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

From: Mariusz Gorski
Date: Sat Dec 06 2014 - 05:19:05 EST

On Sat, Dec 06, 2014 at 01:46:52PM +0530, Sudip Mukherjee wrote:
> 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 ?

Yes, it's based on yesterday's staging-testing + my previous, not yet
applied patch: https://lkml.org/lkml/2014/12/3/732

Cheers,
Mariusz

> thanks
> sudip
>
> > Signed-off-by: Mariusz Gorski <marius.gorski@xxxxxxxxx>
> > ---
> > 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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