/* Only initialize the driver once. */
if (!g_lcd1602.initialized)
{
lcdvdbg("Initializing\n");
/* PMP Master mode configuration */
/* Make sure that interrupts are disabled */
putreg32(INT_PMP, PIC32MX_INT_IEC1CLR);
/* Stop and reset the PMP module and clear the mode and control registers. */
putreg32(0, PIC32MX_PMP_MODE);
putreg32(0, PIC32MX_PMP_AEN);
putreg32(0, PIC32MX_PMP_CON);
putreg32(0, PIC32MX_PMP_ADDR);
/* Set LCD timing values, PMP master mode 3, 8-bit mode, no address
* increment, and no interrupts.
*/
regval = (PMP_MODE_WAITE_RD(0) | PMP_MODE_WAITM(3) | PMP_MODE_WAITB_1TPB |
PMP_MODE_MODE_MODE1 | PMP_MODE_MODE8 | PMP_MODE_INCM_NONE |
PMP_MODE_IRQM_NONE);
putreg32(regval, PIC32MX_PMP_MODE);
/* Enable the PMP for reading and writing
* PMRD/PMWR is active high (1=RD; 0=WR)
* PMENB is active high.
* No chip selects
* Address latch is active high
* Enable PMRD/PMWR, PMENB, and the PMP.
*/
regval = (PMP_CON_RDSP | PMP_CON_WRSP | PMP_CON_ALP |
PMP_CON_CSF_ADDR1415 | PMP_CON_PTRDEN | PMP_CON_PTWREN |
PMP_CON_ADRMUX_NONE | PMP_CON_ON);
putreg32(regval, PIC32MX_PMP_CON);
/* Configure and enable the LCD */
/* Wait > 15 milliseconds afer Vdd > 4.5V */
up_mdelay(100);
/* Select the 8-bit interface. BF cannot be checked before this command.
* This needs to be done a few times with some magic delays.
*/
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_DL8D | HD4478OU_FUNC_N1);
up_mdelay(50);
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_DL8D | HD4478OU_FUNC_N1);
up_udelay(50);
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_DL8D | HD4478OU_FUNC_N1);
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_DL8D | HD4478OU_FUNC_N1);
/* Configure the display */
lcd_wrcommand(HD4478OU_DISPLAY); /* Display, cursor, and blink off */
lcd_wrcommand(HD4478OU_CLEAR); /* Clear the display */
lcd_wrcommand(HD4478OU_INPUT | HD4478OU_INPUT_INCR); /* Increment mode */
lcd_wrcommand(HD4478OU_DISPLAY | HD4478OU_DISPLAY_ON); /* Display on, cursor and blink off */
lcd_wrcommand(HD4478OU_DDRAM_AD(0)); /* Select DDRAM RAM AD=0 */
/* Register the LCD device driver */
ret = register_driver("/dev/lcd1602", &g_lcdops, 0644, &g_lcd1602);
g_lcd1602.initialized = true;
}
return ret;
}
static void lcd_action(enum slcdcode_e code, uint8_t count)
{
lcdvdbg("Action: %d count: %d\n", code, count);
lcd_dumpstate("BEFORE ACTION");
switch (code)
{
/* Erasure */
case SLCDCODE_BACKDEL: /* Backspace (backward delete) N characters */
{
int tmp;
/* If we are at the home position or if the count is zero, then ignore the action */
if (g_lcd1602.curcol < 1 || count < 1)
{
break;
}
/* Otherwise, BACKDEL is like moving the cursor back N characters then doing a
* forward deletion. Decrement the cursor position and fall through.
*/
tmp = (int)g_lcd1602.curcol - count;
if (tmp < 0)
{
tmp = 0;
count = g_lcd1602.curcol;
}
/* Save the updated cursor positions */
g_lcd1602.curcol = tmp;
}
case SLCDCODE_FWDDEL: /* DELete (forward delete) N characters moving text */
if (count > 0)
{
int nchars;
int nmove;
int i;
/* How many characters are to the right of the cursor position
* (including the one at the cursor position)? Then get the
* number of characters to move.
*/
nchars = LCD_NCOLUMNS - g_lcd1602.curcol;
nmove = MIN(nchars, count) - 1;
/* Move all characters after the current cursor position left by 'nmove' characters */
for (i = g_lcd1602.curcol + nmove; i < LCD_NCOLUMNS - 1; i++)
{
uint8_t ch = lcd_readch(g_lcd1602.currow, i);
lcd_writech(ch, g_lcd1602.currow, i - nmove);
}
/* Erase the last 'nmove' characters on the display */
for (i = LCD_NCOLUMNS - nmove; i < LCD_NCOLUMNS; i++)
{
lcd_writech(' ', i, 0);
}
}
break;
case SLCDCODE_ERASE: /* Erase N characters from the cursor position */
if (count > 0)
{
int last;
int i;
/* Get the last position to clear and make sure that the last
* position is on the SLCD.
