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Subject[PATCH v2 11/32] auxdisplay: Move clear_display to hd44780_common
Date
From: Lars Poeschel <poeschel@lemonage.de>

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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
drivers/auxdisplay/charlcd.c | 22 ++++++----------------
drivers/auxdisplay/charlcd.h | 4 ++++
drivers/auxdisplay/hd44780.c | 2 ++
drivers/auxdisplay/hd44780_common.c | 21 +++++++++++++++++++++
drivers/auxdisplay/hd44780_common.h | 1 +
drivers/auxdisplay/panel.c | 3 +++
6 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 44dd6e02eaf9..fc0daf4987d5 100644
--- 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 12c348c1a0ae..0b3dafbbae72 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -42,6 +42,9 @@ 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);
@@ -49,6 +52,7 @@ 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 b0893ea49165..40ea6d25dbe1 100644
--- 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 e659f16e9139..fd638d2091e4 100644
--- 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;
@@ -48,6 +57,18 @@ 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 1365484963d8..11ec4baf6997 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -17,5 +17,6 @@ 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 b1e874f07456..8adf627529f1 100644
--- 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 */
--
2.28.0
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