mainboard/google/reef: provide cros_gpio variant API

Add support for Chrome OS gpio ACPI table information by
providing weak implementation from the baseboard.

BUG=chrome-os-partner:56677

Change-Id: I517764b78f47fb7b3637482ff9efc053cdd1ac69
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/16422
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

src/mainboard/google/reef/chromeos.c

@@ -13,6 +13,7 @@
  * GNU General Public License for more details.
  */
 
+#include <baseboard/variants.h>
 #include <boot/coreboot_tables.h>
 #include <ec/google/chromeec/ec.h>
 #include <gpio.h>
@@ -67,12 +68,11 @@ int get_write_protect_state(void)
 	return gpio_get(GPIO_PCH_WP);
 }
 
-static const struct cros_gpio cros_gpios[] = {
-	CROS_GPIO_REC_AL(CROS_GPIO_VIRTUAL, GPIO_COMM_NW_NAME),
-	CROS_GPIO_WP_AH(PAD_NW(GPIO_PCH_WP), GPIO_COMM_NW_NAME),
-};
-
 void mainboard_chromeos_acpi_generate(void)
 {
-	chromeos_acpi_gpio_generate(cros_gpios, ARRAY_SIZE(cros_gpios));
+	const struct cros_gpio *gpios;
+	size_t num;
+
+	gpios = variant_cros_gpios(&num);
+	chromeos_acpi_gpio_generate(gpios, num);
 }

src/mainboard/google/reef/variants/baseboard/gpio.c

@@ -376,3 +376,14 @@ variant_sleep_gpio_table(size_t *num)
 	*num = ARRAY_SIZE(sleep_gpio_table);
 	return sleep_gpio_table;
 }
+
+static const struct cros_gpio cros_gpios[] = {
+	CROS_GPIO_REC_AL(CROS_GPIO_VIRTUAL, GPIO_COMM_NW_NAME),
+	CROS_GPIO_WP_AH(PAD_NW(GPIO_PCH_WP), GPIO_COMM_NW_NAME),
+};
+
+const struct cros_gpio * __attribute__((weak)) variant_cros_gpios(size_t *num)
+{
+	*num = ARRAY_SIZE(cros_gpios);
+	return cros_gpios;
+}

src/mainboard/google/reef/variants/baseboard/include/baseboard/variants.h

@@ -18,6 +18,7 @@
 
 #include <soc/gpio.h>
 #include <stdint.h>
+#include <vendorcode/google/chromeos/chromeos.h>
 
 /* Return the board id for the current variant board. */
 uint8_t variant_board_id(void);
@@ -28,4 +29,7 @@ const struct pad_config *variant_gpio_table(size_t *num);
 const struct pad_config *variant_early_gpio_table(size_t *num);
 const struct pad_config *variant_sleep_gpio_table(size_t *num);
 
+/* Return ChromeOS gpio table and fill in number of entries. */
+const struct cros_gpio *variant_cros_gpios(size_t *num);
+
 #endif /* BASEBOARD_VARIANTS_H */