Skip to content

Commit

Permalink
auxdisplay: implement various hd44780_common_ functions
Browse files Browse the repository at this point in the history 
This implements various hd44780_common_ functions for hd44780 compatible
display drivers to use. charlcd then calls these functions through its
ops function pointer.
The functions namely are:
- hd44780_common_shift_cursor
- hd44780_common_display_shift
- hd44780_common_display
- hd44780_common_cursor
- hd44780_common_blink
- hd44780_common_fontsize
- hd44780_common_lines

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
  • Loading branch information
@poeschel @ojeda
poeschel authored and ojeda committed Nov 4, 2020
1 parent 01ec46d commit d2f2187
Show file tree
Hide file tree
Showing 6 changed files with 249 additions and 27 deletions.
73 changes: 46 additions & 27 deletions drivers/auxdisplay/charlcd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,10 +31,6 @@
#define LCD_CMD_CURSOR_ON 0x02 /* Set cursor on */
#define LCD_CMD_BLINK_ON 0x01 /* Set blink on */

#define LCD_CMD_SHIFT 0x10 /* Shift cursor/display */
#define LCD_CMD_DISPLAY_SHIFT 0x08 /* Shift display instead of cursor */
#define LCD_CMD_SHIFT_RIGHT 0x04 /* Shift display/cursor to the right */

#define LCD_CMD_FUNCTION_SET 0x20 /* Set function */
#define LCD_CMD_DATA_LEN_8BITS 0x10 /* Set data length to 8 bits */
#define LCD_CMD_TWO_LINES 0x08 /* Set to two display lines */
Expand Down Expand Up @@ -236,26 +232,44 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
switch (*esc) {
case 'D': /* Display ON */
priv->flags |= LCD_FLAG_D;
if (priv->flags != oldflags)
lcd->ops->display(lcd, CHARLCD_ON);

processed = 1;
break;
case 'd': /* Display OFF */
priv->flags &= ~LCD_FLAG_D;
if (priv->flags != oldflags)
lcd->ops->display(lcd, CHARLCD_OFF);

processed = 1;
break;
case 'C': /* Cursor ON */
priv->flags |= LCD_FLAG_C;
if (priv->flags != oldflags)
lcd->ops->cursor(lcd, CHARLCD_ON);

processed = 1;
break;
case 'c': /* Cursor OFF */
priv->flags &= ~LCD_FLAG_C;
if (priv->flags != oldflags)
lcd->ops->cursor(lcd, CHARLCD_OFF);

processed = 1;
break;
case 'B': /* Blink ON */
priv->flags |= LCD_FLAG_B;
if (priv->flags != oldflags)
lcd->ops->blink(lcd, CHARLCD_ON);

processed = 1;
break;
case 'b': /* Blink OFF */
priv->flags &= ~LCD_FLAG_B;
if (priv->flags != oldflags)
lcd->ops->blink(lcd, CHARLCD_OFF);

processed = 1;
break;
case '+': /* Back light ON */
Expand All @@ -272,47 +286,54 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
break;
case 'f': /* Small Font */
priv->flags &= ~LCD_FLAG_F;
if (priv->flags != oldflags)
lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_SMALL);

processed = 1;
break;
case 'F': /* Large Font */
priv->flags |= LCD_FLAG_F;
if (priv->flags != oldflags)
lcd->ops->fontsize(lcd, CHARLCD_FONTSIZE_LARGE);

processed = 1;
break;
case 'n': /* One Line */
priv->flags &= ~LCD_FLAG_N;
if (priv->flags != oldflags)
lcd->ops->lines(lcd, CHARLCD_LINES_1);

processed = 1;
break;
case 'N': /* Two Lines */
priv->flags |= LCD_FLAG_N;
if (priv->flags != oldflags)
lcd->ops->lines(lcd, CHARLCD_LINES_2);

processed = 1;
break;
case 'l': /* Shift Cursor Left */
if (lcd->addr.x > 0) {
/* back one char if not at end of line */
if (lcd->addr.x < hdc->bwidth)
hdc->write_cmd(hdc, LCD_CMD_SHIFT);
lcd->addr.x--;
if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT))
lcd->addr.x--;
}

processed = 1;
break;
case 'r': /* shift cursor right */
if (lcd->addr.x < lcd->width) {
/* allow the cursor to pass the end of the line */
if (lcd->addr.x < (hdc->bwidth - 1))
hdc->write_cmd(hdc,
LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
lcd->addr.x++;
if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_RIGHT))
lcd->addr.x++;
}

