Re: [PATCH v2] staging: panel: Remove magic numbers in LCD commands
From: Sudip Mukherjee
Date: Sat Dec 06 2014 - 03:21:24 EST
On Fri, Dec 05, 2014 at 10:28:19PM +0100, Mariusz Gorski wrote:
> 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@xxxxxxxxx>
> ---
> v2: Found and got rid of two more magic number usages
this one also not applying to next-20141205. is it on staging-testing?
thanks
sudip
>
> drivers/staging/panel/panel.c | 96 +++++++++++++++++++++++++++++--------------
> 1 file changed, 66 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
> index b68a9c3..9c68ccf 100644
> --- a/drivers/staging/panel/panel.c
> +++ b/drivers/staging/panel/panel.c
> @@ -130,6 +130,30 @@
> #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 */
> --
> 2.1.3
>
> --
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