[PATCH v2 2/3] gpio: at91: Implement ops set_flags

[Zixun LI]

Support GPIO configuration with following flags:
- in, out, out_active
- open_drain, pull_up

Signed-off-by: Zixun LI <ad...@hifiphile.com>
---
Changes in v2:
- Return ENOTSUPP if flag is unsupported.
- Inline port output variable.
---
 drivers/gpio/at91_gpio.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/gpio/at91_gpio.c b/drivers/gpio/at91_gpio.c
index 173315d45f..758cb4a806 100644
--- a/drivers/gpio/at91_gpio.c
+++ b/drivers/gpio/at91_gpio.c
@@ -229,6 +229,17 @@ static bool at91_is_port_gpio(struct at91_port *at91_port, 
int offset)
        val = readl(&at91_port->psr);
        return !!(val & mask);
 }
+
+static void at91_set_port_multi_drive(struct at91_port *at91_port, int offset, 
int is_on)
+{
+       u32 mask;
+
+       mask = 1 << offset;
+       if (is_on)
+               writel(mask, &at91_port->mder);
+       else
+               writel(mask, &at91_port->mddr);
+}
 #endif

 static void at91_set_port_input(struct at91_port *at91_port, int offset,
@@ -568,6 +579,33 @@ static int at91_gpio_get_function(struct udevice *dev, 
unsigned offset)
                return GPIOF_INPUT;
 }

+static int at91_gpio_set_flags(struct udevice *dev, unsigned int offset,
+                              ulong flags)
+{
+       struct at91_port_priv *port = dev_get_priv(dev);
+       ulong supported_mask;
+
+       supported_mask = GPIOD_OPEN_DRAIN | GPIOD_MASK_DIR | GPIOD_PULL_UP;
+       if (flags & ~supported_mask)
+               return -ENOTSUPP;
+
+       if (flags & GPIOD_IS_OUT) {
+               if (flags & GPIOD_OPEN_DRAIN)
+                       at91_set_port_multi_drive(port->regs, offset, true);
+               else
+                       at91_set_port_multi_drive(port->regs, offset, false);
+
+               at91_set_port_output(port->regs, offset, flags & 
GPIOD_IS_OUT_ACTIVE);
+
+       } else if (flags & GPIOD_IS_IN) {
+               at91_set_port_input(port->regs, offset, false);
+       }
+       if (flags & GPIOD_PULL_UP)
+               at91_set_port_pullup(port->regs, offset, true);
+
+       return 0;
+}
+
 static const char *at91_get_bank_name(uint32_t base_addr)
 {
        switch (base_addr) {
@@ -596,6 +634,7 @@ static const struct dm_gpio_ops gpio_at91_ops = {
        .get_value              = at91_gpio_get_value,
        .set_value              = at91_gpio_set_value,
        .get_function           = at91_gpio_get_function,
+       .set_flags              = at91_gpio_set_flags,
 };

 static int at91_gpio_probe(struct udevice *dev)
--
2.46.2