From be59b6192f43a9792f5f636b51358196ba11bbf6 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Mon, 12 Oct 2015 16:19:54 -0700
Subject: memory: omap-gpmc: Fix unselectable debug option for GPMC
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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>
---
 drivers/memory/Kconfig | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

(limited to 'drivers/memory')

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"
-- 
cgit v1.2.3