gpio: vx855: use the new open drain callback

The vx855 driver clearly states it has three groups of lines:
GPI, GPO and GPIO. The GPO are assumedly push-pull. The GPIO
are implicit open drain, but if the GPIO subsystem ask for them
to be explicitly open drain (i.e. set the flag on a machine table
that we want open drain) it will currently misbehave: it will
switch the GPIOs to input mode (emulate open drain). Instead:
indicate in the .set_single_ended() callback that we support
open drain and open drain only.

Cc: Daniel Drake <drake@endlessm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-vx855.c b/drivers/gpio/gpio-vx855.c
index 8cdb9f7..4e45012 100644 (file)
--- a/drivers/gpio/gpio-vx855.c
+++ b/drivers/gpio/gpio-vx855.c
@@ -186,6 +186,28 @@ static int vx855gpio_direction_output(struct gpio_chip *gpio,
        return 0;
 }
 
+static int vx855gpio_set_single_ended(struct gpio_chip *gpio,
+                                     unsigned int nr,
+                                     enum single_ended_mode mode)
+{
+       /* The GPI cannot be single-ended */
+       if (nr < NR_VX855_GPI)
+               return -EINVAL;
+
+       /* The GPO's are push-pull */
+       if (nr < NR_VX855_GPInO) {
+               if (mode != LINE_MODE_PUSH_PULL)
+                       return -ENOTSUPP;
+               return 0;
+       }
+
+       /* The GPIO's are open drain */
+       if (mode != LINE_MODE_OPEN_DRAIN)
+               return -ENOTSUPP;
+
+       return 0;
+}
+
 static const char *vx855gpio_names[NR_VX855_GP] = {
        "VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
        "VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
@@ -209,6 +231,7 @@ static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
        c->direction_output = vx855gpio_direction_output;
        c->get = vx855gpio_get;
        c->set = vx855gpio_set;
+       c->set_single_ended = vx855gpio_set_single_ended;
        c->dbg_show = NULL;
        c->base = 0;
        c->ngpio = NR_VX855_GP;