auxdisplay: provide hd44780_common_gotoxy

Provide a hd44780_common_gotoxy function and a pointer in the ops for
charlcd to use to move the cursor.

Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

drivers/auxdisplay/charlcd.c

@@ -55,7 +55,7 @@
 
 #define LCD_CMD_SET_CGRAM_ADDR	0x40	/* Set char generator RAM address */
 
-#define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
+#define LCD_CMD_SET_DDRAM_ADDR 0x80    /* Set display data RAM address */
 
 #define LCD_ESCAPE_LEN		24	/* Max chars for LCD escape command */
 #define LCD_ESCAPE_CHAR		27	/* Use char 27 for escape command */
@@ -140,33 +140,17 @@ void charlcd_poke(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(charlcd_poke);
 
-static void charlcd_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);
-}
-
 static void charlcd_home(struct charlcd *lcd)
 {
 	lcd->addr.x = 0;
 	lcd->addr.y = 0;
-	charlcd_gotoxy(lcd);
+	lcd->ops->gotoxy(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];
 
@@ -174,8 +158,8 @@ static void charlcd_print(struct charlcd *lcd, char c)
 		lcd->addr.x++;
 
 	/* prevents the cursor from wrapping onto the next line */
-	if (lcd->addr.x == lcd->width)
-		charlcd_gotoxy(lcd);
+	if (lcd->addr.x == hdc->bwidth)
+		lcd->ops->gotoxy(lcd);
 }
 
 static void charlcd_clear_fast(struct charlcd *lcd)
@@ -440,7 +424,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 		/* restore cursor position */
 		lcd->addr.x = xs;
 		lcd->addr.y = ys;
-		charlcd_gotoxy(lcd);
+		lcd->ops->gotoxy(lcd);
 		processed = 1;
 		break;
 	}
@@ -499,7 +483,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 			hdc->write_data(hdc, cgbytes[addr]);
 
 		/* ensures that we stop writing to CGRAM */
-		charlcd_gotoxy(lcd);
+		lcd->ops->gotoxy(lcd);
 		processed = 1;
 		break;
 	}
@@ -510,7 +494,7 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
 
 		/* If the command is valid, move to the new address */
 		if (parse_xy(esc, &lcd->addr.x, &lcd->addr.y))
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 
 		/* Regardless of its validity, mark as processed */
 		processed = 1;
@@ -596,12 +580,12 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 
 			lcd->addr.x = 0;
 			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 			break;
 		case '\r':
 			/* go to the beginning of the same line */
 			lcd->addr.x = 0;
-			charlcd_gotoxy(lcd);
+			lcd->ops->gotoxy(lcd);
 			break;
 		case '\t':
 			/* print a space instead of the tab */

drivers/auxdisplay/charlcd.h

@@ -37,14 +37,16 @@ struct charlcd {
  * 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.
+ * @gotoxy: Set cursor to x, y. The x and y values to set the cursor to are
+ * previously set in addr.x and addr.y by charlcd.
  */
 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);
+	int (*gotoxy)(struct charlcd *lcd);
 };
 
 struct charlcd *charlcd_alloc(void);

drivers/auxdisplay/hd44780.c

@@ -127,6 +127,7 @@ 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,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -171,6 +172,7 @@ 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,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static int hd44780_probe(struct platform_device *pdev)

drivers/auxdisplay/hd44780_common.c

@@ -5,6 +5,9 @@
 #include "charlcd.h"
 #include "hd44780_common.h"
 
+/* LCD commands */
+#define LCD_CMD_SET_DDRAM_ADDR	0x80	/* Set display data RAM address */
+
 int hd44780_common_print(struct charlcd *lcd, int c)
 {
 	struct hd44780_common *hdc = lcd->drvdata;
@@ -18,6 +21,26 @@ int hd44780_common_print(struct charlcd *lcd, int c)
 }
 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);
+
 struct hd44780_common *hd44780_common_alloc(void)
 {
 	struct hd44780_common *hd;

drivers/auxdisplay/hd44780_common.h

@@ -15,4 +15,5 @@ struct hd44780_common {
 };
 
 int hd44780_common_print(struct charlcd *lcd, int c);
+int hd44780_common_gotoxy(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);

drivers/auxdisplay/panel.c

@@ -875,16 +875,19 @@ static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
 static const struct charlcd_ops charlcd_serial_ops = {
 	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
 	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
 	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
+	.gotoxy		= hd44780_common_gotoxy,
 };
 
 /* initialize the LCD driver */