auxdisplay: Move clear_display to hd44780_common

This moves the clear_display function from charlcd to hd44780_common.
This is one more step to make charlcd independent from device specific
code. The two hd44780 drivers use the new function from hd44780_common
and charlcd calls this function through its function pointer in its ops
structure.

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

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 44dd6e0..fc0daf4 100644 (file)
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -34,8 +34,6 @@
 #define LCD_FLAG_L             0x0080  /* Backlight enabled */
 
 /* LCD commands */
-#define LCD_CMD_DISPLAY_CLEAR  0x01    /* Clear entire display */
-
 #define LCD_CMD_ENTRY_MODE     0x04    /* Set entry mode */
 #define LCD_CMD_CURSOR_INC     0x02    /* Increment cursor */
 
@@ -178,18 +176,6 @@ static void charlcd_clear_fast(struct charlcd *lcd)
        charlcd_home(lcd);
 }
 
-/* clears the display and resets X/Y */
-static void charlcd_clear_display(struct charlcd *lcd)
-{
-       struct hd44780_common *hdc = lcd->drvdata;
-
-       hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
-       lcd->addr.x = 0;
-       lcd->addr.y = 0;
-       /* we must wait a few milliseconds (15) */
-       long_sleep(15);
-}
-
 static int charlcd_init_display(struct charlcd *lcd)
 {
        void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd);
@@ -254,7 +240,9 @@ static int charlcd_init_display(struct charlcd *lcd)
        /* entry mode set : increment, cursor shifting */
        hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
 
-       charlcd_clear_display(lcd);
+       lcd->ops->clear_display(lcd);
+       lcd->addr.x = 0;
+       lcd->addr.y = 0;
        return 0;
 }
 
@@ -670,8 +658,10 @@ static int charlcd_open(struct inode *inode, struct file *file)
                goto fail;
 
        if (priv->must_clear) {
-               charlcd_clear_display(&priv->lcd);
+               priv->lcd.ops->clear_display(&priv->lcd);
                priv->must_clear = false;
+               priv->lcd.addr.x = 0;
+               priv->lcd.addr.y = 0;
        }
        return nonseekable_open(inode, file);
 

diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index 236fd0e..a6c32c4 100644 (file)
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -43,6 +43,9 @@ 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
+ * function.
  */
 struct charlcd_ops {
        void (*clear_fast)(struct charlcd *lcd);
@@ -50,6 +53,7 @@ struct charlcd_ops {
        int (*print)(struct charlcd *lcd, int c);
        int (*gotoxy)(struct charlcd *lcd);
        int (*home)(struct charlcd *lcd);
+       int (*clear_display)(struct charlcd *lcd);
 };
 
 struct charlcd *charlcd_alloc(void);

diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index b0893ea..40ea6d2 100644 (file)
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -129,6 +129,7 @@ static const struct charlcd_ops hd44780_ops_gpio8 = {
        .print          = hd44780_common_print,
        .gotoxy         = hd44780_common_gotoxy,
        .home           = hd44780_common_home,
+       .clear_display  = hd44780_common_clear_display,
 };
 
 /* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -175,6 +176,7 @@ static const struct charlcd_ops hd44780_ops_gpio4 = {
        .print          = hd44780_common_print,
        .gotoxy         = hd44780_common_gotoxy,
        .home           = hd44780_common_home,
+       .clear_display  = hd44780_common_clear_display,
 };
 
 static int hd44780_probe(struct platform_device *pdev)

diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index ea62bea..2f7d556 100644 (file)
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -1,13 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 #include <linux/module.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 
 #include "charlcd.h"
 #include "hd44780_common.h"
 
 /* LCD commands */
+#define LCD_CMD_DISPLAY_CLEAR  0x01    /* Clear entire display */
+
 #define LCD_CMD_SET_DDRAM_ADDR 0x80    /* Set display data RAM address */
 
+/* sleeps that many milliseconds with a reschedule */
+static void long_sleep(int ms)
+{
+       schedule_timeout_interruptible(msecs_to_jiffies(ms));
+}
+
 int hd44780_common_print(struct charlcd *lcd, int c)
 {
        struct hd44780_common *hdc = lcd->drvdata;
@@ -49,6 +58,18 @@ int hd44780_common_home(struct charlcd *lcd)
 }
 EXPORT_SYMBOL_GPL(hd44780_common_home);
 
+/* clears the display and resets X/Y */
+int hd44780_common_clear_display(struct charlcd *lcd)
+{
+       struct hd44780_common *hdc = lcd->drvdata;
+
+       hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
+       /* we must wait a few milliseconds (15) */
+       long_sleep(15);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_clear_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 c91070e..ef11935 100644 (file)
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -17,4 +17,5 @@ struct hd44780_common {
 int hd44780_common_print(struct charlcd *lcd, int c);
 int hd44780_common_gotoxy(struct charlcd *lcd);
 int hd44780_common_home(struct charlcd *lcd);
+int hd44780_common_clear_display(struct charlcd *lcd);
 struct hd44780_common *hd44780_common_alloc(void);

diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c
index b1e874f..8adf627 100644 (file)
--- a/drivers/auxdisplay/panel.c
+++ b/drivers/auxdisplay/panel.c
@@ -877,6 +877,7 @@ static const struct charlcd_ops charlcd_serial_ops = {
        .backlight      = lcd_backlight,
        .gotoxy         = hd44780_common_gotoxy,
        .home           = hd44780_common_home,
+       .clear_display  = hd44780_common_clear_display,
 };
 
 static const struct charlcd_ops charlcd_parallel_ops = {
@@ -884,6 +885,7 @@ static const struct charlcd_ops charlcd_parallel_ops = {
        .backlight      = lcd_backlight,
        .gotoxy         = hd44780_common_gotoxy,
        .home           = hd44780_common_home,
+       .clear_display  = hd44780_common_clear_display,
 };
 
 static const struct charlcd_ops charlcd_tilcd_ops = {
@@ -891,6 +893,7 @@ static const struct charlcd_ops charlcd_tilcd_ops = {
        .backlight      = lcd_backlight,
        .gotoxy         = hd44780_common_gotoxy,
        .home           = hd44780_common_home,
+       .clear_display  = hd44780_common_clear_display,
 };
 
 /* initialize the LCD driver */