New patch to review for coreboot: gpio: Add support for translating gpio_t into ACPI pin

[Duncan Laurie]

Duncan Laurie ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15512

-gerrit

commit 17c908cc8881c54167503a7525d802c200a7e2ff
Author: Duncan Laurie 
Date:   Wed Jun 29 10:47:22 2016 -0700

gpio: Add support for translating gpio_t into ACPI pin

Add a funtion for an SOC to define that will allow it to map the
    SOC-specific gpio_t value into an appropriate ACPI pin.  The exact
    behavior depends on the GPIO implementation in the SOC, but it can
    be used to provide a pin number that is relative to the community or
    bank that a GPIO resides in.

Change-Id: Icb97ccf7d6a9034877614d49166bc9e4fe659bcf
---
 src/arch/x86/acpi_device.c |  9 +++++++--
 src/include/gpio.h         | 10 ++++++++++
 src/lib/gpio.c             |  6 ++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/arch/x86/acpi_device.c b/src/arch/x86/acpi_device.c
index 69d44f3..940d871 100644
--- a/src/arch/x86/acpi_device.c
+++ b/src/arch/x86/acpi_device.c
@@ -314,8 +314,13 @@ void acpi_device_write_gpio(const struct acpi_gpio *gpio)
    acpi_device_fill_from_len(pin_table_offset, start);

/* Pin Table, one word for each pin */
-	for (pin = 0; pin < gpio->pin_count; pin++)
-		acpigen_emit_word(gpio->pins[pin]);
+	for (pin = 0; pin < gpio->pin_count; pin++) {
+		uint16_t acpi_pin = gpio->pins[pin];
+#if IS_ENABLED(CONFIG_GENERIC_GPIO_LIB)
+		acpi_pin = gpio_acpi_pin(acpi_pin);
+#endif
+		acpigen_emit_word(acpi_pin);
+	}

/* Fill in Resource Source Name Offset */
    acpi_device_fill_from_len(resource_offset, start);
diff --git a/src/include/gpio.h b/src/include/gpio.h
index 3f462df..ec229db 100644
--- a/src/include/gpio.h
+++ b/src/include/gpio.h
@@ -41,6 +41,16 @@ int _gpio_base3_value(gpio_t gpio[], int num_gpio, int binary_first);
 const char *gpio_acpi_path(gpio_t gpio);

/*
+ * This function may be implemented by SoC/board code to provide
+ * a mapping from the internal representation of a GPIO to the 16bit
+ * value used in an ACPI GPIO pin table entry.
+ *
+ * If not implemented by the SOC the default handler will return the
+ * input with no change.
+ */
+uint16_t gpio_acpi_pin(gpio_t gpio);
+
+/*
  * Read the value presented by the set of GPIOs, when each pin is interpreted
  * as a base-2 digit (LOW = 0, HIGH = 1).
  *
diff --git a/src/lib/gpio.c b/src/lib/gpio.c
index b0a5f4d..eeb6306 100644
--- a/src/lib/gpio.c
+++ b/src/lib/gpio.c
@@ -145,3 +145,9 @@ __attribute__((weak)) const char *gpio_acpi_path(gpio_t gpio)
 {
    return NULL;
 }
+
+/* Default handler for ACPI pin is to return unmodified input */
+__attribute__((weak)) uint16_t gpio_acpi_pin(gpio_t gpio)
+{
+	return gpio;
+}