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Date: Mon, 6 Feb 2017 15:38:10 +0100
From: Geert Uytterhoeven <geert@...ux-m68k.org>
To: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@...il.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Willy Tarreau <willy@...roxy.com>,
Ksenija Stanojevic <ksenija.stanojevic@...il.com>,
Arnd Bergmann <arnd@...db.de>
Cc: linux-kernel@...r.kernel.org,
Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: [PATCH 08/13] 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 <geert@...ux-m68k.org>
---
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 9c7b00951c22b1c2..ef2ece0f26afc6b5 100644
--- a/drivers/misc/panel.c
+++ b/drivers/misc/panel.c
@@ -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 @@ struct logical_input {
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;
}
--
1.9.1
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