Re: [PATCH] staging: panel: Remove magic numbers in LCD commands

[Sudip Mukherjee <sudipm.mukherjee@gmail.com>]

On Fri, Dec 05, 2014 at 10:10:43PM +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.
> 
it is not applying to next-20141205. is it based on staging-testing ?

thanks
sudip

> Signed-off-by: Mariusz Gorski <marius.gorski@gmail.com>
> ---
>  drivers/staging/panel/panel.c | 83 +++++++++++++++++++++++++++++--------------
>  1 file changed, 57 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
> index b68a9c3..fbba46f 100644
> --- a/drivers/staging/panel/panel.c
> +++ b/drivers/staging/panel/panel.c
> @@ -130,6 +130,28 @@
>  #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_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 +905,7 @@ 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 +1013,7 @@ 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 +1027,29 @@ 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 */
> +	/* set font height and lines number */
> +	lcd_write_cmd(LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS
>  		      | ((lcd.flags & LCD_FLAG_F) ? 4 : 0)
>  		      | ((lcd.flags & LCD_FLAG_N) ? 8 : 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 +1057,7 @@ 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 +1141,7 @@ 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 +1149,20 @@ 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 +1231,7 @@ 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]);
>  
> @@ -1244,13 +1270,18 @@ static inline int handle_lcd_special_code(void)
>  		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));
> +			/* TODO: This indent party here got ugly, clean it! */
> +			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_write_cmd(LCD_CMD_FUNCTION_SET
> +				      | LCD_CMD_DATA_LEN_8BITS
>  				      | ((lcd.flags & LCD_FLAG_F) ? 4 : 0)
>  				      | ((lcd.flags & LCD_FLAG_N) ? 8 : 0));
>  		/* check whether L flag was changed */
> @@ -1291,13 +1322,13 @@ 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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