mainboard/google/poppy: Provide cros_gpio variant API

Add support for ChromeOS GPIO ACPI table information by providing weak
implementation from the baseboard.

BUG=b:37375693

Change-Id: I641afe6bb45f106ddebde081a8ac2c64278ebeb9
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19324
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/mainboard/google/poppy/chromeos.c

@@ -14,6 +14,7 @@
  */
 
 #include <arch/acpi.h>
+#include <baseboard/variants.h>
 #include <gpio.h>
 #include <rules.h>
 #include <soc/gpe.h>
@@ -47,14 +48,13 @@ 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, CROS_GPIO_DEVICE_NAME),
-	CROS_GPIO_WP_AH(GPIO_PCH_WP, CROS_GPIO_DEVICE_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);
 }
 
 int tis_plat_irq_status(void)

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

@@ -387,3 +387,14 @@ const struct pad_config * __attribute__((weak))
 	*num = ARRAY_SIZE(early_gpio_table);
 	return early_gpio_table;
 }
+
+static const struct cros_gpio cros_gpios[] = {
+	CROS_GPIO_REC_AL(CROS_GPIO_VIRTUAL, CROS_GPIO_DEVICE_NAME),
+	CROS_GPIO_WP_AH(GPIO_PCH_WP, CROS_GPIO_DEVICE_NAME),
+};
+
+const struct cros_gpio * __attribute__((weak)) variant_cros_gpios(size_t *num)
+{
+	*num = ARRAY_SIZE(cros_gpios);
+	return cros_gpios;
+}

src/mainboard/google/poppy/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);
@@ -29,5 +30,6 @@ uint8_t variant_board_id(void);
 const struct pad_config *variant_gpio_table(size_t *num);
 const struct pad_config *variant_early_gpio_table(size_t *num);
 
+const struct cros_gpio *variant_cros_gpios(size_t *num);
 
 #endif /* __BASEBOARD_VARIANTS_H__ */