gpio: xtensa: Implement .direction_input and .direction_output callbacks

The implementation of _gpiod_direction_output_raw() checks both .set and .direction_output callbacks. To make gpio_direction_output() works, both .set and .direction_output callbacks needs to be implemented in the driver.

Similarly, gpiod_direction_input() checks both .get and .direction_input callbacks. To make gpio_direction_input() works, both .get and .direction_input needs to be implemented in the driver.

Signed-off-by Axel Lin <[email protected]>

---
Hi Baruch,
I don't have this h/w to test, so this patch needs test.
I think both gpio_direction_output() and gpio_direction_input() do not work without this patch. Which means gpio_request_one() also does not work.

BTW, I also hit below build error.
CC drivers/gpio/gpio-xtensa.o
drivers/gpio/gpio-xtensa.c: Assembler messages:
drivers/gpio/gpio-xtensa.c:87: Error: unknown opcode or format name 'read_impwire' drivers/gpio/gpio-xtensa.c:116: Error: unknown opcode or format name 'rur.expstate' drivers/gpio/gpio-xtensa.c:130: Error: unknown opcode or format name 'wrmsk_expstate' make[2]: *** [drivers/gpio/gpio-xtensa.o] Error 1
make[1]: *** [drivers/gpio] Error 2
make: *** [drivers] Error 2
(I found the same build error is already reported by Geert Uytterhoeven.)

 drivers/gpio/gpio-xtensa.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

drivers/gpio/gpio-xtensa.c +15 -0

index 7081304..ed6d874 100644
@@ -96,6 +96,12 @@ static void xtensa_impwire_set_value(struct gpio_chip *gc, unsigned offset,
 	BUG(); /* output only; should never be called */
 }
 
+static int xtensa_impwire_direction_input(struct gpio_chip *gc,
+					  unsigned offset)
+{
+	return 0;
+}
+
 static int xtensa_expstate_get_direction(struct gpio_chip *gc, unsigned offset)
 {
 	return 0; /* output only */

@@ -126,6 +132,13 @@ static void xtensa_expstate_set_value(struct gpio_chip *gc, unsigned offset,
 	disable_cp(flags, saved_cpenable);
 }
 
+static int xtensa_expstate_direction_output(struct gpio_chip *gc,
+					    unsigned offset, int value)
+{
+	xtensa_expstate_set_value(gc, offset, value);
+	return 0;
+}
+
 static struct gpio_chip impwire_chip = {
 	.label		= "impwire",
 	.base		= -1,

@@ -133,6 +146,7 @@ static struct gpio_chip impwire_chip = {
 	.get_direction	= xtensa_impwire_get_direction,
 	.get		= xtensa_impwire_get_value,
 	.set		= xtensa_impwire_set_value,
+	.direction_input = xtensa_impwire_direction_input,
 };
 
 static struct gpio_chip expstate_chip = {

@@ -142,6 +156,7 @@ static struct gpio_chip expstate_chip = {
 	.get_direction	= xtensa_expstate_get_direction,
 	.get		= xtensa_expstate_get_value,
 	.set		= xtensa_expstate_set_value,
+	.direction_output = xtensa_expstate_direction_output,
 };
 
 static int xtensa_gpio_probe(struct platform_device *pdev)