Add --dcs-no-get-brightness to disable generating get_brightness() for DCS

This is broken for some panels.

Author: stephan-gh

driver.py

@@ -289,7 +289,10 @@ def generate_backlight(p: Panel, options: Options) -> str:
 
 	return 0;
 }}
+'''
 
+	if options.dcs_get_brightness:
+		s += f'''
 // TODO: Check if /sys/class/backlight/.../actual_brightness actually returns
 // correct values. If not, remove this function.
 static int {p.short_id}_bl_get_brightness(struct backlight_device *bl)
@@ -308,10 +311,14 @@ def generate_backlight(p: Panel, options: Options) -> str:
 
 	return brightness{brightness_mask};
 }}
+'''
+		get_brightness = f'\n\t.get_brightness = {p.short_id}_bl_get_brightness,'
+	else:
+		get_brightness = ''
 
+	s += f'''
 static const struct backlight_ops {p.short_id}_bl_ops = {{
-	.update_status = {p.short_id}_bl_update_status,
-	.get_brightness = {p.short_id}_bl_get_brightness,
+	.update_status = {p.short_id}_bl_update_status,{get_brightness}
 }};
 '''
 	s += f'''

generator.py

@@ -17,6 +17,7 @@ class Options:
 	regulator: Optional[List[str]]
 	backlight: bool
 	backlight_gpio: bool
+	dcs_get_brightness: bool
 	ignore_wait: int
 	dumb_dcs: bool
 

lmdpdg.py

@@ -42,6 +42,10 @@ def generate(p: Panel, options: generator.Options) -> None:
 parser.add_argument('--no-backlight', dest='backlight', action='store_false', default=True, help="""
 	Do not generate any backlight/brightness related code.
 """)
+parser.add_argument('--dcs-no-get-brightness', dest='dcs_get_brightness', action='store_false', default=True, help="""
+	Do not generate get_brightness() function for DCS backlight/brightness code.
+	Some panels do not implement the MIPI DCS Get Display Brightness command correctly.
+""")
 parser.add_argument('--ignore-wait', type=int, default=0, help="""
 	Ignore wait in command sequences that is smaller that the specified value.
 	Some device trees add a useless 1ms wait after each command, making the driver