[PATCH v4 1/4] rtc: OMAP: Add system pm_power_off to rtc driver

[AnilKumar Ch]

From: Colin Foe-Parker <colin.foeparker at logicpd.com>

Add system power off control to rtc driver which is the in-charge
of controlling the BeagleBone system power. The power_off routine
can be hooked up to "pm_power_off" system call.

System power off sequence:-
* Set PMIC STATUS_OFF when PMIC_POWER_EN is pulled low
* Enable PMIC_POWER_EN in rtc module
* Set rtc ALARM2 time
* Enable ALARM2 interrupt

Signed-off-by: Colin Foe-Parker <colin.foeparker at logicpd.com>
[anilkumar at ti.com: move poweroff additions to rtc driver]
Signed-off-by: AnilKumar Ch <anilkumar at ti.com>
---
 Documentation/devicetree/bindings/rtc/rtc-omap.txt |    5 ++
 drivers/rtc/rtc-omap.c                             |   74 +++++++++++++++++++-
 2 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/rtc/rtc-omap.txt b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
index b47aa41..8d9f4f9 100644
--- a/Documentation/devicetree/bindings/rtc/rtc-omap.txt
+++ b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
@@ -6,6 +6,10 @@ Required properties:
 - interrupts: rtc timer, alarm interrupts in order
 - interrupt-parent: phandle for the interrupt controller
 
+Optional properties:
+- ti,system-power-controller: Telling whether or not rtc is controlling
+  the system power.
+
 Example:
 
 rtc at 1c23000 {
@@ -14,4 +18,5 @@ rtc at 1c23000 {
 	interrupts = <19
 		      19>;
 	interrupt-parent = <&intc>;
+	ti,system-power-controller;
 };
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 6009714..e6d4878 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -72,6 +72,14 @@
 #define OMAP_RTC_KICK0_REG		0x6c
 #define OMAP_RTC_KICK1_REG		0x70
 
+#define OMAP_RTC_ALARM2_SECONDS_REG	0x80
+#define OMAP_RTC_ALARM2_MINUTES_REG	0x84
+#define OMAP_RTC_ALARM2_HOURS_REG	0x88
+#define OMAP_RTC_ALARM2_DAYS_REG	0x8c
+#define OMAP_RTC_ALARM2_MONTHS_REG	0x90
+#define OMAP_RTC_ALARM2_YEARS_REG	0x94
+#define OMAP_RTC_PMIC_REG		0x98
+
 /* OMAP_RTC_CTRL_REG bit fields: */
 #define OMAP_RTC_CTRL_SPLIT		(1<<7)
 #define OMAP_RTC_CTRL_DISABLE		(1<<6)
@@ -93,15 +101,21 @@
 #define OMAP_RTC_STATUS_BUSY            (1<<0)
 
 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
+#define OMAP_RTC_INTERRUPTS_IT_ALARM2   (1<<4)
 #define OMAP_RTC_INTERRUPTS_IT_ALARM    (1<<3)
 #define OMAP_RTC_INTERRUPTS_IT_TIMER    (1<<2)
 
+/* OMAP_RTC_PMIC_REG bit fields: */
+#define OMAP_RTC_PMIC_POWER_EN_EN       (1<<16)
+
 /* OMAP_RTC_KICKER values */
 #define	KICK0_VALUE			0x83e70b13
 #define	KICK1_VALUE			0x95a4f1e0
 
 #define	OMAP_RTC_HAS_KICKER		0x1
 
+#define SHUTDOWN_TIME_SEC		2
+
 static void __iomem	*rtc_base;
 
 #define rtc_read(addr)		readb(rtc_base + (addr))
@@ -290,6 +304,56 @@ static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 	return 0;
 }
 
+/*
+ * rtc_power_off: Set the pmic power off sequence. The RTC generates
+ * pmic_pwr_enable control, which can be used to control an external
+ * PMIC.
+ */
+static void rtc_power_off(void)
+{
+	u32 val;
+	struct rtc_time tm;
+	unsigned long time;
+
+	/* Set PMIC power enable */
+	val = readl(rtc_base + OMAP_RTC_PMIC_REG);
+	writel(val | OMAP_RTC_PMIC_POWER_EN_EN, rtc_base + OMAP_RTC_PMIC_REG);
+
+	/* Read rtc time */
+	omap_rtc_read_time(NULL, &tm);
+
+	/* Convert Gregorian date to seconds since 01-01-1970 00:00:00 */
+	rtc_tm_to_time(&tm, &time);
+
+	/* Add shutdown time to the current value */
+	time += SHUTDOWN_TIME_SEC;
+
+	/* Convert seconds since 01-01-1970 00:00:00 to Gregorian date */
+	rtc_time_to_tm(time, &tm);
+
+	if (tm2bcd(&tm) < 0)
+		return;
+
+	pr_info("System will go to power_off state in approx. %d secs\n",
+			SHUTDOWN_TIME_SEC);
+
+	/*
+	 * pmic_pwr_enable is controlled by means of ALARM2 event. So here
+	 * programming alarm2 expiry time and enabling alarm2 interrupt
+	 */
+	rtc_write(tm.tm_sec, OMAP_RTC_ALARM2_SECONDS_REG);
+	rtc_write(tm.tm_min, OMAP_RTC_ALARM2_MINUTES_REG);
+	rtc_write(tm.tm_hour, OMAP_RTC_ALARM2_HOURS_REG);
+	rtc_write(tm.tm_mday, OMAP_RTC_ALARM2_DAYS_REG);
+	rtc_write(tm.tm_mon, OMAP_RTC_ALARM2_MONTHS_REG);
+	rtc_write(tm.tm_year, OMAP_RTC_ALARM2_YEARS_REG);
+
+	/* Enable alarm2 interrupt */
+	val = readl(rtc_base + OMAP_RTC_INTERRUPTS_REG);
+	writel(val | OMAP_RTC_INTERRUPTS_IT_ALARM2,
+				rtc_base + OMAP_RTC_INTERRUPTS_REG);
+}
+
 static struct rtc_class_ops omap_rtc_ops = {
 	.read_time	= omap_rtc_read_time,
 	.set_time	= omap_rtc_set_time,
@@ -327,12 +391,16 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
 	struct resource		*res, *mem;
 	struct rtc_device	*rtc;
 	u8			reg, new_ctrl;
+	bool			pm_off = false;
 	const struct platform_device_id *id_entry;
 	const struct of_device_id *of_id;
 
 	of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
-	if (of_id)
+	if (of_id) {
 		pdev->id_entry = of_id->data;
+		pm_off = of_property_read_bool(pdev->dev.of_node,
+					"ti,system-power-controller");
+	}
 
 	omap_rtc_timer = platform_get_irq(pdev, 0);
 	if (omap_rtc_timer <= 0) {
@@ -385,6 +453,10 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, rtc);
 	dev_set_drvdata(&rtc->dev, mem);
 
+	/* RTC power off */
+	if (pm_off && !pm_power_off)
+		pm_power_off = rtc_power_off;
+
 	/* clear pending irqs, and set 1/second periodic,
 	 * which we'll use instead of update irqs
 	 */
-- 
1.7.9.5