Change in coreboot[master]: soc/amd/cezanne: Force resets to be cold

[Martin Roth (Code Review)]

Martin Roth has submitted this change. ( https://review.coreboot.org/c/coreboot/+/52982 )

Change subject: soc/amd/cezanne: Force resets to be cold
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soc/amd/cezanne: Force resets to be cold

Cezanne must use cold resets.  Change the warm reset request to always
set TOGGLE_ALL_PWR_GOOD.  And, since the bit is sticky across power
cycles, set it early for good measure.

BUG=b:184281092
TEST=Majolica successfully resets using 0xcf9

Signed-off-by: Marshall Dawson 
Change-Id: I7d4ca5665335b20100a5c802d12d79c0d0597ad9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52982
Tested-by: build bot (Jenkins) 
Reviewed-by: Martin Roth 
---
M src/soc/amd/cezanne/fch.c
M src/soc/amd/cezanne/reset.c
2 files changed, 10 insertions(+), 4 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Martin Roth: Looks good to me, approved

diff --git a/src/soc/amd/cezanne/fch.c b/src/soc/amd/cezanne/fch.c
index 028ffec..f02d1ac 100644
--- a/src/soc/amd/cezanne/fch.c
+++ b/src/soc/amd/cezanne/fch.c
@@ -113,8 +113,14 @@
    			PM_ACPI_TIMER_EN_EN);
 }

+static void fch_init_resets(void)
+{
+	pm_write16(PWR_RESET_CFG, pm_read16(PWR_RESET_CFG) | TOGGLE_ALL_PWR_GOOD);
+}
+
 void fch_init(void *chip_info)
 {
+	fch_init_resets();
    i2c_soc_init();
    fch_init_acpi_ports();

diff --git a/src/soc/amd/cezanne/reset.c b/src/soc/amd/cezanne/reset.c
index aae76bf..d97f79e 100644
--- a/src/soc/amd/cezanne/reset.c
+++ b/src/soc/amd/cezanne/reset.c
@@ -7,6 +7,7 @@
 #include <amdblocks/acpimmio.h>
 #include <amdblocks/reset.h>

+/* TODO: is NCP_ERR still valid?  It appears reserved and always 0xff.  b/184281092 */
 void set_warm_reset_flag(void)
 {
    uint8_t ncp = inw(NCP_ERR);
@@ -29,14 +30,13 @@

void do_warm_reset(void)
 {
-	set_warm_reset_flag();
-
-	/* Assert reset signals only. */
+	/* Warm resets are not supported and must be executed as cold */
+	pm_write16(PWR_RESET_CFG, pm_read16(PWR_RESET_CFG) |
+		TOGGLE_ALL_PWR_GOOD);
    outb(RST_CPU | SYS_RST, RST_CNT);
 }

void do_board_reset(void)
 {
-	/* TODO: Would a warm_reset() suffice? */
    do_cold_reset();
 }