staging: panel: Remove magic numbers in LCD commands
authorMariusz Gorski <marius.gorski@gmail.com>
Fri, 5 Dec 2014 21:28:19 +0000 (22:28 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 12 Jan 2015 14:39:33 +0000 (06:39 -0800)
Get rid of magic numbers in LCD commands and replace them with defined
values, so that it's more obvious that the commands are doing.

Signed-off-by: Mariusz Gorski <marius.gorski@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/panel/panel.c

index b68a9c3..9c68ccf 100644 (file)
 #define LCD_FLAG_N             0x0040  /* 2-rows mode */
 #define LCD_FLAG_L             0x0080  /* backlight enabled */
 
+/* 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 */
+
 #define LCD_ESCAPE_LEN         24      /* max chars for LCD escape command */
 #define LCD_ESCAPE_CHAR        27      /* use char 27 for escape command */
 
@@ -883,7 +907,7 @@ static void lcd_write_data_tilcd(int data)
 
 static void lcd_gotoxy(void)
 {
-       lcd_write_cmd(0x80      /* set DDRAM address */
+       lcd_write_cmd(LCD_CMD_SET_DDRAM_ADDR
                      | (lcd.addr.y ? lcd.hwidth : 0)
                      /* we force the cursor to stay at the end of the
                         line if it wants to go farther */
@@ -991,7 +1015,7 @@ static void lcd_clear_fast_tilcd(void)
 /* clears the display and resets X/Y */
 static void lcd_clear_display(void)
 {
-       lcd_write_cmd(0x01);    /* clear display */
+       lcd_write_cmd(LCD_CMD_DISPLAY_CLEAR);
        lcd.addr.x = 0;
        lcd.addr.y = 0;
        /* we must wait a few milliseconds (15) */
@@ -1005,26 +1029,29 @@ static void lcd_init_display(void)
 
        long_sleep(20);         /* wait 20 ms after power-up for the paranoid */
 
-       lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
+       /* 8bits, 1 line, small fonts; let's do it 3 times */
+       lcd_write_cmd(LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS);
        long_sleep(10);
-       lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
+       lcd_write_cmd(LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS);
        long_sleep(10);
-       lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
+       lcd_write_cmd(LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS);
        long_sleep(10);
 
-       lcd_write_cmd(0x30      /* set font height and lines number */
-                     | ((lcd.flags & LCD_FLAG_F) ? 4 : 0)
-                     | ((lcd.flags & LCD_FLAG_N) ? 8 : 0)
+       /* set font height and lines number */
+       lcd_write_cmd(LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS
+                     | ((lcd.flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0)
+                     | ((lcd.flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0)
            );
        long_sleep(10);
 
-       lcd_write_cmd(0x08);    /* display off, cursor off, blink off */
+       /* display off, cursor off, blink off */
+       lcd_write_cmd(LCD_CMD_DISPLAY_CTRL);
        long_sleep(10);
 
-       lcd_write_cmd(0x08      /* set display mode */
-                     | ((lcd.flags & LCD_FLAG_D) ? 4 : 0)
-                     | ((lcd.flags & LCD_FLAG_C) ? 2 : 0)
-                     | ((lcd.flags & LCD_FLAG_B) ? 1 : 0)
+       lcd_write_cmd(LCD_CMD_DISPLAY_CTRL      /* set display mode */
+                     | ((lcd.flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0)
+                     | ((lcd.flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0)
+                     | ((lcd.flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0)
            );
 
        lcd_backlight((lcd.flags & LCD_FLAG_L) ? 1 : 0);
@@ -1032,7 +1059,7 @@ static void lcd_init_display(void)
        long_sleep(10);
 
