memory: omap-gpmc: Fix unselectable debug option for GPMC

Commit 63aa945b1013 ("memory: omap-gpmc: Add Kconfig option for debug")
added a debug option for GPMC, but somehow managed to keep it unselectable.

This probably happened because I had some uncommitted changes and the
GPMC option is selected in the platform specific Kconfig.

Let's also update the description a bit, it does not mention that
enabling the debug option also disables the reset of GPMC controller
during the init as pointed out by Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> and Roger Quadros <rogerq@ti.com>.

Fixes: 63aa945b1013 ("memory: omap-gpmc: Add Kconfig option for debug")
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index c6a644b22af4..6f3154613dc7 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -58,12 +58,18 @@ config OMAP_GPMC
           memory drives like NOR, NAND, OneNAND, SRAM.
 
 config OMAP_GPMC_DEBUG
-        bool
+        bool "Enable GPMC debug output and skip reset of GPMC during init"
         depends on OMAP_GPMC
         help
           Enables verbose debugging mostly to decode the bootloader provided
-          timings. Enable this during development to configure devices
-          connected to the GPMC bus.
+          timings. To preserve the bootloader provided timings, the reset
+          of GPMC is skipped during init. Enable this during development to
+          configure devices connected to the GPMC bus.
+
+          NOTE: In addition to matching the register setup with the bootloader
+          you also need to match the GPMC FCLK frequency used by the
+          bootloader or else the GPMC timings won't be identical with the
+          bootloader timings.
 
 config MVEBU_DEVBUS
         bool "Marvell EBU Device Bus Controller"