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// 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;
if (lcd->addr.x < hdc->bwidth) {
hdc->write_data(hdc, c);
return 0;
}
return 1;
}
EXPORT_SYMBOL_GPL(hd44780_common_print);
int hd44780_common_gotoxy(struct charlcd *lcd)
{
struct hd44780_common *hdc = lcd->drvdata;
unsigned int addr;
/*
* we force the cursor to stay at the end of the
* line if it wants to go farther
*/
addr = lcd->addr.x < hdc->bwidth ? lcd->addr.x & (hdc->hwidth - 1)
: hdc->bwidth - 1;
if (lcd->addr.y & 1)
addr += hdc->hwidth;
if (lcd->addr.y & 2)
addr += hdc->bwidth;
hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
int hd44780_common_home(struct charlcd *lcd)
{
lcd->addr.x = 0;
lcd->addr.y = 0;
return hd44780_common_gotoxy(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;
hd = kzalloc(sizeof(*hd), GFP_KERNEL);
if (!hd)
return NULL;
hd->ifwidth = 8;
hd->bwidth = DEFAULT_LCD_BWIDTH;
hd->hwidth = DEFAULT_LCD_HWIDTH;
return hd;
}
EXPORT_SYMBOL_GPL(hd44780_common_alloc);
MODULE_LICENSE("GPL");
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