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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/auxdisplay/hd44780_common.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/auxdisplay/hd44780_common.c')
-rw-r--r--drivers/auxdisplay/hd44780_common.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
new file mode 100644
index 0000000000..7cbf375b0f
--- /dev/null
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -0,0 +1,369 @@
+// 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_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_SHIFT 0x10 /* Shift cursor/display */
+#define LCD_CMD_DISPLAY_SHIFT 0x08 /* Shift display instead of cursor */
+#define LCD_CMD_SHIFT_RIGHT 0x04 /* Shift display/cursor to the right */
+
+#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_CGRAM_ADDR 0x40 /* Set char generator RAM address */
+
+#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;
+
+ if (lcd->addr.x < hdc->bwidth) {
+ hdc->write_data(hdc, c);
+ return 0;
+ }
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_print);
+
+int hd44780_common_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+ unsigned int addr;
+
+ /*
+ * we force the cursor to stay at the end of the
+ * line if it wants to go farther
+ */
+ addr = x < hdc->bwidth ? x & (hdc->hwidth - 1) : hdc->bwidth - 1;
+ if (y & 1)
+ addr += hdc->hwidth;
+ if (y & 2)
+ addr += hdc->bwidth;
+ hdc->write_cmd(hdc, LCD_CMD_SET_DDRAM_ADDR | addr);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_gotoxy);
+
+int hd44780_common_home(struct charlcd *lcd)
+{
+ return hd44780_common_gotoxy(lcd, 0, 0);
+}
+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);
+ /* datasheet says to wait 1,64 milliseconds */
+ long_sleep(2);
+
+ /*
+ * The Hitachi HD44780 controller (and compatible ones) reset the DDRAM
+ * address when executing the DISPLAY_CLEAR command, thus the
+ * following call is not required. However, other controllers do not
+ * (e.g. NewHaven NHD-0220DZW-AG5), thus move the cursor to home
+ * unconditionally to support both.
+ */
+ return hd44780_common_home(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);
+
+int hd44780_common_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (dir == CHARLCD_SHIFT_LEFT) {
+ /* back one char if not at end of line */
+ if (lcd->addr.x < hdc->bwidth)
+ hdc->write_cmd(hdc, LCD_CMD_SHIFT);
+ } else if (dir == CHARLCD_SHIFT_RIGHT) {
+ /* allow the cursor to pass the end of the line */
+ if (lcd->addr.x < (hdc->bwidth - 1))
+ hdc->write_cmd(hdc,
+ LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_shift_cursor);
+
+int hd44780_common_shift_display(struct charlcd *lcd,
+ enum charlcd_shift_dir dir)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (dir == CHARLCD_SHIFT_LEFT)
+ hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
+ else if (dir == CHARLCD_SHIFT_RIGHT)
+ hdc->write_cmd(hdc, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
+ LCD_CMD_SHIFT_RIGHT);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_shift_display);
+
+static void hd44780_common_set_mode(struct hd44780_common *hdc)
+{
+ hdc->write_cmd(hdc,
+ LCD_CMD_DISPLAY_CTRL |
+ ((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));
+}
+
+int hd44780_common_display(struct charlcd *lcd, enum charlcd_onoff on)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (on == CHARLCD_ON)
+ hdc->hd44780_common_flags |= LCD_FLAG_D;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_D;
+
+ hd44780_common_set_mode(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_display);
+
+int hd44780_common_cursor(struct charlcd *lcd, enum charlcd_onoff on)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (on == CHARLCD_ON)
+ hdc->hd44780_common_flags |= LCD_FLAG_C;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_C;
+
+ hd44780_common_set_mode(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_cursor);
+
+int hd44780_common_blink(struct charlcd *lcd, enum charlcd_onoff on)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (on == CHARLCD_ON)
+ hdc->hd44780_common_flags |= LCD_FLAG_B;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_B;
+
+ hd44780_common_set_mode(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_blink);
+
+static void hd44780_common_set_function(struct hd44780_common *hdc)
+{
+ 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));
+}
+
+int hd44780_common_fontsize(struct charlcd *lcd, enum charlcd_fontsize size)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (size == CHARLCD_FONTSIZE_LARGE)
+ hdc->hd44780_common_flags |= LCD_FLAG_F;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_F;
+
+ hd44780_common_set_function(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_fontsize);
+
+int hd44780_common_lines(struct charlcd *lcd, enum charlcd_lines lines)
+{
+ struct hd44780_common *hdc = lcd->drvdata;
+
+ if (lines == CHARLCD_LINES_2)
+ hdc->hd44780_common_flags |= LCD_FLAG_N;
+ else
+ hdc->hd44780_common_flags &= ~LCD_FLAG_N;
+
+ hd44780_common_set_function(hdc);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_lines);
+
+int hd44780_common_redefine_char(struct charlcd *lcd, char *esc)
+{
+ /* Generator : LGcxxxxx...xx; must have <c> between '0'
+ * and '7', representing the numerical ASCII code of the
+ * redefined character, and <xx...xx> a sequence of 16
+ * hex digits representing 8 bytes for each character.
+ * Most LCDs will only use 5 lower bits of the 7 first
+ * bytes.
+ */
+
+ struct hd44780_common *hdc = lcd->drvdata;
+ unsigned char cgbytes[8];
+ unsigned char cgaddr;
+ int cgoffset;
+ int shift;
+ char value;
+ int addr;
+
+ if (!strchr(esc, ';'))
+ return 0;
+
+ esc++;
+
+ cgaddr = *(esc++) - '0';
+ if (cgaddr > 7)
+ return 1;
+
+ cgoffset = 0;
+ shift = 0;
+ value = 0;
+ while (*esc && cgoffset < 8) {
+ int half;
+
+ shift ^= 4;
+ half = hex_to_bin(*esc++);
+ if (half < 0)
+ continue;
+
+ value |= half << shift;
+ if (shift == 0) {
+ cgbytes[cgoffset++] = value;
+ value = 0;
+ }
+ }
+
+ hdc->write_cmd(hdc, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
+ for (addr = 0; addr < cgoffset; addr++)
+ hdc->write_data(hdc, cgbytes[addr]);
+
+ /* ensures that we stop writing to CGRAM */
+ lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_redefine_char);
+
+struct hd44780_common *hd44780_common_alloc(void)
+{
+ struct hd44780_common *hd;
+
+ hd = kzalloc(sizeof(*hd), GFP_KERNEL);
+ if (!hd)
+ return NULL;
+
+ hd->ifwidth = 8;
+ hd->bwidth = DEFAULT_LCD_BWIDTH;
+ hd->hwidth = DEFAULT_LCD_HWIDTH;
+ return hd;
+}
+EXPORT_SYMBOL_GPL(hd44780_common_alloc);
+
+MODULE_LICENSE("GPL");