auxdisplay: Move clear_display to hd44780_common

This moves the clear_display function from charlcd to hd44780_common.
This is one more step to make charlcd independent from device specific
code. The two hd44780 drivers use the new function from hd44780_common
and charlcd calls this function through its function pointer in its ops
structure.

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 10:58:14 +01:00 committed by Miguel Ojeda
parent 88645a86e3
commit 45421ffefb
6 changed files with 37 additions and 16 deletions

View File

@ -34,8 +34,6 @@
#define LCD_FLAG_L 0x0080 /* Backlight enabled */
/* LCD commands */
#define LCD_CMD_DISPLAY_CLEAR 0x01 /* Clear entire display */
#define LCD_CMD_ENTRY_MODE 0x04 /* Set entry mode */
#define LCD_CMD_CURSOR_INC 0x02 /* Increment cursor */
@ -178,18 +176,6 @@ static void charlcd_clear_fast(struct charlcd *lcd)
charlcd_home(lcd);
}
/* clears the display and resets X/Y */
static void charlcd_clear_display(struct charlcd *lcd)
{
struct hd44780_common *hdc = lcd->drvdata;
hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
lcd->addr.x = 0;
lcd->addr.y = 0;
/* we must wait a few milliseconds (15) */
long_sleep(15);
}
static int charlcd_init_display(struct charlcd *lcd)
{
void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
@ -254,7 +240,9 @@ static int charlcd_init_display(struct charlcd *lcd)
/* entry mode set : increment, cursor shifting */
hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
charlcd_clear_display(lcd);
lcd->ops->clear_display(lcd);
lcd->addr.x = 0;
lcd->addr.y = 0;
return 0;
}
@ -670,8 +658,10 @@ static int charlcd_open(struct inode *inode, struct file *file)
goto fail;
if (priv->must_clear) {
charlcd_clear_display(&priv->lcd);
priv->lcd.ops->clear_display(&priv->lcd);
priv->must_clear = false;
priv->lcd.addr.x = 0;
priv->lcd.addr.y = 0;
}
return nonseekable_open(inode, file);

View File

@ -43,6 +43,9 @@ struct charlcd {
* previously set in addr.x and addr.y by charlcd.
* @home: Set cursor to 0, 0. The values in addr.x and addr.y are set to 0, 0 by
* charlcd prior to calling this function.
* @clear_display: Again clear the whole display, set the cursor to 0, 0. The
* values in addr.x and addr.y are set to 0, 0 by charlcd prior to calling this
* function.
*/
struct charlcd_ops {
void (*clear_fast)(struct charlcd *lcd);
@ -50,6 +53,7 @@ struct charlcd_ops {
int (*print)(struct charlcd *lcd, int c);
int (*gotoxy)(struct charlcd *lcd);
int (*home)(struct charlcd *lcd);
int (*clear_display)(struct charlcd *lcd);
};
struct charlcd *charlcd_alloc(void);

View File

@ -129,6 +129,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
.print = hd44780_common_print,
.gotoxy = hd44780_common_gotoxy,
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
};
/* Send a command to the LCD panel in 4 bit GPIO mode */
@ -175,6 +176,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
.print = hd44780_common_print,
.gotoxy = hd44780_common_gotoxy,
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
};
static int hd44780_probe(struct platform_device *pdev)

View File

@ -1,13 +1,22 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "charlcd.h"
#include "hd44780_common.h"
/* LCD commands */
#define LCD_CMD_DISPLAY_CLEAR 0x01 /* Clear entire display */
#define LCD_CMD_SET_DDRAM_ADDR 0x80 /* Set display data RAM address */
/* sleeps that many milliseconds with a reschedule */
static void long_sleep(int ms)
{
schedule_timeout_interruptible(msecs_to_jiffies(ms));
}
int hd44780_common_print(struct charlcd *lcd, int c)
{
struct hd44780_common *hdc = lcd->drvdata;
@ -49,6 +58,18 @@ int hd44780_common_home(struct charlcd *lcd)
}
EXPORT_SYMBOL_GPL(hd44780_common_home);
/* clears the display and resets X/Y */
int hd44780_common_clear_display(struct charlcd *lcd)
{
struct hd44780_common *hdc = lcd->drvdata;
hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
/* we must wait a few milliseconds (15) */
long_sleep(15);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
struct hd44780_common *hd44780_common_alloc(void)
{
struct hd44780_common *hd;

View File

@ -17,4 +17,5 @@ struct hd44780_common {
int hd44780_common_print(struct charlcd *lcd, int c);
int hd44780_common_gotoxy(struct charlcd *lcd);
int hd44780_common_home(struct charlcd *lcd);
int hd44780_common_clear_display(struct charlcd *lcd);
struct hd44780_common *hd44780_common_alloc(void);

View File

@ -877,6 +877,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
.backlight = lcd_backlight,
.gotoxy = hd44780_common_gotoxy,
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
};
static const struct charlcd_ops charlcd_parallel_ops = {
@ -884,6 +885,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
.backlight = lcd_backlight,
.gotoxy = hd44780_common_gotoxy,
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
};
static const struct charlcd_ops charlcd_tilcd_ops = {
@ -891,6 +893,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
.backlight = lcd_backlight,
.gotoxy = hd44780_common_gotoxy,
.home = hd44780_common_home,
.clear_display = hd44780_common_clear_display,
};
/* initialize the LCD driver */