[PATCH v2 17/32] auxdisplay: Implement a hd44780_common_display

From: poeschel
Date: Mon Sep 21 2020 - 10:49:25 EST


From: Lars Poeschel <poeschel@xxxxxxxxxxx>

Implement a hd44780_common_display function to turn the whole display on
or off. The hd44780 drivers can use this and charlcd uses this through
its ops function pointer.

Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
---
drivers/auxdisplay/charlcd.c | 6 ++++++
drivers/auxdisplay/charlcd.h | 2 ++
drivers/auxdisplay/hd44780.c | 2 ++
drivers/auxdisplay/hd44780_common.c | 26 ++++++++++++++++++++++++++
drivers/auxdisplay/hd44780_common.h | 1 +
drivers/auxdisplay/panel.c | 3 +++
6 files changed, 40 insertions(+)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index e48287197732..9bd3c0f2c470 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -232,10 +232,16 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
switch (*esc) {
case 'D': /* Display ON */
priv->flags |= LCD_FLAG_D;
+ if (priv->flags != oldflags)
+ lcd->ops->display(lcd, CHARLCD_ON);
+
processed = 1;
break;
case 'd': /* Display OFF */
priv->flags &= ~LCD_FLAG_D;
+ if (priv->flags != oldflags)
+ lcd->ops->display(lcd, CHARLCD_OFF);
+
processed = 1;
break;
case 'C': /* Cursor ON */
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 6fd4a77f5794..ec739a25195e 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -60,6 +60,7 @@ struct charlcd {
* @init_display: Initialize the display.
* @shift_cursor: Shift cursor left or right one position.
* @shift_display: Shift whole display content left or right.
+ * @display: Turn display on or off.
*/
struct charlcd_ops {
void (*clear_fast)(struct charlcd *lcd);
@@ -71,6 +72,7 @@ struct charlcd_ops {
int (*init_display)(struct charlcd *lcd);
int (*shift_cursor)(struct charlcd *lcd, enum charlcd_shift_dir dir);
int (*shift_display)(struct charlcd *lcd, enum charlcd_shift_dir dir);
+ int (*display)(struct charlcd *lcd, enum charlcd_onoff on);
};

void charlcd_backlight(struct charlcd *lcd, enum charlcd_onoff on);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index a3b18bbc2e4a..0f76b812fa20 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -133,6 +133,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
+ .display = hd44780_common_display,
};

/* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -183,6 +184,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
+ .display = hd44780_common_display,
};

static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 318ad81a39ed..d375a621c52d 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -195,6 +195,32 @@ int hd44780_common_shift_display(struct charlcd *lcd,
}
EXPORT_SYMBOL_GPL(hd44780_common_shift_display);

+static void hd44780_common_set_mode(struct hd44780_common *hdc)
+{
+ hdc->write_cmd(hdc,
+ LCD_CMD_DISPLAY_CTRL |
+ ((hdc->hd44780_common_flags & LCD_FLAG_D) ?
+ LCD_CMD_DISPLAY_ON : 0) |
+ ((hdc->hd44780_common_flags & LCD_FLAG_C) ?
+ LCD_CMD_CURSOR_ON : 0) |
+ ((hdc->hd44780_common_flags & LCD_FLAG_B) ?
+ LCD_CMD_BLINK_ON : 0));
+}
+
+int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (on == CHARLCD_ON)
+ hdc->hd44780_common_flags |= LCD_FLAG_D;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_D;
+
+ hd44780_common_set_mode(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_display);
+
struct hd44780_common *hd44780_common_alloc(void)
{
struct hd44780_common *hd;
diff --git a/drivers/auxdisplay/hd44780_common.h b/drivers/auxdisplay/hd44780_common.h
index 7badb96cb8a9..1550fa77b956 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -24,5 +24,6 @@ int hd44780_common_shift_cursor(struct charlcd *lcd,
enum charlcd_shift_dir dir);
int hd44780_common_shift_display(struct charlcd *lcd,
enum charlcd_shift_dir dir);
+int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on);
struct hd44780_common *hd44780_common_alloc(void);

diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index 7ebbfb338518..9cb895c74cfb 100644
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -881,6 +881,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
+ .display = hd44780_common_display,
};

static const struct charlcd_ops charlcd_parallel_ops = {
@@ -892,6 +893,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
+ .display = hd44780_common_display,
};

static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -903,6 +905,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
.init_display = hd44780_common_init_display,
.shift_cursor = hd44780_common_shift_cursor,
.shift_display = hd44780_common_shift_display,
+ .display = hd44780_common_display,
};

/* initialize the LCD driver */
--
2.28.0