diff options
author | Lars Poeschel <poeschel@lemonage.de> | 2020-11-03 10:58:17 +0100 |
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committer | Miguel Ojeda <ojeda@kernel.org> | 2020-11-04 11:04:04 +0100 |
commit | 01ec46dfa633a52ccfe38d4a194460d6adb2ba00 (patch) | |
tree | 14e67817c60048d0e3c361d498041b6ef64039da /drivers/auxdisplay/hd44780_common.c | |
parent | bd26b181d14af003a1c9903831f5735f431530f6 (diff) | |
download | linux-01ec46dfa633a52ccfe38d4a194460d6adb2ba00.tar.bz2 |
auxdisplay: Move init_display to hd44780_common
The init_display function is moved over to hd44780_common. charlcd uses
it via its ops function pointer and drivers initialize the ops with the
common hd44780_common_init_display function.
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 | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c index 2f7d55668eb4..7d4aea36cc55 100644 --- a/drivers/auxdisplay/hd44780_common.c +++ b/drivers/auxdisplay/hd44780_common.c @@ -9,6 +9,19 @@ /* 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 */ + +#define LCD_CMD_DISPLAY_CTRL 0x08 /* Display control */ +#define LCD_CMD_DISPLAY_ON 0x04 /* Set display on */ +#define LCD_CMD_CURSOR_ON 0x02 /* Set cursor on */ +#define LCD_CMD_BLINK_ON 0x01 /* Set blink on */ + +#define LCD_CMD_FUNCTION_SET 0x20 /* Set function */ +#define LCD_CMD_DATA_LEN_8BITS 0x10 /* Set data length to 8 bits */ +#define LCD_CMD_TWO_LINES 0x08 /* Set to two display lines */ +#define LCD_CMD_FONT_5X10_DOTS 0x04 /* Set char font to 5x10 dots */ + #define LCD_CMD_SET_DDRAM_ADDR 0x80 /* Set display data RAM address */ /* sleeps that many milliseconds with a reschedule */ @@ -70,6 +83,81 @@ int hd44780_common_clear_display(struct charlcd *lcd) } EXPORT_SYMBOL_GPL(hd44780_common_clear_display); +int hd44780_common_init_display(struct charlcd *lcd) +{ + struct hd44780_common *hdc = lcd->drvdata; + + void (*write_cmd_raw)(struct hd44780_common *hdc, int cmd); + u8 init; + + if (hdc->ifwidth != 4 && hdc->ifwidth != 8) + return -EINVAL; + + hdc->hd44780_common_flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | + LCD_FLAG_D | LCD_FLAG_C | LCD_FLAG_B; + + long_sleep(20); /* wait 20 ms after power-up for the paranoid */ + + /* + * 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure + * the LCD is in 8-bit mode afterwards + */ + init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS; + if (hdc->ifwidth == 4) { + init >>= 4; + write_cmd_raw = hdc->write_cmd_raw4; + } else { + write_cmd_raw = hdc->write_cmd; + } + write_cmd_raw(hdc, init); + long_sleep(10); + write_cmd_raw(hdc, init); + long_sleep(10); + write_cmd_raw(hdc, init); + long_sleep(10); + + if (hdc->ifwidth == 4) { + /* Switch to 4-bit mode, 1 line, small fonts */ + hdc->write_cmd_raw4(hdc, LCD_CMD_FUNCTION_SET >> 4); + long_sleep(10); + } + + /* set font height and lines number */ + hdc->write_cmd(hdc, + LCD_CMD_FUNCTION_SET | + ((hdc->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) | + ((hdc->hd44780_common_flags & LCD_FLAG_F) ? + LCD_CMD_FONT_5X10_DOTS : 0) | + ((hdc->hd44780_common_flags & LCD_FLAG_N) ? + LCD_CMD_TWO_LINES : 0)); + long_sleep(10); + + /* display off, cursor off, blink off */ + hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CTRL); + long_sleep(10); + + hdc->write_cmd(hdc, + LCD_CMD_DISPLAY_CTRL | /* set display mode */ + ((hdc->hd44780_common_flags & LCD_FLAG_D) ? + LCD_CMD_DISPLAY_ON : 0) | + ((hdc->hd44780_common_flags & LCD_FLAG_C) ? + LCD_CMD_CURSOR_ON : 0) | + ((hdc->hd44780_common_flags & LCD_FLAG_B) ? + LCD_CMD_BLINK_ON : 0)); + + charlcd_backlight(lcd, + (hdc->hd44780_common_flags & LCD_FLAG_L) ? 1 : 0); + + long_sleep(10); + + /* entry mode set : increment, cursor shifting */ + hdc->write_cmd(hdc, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC); + + hd44780_common_clear_display(lcd); + return 0; +} +EXPORT_SYMBOL_GPL(hd44780_common_init_display); + struct hd44780_common *hd44780_common_alloc(void) { struct hd44780_common *hd; |