drivers/ipmi: Add IPMI BMC FRB2 watchdog timer support

Add a function for initializing and starting FRB2 timer with the
provided countdown and action values, and a stop function for
stopping the timer.

Tested on OCP Monolake.

Change-Id: Ic91905e5f01b962473b6b3a9616266d2d95b1d6b
Signed-off-by: Johnny Lin <johnny_lin@wiwynn.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36179
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

src/drivers/ipmi/Makefile.inc

@@ -1,2 +1,3 @@
 ramstage-$(CONFIG_IPMI_KCS) += ipmi_kcs.c
 ramstage-$(CONFIG_IPMI_KCS) += ipmi_kcs_ops.c
+ramstage-$(CONFIG_IPMI_KCS) += ipmi_ops.c

src/drivers/ipmi/ipmi_ops.c

@@ -0,0 +1,106 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Wiwynn Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <console/console.h>
+#include "ipmi_ops.h"
+
+enum cb_err ipmi_init_and_start_bmc_wdt(const int port, uint16_t countdown,
+				uint8_t action)
+{
+	int ret;
+	struct ipmi_wdt_req req = {0};
+	struct ipmi_rsp rsp;
+	printk(BIOS_INFO, "Initializing IPMI BMC watchdog timer\n");
+	/* BIOS FRB2 */
+	req.timer_use = 1;
+	req.timer_actions = action;
+	/* clear BIOS FRB2 expiration flag */
+	req.timer_use_expiration_flags_clr = 2;
+	req.initial_countdown_val = countdown;
+	ret = ipmi_kcs_message(port, IPMI_NETFN_APPLICATION, 0x0,
+			IPMI_BMC_SET_WDG_TIMER,
+			(const unsigned char *) &req, sizeof(req),
+			(unsigned char *) &rsp, sizeof(rsp));
+
+	if (ret < sizeof(struct ipmi_rsp) || rsp.completion_code) {
+		printk(BIOS_ERR, "IPMI: %s set wdt command failed "
+			"(ret=%d resp=0x%x), failed to initialize and start "
+			"IPMI BMC watchdog timer\n", __func__,
+			ret, rsp.completion_code);
+		return CB_ERR;
+	}
+
+	/* Reset command to start timer */
+	ret = ipmi_kcs_message(port, IPMI_NETFN_APPLICATION, 0x0,
+			IPMI_BMC_RESET_WDG_TIMER, NULL, 0,
+			(unsigned char *) &rsp, sizeof(rsp));
+
+	if (ret < sizeof(struct ipmi_rsp) || rsp.completion_code) {
+		printk(BIOS_ERR, "IPMI: %s reset wdt command failed "
+			"(ret=%d resp=0x%x), failed to initialize and start "
+			"IPMI BMC watchdog timer\n", __func__,
+			ret, rsp.completion_code);
+		return CB_ERR;
+	}
+
+	printk(BIOS_INFO, "IPMI BMC watchdog initialized and started.\n");
+	return CB_SUCCESS;
+}
+
+enum cb_err ipmi_stop_bmc_wdt(const int port)
+{
+	int ret;
+	struct ipmi_wdt_req req;
+	struct ipmi_wdt_rsp rsp = {0};
+	struct ipmi_rsp resp;
+
+	/* Get current timer first */
+	ret = ipmi_kcs_message(port, IPMI_NETFN_APPLICATION, 0x0,
+			IPMI_BMC_GET_WDG_TIMER, NULL, 0,
+			(unsigned char *) &rsp, sizeof(rsp));
+
+	if (ret < sizeof(struct ipmi_rsp) || rsp.resp.completion_code) {
+		printk(BIOS_ERR, "IPMI: %s get wdt command failed "
+			"(ret=%d resp=0x%x), IPMI BMC watchdog timer may still "
+			"be running\n", __func__, ret,
+			 rsp.resp.completion_code);
+		return CB_ERR;
+	}
+	/* If bit 6 in timer_use is 0 then it's already stopped. */
+	if (!(rsp.data.timer_use & (1 << 6))) {
+		printk(BIOS_DEBUG, "IPMI BMC watchdog is already stopped\n");
+		return CB_SUCCESS;
+	}
+	/* Set timer stop running by clearing bit 6. */
+	rsp.data.timer_use &= ~(1 << 6);
+	rsp.data.initial_countdown_val = 0;
+	req = rsp.data;
+	ret = ipmi_kcs_message(port, IPMI_NETFN_APPLICATION, 0x0,
+			IPMI_BMC_SET_WDG_TIMER,
+			(const unsigned char *) &req, sizeof(req),
+			(unsigned char *) &resp, sizeof(resp));
+
+	if (ret < sizeof(struct ipmi_rsp) || resp.completion_code) {
+		printk(BIOS_ERR, "IPMI: %s set wdt command stop timer failed "
+			"(ret=%d resp=0x%x), failed to stop IPMI "
+			"BMC watchdog timer\n", __func__, ret,
+			resp.completion_code);
+		return CB_ERR;
+	}
+	printk(BIOS_DEBUG, "IPMI BMC watchdog is stopped\n");
+
+	return CB_SUCCESS;
+}

src/drivers/ipmi/ipmi_ops.h

@@ -0,0 +1,57 @@
+#ifndef __IPMI_OPS_H
+#define __IPMI_OPS_H
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Wiwynn Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <types.h>
+#include "ipmi_kcs.h"
+#define IPMI_BMC_RESET_WDG_TIMER 0x22
+#define IPMI_BMC_SET_WDG_TIMER 0x24
+#define IPMI_BMC_GET_WDG_TIMER 0x25
+
+/* BMC watchdog timeout action */
+enum ipmi_bmc_timeout_action_type {
+	TIMEOUT_NO_ACTION = 0x00,
+	TIMEOUT_HARD_RESET = 0x01,
+	TIMEOUT_POWER_DOWN = 0x02,
+	TIMEOUT_POWER_CYCLE = 0x03,
+};
+/* BMC Watchdog timer */
+struct ipmi_wdt_req {
+	uint8_t timer_use;
+	uint8_t timer_actions;
+	uint8_t pretimeout_interval;
+	uint8_t timer_use_expiration_flags_clr;
+	uint16_t initial_countdown_val;
+} __packed;
+
+struct ipmi_wdt_rsp {
+	struct ipmi_rsp resp;
+	struct ipmi_wdt_req data;
+	uint16_t present_countdown_val;
+} __packed;
+
+/*
+ * Initialize and start BMC FRB2 watchdog timer with the
+ * provided timer countdown and action values.
+ * Returns CB_SUCCESS on success and CB_ERR if an error occurred
+ */
+enum cb_err ipmi_init_and_start_bmc_wdt(const int port, uint16_t countdown,
+				uint8_t action);
+/* Returns CB_SUCCESS on success and CB_ERR if an error occurred */
+enum cb_err ipmi_stop_bmc_wdt(const int port);
+
+#endif