processed = 1;
break;
case 'L': /* shift display left */
hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
lcd->ops->shift_display(lcd, CHARLCD_SHIFT_LEFT);
processed = 1;
break;
case 'R': /* shift display right */
hdc->write_cmd(hdc,
LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
LCD_CMD_SHIFT_RIGHT);
lcd->ops->shift_display(lcd, CHARLCD_SHIFT_RIGHT);
processed = 1;
break;
case 'k': { /* kill end of line */
Expand Down Expand Up @@ -456,19 +477,17 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
case '\b':
/* go back one char and clear it */
if (lcd->addr.x > 0) {
/*
* check if we're not at the
* end of the line
*/
if (lcd->addr.x < hdc->bwidth)
/* back one char */
hdc->write_cmd(hdc, LCD_CMD_SHIFT);
lcd->addr.x--;
/* back one char */
if (!lcd->ops->shift_cursor(lcd,
CHARLCD_SHIFT_LEFT))
lcd->addr.x--;
}
/* replace with a space */
hdc->write_data(hdc, ' ');
charlcd_print(lcd, ' ');
/* back one char again */
hdc->write_cmd(hdc, LCD_CMD_SHIFT);
if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT))
lcd->addr.x--;

break;
case '\f':
/* quickly clear the display */
Expand Down
28 changes: 28 additions & 0 deletions drivers/auxdisplay/charlcd.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,21 @@ enum charlcd_onoff {
CHARLCD_ON,
};

enum charlcd_shift_dir {
CHARLCD_SHIFT_LEFT,
CHARLCD_SHIFT_RIGHT,
};

enum charlcd_fontsize {
CHARLCD_FONTSIZE_SMALL,
CHARLCD_FONTSIZE_LARGE,
};

enum charlcd_lines {
CHARLCD_LINES_1,
CHARLCD_LINES_2,
};

struct charlcd {
const struct charlcd_ops *ops;
const unsigned char *char_conv; /* Optional */
Expand Down Expand Up @@ -54,6 +69,12 @@ struct charlcd {
* values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
* function.
* @init_display: Initialize the display.
* @shift_cursor: Shift cursor left or right one position.
* @shift_display: Shift whole display content left or right.
* @display: Turn display on or off.
* @cursor: Turn cursor on or off.
* @blink: Turn cursor blink on or off.
* @lines: One or two lines.
*/
struct charlcd_ops {
void (*clear_fast)(struct charlcd *lcd);
Expand All @@ -63,6 +84,13 @@ struct charlcd_ops {
int (*home)(struct charlcd *lcd);
int (*clear_display)(struct charlcd *lcd);
int (*init_display)(struct charlcd *lcd);
int (*shift_cursor)(struct charlcd *lcd, enum charlcd_shift_dir dir);
int (*shift_display)(struct charlcd *lcd, enum charlcd_shift_dir dir);
int (*display)(struct charlcd *lcd, enum charlcd_onoff on);
int (*cursor)(struct charlcd *lcd, enum charlcd_onoff on);
int (*blink)(struct charlcd *lcd, enum charlcd_onoff on);
int (*fontsize)(struct charlcd *lcd, enum charlcd_fontsize size);
int (*lines)(struct charlcd *lcd, enum charlcd_lines lines);
};

void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
Expand Down
14 changes: 14 additions & 0 deletions drivers/auxdisplay/hd44780.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -131,6 +131,13 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
.display = hd44780_common_display,
.cursor = hd44780_common_cursor,
.blink = hd44780_common_blink,
.fontsize = hd44780_common_fontsize,
.lines = hd44780_common_lines,
};

/* Send a command to the LCD panel in 4 bit GPIO mode */
Expand Down Expand Up @@ -179,6 +186,13 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
.display = hd44780_common_display,
.cursor = hd44780_common_cursor,
.blink = hd44780_common_blink,
.fontsize = hd44780_common_fontsize,
.lines = hd44780_common_lines,
};

static int hd44780_probe(struct platform_device *pdev)
Expand Down
131 changes: 131 additions & 0 deletions drivers/auxdisplay/hd44780_common.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,10 @@
#define LCD_CMD_CURSOR_ON 0x02 /* Set cursor on */
#define LCD_CMD_BLINK_ON 0x01 /* Set blink on */

#define LCD_CMD_SHIFT 0x10 /* Shift cursor/display */
#define LCD_CMD_DISPLAY_SHIFT 0x08 /* Shift display instead of cursor */
#define LCD_CMD_SHIFT_RIGHT 0x04 /* Shift display/cursor to the right */

