[PATCH v2] gpio/omap: fix incorrect initialization of omap_gpio_mod_init

Tarun Kanti DebBarma tarun.kanti at ti.com
Mon Apr 30 03:20:12 EDT 2012


Initialization of irqenable, irqstatus registers is the common
operation done in this function for all OMAP platforms, viz. OMAP1,
OMAP2+. The latter _gpio_rmw()'s which supposedly got introduced
wrongly to take care of OMAP2+ platforms were overwriting initially
programmed OMAP1 value breaking functionality on OMAP1.
Somehow incorrect assumption was made that each _gpio_rmw()'s were
mutually exclusive. On close observation it is found that the first
_gpio_rmw() which is supposedly done to take care of OMAP1 platform
is generic enough and takes care of OMAP2+ platform as well.
Therefore remove the latter _gpio_rmw() to irqenable as they are
redundant now.

Writing to ctrl and debounce_en registers for OMAP2+ platforms are
modified to match the original(pre-cleanup) code where the registers
are initialized with 0. In the cleanup series since we are using
_gpio_rmw(reg, 0, 1), instead of __raw_writel(), we are just reading
and writing the same values to ctrl and debounce_en. This is not an
issue for debounce_en register because it has 0x0 as the default value.
But in the case of ctrl register the default value is 0x2 (GATINGRATIO
 = 0x1) so that we end up writing 0x2 instead of intended 0 value.
Therefore changing back to __raw_writel() as this is sufficient for
this case besides simpler to understand.

Also, change irqstatus initalization logic that avoids comparison
with bool, besides making it fit in a single line.

Cc: stable at vger.kernel.org
Cc: Tony Lindgren <tony at atomide.com>
Cc: Kevin Hilman <khilman at ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
Cc: Grant Likely <grant.likely at secretlab.ca>
Reported-by: Janusz Krzysztofik <jkrzyszt at tis.icnet.pl>
Signed-off-by: Tarun Kanti DebBarma <tarun.kanti at ti.com>
---
v2:
Avoid irqstatus initialization sequence change.
Use __raw_writel() to update debounce_en and ctrl registers.
Update changelog to elaborate how redundant _gpio_rmw() got added.

 drivers/gpio/gpio-omap.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 59a4af1..9b71f04 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -957,18 +957,15 @@ static void omap_gpio_mod_init(struct gpio_bank *bank)
 	}
 
 	_gpio_rmw(base, bank->regs->irqenable, l, bank->regs->irqenable_inv);
-	_gpio_rmw(base, bank->regs->irqstatus, l,
-					bank->regs->irqenable_inv == false);
-	_gpio_rmw(base, bank->regs->irqenable, l, bank->regs->debounce_en != 0);
-	_gpio_rmw(base, bank->regs->irqenable, l, bank->regs->ctrl != 0);
+	_gpio_rmw(base, bank->regs->irqstatus, l, !bank->regs->irqenable_inv);
 	if (bank->regs->debounce_en)
-		_gpio_rmw(base, bank->regs->debounce_en, 0, 1);
+		__raw_writel(0, base + bank->regs->debounce_en);
 
 	/* Save OE default value (0xffffffff) in the context */
 	bank->context.oe = __raw_readl(bank->base + bank->regs->direction);
 	 /* Initialize interface clk ungated, module enabled */
 	if (bank->regs->ctrl)
-		_gpio_rmw(base, bank->regs->ctrl, 0, 1);
+		__raw_writel(0, base + bank->regs->ctrl);
 }
 
 static __devinit void
-- 
1.7.0.4




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