Commit 377cf2cb authored by Lars Poeschel's avatar Lars Poeschel Committed by Miguel Ojeda
Browse files

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/20200922092121.GG16421@1wt.eu/



Signed-off-by: default avatarLars Poeschel <poeschel@lemonage.de>
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent 7b231bb5

drivers/auxdisplay/charlcd.c

+6 −15
Original line number Diff line number Diff line
@@ -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

+2 −5
Original line number Diff line number Diff line
@@ -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

+0 −67
Original line number Diff line number Diff line
@@ -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,