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auxdisplay: hd44780_common_print

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We create a hd44780_common_print function. It is derived from the
original charlcd_print. charlcd_print becomes a device independent print
function, that then only calls via its ops function pointers, into the
print function offered by drivers.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This commit is contained in:
Lars Poeschel 2020-11-03 10:58:11 +01:00 committed by Miguel Ojeda
parent 11588b59cf
commit b26deabb1d
5 changed files with 44 additions and 13 deletions
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28
drivers/auxdisplay/charlcd.c
View File

@ -167,18 +167,15 @@ static void charlcd_home(struct charlcd *lcd)
static void charlcd_print(struct charlcd *lcd, char c)
{
struct hd44780_common *hdc = lcd->drvdata;
if (lcd->char_conv)
c = lcd->char_conv[(unsigned char)c];
if (lcd->addr.x < hdc->bwidth) {
if (lcd->char_conv)
c = lcd->char_conv[(unsigned char)c];
hdc->write_data(hdc, c);
if (!lcd->ops->print(lcd, c))
lcd->addr.x++;
/* prevents the cursor from wrapping onto the next line */
if (lcd->addr.x == hdc->bwidth)
charlcd_gotoxy(lcd);
}
/* prevents the cursor from wrapping onto the next line */
if (lcd->addr.x == lcd->width)
charlcd_gotoxy(lcd);
}
static void charlcd_clear_fast(struct charlcd *lcd)
@ -192,7 +189,7 @@ static void charlcd_clear_fast(struct charlcd *lcd)
lcd->ops->clear_fast(lcd);
else
for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
hdc->write_data(hdc, ' ');
lcd->ops->print(lcd, ' ');
charlcd_home(lcd);
}
@ -433,12 +430,16 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
processed = 1;
break;
case 'k': { /* kill end of line */
int x;
int x, xs, ys;
xs = lcd->addr.x;
ys = lcd->addr.y;
for (x = lcd->addr.x; x < hdc->bwidth; x++)
hdc->write_data(hdc, ' ');
lcd->ops->print(lcd, ' ');
/* restore cursor position */
lcd->addr.x = xs;
lcd->addr.y = ys;
charlcd_gotoxy(lcd);
processed = 1;
break;
@ -591,7 +592,8 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
* go to the beginning of the next line
*/
for (; lcd->addr.x < hdc->bwidth; lcd->addr.x++)
hdc->write_data(hdc, ' ');
lcd->ops->print(lcd, ' ');
lcd->addr.x = 0;
lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
charlcd_gotoxy(lcd);

12
drivers/auxdisplay/charlcd.h
View File

@ -30,9 +30,21 @@ struct charlcd {
void *drvdata;
};
/**
* struct charlcd_ops - Functions used by charlcd. Drivers have to implement
* these.
* @clear_fast: Clear the whole display and set cursor to position 0, 0.
* Optional.
* @backlight: Turn backlight on or off. Optional.
* @print: Print one character to the display at current cursor position.
* The cursor is advanced by charlcd.
* The buffered cursor position is advanced by charlcd. The cursor should not
* wrap to the next line at the end of a line.
*/
struct charlcd_ops {
void (*clear_fast)(struct charlcd *lcd);
void (*backlight)(struct charlcd *lcd, enum charlcd_onoff on);
int (*print)(struct charlcd *lcd, int c);
};
struct charlcd *charlcd_alloc(void);

2
drivers/auxdisplay/hd44780.c
View File

@ -126,6 +126,7 @@ static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)
static const struct charlcd_ops hd44780_ops_gpio8 = {
.backlight = hd44780_backlight,
.print = hd44780_common_print,
};
/* Send a command to the LCD panel in 4 bit GPIO mode */
@ -169,6 +170,7 @@ static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)
static const struct charlcd_ops hd44780_ops_gpio4 = {
.backlight = hd44780_backlight,
.print = hd44780_common_print,
};
static int hd44780_probe(struct platform_device *pdev)

14
drivers/auxdisplay/hd44780_common.c
View File

@ -2,8 +2,22 @@
#include <linux/module.h>
#include <linux/slab.h>
#include "charlcd.h"
#include "hd44780_common.h"
int hd44780_common_print(struct charlcd *lcd, int c)
{
struct hd44780_common *hdc = lcd->drvdata;
if (lcd->addr.x < hdc->bwidth) {
hdc->write_data(hdc, c);
return 0;
}
return 1;
}
EXPORT_SYMBOL_GPL(hd44780_common_print);
struct hd44780_common *hd44780_common_alloc(void)
{
struct hd44780_common *hd;

1
drivers/auxdisplay/hd44780_common.h
View File

@ -14,4 +14,5 @@ struct hd44780_common {
void *hd44780;
};
int hd44780_common_print(struct charlcd *lcd, int c);
struct hd44780_common *hd44780_common_alloc(void);