From fda4ae1819ce3603857a6baceda53d2c46d5bbd9 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 6 Feb 2017 15:38:10 +0100 Subject: [PATCH] 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: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/misc/panel.c | 101 +++++++++++++++++++++++++------------------ 1 file changed, 60 insertions(+), 41 deletions(-) diff --git a/drivers/misc/panel.c b/drivers/misc/panel.c index 9c7b00951c22..ef2ece0f26af 100644 --- a/drivers/misc/panel.c +++ b/drivers/misc/panel.c @@ -56,6 +56,7 @@ #include #include #include +#include #include #include @@ -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; } -- 2.20.1