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Subject[PATCH v2 08/32] auxdisplay: hd44780_common_print
Date
From: Lars Poeschel <poeschel@lemonage.de>

We create a hd44780_common_print function. It is derived from the
original charlcd_print. charlcd_print becomes a device independent print
function, that then only calles via it's ops function pointers, into the
print function offered by drivers.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
drivers/auxdisplay/charlcd.c | 28 +++++++++++++++-------------
drivers/auxdisplay/charlcd.h | 11 +++++++++++
drivers/auxdisplay/hd44780.c | 2 ++
drivers/auxdisplay/hd44780_common.c | 13 +++++++++++++
drivers/auxdisplay/hd44780_common.h | 1 +
5 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 1b37d4bc38f9..72ed004a8980 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -167,18 +167,15 @@ static void charlcd_home(struct charlcd *lcd)

static void charlcd_print(struct charlcd *lcd, char c)
{
- struct hd44780_common *hdc = lcd->drvdata;
+ if (lcd->char_conv)
+ c = lcd->char_conv[(unsigned char)c];

- if (lcd->addr.x < hdc->bwidth) {
- if (lcd->char_conv)
- c = lcd->char_conv[(unsigned char)c];
- hdc->write_data(hdc, c);
+ if (!lcd->ops->print(lcd, c))
lcd->addr.x++;

- /* prevents the cursor from wrapping onto the next line */
- if (lcd->addr.x == hdc->bwidth)
- charlcd_gotoxy(lcd);
- }
+ /* prevents the cursor from wrapping onto the next line */
+ if (lcd->addr.x == lcd->width)
+ charlcd_gotoxy(lcd);
}

static void charlcd_clear_fast(struct charlcd *lcd)
@@ -192,7 +189,7 @@ static void charlcd_clear_fast(struct charlcd *lcd)
lcd->ops->clear_fast(lcd);
else
for (pos = 0; pos < min(2, lcd->height) * hdc->hwidth; pos++)
- hdc->write_data(hdc, ' ');
+ lcd->ops->print(lcd, ' ');

charlcd_home(lcd);
}
@@ -433,12 +430,16 @@ static inline int handle_lcd_special_code(struct charlcd *lcd)
processed = 1;
break;
case 'k': { /* kill end of line */
- int x;
+ int x, xs, ys;

+ xs = lcd->addr.x;
+ ys = lcd->addr.y;
for (x = lcd->addr.x; x < hdc->bwidth; x++)
- hdc->write_data(hdc, ' ');
+ lcd->ops->print(lcd, ' ');

/* restore cursor position */
+ lcd->addr.x = xs;
+ lcd->addr.y = ys;
charlcd_gotoxy(lcd);
processed = 1;
break;
@@ -591,7 +592,8 @@ static void charlcd_write_char(struct charlcd *lcd, char c)
* go to the beginning of the next line
*/
for (; lcd->addr.x < hdc->bwidth; lcd->addr.x++)
- hdc->write_data(hdc, ' ');
+ lcd->ops->print(lcd, ' ');
+
lcd->addr.x = 0;
lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
charlcd_gotoxy(lcd);
diff --git a/drivers/auxdisplay/charlcd.h b/drivers/auxdisplay/charlcd.h
index ff4896af2189..874519f079b4 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -30,9 +30,20 @@ struct charlcd {
void *drvdata;
};

+/**
+ * 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 cursor is advanced by charlcd.
+ * The buffered cursor position is advanced by charlcd. The cursor should not
+ * wrap to the next line at the end of a line.
+ */
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);
};

struct charlcd *charlcd_alloc(void);
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index dc4738563298..9680bb611639 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -126,6 +126,7 @@ static void hd44780_write_data_gpio8(struct hd44780_common *hdc, int data)

static const struct charlcd_ops hd44780_ops_gpio8 = {
.backlight = hd44780_backlight,
+ .print = hd44780_common_print,
};

/* Send a command to the LCD panel in 4 bit GPIO mode */
@@ -169,6 +170,7 @@ static void hd44780_write_data_gpio4(struct hd44780_common *hdc, int data)

static const struct charlcd_ops hd44780_ops_gpio4 = {
.backlight = hd44780_backlight,
+ .print = hd44780_common_print,
};

static int hd44780_probe(struct platform_device *pdev)
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 285073a00302..da296c5ad7a5 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -2,8 +2,21 @@
#include <linux/module.h>
#include <linux/slab.h>

+#include "charlcd.h"
#include "hd44780_common.h"

+int hd44780_common_print(struct charlcd *lcd, int c)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (lcd->addr.x < hdc->bwidth) {
+ hdc->write_data(hdc, c);
+ return 0;
+ }
+
+ return 1;
+}
+
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 6c38ddf8f2ce..02d650903e35 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -14,5 +14,6 @@ struct hd44780_common {
void *hd44780;
};

+int hd44780_common_print(struct charlcd *lcd, int c);
struct hd44780_common *hd44780_common_alloc(void);

--
2.28.0
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