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Subject[PATCH 1/1] gpio: mmio: Fix bgpio_get_set & bgpio_get_set_multiple
Date
During my regression testing I noticed the cadence GPIO driver
fails on the latest gpio for-next tree.

I think the reason is this patch:
commit 96cd559817f2 ("Merge branch 'devel' into for-next")

Here is a part of the test log:

Loopback 8 -> 24
TESTING: gpio: 488: output direction PASSED
TESTING: gpio: 504: input direction PASSED
TESTING: gpio: 488: 0 PASSED
TESTING: gpio: 488 -> 504: 0 PASSED
TESTING: gpio: 488: 1 FAILED
TESTING: gpio: 488 -> 504: 1 FAILED
TESTING: gpio: 488: 0 PASSED
TESTING: gpio: 488 -> 504: 0 PASSED

It looks like the issue is that gc->bgpio_dir has changed its meaning.
It used to be set to the register value (so it was being inverted).

Now it's always set to 1 for output and 0 for input.
However the bgpio_get_set functions were not updated.
So they invert the bit again, which means a wrong register
is being accessed.

This patch fixes that by removing the unnecessary inversion.

Signed-off-by: Jan Kotas <jank@cadence.com>
---
drivers/gpio/gpio-mmio.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
index f172b4382d..04be18b954 100644
--- a/drivers/gpio/gpio-mmio.c
+++ b/drivers/gpio/gpio-mmio.c
@@ -134,17 +134,6 @@ static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
unsigned long pinmask = bgpio_line2mask(gc, gpio);
bool dir = !!(gc->bgpio_dir & pinmask);

- /*
- * If the direction is OUT we read the value from the SET
- * register, and if the direction is IN we read the value
- * from the DAT register.
- *
- * If the direction bits are inverted, naturally this gets
- * inverted too.
- */
- if (gc->bgpio_dir_inverted)
- dir = !dir;
-
if (dir)
return !!(gc->read_reg(gc->reg_set) & pinmask);
else
@@ -164,14 +153,8 @@ static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
/* Make sure we first clear any bits that are zero when we read the register */
*bits &= ~*mask;

- /* Exploit the fact that we know which directions are set */
- if (gc->bgpio_dir_inverted) {
- set_mask = *mask & ~gc->bgpio_dir;
- get_mask = *mask & gc->bgpio_dir;
- } else {
- set_mask = *mask & gc->bgpio_dir;
- get_mask = *mask & ~gc->bgpio_dir;
- }
+ set_mask = *mask & gc->bgpio_dir;
+ get_mask = *mask & ~gc->bgpio_dir;

if (set_mask)
*bits |= gc->read_reg(gc->reg_set) & set_mask;
--
2.15.0
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