| Message ID | 20190401090942.12408-1-jank@cadence.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/1] gpio: mmio: Fix bgpio_get_set & bgpio_get_set_multiple | expand |
On Mon, Apr 1, 2019 at 4:10 PM Jan Kotas <jank@cadence.com> wrote: > 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> Patch applied! Yours, Linus Walleij
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;
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(-)