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| author | Lars Poeschel <poeschel@lemonage.de> | 2020-11-03 12:58:14 +0300 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2020-11-04 13:04:03 +0300 |
| commit | 45421ffefbb5f195de02ead952755329ef8576d8 (patch) | |
| tree | 37fb7be29a8b25c6df3648512212d669d6dd90d8 /drivers/auxdisplay/hd44780_common.c | |
| parent | 88645a86e3420cddfe5bb9cd8d7c15aff8f54b46 (diff) | |
| download | linux-45421ffefbb5f195de02ead952755329ef8576d8.tar.xz | |
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>
Diffstat (limited to 'drivers/auxdisplay/hd44780_common.c')
| -rw-r--r-- | drivers/auxdisplay/hd44780_common.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c index ea62beada9d8..2f7d55668eb4 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; @@ -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; |