+Andrew Morton

On Tue, Nov 20, 2012 at 15:18:43, AnilKumar, Chimata wrote:
> From: Colin Foe-Parker <colin.foepar...@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
> 
> 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.

Hi All,

ACK from reviewers will help this patch get in.

Andrew,

Could you please pull this patch?

Thanks
AnilKumar

> Signed-off-by: Colin Foe-Parker <colin.foepar...@logicpd.com>
> [anilku...@ti.com: move poweroff additions to rtc driver]
> Signed-off-by: AnilKumar Ch <anilku...@ti.com>
> ---
>  Documentation/devicetree/bindings/rtc/rtc-omap.txt |    5 ++
>  drivers/rtc/rtc-omap.c                             |   81 
> +++++++++++++++++++-
>  2 files changed, 85 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@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..c31f93a 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 +304,63 @@ 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, time;
> +
> +     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);
> +
> +     /* 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);
> +
> +     /* 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 +398,16 @@ 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 +460,10 @@ 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
> 
> 

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