device: Consider fw_config probing in `is_dev_enabled()`

With the introduction of fw_config support in coreboot, it is possible
for mainboards to control the state of a device (on/off) in ramstage
using fw_config probe conditions. However, the device tree in
immutable in all other stages and hence `is_dev_enabled()` does not
really reflect the true state as in ramstage.

This change adds a call to `fw_config_probe_dev()` in
`is_dev_enabled()` when device tree is immutable (by checking
DEVTREE_EARLY) to first check if device is disabled because of device
probe conditions. If so, then it reports device as being
disabled. Else, dev->enabled is used to report the device state.

This allows early stages (bootblock, romstage) to use
`is_dev_enabled()` to get the true state of the device by taking probe
conditions into account and eliminates the need for each caller to
perform their own separate probing.

Change-Id: Ifede6775bda245cba199d3419aebd782dc690f2c
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54752
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/device/device_const.c b/src/device/device_const.c
index 2ce76c61e5..20afe7e445 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -7,6 +7,7 @@
 #include <device/pci.h>
 #include <device/pci_def.h>
 #include <device/resource.h>
+#include <fw_config.h>
 
 /** Linked list of ALL devices */
 DEVTREE_CONST struct device *DEVTREE_CONST all_devices = &dev_root;
@@ -383,3 +384,16 @@ DEVTREE_CONST struct device *dev_bus_each_child(const struct bus *parent,
 
 	return dev;
 }
+
+bool is_dev_enabled(const struct device *dev)
+{
+	if (!dev)
+		return false;
+
+	/* For stages with immutable device tree, first check if device is disabled because of
+	   fw_config probing. In these stages, dev->enabled does not reflect the true state of a
+	   device that uses fw_config probing. */
+	if (DEVTREE_EARLY && !fw_config_probe_dev(dev, NULL))
+		return false;
+	return dev->enabled;
+}