#define LCD_CMD_FUNCTION_SET 0x20 /* Set function */
#define LCD_CMD_DATA_LEN_8BITS 0x10 /* Set data length to 8 bits */
#define LCD_CMD_TWO_LINES 0x08 /* Set to two display lines */
Expand Down Expand Up @@ -158,6 +162,133 @@ int hd44780_common_init_display(struct charlcd *lcd)
}
EXPORT_SYMBOL_GPL(hd44780_common_init_display);

int hd44780_common_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir)
{
struct hd44780_common *hdc = lcd->drvdata;

if (dir == CHARLCD_SHIFT_LEFT) {
/* back one char if not at end of line */
if (lcd->addr.x < hdc->bwidth)
hdc->write_cmd(hdc, LCD_CMD_SHIFT);
} else if (dir == CHARLCD_SHIFT_RIGHT) {
/* allow the cursor to pass the end of the line */
if (lcd->addr.x < (hdc->bwidth - 1))
hdc->write_cmd(hdc,
LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
}

return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_shift_cursor);

int hd44780_common_shift_display(struct charlcd *lcd,
enum charlcd_shift_dir dir)
{
struct hd44780_common *hdc = lcd->drvdata;

if (dir == CHARLCD_SHIFT_LEFT)
hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
else if (dir == CHARLCD_SHIFT_RIGHT)
hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
LCD_CMD_SHIFT_RIGHT);

return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_shift_display);

static void hd44780_common_set_mode(struct hd44780_common *hdc)
{
hdc->write_cmd(hdc,
LCD_CMD_DISPLAY_CTRL |
((hdc->hd44780_common_flags & LCD_FLAG_D) ?
LCD_CMD_DISPLAY_ON : 0) |
((hdc->hd44780_common_flags & LCD_FLAG_C) ?
LCD_CMD_CURSOR_ON : 0) |
((hdc->hd44780_common_flags & LCD_FLAG_B) ?
LCD_CMD_BLINK_ON : 0));
}

int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on)
{
struct hd44780_common *hdc = lcd->drvdata;

if (on == CHARLCD_ON)
hdc->hd44780_common_flags |= LCD_FLAG_D;
else
hdc->hd44780_common_flags &= ~LCD_FLAG_D;

hd44780_common_set_mode(hdc);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_display);

int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on)
{
struct hd44780_common *hdc = lcd->drvdata;

if (on == CHARLCD_ON)
hdc->hd44780_common_flags |= LCD_FLAG_C;
else
hdc->hd44780_common_flags &= ~LCD_FLAG_C;

hd44780_common_set_mode(hdc);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_cursor);

int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on)
{
struct hd44780_common *hdc = lcd->drvdata;

if (on == CHARLCD_ON)
hdc->hd44780_common_flags |= LCD_FLAG_B;
else
hdc->hd44780_common_flags &= ~LCD_FLAG_B;

hd44780_common_set_mode(hdc);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_blink);

static void hd44780_common_set_function(struct hd44780_common *hdc)
{
hdc->write_cmd(hdc,
LCD_CMD_FUNCTION_SET |
((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) |
((hdc->hd44780_common_flags & LCD_FLAG_F) ?
LCD_CMD_FONT_5X10_DOTS : 0) |
((hdc->hd44780_common_flags & LCD_FLAG_N) ?
LCD_CMD_TWO_LINES : 0));
}

int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size)
{
struct hd44780_common *hdc = lcd->drvdata;

if (size == CHARLCD_FONTSIZE_LARGE)
hdc->hd44780_common_flags |= LCD_FLAG_F;
else
hdc->hd44780_common_flags &= ~LCD_FLAG_F;

hd44780_common_set_function(hdc);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_fontsize);

int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines)
{
struct hd44780_common *hdc = lcd->drvdata;

if (lines == CHARLCD_LINES_2)
hdc->hd44780_common_flags |= LCD_FLAG_N;
else
hdc->hd44780_common_flags &= ~LCD_FLAG_N;

hd44780_common_set_function(hdc);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_lines);

struct hd44780_common *hd44780_common_alloc(void)
{
struct hd44780_common *hd;
Expand Down
9 changes: 9 additions & 0 deletions drivers/auxdisplay/hd44780_common.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,4 +20,13 @@ int hd44780_common_gotoxy(struct charlcd *lcd);
int hd44780_common_home(struct charlcd *lcd);
int hd44780_common_clear_display(struct charlcd *lcd);
int hd44780_common_init_display(struct charlcd *lcd);
int hd44780_common_shift_cursor(struct charlcd *lcd,
enum charlcd_shift_dir dir);
int hd44780_common_shift_display(struct charlcd *lcd,
enum charlcd_shift_dir dir);
int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on);
int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on);
int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on);
int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size);
int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines);
struct hd44780_common *hd44780_common_alloc(void);
Loading

0 comments on commit d2f2187

Please sign in to comment.