On Mon, Nov 05, 2012 at 22:13:25, Cousson, Benoit wrote:
> Hi Anil / Colin,
>
> On 11/05/2012 10:42 AM, AnilKumar Ch wrote:
> > From: Colin Foe-Parker <colin.foeparker@xxxxxxxxxxx>
> >
> > 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
> >
> > Added while (1); after the above steps to make sure that no other
> > process acquire cpu. Otherwise we might see an unexpected behaviour
> > because we are shutting down all the power rails of SoC except RTC.
> >
> > Signed-off-by: Colin Foe-Parker <colin.foeparker@xxxxxxxxxxx>
> > [anilkumar@xxxxxx: move poweroff additions to rtc driver]
> > Signed-off-by: AnilKumar Ch <anilkumar@xxxxxx>
> > ---
> > Documentation/devicetree/bindings/rtc/rtc-omap.txt | 5 ++
> > drivers/rtc/rtc-omap.c | 79 +++++++++++++++++++-
> > 2 files changed, 83 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.
>
> I don't know how it is connected at board level, but I'm not sure the
> binding is the proper one.
Hi Benoit,
________________________________
| ______ _______ |
| | | | | |
| |RTC | | | |
| |PMIC | Line | | |
| |PWR_EN|=======>|PWR_EN | |
| |______| |_______| |
| AM335x SoC TPS65217 |
| |
|________________________________|
BeagleBone
This is how RTC PMIC_PWR_EN is connected to PWR_EN of TPS65217 PMIC. Only when
RTC pull low in PMIC_PWR_EN then PMIC will go to power off state provided TPS65217
status should be changed to STATUS_OFF.
ALARM2 event should be trigger to configure PMIC_PWR_EN properly then the "Line"
driven low so that PMIC will go to shutdown mode.
Thanks
AnilKumar
> It does not look super generic, and I'm wondering if we should not use
> instead some regulator binding to reflect the connection of the RTC to a
> regulator.
>
> But without the board / soc spec it is hard to tell :-(
>
> Regards,
> Benoit
>
>
> > +
> > Example:
> >
> > rtc@1c23000 {
> > @@ -14,4 +18,5 @@ rtc@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..2d90170 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 +101,24 @@
> > #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
> > +#define SECS_IN_MIN 60
> > +#define WAIT_AFTER (SECS_IN_MIN - SHUTDOWN_TIME_SEC)
> > +#define WAIT_TIME_MS (SHUTDOWN_TIME_SEC * 1000)
> > +
> > static void __iomem *rtc_base;
> >
> > #define rtc_read(addr) readb(rtc_base + (addr))
> > @@ -290,6 +307,58 @@ 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;
> > + spinlock_t lock;
> > + unsigned long flags;
> > +
> > + spin_lock_init(&lock);
> > +
> > + /* 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);
> > +
> > + /* Wait few seconds instead of rollover */
> > + do {
> > + omap_rtc_read_time(NULL, &tm);
> > + if (WAIT_AFTER <= tm.tm_sec)
> > + mdelay(WAIT_TIME_MS);
> > + } while (WAIT_AFTER <= tm.tm_sec);
> > +
> > + /* Add shutdown time to the current value */
> > + tm.tm_sec += SHUTDOWN_TIME_SEC;
> > +
> > + if (tm2bcd(&tm) < 0)
> > + return;
> > +
> > + pr_info("System will go to power_off state in approx. %d secs\n",
> > + SHUTDOWN_TIME_SEC);
> > +
> > + /* Set the ALARM2 time */
> > + 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);
> > +
> > + /* Do not allow to execute any other task */
> > + spin_lock_irqsave(&lock, flags);
> > + while (1);
> > +}
> > +
> > static struct rtc_class_ops omap_rtc_ops = {
> > .read_time = omap_rtc_read_time,
> > .set_time = omap_rtc_set_time,
> > @@ -327,12 +396,16 @@ 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 +458,10 @@ 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
> > */
> >
>
>
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