Add support to turn off Beaglebone with poweroff(8) or shutdown(8) -p.

To cut off the power we need to start the shutdown sequence by writing
the OFF bit on PMIC.

Once the PMIC is programmed the SoC needs to toggle the PMIC_PWR_ENABLE
pin when it is ready for the PMIC to cut off the power.  This is done by
triggering the ALARM2 interrupt on SoC RTC.

The RTC driver only works in power management mode which means it won't
provide any kind of time keeping functionality.  It only implements a way
to trigger the ALARM2 interrupt when requested.

Differential Revision:	https://reviews.freebsd.org/D1489
Reviewed by:	rpaulo
MFC after:	2 weeks

1 files changed, 76 insertions, 0 deletions

diff --git a/sys/arm/ti/am335x/am335x_rtcreg.h b/sys/arm/ti/am335x/am335x_rtcreg.h
new file mode 100644
index 0000000..a4b5cc8
--- /dev/null
+++ b/sys/arm/ti/am335x/am335x_rtcreg.h
@@ -0,0 +1,76 @@
+/*-
+ * Copyright 2015 Luiz Otavio O Souza <loos@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _AM335X_RTCREG_H_
+#define _AM335X_RTCREG_H_
+
+#define	RTC_SECONDS		0x00
+#define	RTC_MINUTES		0x04
+#define	RTC_HOURS		0x08
+#define	RTC_DAYS		0x0c
+#define	RTC_MONTHS		0x10
+#define	RTC_YEARS		0x14
+#define	RTC_WEEK		0x18
+#define	RTC_CTRL		0x40
+#define	RTC_CTRL_DISABLE		(1U << 6)
+#define	RTC_CTRL_RUN			(1U << 0)
+#define	RTC_STATUS		0x44
+#define	RTC_STATUS_ALARM2		(1U << 7)
+#define	RTC_STATUS_ALARM		(1U << 6)
+#define	RTC_STATUS_1D_EVENT		(1U << 5)
+#define	RTC_STATUS_1H_EVENT		(1U << 4)
+#define	RTC_STATUS_1M_EVENT		(1U << 3)
+#define	RTC_STATUS_1S_EVENT		(1U << 2)
+#define	RTC_STATUS_RUN			(1U << 1)
+#define	RTC_STATUS_BUSY			(1U << 0)
+#define	RTC_INTR		0x48
+#define	RTC_INTR_ALARM2			(1U << 4)
+#define	RTC_INTR_ALARM			(1U << 3)
+#define	RTC_INTR_TIMER			(1U << 2)
+#define	RTC_OSC			0x54
+#define	RTC_OSC_32KCLK_EN		(1U << 6)
+#define	RTC_OSC_OSC32K_GZ		(1U << 4)
+#define	RTC_OSC_32KCLK_SEL		(1U << 3)
+#define	RTC_OSC_RES_SELECT		(1U << 2)
+#define	RTC_OSC_SW2			(1U << 1)
+#define	RTC_OSC_SW1			(1U << 0)
+#define	RTC_KICK0R		0x6c
+#define	RTC_KICK0R_PASS			0x83e70b13
+#define	RTC_KICK1R		0x70
+#define	RTC_KICK1R_PASS			0x95a4f1e0
+#define	RTC_REVISION		0x74
+#define	RTC_ALARM2_SECONDS	0x80
+#define	RTC_ALARM2_MINUTES	0x84
+#define	RTC_ALARM2_HOURS	0x88
+#define	RTC_ALARM2_DAYS		0x8c
+#define	RTC_ALARM2_MONTHS	0x90
+#define	RTC_ALARM2_YEARS	0x94
+#define	RTC_PMIC		0x98
+#define	PMIC_PWR_ENABLE			(1U << 16)
+
+#endif /* _AM335X_RTCREG_H_ */