auxdisplay: charlcd: make backlight initial state configurable

The charlcd driver currently flashes the backlight once on init.
This may not be desirable.  Thus, add options for turning the
backlight off or on as well.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index 7d3fe27d6868c72b8989c45dc74ff28629148e77..c52c738e554a2dfe8e660973ce8a2685d9a1934b 100644 (file)
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -445,6 +445,27 @@ config PANEL_BOOT_MESSAGE
          An empty message will only clear the display at driver init time. Any other
          printf()-formatted message is valid with newline and escape codes.
 
+choice
+       prompt "Backlight initial state"
+       default CHARLCD_BL_FLASH
+
+       config CHARLCD_BL_OFF
+               bool "Off"
+               help
+                 Backlight is initially turned off
+
+       config CHARLCD_BL_ON
+               bool "On"
+               help
+                 Backlight is initially turned on
+
+       config CHARLCD_BL_FLASH
+               bool "Flash"
+               help
+                 Backlight is flashed briefly on init
+
+endchoice
+
 endif # AUXDISPLAY
 
 config PANEL

diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 5212675564d783f37b2c3b6f344594dadd94ce84..92745efefb540e5d723f5bbaa3aefd11735b0f29 100644 (file)
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -769,6 +769,14 @@ static void charlcd_puts(struct charlcd *lcd, const char *s)
 #define LCD_INIT_TEXT "Linux-" UTS_RELEASE "\n"
 #endif
 
+#ifdef CONFIG_CHARLCD_BL_ON
+#define LCD_INIT_BL "\x1b[L+"
+#elif defined(CONFIG_CHARLCD_BL_FLASH)
+#define LCD_INIT_BL "\x1b[L*"
+#else
+#define LCD_INIT_BL "\x1b[L-"
+#endif
+
 /* initialize the LCD driver */
 static int charlcd_init(struct charlcd *lcd)
 {
@@ -790,7 +798,7 @@ static int charlcd_init(struct charlcd *lcd)
                return ret;
 
        /* display a short message */
-       charlcd_puts(lcd, "\x1b[Lc\x1b[Lb\x1b[L*" LCD_INIT_TEXT);
+       charlcd_puts(lcd, "\x1b[Lc\x1b[Lb" LCD_INIT_BL LCD_INIT_TEXT);
 
        /* clear the display on the next device opening */
        priv->must_clear = true;