        /* entry mode set : increment, cursor shifting */
-       lcd_write_cmd(0x06);
+       lcd_write_cmd(LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC);
 
        lcd_clear_display();
 }
@@ -1116,7 +1143,7 @@ static inline int handle_lcd_special_code(void)
                if (lcd.addr.x > 0) {
                        /* back one char if not at end of line */
                        if (lcd.addr.x < lcd.bwidth)
-                               lcd_write_cmd(0x10);
+                               lcd_write_cmd(LCD_CMD_SHIFT);
                        lcd.addr.x--;
                }
                processed = 1;
@@ -1124,19 +1151,20 @@ static inline int handle_lcd_special_code(void)
        case 'r':       /* shift cursor right */
                if (lcd.addr.x < lcd.width) {
                        /* allow the cursor to pass the end of the line */
-                       if (lcd.addr.x <
-                           (lcd.bwidth - 1))
-                               lcd_write_cmd(0x14);
+                       if (lcd.addr.x < (lcd.bwidth - 1))
+                               lcd_write_cmd(LCD_CMD_SHIFT |
+                                               LCD_CMD_SHIFT_RIGHT);
                        lcd.addr.x++;
                }
                processed = 1;
                break;
        case 'L':       /* shift display left */
-               lcd_write_cmd(0x18);
+               lcd_write_cmd(LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT);
                processed = 1;
                break;
        case 'R':       /* shift display right */
-               lcd_write_cmd(0x1C);
+               lcd_write_cmd(LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT |
+                               LCD_CMD_SHIFT_RIGHT);
                processed = 1;
                break;
        case 'k': {     /* kill end of line */
@@ -1205,7 +1233,7 @@ static inline int handle_lcd_special_code(void)
                        esc++;
                }
 
-               lcd_write_cmd(0x40 | (cgaddr * 8));
+               lcd_write_cmd(LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8));
                for (addr = 0; addr < cgoffset; addr++)
                        lcd_write_data(cgbytes[addr]);
 
@@ -1238,21 +1266,29 @@ static inline int handle_lcd_special_code(void)
                break;
        }
 
+       /* TODO: This indent party here got ugly, clean it! */
        /* Check whether one flag was changed */
        if (oldflags != lcd.flags) {
                /* check whether one of B,C,D flags were changed */
                if ((oldflags ^ lcd.flags) &
                    (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D))
                        /* set display mode */
-                       lcd_write_cmd(0x08
-                                     | ((lcd.flags & LCD_FLAG_D) ? 4 : 0)
-                                     | ((lcd.flags & LCD_FLAG_C) ? 2 : 0)
-                                     | ((lcd.flags & LCD_FLAG_B) ? 1 : 0));
+                       lcd_write_cmd(LCD_CMD_DISPLAY_CTRL
+                                     | ((lcd.flags & LCD_FLAG_D)
+                                                     ? LCD_CMD_DISPLAY_ON : 0)
+                                     | ((lcd.flags & LCD_FLAG_C)
+                                                     ? LCD_CMD_CURSOR_ON : 0)
+                                     | ((lcd.flags & LCD_FLAG_B)
+                                                     ? LCD_CMD_BLINK_ON : 0));
                /* check whether one of F,N flags was changed */
                else if ((oldflags ^ lcd.flags) & (LCD_FLAG_F | LCD_FLAG_N))
-                       lcd_write_cmd(0x30
-                                     | ((lcd.flags & LCD_FLAG_F) ? 4 : 0)
-                                     | ((lcd.flags & LCD_FLAG_N) ? 8 : 0));
+                       lcd_write_cmd(LCD_CMD_FUNCTION_SET
+                                     | LCD_CMD_DATA_LEN_8BITS
+                                     | ((lcd.flags & LCD_FLAG_F)
+                                                     ? LCD_CMD_TWO_LINES : 0)
+                                     | ((lcd.flags & LCD_FLAG_N)
+                                                     ? LCD_CMD_FONT_5X10_DOTS
+                                                                     : 0));
                /* check whether L flag was changed */
                else if ((oldflags ^ lcd.flags) & (LCD_FLAG_L)) {
                        if (lcd.flags & (LCD_FLAG_L))
@@ -1291,13 +1327,13 @@ static void lcd_write_char(char c)
                                   end of the line */
                                if (lcd.addr.x < lcd.bwidth)
                                        /* back one char */
-                                       lcd_write_cmd(0x10);
+                                       lcd_write_cmd(LCD_CMD_SHIFT);
                                lcd.addr.x--;
                        }
                        /* replace with a space */
                        lcd_write_data(' ');
                        /* back one char again */
-                       lcd_write_cmd(0x10);
+                       lcd_write_cmd(LCD_CMD_SHIFT);
                        break;
                case '\014':
                        /* quickly clear the display */