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authorDuncan Laurie <dlaurie@chromium.org>2016-06-29 10:47:22 -0700
committerDuncan Laurie <dlaurie@chromium.org>2016-07-02 01:18:53 +0200
commit5b6c28c43dee455b643e13d7f0debd79835a5f50 (patch)
tree03651a1be906565bd9b00457e936f612db4361bf /src
parentd48d5a626b02e28ab6949263dad85abe92f9214c (diff)
downloadcoreboot-5b6c28c43dee455b643e13d7f0debd79835a5f50.tar.xz
gpio: Add support for translating gpio_t into ACPI pin
Add a function 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 Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://review.coreboot.org/15512 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src')
-rw-r--r--src/arch/x86/acpi_device.c9
-rw-r--r--src/include/gpio.h10
-rw-r--r--src/lib/gpio.c6
3 files changed, 23 insertions, 2 deletions
diff --git a/src/arch/x86/acpi_device.c b/src/arch/x86/acpi_device.c
index 69d44f3f33..940d87156d 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 3f462df295..69a0828f58 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 0
+ * because the underlying type of gpio_t is unknown.
+ */
+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 b0a5f4dfc3..81d6f6bbad 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 returns 0 because type of gpio_t is unknown */
+__attribute__((weak)) uint16_t gpio_acpi_pin(gpio_t gpio)
+{
+ return 0;
+}