[U-Boot] [PATCH v4 02/33] pinctrl: Add help text to Kconfig

[Simon Glass]

The pinctrl Kconfig options should have help messages. Add this to a few
options.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/pinctrl/Kconfig | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index c6229d9..30617f0 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -18,6 +18,12 @@ config PINCTRL_GENERIC
 config PINMUX
 	bool "Support pin multiplexing controllers"
 	depends on PINCTRL_GENERIC
+	help
+	  Support pin multiplexing control in U-Boot. Most SoCs have their own
+	  own multiplexing arrangement where a single pin can be used for
+	  several functions. An SoC pinctrl driver allows the required
+	  function to be selected for each pin. The driver is typically
+	  controlled by the device tree.
 
 config PINCONF
 	bool "Support pin configuration controllers"
@@ -38,6 +44,13 @@ config SPL_PINCTRL_GENERIC
 config SPL_PINMUX
 	bool "Support pin multiplexing controllers in SPL"
 	depends on SPL_PINCTRL_GENERIC
+	help
+	  The pinctrl subsystem can add a substantial overhead to the SPL
+	  image since it typically requires quite a few tables either in the
+	  driver or in the device tree. If this is acceptable and you need
+	  to adjust pin multiplexing in SPL in order to boot into U-Boot,
+	  enable this option. You will need to enable device tree in SPL
+	  for this to work.
 
 config SPL_PINCONF
 	bool "Support pin configuration controllers in SPL"
-- 
2.5.0.457.gab17608