gpio: Extend common GPIO header, simplify function names

We've had gpiolib.h which defines a few common GPIO access functions for
a while, but it wasn't really complete. This patch adds the missing
gpio_output() function, and also renames the unwieldy
gpio_get_in_value() and gpio_set_out_value() to the much easier to
handle gpio_get() and gpio_set(). The header is renamed to the simpler
gpio.h while we're at it (there was never really anything "lib" about
it, and it was presumably just chosen due to the IPQ806x include/
conflict problem that is now resolved).

It also moves the definition of gpio_t into SoC-specific code, so that
different implementations are free to encode their platform-specific
GPIO parameters in those 4 bytes in the most convenient way (such as the
rk3288 with a bitfield struct). Every SoC intending to use this common
API should supply a <soc/gpio.h> that typedefs gpio_t to a type at most
4 bytes in length. Files accessing the API only need to include <gpio.h>
which may pull in additional things (like a gpio_t creation macro) from
<soc/gpio.h> on its own.

For now the API is still only used on non-x86 SoCs. Whether it makes
sense to expand it to x86 as well should be separately evaluated at a
later point (by someone who understands those systems better). Also,
Exynos retains its old, incompatible GPIO API even though it would be a
prime candidate, because it's currently just not worth the effort.

BUG=None
TEST=Compiled on Daisy, Peach_Pit, Nyan_Blaze, Rush_Ryu, Storm and
Veyron_Pinky.

Change-Id: Ieee77373c2bd13d07ece26fa7f8b08be324842fe
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 9e04902ada56b929e3829f2c3b4aeb618682096e
Original-Change-Id: I6c1e7d1e154d9b02288aabedb397e21e1aadfa15
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/220975
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9400
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

3 files changed, 23 insertions, 26 deletions

diff --git a/src/soc/nvidia/tegra/gpio.c b/src/soc/nvidia/tegra/gpio.c
index 9f09f24547..009334f74c 100644
--- a/src/soc/nvidia/tegra/gpio.c
+++ b/src/soc/nvidia/tegra/gpio.c
@@ -19,16 +19,15 @@
 
 #include <arch/io.h>
 #include <console/console.h>
+#include <gpio.h>
 #include <soc/addressmap.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <delay.h>
-#include <gpiolib.h>
 
-#include "gpio.h"
 #include "pinmux.h"
 
-void __gpio_input(gpio_t gpio, u32 pull)
+static void __gpio_input(gpio_t gpio, u32 pull)
 {
 	u32 pinmux_config = PINMUX_INPUT_ENABLE | pull;
 
@@ -38,10 +37,10 @@ void __gpio_input(gpio_t gpio, u32 pull)
 	pinmux_set_config(gpio >> GPIO_PINMUX_SHIFT, pinmux_config);
 }
 
-void __gpio_output(gpio_t gpio, int value, u32 od)
+static void __gpio_output(gpio_t gpio, int value, u32 od)
 {
 	gpio_set_int_enable(gpio, 0);
-	gpio_set_out_value(gpio, value);
+	gpio_set(gpio, value);
 	gpio_set_out_enable(gpio, 1);
 	gpio_set_mode(gpio, GPIO_MODE_GPIO);
 	pinmux_set_config(gpio >> GPIO_PINMUX_SHIFT, PINMUX_PULL_NONE | od);
@@ -121,7 +120,7 @@ int gpio_get_out_enable(gpio_t gpio)
 	return (port & (1 << bit)) != 0;
 }
 
-void gpio_set_out_value(gpio_t gpio, int value)
+void gpio_set(gpio_t gpio, int value)
 {
 	int bit = gpio % GPIO_GPIOS_PER_PORT;
 	gpio_write_port(gpio & ((1 << GPIO_PINMUX_SHIFT) - 1),
@@ -137,7 +136,7 @@ int gpio_get_out_value(gpio_t gpio)
 	return (port & (1 << bit)) != 0;
 }
 
-int gpio_get_in_value(gpio_t gpio)
+int gpio_get(gpio_t gpio)
 {
 	int bit = gpio % GPIO_GPIOS_PER_PORT;
 	u32 port = gpio_read_port(gpio & ((1 << GPIO_PINMUX_SHIFT) - 1),
@@ -212,3 +211,13 @@ void gpio_input(gpio_t gpio)
 {
 	__gpio_input(gpio, PINMUX_PULL_NONE);
 }
+
+void gpio_output(gpio_t gpio, int value)
+{
+	__gpio_output(gpio, value, 0);
+}
+
+void gpio_output_open_drain(gpio_t gpio, int value)
+{
+	__gpio_output(gpio, value, PINMUX_OPEN_DRAIN);
+}
diff --git a/src/soc/nvidia/tegra/gpio.h b/src/soc/nvidia/tegra/gpio.h
index 2ad3ab3e5f..72c7179f7c 100644
--- a/src/soc/nvidia/tegra/gpio.h
+++ b/src/soc/nvidia/tegra/gpio.h
@@ -21,29 +21,15 @@
 #define __SOC_NVIDIA_TEGRA_GPIO_H__
 
 #include <stdint.h>
-#include <gpiolib.h>
 
 #include "pinmux.h"
 
+typedef u32 gpio_t;
+
 #define GPIO_PINMUX_SHIFT 16
 #define GPIO(name) ((gpio_t)(GPIO_##name##_INDEX | \
 			     (PINMUX_GPIO_##name << GPIO_PINMUX_SHIFT)))
 
-void __gpio_output(gpio_t gpio, int value, u32 open_drain);
-void __gpio_input(gpio_t gpio, u32 pull);
-
-/* Higher level function wrappers for common GPIO configurations. */
-
-static inline void gpio_output(gpio_t gpio, int value)
-{
-	__gpio_output(gpio, value, 0);
-}
-
-static inline void gpio_output_open_drain(gpio_t gpio, int value)
-{
-	__gpio_output(gpio, value, PINMUX_OPEN_DRAIN);
-}
-
 /* Functions to modify specific GPIO control values. */
 
 enum gpio_mode {
@@ -72,6 +58,8 @@ void gpio_get_int_level(gpio_t gpio, int *high_rise, int *edge, int *delta);
 
 void gpio_set_int_clear(gpio_t gpio);
 
+void gpio_output_open_drain(gpio_t gpio, int value);
+
 /* Hardware definitions. */
 
 enum {
diff --git a/src/soc/nvidia/tegra/software_i2c.c b/src/soc/nvidia/tegra/software_i2c.c
index 35fc1af3cc..d1172bcde6 100644
--- a/src/soc/nvidia/tegra/software_i2c.c
+++ b/src/soc/nvidia/tegra/software_i2c.c
@@ -18,7 +18,7 @@
  */
 
 #include <device/i2c.h>
-#include <soc/gpio.h>
+#include <gpio.h>
 #include <soc/pinmux.h>
 
 #include "i2c.h"
@@ -58,12 +58,12 @@ static void tegra_set_scl(unsigned bus, int high)
 
 static int tegra_get_sda(unsigned bus)
 {
-	return gpio_get_in_value(pins[bus].sda);
+	return gpio_get(pins[bus].sda);
 }
 
 static int tegra_get_scl(unsigned bus)
 {
-	return gpio_get_in_value(pins[bus].scl);
+	return gpio_get(pins[bus].scl);
 }
 
 static struct software_i2c_ops tegra_ops = {