This works around an issue with the hardware where both OE and
DAT are exposed in the same register. If both are updated
simultaneously, the harware makes no guarantees that OE or DAT
will actually change in any given order and may result in a
glitch of a few ns on a GPIO pin when changing direction and value
in a single write.
Setting direction to input now only affects OE bit. Setting
direction to output updates DAT first, then OE.
Fixes: 9c6686322d ("gpio: add Technologic I2C-FPGA gpio support")
Signed-off-by: Mark Featherston <mark@embeddedTS.com>
Signed-off-by: Kris Bahnsen <kris@embeddedTS.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
It's hard for occasional GPIO code reader/writer to know if values 0/1
equal to IN or OUT. Use defined GPIO_LINE_DIRECTION_IN and
GPIO_LINE_DIRECTION_OUT to help them out.
NOTE - for gpio-amd-fch and gpio-bd9571mwv:
This commit also changes the return value for direction get to equal 1
for direction INPUT. Prior this commit these drivers might have
returned some other positive value but 1 for INPUT.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Use of_device_get_match_data() instead of open-coding it.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
These structures are only used to copy into other structures, so declare
them as const.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct gpio_chip i@p = { ... };
@ok@
identifier r.i;
expression e;
position p;
@@
e = i@p;
@bad@
position p != {r.p,ok.p};
identifier r.i;
struct gpio_chip e;
@@
e@i@p
@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct gpio_chip i = { ... };
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This driver is generic and aims to support all Technologic Systems's
boards embedding FPGA GPIOs with an I2C interface.
This driver supports TS-4900, TS-7970, TS-7990 and TS-4100 series.
Signed-off-by: Lucile Quirion <lucile.quirion@savoirfairelinux.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
