Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fda4ae18 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
Browse files

misc: panel: Abstract temporary backlight handling 



Currently the periodic scan timer is used for three purposes,
entangling keypad and display handling, which are both optional:
  1. Scanning the keypad,
  2. Flashing the backlight when a key is pressed,
  3. Disabling temporary backlighting after a fixed period of time.

Abstract the second purpose using a new lcd_poke() function.
Make the non-periodic temporary backlight handling independent from
keypad handling by converting it to a delayed workqueue.

Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 204a4f6d

drivers/misc/panel.c

+60 −41
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ 
#include <linux/list.h>

#include <linux/notifier.h>

#include <linux/reboot.h>

#include <linux/workqueue.h>

#include <generated/utsrelease.h>



#include <linux/io.h>
@@ -75,8 +76,8 @@ 
/* a key repeats this times INPUT_POLL_TIME */

#define KEYPAD_REP_DELAY	(2)



/* keep the light on this times INPUT_POLL_TIME for each flash */

#define FLASH_LIGHT_TEMPO	(200)

/* keep the light on this many seconds for each flash */

#define FLASH_LIGHT_TEMPO	(4)



/* converts an r_str() input to an active high, bits string : 000BAOSE */

#define PNL_PINPUT(a)		((((unsigned char)(a)) ^ 0x7F) >> 3)
@@ -252,7 +253,10 @@ static struct { 
	int hwidth;

	int charset;

	int proto;

	int light_tempo;



	struct delayed_work bl_work;

	struct mutex bl_tempo_lock;	/* Protects access to bl_tempo */

	bool bl_tempo;



	/* TODO: use union here? */

	struct {
@@ -657,8 +661,6 @@ static void lcd_get_bits(unsigned int port, int *val) 
	}

}



static void init_scan_timer(void);



/* sets data port bits according to current signals values */

static int set_data_bits(void)

{
@@ -790,11 +792,8 @@ static void lcd_send_serial(int byte) 
}



/* turn the backlight on or off */

static void lcd_backlight(int on)

static void __lcd_backlight(int on)

{

	if (lcd.pins.bl == PIN_NONE)

		return;



	/* The backlight is activated by setting the AUTOFEED line to +5V  */

	spin_lock_irq(&pprt_lock);

	if (on)
@@ -805,6 +804,44 @@ static void lcd_backlight(int on) 
	spin_unlock_irq(&pprt_lock);

}



static void lcd_backlight(int on)

{

	if (lcd.pins.bl == PIN_NONE)

		return;



	mutex_lock(&lcd.bl_tempo_lock);

	if (!lcd.bl_tempo)

		__lcd_backlight(on);

	mutex_unlock(&lcd.bl_tempo_lock);

}



static void lcd_bl_off(struct work_struct *work)

{

	mutex_lock(&lcd.bl_tempo_lock);

	if (lcd.bl_tempo) {

		lcd.bl_tempo = false;

		if (!(lcd.flags & LCD_FLAG_L))

			__lcd_backlight(0);

	}

	mutex_unlock(&lcd.bl_tempo_lock);

}



/* turn the backlight on for a little while */

static void lcd_poke(void)

{

	if (lcd.pins.bl == PIN_NONE)

		return;



	cancel_delayed_work_sync(&lcd.bl_work);



	mutex_lock(&lcd.bl_tempo_lock);

	if (!lcd.bl_tempo && !(lcd.flags & LCD_FLAG_L))

		__lcd_backlight(1);

	lcd.bl_tempo = true;

	schedule_delayed_work(&lcd.bl_work, FLASH_LIGHT_TEMPO * HZ);

	mutex_unlock(&lcd.bl_tempo_lock);

}



/* send a command to the LCD panel in serial mode */

static void lcd_write_cmd_s(int cmd)

{
@@ -1099,13 +1136,8 @@ static inline int handle_lcd_special_code(void) 
		processed = 1;

		break;

	case '*':

		/* flash back light using the keypad timer */

		if (scan_timer.function) {

			if (lcd.light_tempo == 0 &&

			    ((lcd.flags & LCD_FLAG_L) == 0))

				lcd_backlight(1);

			lcd.light_tempo = FLASH_LIGHT_TEMPO;

		}

		/* flash back light */

		lcd_poke();

		processed = 1;

		break;

	case 'f':	/* Small Font */
@@ -1275,16 +1307,8 @@ static inline int handle_lcd_special_code(void) 
						      ? LCD_CMD_TWO_LINES

								      : 0));

		/* check whether L flag was changed */

		else if ((oldflags ^ lcd.flags) & (LCD_FLAG_L)) {

			if (lcd.flags & (LCD_FLAG_L))

				lcd_backlight(1);

			else if (lcd.light_tempo == 0)

				/*

				 * switch off the light only when the tempo

				 * lighting is gone

				 */

				lcd_backlight(0);

		}

		else if ((oldflags ^ lcd.flags) & (LCD_FLAG_L))

			lcd_backlight(!!(lcd.flags & LCD_FLAG_L));

	}



	return processed;
@@ -1615,8 +1639,10 @@ static void lcd_init(void) 
	else

		lcd_char_conv = NULL;



	if (lcd.pins.bl != PIN_NONE)

		init_scan_timer();

	if (lcd.pins.bl != PIN_NONE) {

		mutex_init(&lcd.bl_tempo_lock);

		INIT_DELAYED_WORK(&lcd.bl_work, lcd_bl_off);

	}



	pin_to_bits(lcd.pins.e, lcd_bits[LCD_PORT_D][LCD_BIT_E],

		    lcd_bits[LCD_PORT_C][LCD_BIT_E]);
@@ -1984,19 +2010,8 @@ static void panel_scan_timer(void) 
			panel_process_inputs();

	}



	if (lcd.enabled && lcd.initialized) {

		if (keypressed) {

			if (lcd.light_tempo == 0 &&

			    ((lcd.flags & LCD_FLAG_L) == 0))

				lcd_backlight(1);

			lcd.light_tempo = FLASH_LIGHT_TEMPO;

		} else if (lcd.light_tempo > 0) {

			lcd.light_tempo--;

			if (lcd.light_tempo == 0 &&

			    ((lcd.flags & LCD_FLAG_L) == 0))

				lcd_backlight(0);

		}

	}

	if (keypressed && lcd.enabled && lcd.initialized)

		lcd_poke();



	mod_timer(&scan_timer, jiffies + INPUT_POLL_TIME);

}
@@ -2265,6 +2280,10 @@ static void panel_detach(struct parport *port) 
	if (lcd.enabled) {

		panel_lcd_print("\x0cLCD driver unloaded.\x1b[Lc\x1b[Lb\x1b[L-");

		misc_deregister(&lcd_dev);

		if (lcd.pins.bl != PIN_NONE) {

			cancel_delayed_work_sync(&lcd.bl_work);

			__lcd_backlight(0);

		}

		lcd.initialized = false;

	}