soc/intel/common: Add virtual wire mapping entries to GPIO communities

Some SoCs may define virtual wire entries for certain GPIOs. This patch
allows SoC code to provide the mappings from GPIO pads to virtual wire
indexes and bits when they are provided. Also a function
`gpio_get_vw_info` is added to return this information.

Change-Id: I87adf0ca06cb5b7969bb2c258d6daebd44bb9748
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52588
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 43 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/gpio/gpio.c b/src/soc/intel/common/block/gpio/gpio.c
index 4398c9fb62..db7654537a 100644
--- a/src/soc/intel/common/block/gpio/gpio.c
+++ b/src/soc/intel/common/block/gpio/gpio.c
@@ -763,3 +763,27 @@ static void snapshot_cleanup(void *unused)
 
 BOOT_STATE_INIT_ENTRY(BS_OS_RESUME,    BS_ON_EXIT, snapshot_cleanup, NULL);
 BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT, snapshot_cleanup, NULL);
+
+bool gpio_get_vw_info(gpio_t pad, unsigned int *vw_index, unsigned int *vw_bit)
+{
+	const struct pad_community *comm;
+	unsigned int offset = 0;
+	size_t i;
+
+	comm = gpio_get_community(pad);
+	for (i = 0; i < comm->num_vw_entries; i++) {
+		if (pad >= comm->vw_entries[i].first_pad && pad <= comm->vw_entries[i].last_pad)
+			break;
+
+		offset += 1 + comm->vw_entries[i].last_pad - comm->vw_entries[i].first_pad;
+	}
+
+	if (i == comm->num_vw_entries)
+		return false;
+
+	offset += pad - comm->vw_entries[i].first_pad;
+	*vw_index = comm->vw_base + offset / 8;
+	*vw_bit = offset % 8;
+
+	return true;
+}
diff --git a/src/soc/intel/common/block/include/intelblocks/gpio.h b/src/soc/intel/common/block/include/intelblocks/gpio.h
index a7419dca59..eab257361e 100644
--- a/src/soc/intel/common/block/include/intelblocks/gpio.h
+++ b/src/soc/intel/common/block/include/intelblocks/gpio.h
@@ -96,6 +96,12 @@ struct pad_group {
 	int		acpi_pad_base;
 };
 
+/* A range of consecutive virtual-wire entries in a community */
+struct vw_entries {
+	gpio_t first_pad;
+	gpio_t last_pad;
+};
+
 /* This structure will be used to describe a community or each group within a
  * community when multiple groups exist inside a community
  */
@@ -123,6 +129,13 @@ struct pad_community {
 	size_t		num_reset_vals;
 	const struct pad_group	*groups;
 	size_t		num_groups;
+	unsigned int	vw_base;
+	/*
+	 * Note: The entries must be in the same order here as the order in
+	 * which they map to VW indexes (beginning with VW base)
+	 */
+	const struct vw_entries	*vw_entries;
+	size_t		num_vw_entries;
 };
 
 /*
@@ -237,5 +250,11 @@ bool gpio_routes_ioapic_irq(unsigned int irq);
 
 size_t gpio_get_index_in_group(gpio_t pad);
 
+/*
+ * Returns true and stuffs out params for virtual-wire index and bit position
+ * for the given GPIO, otherwise false if there is no VW index for the pad.
+ */
+bool gpio_get_vw_info(gpio_t pad, unsigned int *vw_index, unsigned int *vw_bit);
+
 #endif
 #endif /* _SOC_INTELBLOCKS_GPIO_H_ */