On Mon, 22 March 2010 Jiri Kosina [off-list ref] wrote:

On Sat, 20 Mar 2010, Bruno Prémont wrote:

quoted

Add backlight support to PicoLCD device.

Backlight support depends on backlight class and is only being
compiled if backlight class has been selected.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
---
 drivers/hid/Kconfig       |    2 +-
 drivers/hid/hid-picolcd.c |  134 ++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 134 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index a474bcd..5ec3cb7 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig

@@ -243,8 +243,8 @@ config HID_PICOLCD
 	  - Keypad
 	  - Switching between Firmware and Flash mode
 	  - Framebuffer for monochrome 256x64 display
+	  - Backlight control    (needs CONFIG_BACKLIGHT_CLASS_DEVICE)

Wouldn't it be better to have Kconfig rules actually resolve the 
dependency?

I don't see any issue with HID_PICOLCD directly selecting 
BACKLIGHT_CLASS_DEVICE. Or you can do a separate sub-option for that, if 
you really want to avoid the direct dependency of the whole driver.

I could select both BACKLIGHT_CLASS_DEVICE and LCD_CLASS_DEVICE (as
well as their common parent -- same applies to FB) though for the
LEDS_CLASS I would definitely rather go the path of a sub-option, by
default the GPO pins operated with the LEDs are not connected to
anything.

Thanks for the review,
Bruno