*/
last = g_lcd1602.curcol + count - 1;
if (last >= LCD_NCOLUMNS)
{
last = LCD_NCOLUMNS - 1;
}
/* Erase N characters after the current cursor position left by one */
for (i = g_lcd1602.curcol; i < last; i++)
{
lcd_writech(' ', g_lcd1602.currow, i);
}
}
break;
case SLCDCODE_CLEAR: /* Home the cursor and erase the entire display */
{
/* Clear the display */
lcd_wrcommand(HD4478OU_CLEAR);
/* And home the cursor */
g_lcd1602.currow = 0;
g_lcd1602.curcol = 0;
}
break;
case SLCDCODE_ERASEEOL: /* Erase from the cursor position to the end of line */
{
int i;
/* Erase characters after the current cursor position to the end of the line */
for (i = g_lcd1602.curcol; i < LCD_NCOLUMNS; i++)
{
lcd_writech(' ', g_lcd1602.currow, i);
}
}
break;
/* Cursor movement */
case SLCDCODE_HOME: /* Cursor home */
{
g_lcd1602.currow = 0;
g_lcd1602.curcol = 0;
}
break;
case SLCDCODE_END: /* Cursor end */
{
g_lcd1602.curcol = LCD_NCOLUMNS - 1;
}
break;
case SLCDCODE_LEFT: /* Cursor left by N characters */
{
int tmp = (int)g_lcd1602.curcol - count;
/* Don't permit movement past the beginning of the SLCD */
if (tmp < 0)
{
tmp = 0;
}
/* Save the new cursor position */
g_lcd1602.curcol = (uint8_t)tmp;
}
break;
case SLCDCODE_RIGHT: /* Cursor right by N characters */
{
int tmp = (int)g_lcd1602.curcol + count;
/* Don't permit movement past the end of the SLCD */
if (tmp >= LCD_NCOLUMNS)
{
tmp = LCD_NCOLUMNS - 1;
}
/* Save the new cursor position */
g_lcd1602.curcol = (uint8_t)tmp;
}
break;
case SLCDCODE_UP: /* Cursor up by N lines */
{
int tmp = (int)g_lcd1602.currow - count;
/* Don't permit movement past the top of the SLCD */
if (tmp < 0)
{
tmp = 0;
}
/* Save the new cursor position */
g_lcd1602.currow = (uint8_t)tmp;
}
break;
case SLCDCODE_DOWN: /* Cursor down by N lines */
{
int tmp = (int)g_lcd1602.currow + count;
/* Don't permit movement past the bottom of the SLCD */
if (tmp >= LCD_NROWS)
{
tmp = LCD_NROWS - 1;
}
/* Save the new cursor position */
g_lcd1602.currow = (uint8_t)tmp;
}
break;
case SLCDCODE_PAGEUP: /* Cursor up by N pages */
case SLCDCODE_PAGEDOWN: /* Cursor down by N pages */
break; /* Not supportable on this SLCD */
/* Blinking */
case SLCDCODE_BLINKSTART: /* Start blinking with current cursor position */
case SLCDCODE_BLINKEND: /* End blinking after the current cursor position */
case SLCDCODE_BLINKOFF: /* Turn blinking off */
break; /* Not implemented */
/* These are actually unreportable errors */
default:
case SLCDCODE_NORMAL: /* Not a special keycode */
break;
}
lcd_dumpstate("AFTER ACTION");
}
int up_lcd1602_initialize(void)
{
int ret = OK;
/* Only initialize the driver once. */
if (!g_lcd1602.initialized)
{
lcdinfo("Initializing\n");
/* Configure GPIO pins */
putreg16(0, PIC32MX_IOPORTE_TRIS); /* Set DB0-15 as outputs */
pic32mx_configgpio(GPIO_LCD_RS); /* RS: Selects commnand or data */
pic32mx_configgpio(GPIO_LCD_RW); /* RW: Selects read or write */
pic32mx_configgpio(GPIO_LCD_E); /* E: Starts transfer */
/* Configure LCD power in the OFF state */
pic32mx_configgpio(GPIO_LCD_LIGHT); /* K */
pic32mx_configgpio(GPIO_LCD_COMP); /* Vo */
pic32mx_configgpio(GPIO_LCD_PWR); /* Vbuson/AN5/RB5 controls +5V USB */
g_lcd1602.brightness = 0; /* Remember tht the light is off */
/* A small delay is necessary between when GPIO_LCD_E was set up as an
* output with initial value of 0 and this operation. That delay should
* be well covered by the intervening GPIO configurations.
*/
pic32mx_gpiowrite(GPIO_LCD_E, true); /* Enable transfer */
/* Configure and enable the LCD */
/* Delay for 4.1MS or more */
up_mdelay(5);
/* Select the 8-bit interface. BF cannot be checked before this command.
* This needs to be done a few times with some magic delays.
*
* Function set: 5x7 Style | N=2R | DL=8D
*/
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_F5x7 | HD4478OU_FUNC_N1 | HD4478OU_FUNC_DL8D);
up_udelay(100); /* Delay more than 100uS */
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_F5x7 | HD4478OU_FUNC_N1 | HD4478OU_FUNC_DL8D);
up_udelay(40); /* Delay more than 40uS */
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_F5x7 | HD4478OU_FUNC_N1 | HD4478OU_FUNC_DL8D);
lcd_waitbusy();
lcd_wrcommand(HD4478OU_FUNC | HD4478OU_FUNC_F5x7 | HD4478OU_FUNC_N1 | HD4478OU_FUNC_DL8D);
lcd_waitbusy();
/* Display ON, cursor OFF, blink OFF */
lcd_wrcommand(HD4478OU_DISPLAY | HD4478OU_DISPLAY_ON);
lcd_waitbusy();
/* Clear the display and home the cursor */
lcd_wrcommand(HD4478OU_CLEAR); /* Clear display */
lcd_waitbusy();
lcd_wrcommand(HD4478OU_RETURN); /* Return home: AC=0 */
lcd_waitbusy();
/* Entry Mode Set:
*
* - Increment address by one,
* - Shift cursor to right (display is not shifted)
*/
lcd_wrcommand(HD4478OU_INPUT | HD4478OU_INPUT_INCR);
/* Register the LCD device driver */
ret = register_driver("/dev/lcd1602", &g_lcdops, 0644, &g_lcd1602);
g_lcd1602.initialized = true;
}
return ret;
}
