soc/intel/{adl, common}: Add routines into CSE IA-common code

This patch adds routines to keep CSE and other HECI devices into the
lower power device state (AKA D0I3).
- cse_set_to_d0i3    =>  Set CSE device state to D0I3
- heci_set_to_d0i3   =>  Function sets D0I3 for all HECI devices

Additionally, creates a config `MAX_HECI_DEVICES` to pass the HECI
device count info from SoC layer to common CSE block.

As per PCH EDS, the HECI device count for various SoCs are:

ADL/CNL/EHL/ICL/JSL/TGL => 6 (CSE, IDE-R, KT, CSE2, CSE3 and CSE4)
APL                     => 1 (CSE)
SKL/Xeon_SP             => 5 (CSE, IDE-R, KT, CSE2 and CSE3)

BUG=b:211954778
TEST=Able to build and boot Brya.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: Ie32887196628fe6386896604e50338f4bc0bedfe
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61518
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/cse/cse.c b/src/soc/intel/common/block/cse/cse.c
index 32f6d4f0c2..6dfe329fc4 100644
--- a/src/soc/intel/common/block/cse/cse.c
+++ b/src/soc/intel/common/block/cse/cse.c
@@ -988,6 +988,26 @@ bool set_cse_device_state(unsigned int devfn, enum cse_device_state requested_st
 	return true;
 }
 
+void cse_set_to_d0i3(void)
+{
+	if (!is_cse_devfn_visible(PCH_DEVFN_CSE))
+		return;
+
+	set_cse_device_state(PCH_DEVFN_CSE, DEV_IDLE);
+}
+
+/* Function to set D0I3 for all HECI devices */
+void heci_set_to_d0i3(void)
+{
+	for (int i = 0; i < CONFIG_MAX_HECI_DEVICES; i++) {
+		pci_devfn_t dev = PCI_DEV(0, PCI_SLOT(PCH_DEV_SLOT_CSE), PCI_FUNC(i));
+		if (!is_cse_devfn_visible(dev))
+			continue;
+
+		set_cse_device_state(dev, DEV_IDLE);
+	}
+}
+
 #if ENV_RAMSTAGE
 
 /*