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authorLars Poeschel <poeschel@lemonage.de>2020-11-03 12:58:11 +0300
committerMiguel Ojeda <ojeda@kernel.org>2020-11-04 13:04:03 +0300
commitb26deabb1d915fe87d395081bbd3058b938dee89 (patch)
treeea623cab5ff65fe59f1e514c85ea41692e0bb5e6
parent11588b59cf620305e78523f57918b986b5e32214 (diff)
downloadlinux-b26deabb1d915fe87d395081bbd3058b938dee89.tar.xz
auxdisplay: hd44780_common_print
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 calls via its ops function pointers, into the print function offered by drivers. Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
-rw-r--r--drivers/auxdisplay/charlcd.c28
-rw-r--r--drivers/auxdisplay/charlcd.h12
-rw-r--r--drivers/auxdisplay/hd44780.c2
-rw-r--r--drivers/auxdisplay/hd44780_common.c14
-rw-r--r--drivers/auxdisplay/hd44780_common.h1
5 files changed, 44 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..94922e3c1c4c 100644
--- a/drivers/auxdisplay/charlcd.h
+++ b/drivers/auxdisplay/charlcd.h
@@ -30,9 +30,21 @@ 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.
+ * Optional.
+ * @backlight: Turn backlight on or off. Optional.
+ * @print: 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 4968461f0c4a..1dfcb2cdbc70 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -2,8 +2,22 @@
#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;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_print);
+
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 73dd4c7c6de3..ac404a44889b 100644
--- a/drivers/auxdisplay/hd44780_common.h
+++ b/drivers/auxdisplay/hd44780_common.h
@@ -14,4 +14,5 @@ struct hd44780_common {
void *hd44780;
};
+int hd44780_common_print(struct charlcd *lcd, int c);
struct hd44780_common *hd44780_common_alloc(void);