[Skiboot] [PATCH] plat/qemu: add BT and IPMI support

[Cédric Le Goater]

This brings the qemu platform to the level of an Open Power platform.
It adds the BT device used to communicate with the BMC using IPMI
messaging, power_downs and reboots the way OpenPower systems operate.

The device tree is also checked for UART and RTC device nodes and
updated if qemu has not defined them already. The initialization of
the BT and IPMI interfaces depends on the availability of the BT
device which needs to be explicitly defined by qemu. These tests
enable skiboot to maintain compatibility with previous versions of
qemu which did not update the device tree with enabled devices.

Signed-off-by: Cédric Le Goater <clg at kaod.org>
---

 The only significant difference now with the ast platform is on the
 RTC device which lives under the LPC bus on qemu.

 Tested with the latest qemu powernv+ipmi patchset :

	https://github.com/legoater/qemu/tree/powernv-ipmi-2.7

 which is now based on a v2.7.0-rc1.

 Also tested with Ben's qemu for compatibility. 

 Cheers,


 platforms/qemu/qemu.c |  115 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)

Index: skiboot.git/platforms/qemu/qemu.c
===================================================================
--- skiboot.git.orig/platforms/qemu/qemu.c
+++ skiboot.git/platforms/qemu/qemu.c
@@ -21,6 +21,60 @@
 #include <console.h>
 #include <opal.h>
 #include <psi.h>
+#include <bt.h>
+#include <errorlog.h>
+#include <ipmi.h>
+
+/* BT config */
+#define BT_IO_BASE	0xe4
+#define BT_IO_COUNT	3
+#define BT_LPC_IRQ	10
+
+static bool bt_device_present;
+
+static void qemu_ipmi_error(struct ipmi_msg *msg)
+{
+	prlog(PR_DEBUG, "QEMU: error sending msg. cc = %02x\n", msg->cc);
+
+	ipmi_free_msg(msg);
+}
+
+static void qemu_ipmi_setenables(void)
+{
+	struct ipmi_msg *msg;
+
+	struct {
+		uint8_t oem2_en : 1;
+		uint8_t oem1_en : 1;
+		uint8_t oem0_en : 1;
+		uint8_t reserved : 1;
+		uint8_t sel_en : 1;
+		uint8_t msgbuf_en : 1;
+		uint8_t msgbuf_full_int_en : 1;
+		uint8_t rxmsg_queue_int_en : 1;
+	} data;
+
+	memset(&data, 0, sizeof(data));
+
+	/* The spec says we need to read-modify-write to not clobber
+	 * the state of the other flags. These are set on by the bmc */
+	data.rxmsg_queue_int_en = 1;
+	data.sel_en = 1;
+
+	/* These are the ones we want to set on */
+	data.msgbuf_en = 1;
+
+	msg = ipmi_mkmsg_simple(IPMI_SET_ENABLES, &data, sizeof(data));
+	if (!msg) {
+		prlog(PR_ERR, "QEMU: failed to set enables\n");
+		return;
+	}
+
+	msg->error = qemu_ipmi_error;
+
+	ipmi_queue_msg(msg);
+
+}
 
 static void qemu_init(void)
 {
@@ -32,6 +86,27 @@ static void qemu_init(void)
 	 * chiptod_init()
 	 */
 	lpc_rtc_init();
+
+	if (!bt_device_present)
+		return;
+
+	/* Register the BT interface with the IPMI layer */
+	bt_init();
+	/* Initialize elog */
+	elog_init();
+	ipmi_sel_init();
+	ipmi_wdt_init();
+	ipmi_opal_init();
+	ipmi_fru_init(0);
+	ipmi_sensor_init();
+
+	/* As soon as IPMI is up, inform BMC we are in "S0" */
+	ipmi_set_power_state(IPMI_PWR_SYS_S0_WORKING, IPMI_PWR_NOCHANGE);
+
+	/* Enable IPMI OEM message interrupts */
+	qemu_ipmi_setenables();
+
+	ipmi_set_fw_progress_sensor(IPMI_FW_MOTHERBOARD_INIT);
 }
 
 static void qemu_dt_fixup_uart(struct dt_node *lpc)
@@ -53,6 +128,14 @@ static void qemu_dt_fixup_uart(struct dt
 #define UART_IO_COUNT	8
 #define UART_LPC_IRQ	4
 
+	/* check if the UART device was defined by qemu */
+	dt_for_each_child(lpc, uart) {
+		if (dt_node_is_compatible(uart, "pnpPNP,501")) {
+			prlog(PR_WARNING, "QEMU: uart device already here\n");
+			return;
+		}
+	}
+
 	snprintf(namebuf, sizeof(namebuf), "serial at i%x", UART_IO_BASE);
 	uart = dt_new(lpc, namebuf);
 
@@ -84,6 +167,14 @@ static void qemu_dt_fixup_rtc(struct dt_
 	struct dt_node *rtc;
 	char namebuf[32];
 
+	/* check if the RTC device was defined by qemu */
+	dt_for_each_child(lpc, rtc) {
+		if (dt_node_is_compatible(rtc, "pnpPNP,b00")) {
+			prlog(PR_WARNING, "QEMU: rtc device already here\n");
+			return;
+		}
+	}
+
 	/*
 	 * Follows the structure expected by the kernel file
 	 * arch/powerpc/sysdev/rtc_cmos_setup.c
@@ -113,6 +204,12 @@ static void qemu_dt_fixup(void)
 
 	qemu_dt_fixup_rtc(primary_lpc);
 	qemu_dt_fixup_uart(primary_lpc);
+
+	/* check if the BT device was defined by qemu */
+	dt_for_each_child(primary_lpc, n) {
+		if (dt_node_is_compatible(n, "bt"))
+			bt_device_present = true;
+	}
 }
 
 static void qemu_ext_irq_serirq_cpld(unsigned int chip_id)
@@ -120,6 +217,21 @@ static void qemu_ext_irq_serirq_cpld(uns
 	lpc_all_interrupts(chip_id);
 }
 
+static int64_t qemu_ipmi_power_down(uint64_t request)
+{
+	if (request != IPMI_CHASSIS_PWR_DOWN) {
+		prlog(PR_WARNING, "PLAT: unexpected shutdown request %llx\n",
+				   request);
+	}
+
+	return ipmi_chassis_control(request);
+}
+
+static int64_t qemu_ipmi_reboot(void)
+{
+	return ipmi_chassis_control(IPMI_CHASSIS_HARD_RESET);
+}
+
 static bool qemu_probe(void)
 {
 	if (!dt_node_is_compatible(dt_root, "qemu,powernv"))
@@ -145,4 +257,7 @@ DECLARE_PLATFORM(qemu) = {
 	.probe		= qemu_probe,
 	.init		= qemu_init,
 	.external_irq   = qemu_ext_irq_serirq_cpld,
+	.cec_power_down = qemu_ipmi_power_down,
+	.cec_reboot     = qemu_ipmi_reboot,
+	.terminate	= ipmi_terminate,
 };