auxdisplay: hd44780: Remove clear_fast

We remove the hd44780_clear_fast (display) clear implementation. With
the new timeout the normal clear_display is reasonably fast. So there is
no need for a clear_fast anymore.

Link: https://lore.kernel.org/lkml/[email protected]/

Signed-off-by: Lars Poeschel <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

Author: poeschel

drivers/auxdisplay/charlcd.c

@@ -125,20 +125,11 @@ static void charlcd_print(struct charlcd *lcd, char c)
 		lcd->ops->gotoxy(lcd);
 }
 
-static void charlcd_clear_fast(struct charlcd *lcd)
+static void charlcd_clear_display(struct charlcd *lcd)
 {
-	struct hd44780_common *hdc = lcd->drvdata;
-	int pos;
-
-	charlcd_home(lcd);
-
-	if (lcd->ops->clear_fast)
-		lcd->ops->clear_fast(lcd);
-	else
-		for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
-			lcd->ops->print(lcd, ' ');
-
-	charlcd_home(lcd);
+	lcd->ops->clear_display(lcd);
+	lcd->addr.x = 0;
+	lcd->addr.y = 0;
 }
 
 /*
@@ -409,7 +400,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 			break;
 		case '\f':
 			/* quickly clear the display */
-			charlcd_clear_fast(lcd);
+			charlcd_clear_display(lcd);
 			break;
 		case '\n':
 			/*
@@ -448,7 +439,7 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
 
 		if (!strcmp(priv->esc_seq.buf, "[2J")) {
 			/* clear the display */
-			charlcd_clear_fast(lcd);
+			charlcd_clear_display(lcd);
 			processed = 1;
 		} else if (!strcmp(priv->esc_seq.buf, "[H")) {
 			/* cursor to home */

drivers/auxdisplay/charlcd.h

@@ -55,8 +55,6 @@ struct charlcd {
 /**
  * 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 buffered cursor position is advanced by charlcd. The cursor should not
@@ -65,8 +63,8 @@ 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
+ * @clear_display: Clear the whole display and set the cursor to 0, 0. The
+ * values in addr.x and addr.y are set to 0, 0 by charlcd after to calling this
  * function.
  * @init_display: Initialize the display.
  * @shift_cursor: Shift cursor left or right one position.
@@ -78,7 +76,6 @@ struct charlcd {
  * @redefine_char: Redefine the actual pixel matrix of character.
  */
 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);

drivers/auxdisplay/panel.c

@@ -808,72 +808,7 @@ static void lcd_write_data_tilcd(struct hd44780_common *hdc, int data)
 	spin_unlock_irq(&pprt_lock);
 }
 
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_s(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
-		lcd_send_serial(' ' & 0x0F);
-		lcd_send_serial((' ' >> 4) & 0x0F);
-		/* the shortest data takes at least 40 us */
-		udelay(40);
-	}
-	spin_unlock_irq(&pprt_lock);
-}
-
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_p8(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		/* present the data to the data port */
-		w_dtr(pprt, ' ');
-
-		/* maintain the data during 20 us before the strobe */
-		udelay(20);
-
-		set_bit(LCD_BIT_E, bits);
-		set_bit(LCD_BIT_RS, bits);
-		clear_bit(LCD_BIT_RW, bits);
-		set_ctrl_bits();
-
-		/* maintain the strobe during 40 us */
-		udelay(40);
-
-		clear_bit(LCD_BIT_E, bits);
-		set_ctrl_bits();
-
-		/* the shortest data takes at least 45 us */
-		udelay(45);
-	}
-	spin_unlock_irq(&pprt_lock);
-}
-
-/* fills the display with spaces and resets X/Y */
-static void lcd_clear_fast_tilcd(struct charlcd *charlcd)
-{
-	struct hd44780_common *hdc = charlcd->drvdata;
-	int pos;
-
-	spin_lock_irq(&pprt_lock);
-	for (pos = 0; pos < charlcd->height * hdc->hwidth; pos++) {
-		/* present the data to the data port */
-		w_dtr(pprt, ' ');
-		udelay(60);
-	}
-
-	spin_unlock_irq(&pprt_lock);
-}
-
 static const struct charlcd_ops charlcd_serial_ops = {
-	.clear_fast	= lcd_clear_fast_s,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
@@ -890,7 +825,6 @@ static const struct charlcd_ops charlcd_serial_ops = {
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
-	.clear_fast	= lcd_clear_fast_p8,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,
@@ -907,7 +841,6 @@ static const struct charlcd_ops charlcd_parallel_ops = {
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
-	.clear_fast	= lcd_clear_fast_tilcd,
 	.backlight	= lcd_backlight,
 	.gotoxy		= hd44780_common_gotoxy,
 	.home		= hd44780_common_home,