[PATCH v3 27/32] auxdisplay: hd44780: Remove clear_fast

From: poeschel
Date: Mon Oct 05 2020 - 08:13:28 EST


From: Lars Poeschel <poeschel@xxxxxxxxxxx>

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@xxxxxx/

Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
---
Changes in v3:
- This patch is squashed together from 26, 27 and 28 from previous patch
set:
Link: https://lore.kernel.org/lkml/20200921144645.2061313-27-poeschel@xxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/20200921144645.2061313-28-poeschel@xxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/20200921144645.2061313-29-poeschel@xxxxxxxxxxx/

- Additionally this now removes clear_fast from charlcd_ops and from
panel driver.

---
drivers/auxdisplay/charlcd.c | 21 ++++-------
drivers/auxdisplay/charlcd.h | 6 ++--
drivers/auxdisplay/panel.c | 67 ------------------------------------
3 files changed, 8 insertions(+), 86 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 0f0568a4bd35..077c01e87127 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/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 */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 83fa989d37fa..024f7188b5cc 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -55,7 +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.
* @backlight: Turn backlight on or off. Optional.
* @print: just Print one character to the display at current cursor position.
* The buffered cursor position is advanced by charlcd. The cursor should not
@@ -64,8 +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.
@@ -77,7 +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);
diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index b0d2ae5b9be8..e07fadac281d 100644
--- a/drivers/auxdisplay/panel.c
+++ b/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,
--
2.28.0