1 files changed, 100 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index c508e45ca3ce..e83f51ae7f63 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -68,6 +68,15 @@
 
 #define OMAP_RTC_IRQWAKEEN              0x7c
 
+#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             BIT(7)
 #define OMAP_RTC_CTRL_DISABLE           BIT(6)
@@ -80,6 +89,7 @@
 
 /* OMAP_RTC_STATUS_REG bit fields: */
 #define OMAP_RTC_STATUS_POWER_UP        BIT(7)
+#define OMAP_RTC_STATUS_ALARM2          BIT(7)
 #define OMAP_RTC_STATUS_ALARM           BIT(6)
 #define OMAP_RTC_STATUS_1D_EVENT        BIT(5)
 #define OMAP_RTC_STATUS_1H_EVENT        BIT(4)
@@ -89,6 +99,7 @@
 #define OMAP_RTC_STATUS_BUSY            BIT(0)
 
 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
+#define OMAP_RTC_INTERRUPTS_IT_ALARM2   BIT(4)
 #define OMAP_RTC_INTERRUPTS_IT_ALARM    BIT(3)
 #define OMAP_RTC_INTERRUPTS_IT_TIMER    BIT(2)
 
@@ -98,6 +109,9 @@
 /* OMAP_RTC_IRQWAKEEN bit fields: */
 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1)
 
+/* OMAP_RTC_PMIC bit fields: */
+#define OMAP_RTC_PMIC_POWER_EN_EN       BIT(16)
+
 /* OMAP_RTC_KICKER values */
 #define KICK0_VALUE                     0x83e70b13
 #define KICK1_VALUE                     0x95a4f1e0
@@ -106,6 +120,7 @@ struct omap_rtc_device_type {
         bool has_32kclk_en;
         bool has_kicker;
         bool has_irqwakeen;
+        bool has_pmic_mode;
         bool has_power_up_reset;
 };
 
@@ -115,6 +130,7 @@ struct omap_rtc {
         int irq_alarm;
         int irq_timer;
         u8 interrupts_reg;
+        bool is_pmic_controller;
         const struct omap_rtc_device_type *type;
 };
 
@@ -345,6 +361,70 @@ static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
         return 0;
 }
 
+static struct omap_rtc *omap_rtc_power_off_rtc;
+
+/*
+ * omap_rtc_poweroff: RTC-controlled power off
+ *
+ * The RTC can be used to control an external PMIC via the pmic_power_en pin,
+ * which can be configured to transition to OFF on ALARM2 events.
+ *
+ * Notes:
+ * The two-second alarm offset is the shortest offset possible as the alarm
+ * registers must be set before the next timer update and the offset
+ * calculation is too heavy for everything to be done within a single access
+ * period (~15 us).
+ *
+ * Called with local interrupts disabled.
+ */
+static void omap_rtc_power_off(void)
+{
+        struct omap_rtc *rtc = omap_rtc_power_off_rtc;
+        struct rtc_time tm;
+        unsigned long now;
+        u32 val;
+
+        /* enable pmic_power_en control */
+        val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
+        rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
+
+        /* set alarm two seconds from now */
+        omap_rtc_read_time_raw(rtc, &tm);
+        bcd2tm(&tm);
+        rtc_tm_to_time(&tm, &now);
+        rtc_time_to_tm(now + 2, &tm);
+
+        if (tm2bcd(&tm) < 0) {
+                dev_err(&rtc->rtc->dev, "power off failed\n");
+                return;
+        }
+
+        rtc_wait_not_busy(rtc);
+
+        rtc_write(rtc, OMAP_RTC_ALARM2_SECONDS_REG, tm.tm_sec);
+        rtc_write(rtc, OMAP_RTC_ALARM2_MINUTES_REG, tm.tm_min);
+        rtc_write(rtc, OMAP_RTC_ALARM2_HOURS_REG, tm.tm_hour);
+        rtc_write(rtc, OMAP_RTC_ALARM2_DAYS_REG, tm.tm_mday);
+        rtc_write(rtc, OMAP_RTC_ALARM2_MONTHS_REG, tm.tm_mon);
+        rtc_write(rtc, OMAP_RTC_ALARM2_YEARS_REG, tm.tm_year);
+
+        /*
+         * enable ALARM2 interrupt
+         *
+         * NOTE: this fails on AM3352 if rtc_write (writeb) is used
+         */
+        val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
+        rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
+                        val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
+
+        /*
+         * Wait for alarm to trigger (within two seconds) and external PMIC to
+         * power off the system. Add a 500 ms margin for external latencies
+         * (e.g. debounce circuits).
+         */
+        mdelay(2500);
+}
+
 static struct rtc_class_ops omap_rtc_ops = {
         .read_time      = omap_rtc_read_time,
         .set_time       = omap_rtc_set_time,
@@ -361,6 +441,7 @@ static const struct omap_rtc_device_type omap_rtc_am3352_type = {
         .has_32kclk_en  = true,
         .has_kicker     = true,
         .has_irqwakeen  = true,
+        .has_pmic_mode  = true,
 };
 
 static const struct omap_rtc_device_type omap_rtc_da830_type = {
@@ -412,6 +493,9 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
         of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
         if (of_id) {
                 rtc->type = of_id->data;
+                rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
+                                of_property_read_bool(pdev->dev.of_node,
+                                                "ti,system-power-controller");
         } else {
                 id_entry = platform_get_device_id(pdev);
                 rtc->type = (void *)id_entry->driver_data;
@@ -460,6 +544,9 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
 
         mask = OMAP_RTC_STATUS_ALARM;
 
+        if (rtc->type->has_pmic_mode)
+                mask |= OMAP_RTC_STATUS_ALARM2;
+
         if (rtc->type->has_power_up_reset) {
                 mask |= OMAP_RTC_STATUS_POWER_UP;
                 if (reg & OMAP_RTC_STATUS_POWER_UP)
@@ -520,6 +607,13 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
                         goto err;
         }
 
+        if (rtc->is_pmic_controller) {
+                if (!pm_power_off) {
+                        omap_rtc_power_off_rtc = rtc;
+                        pm_power_off = omap_rtc_power_off;
+                }
+        }
+
         return 0;
 
 err:
@@ -536,6 +630,12 @@ static int __exit omap_rtc_remove(struct platform_device *pdev)
 {
         struct omap_rtc *rtc = platform_get_drvdata(pdev);
 
+        if (pm_power_off == omap_rtc_power_off &&
+                        omap_rtc_power_off_rtc == rtc) {
+                pm_power_off = NULL;
+                omap_rtc_power_off_rtc = NULL;
+        }
+
         device_init_wakeup(&pdev->dev, 0);
 
         /* leave rtc running, but disable irqs */