mb/siemens/mc_ehl: Add code to wait for legacy devices before PCI scan

Boards based on mc_ehl have, just like some mc_apl variants, legacy
devices on the PCI bus which take longer to boot. In order to ensure
that they will be enumerated correctly wait for them to come up before
PCI scan starts.

TEST=Checked that the new message is visible in the log.

Change-Id: If2f935b69ddaa9364566deacfada5e7d41fcdabd
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56631
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/mainboard/siemens/mc_ehl/mainboard.c b/src/mainboard/siemens/mc_ehl/mainboard.c
index fc7d31f29d..4cc5490f2a 100644
--- a/src/mainboard/siemens/mc_ehl/mainboard.c
+++ b/src/mainboard/siemens/mc_ehl/mainboard.c
@@ -1,12 +1,15 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <baseboard/variants.h>
+#include <bootstate.h>
 #include <console/console.h>
 #include <device/device.h>
 #include <hwilib.h>
 #include <i210.h>
 #include <soc/gpio.h>
 #include <string.h>
+#include <timer.h>
+#include <timestamp.h>
 
 #define MAX_PATH_DEPTH		12
 #define MAX_NUM_MAPPINGS	10
@@ -83,6 +86,31 @@ enum cb_err mainboard_get_mac_address(struct device *dev, uint8_t mac[MAC_ADDR_L
 	return CB_ERR;
 }
 
+static void wait_for_legacy_dev(void *unused)
+{
+	uint32_t legacy_delay, us_since_boot;
+	struct stopwatch sw;
+
+	/* Open main hwinfo block. */
+	if (hwilib_find_blocks("hwinfo.hex") != CB_SUCCESS)
+		return;
+
+	/* Get legacy delay parameter from hwinfo. */
+	if (hwilib_get_field(LegacyDelay, (uint8_t *) &legacy_delay,
+			      sizeof(legacy_delay)) != sizeof(legacy_delay))
+		return;
+
+	us_since_boot = get_us_since_boot();
+	/* No need to wait if the time since boot is already long enough.*/
+	if (us_since_boot > legacy_delay)
+		return;
+	stopwatch_init_msecs_expire(&sw, (legacy_delay - us_since_boot) / 1000);
+	printk(BIOS_NOTICE, "Wait remaining %d of %d us for legacy devices...",
+			legacy_delay - us_since_boot, legacy_delay);
+	stopwatch_wait_until_expired(&sw);
+	printk(BIOS_NOTICE, "done!\n");
+}
+
 static void mainboard_init(void *chip_info)
 {
 	const struct pad_config *pads;
@@ -95,3 +123,5 @@ static void mainboard_init(void *chip_info)
 struct chip_operations mainboard_ops = {
 	.init = mainboard_init,
 };
+
+BOOT_STATE_INIT_ENTRY(BS_DEV_ENUMERATE, BS_ON_ENTRY, wait_for_legacy_dev, NULL);