Merge tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux...

[linux-2.6-microblaze.git] / drivers / rtc / rtc-at91rm9200.c

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index 5e811e0..fe396d2 100644 (file)
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -36,6 +36,10 @@
 #define                AT91_RTC_UPDCAL         BIT(1)          /* Update Request Calendar Register */
 
 #define        AT91_RTC_MR             0x04                    /* Mode Register */
+#define                AT91_RTC_HRMOD          BIT(0)          /* 12/24 hour mode */
+#define                AT91_RTC_NEGPPM         BIT(4)          /* Negative PPM correction */
+#define                AT91_RTC_CORRECTION     GENMASK(14, 8)  /* Slow clock correction */
+#define                AT91_RTC_HIGHPPM        BIT(15)         /* High PPM correction */
 
 #define        AT91_RTC_TIMR           0x08                    /* Time Register */
 #define                AT91_RTC_SEC            GENMASK(6, 0)   /* Current Second */
@@ -77,6 +81,9 @@
 #define                AT91_RTC_NVTIMALR       BIT(2)          /* Non valid Time Alarm */
 #define                AT91_RTC_NVCALALR       BIT(3)          /* Non valid Calendar Alarm */
 
+#define AT91_RTC_CORR_DIVIDEND         3906000
+#define AT91_RTC_CORR_LOW_RATIO                20
+
 #define at91_rtc_read(field) \
        readl_relaxed(at91_rtc_regs + field)
 #define at91_rtc_write(field, val) \
@@ -84,6 +91,7 @@
 
 struct at91_rtc_config {
        bool use_shadow_imr;
+       bool has_correction;
 };
 
 static const struct at91_rtc_config *at91_rtc_config;
@@ -293,6 +301,75 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
        return 0;
 }
 
+static int at91_rtc_readoffset(struct device *dev, long *offset)
+{
+       u32 mr = at91_rtc_read(AT91_RTC_MR);
+       long val = FIELD_GET(AT91_RTC_CORRECTION, mr);
+
+       if (!val) {
+               *offset = 0;
+               return 0;
+       }
+
+       val++;
+
+       if (!(mr & AT91_RTC_NEGPPM))
+               val = -val;
+
+       if (!(mr & AT91_RTC_HIGHPPM))
+               val *= AT91_RTC_CORR_LOW_RATIO;
+
+       *offset = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, val);
+
+       return 0;
+}
+
+static int at91_rtc_setoffset(struct device *dev, long offset)
+{
+       long corr;
+       u32 mr;
+
+       if (offset > AT91_RTC_CORR_DIVIDEND / 2)
+               return -ERANGE;
+       if (offset < -AT91_RTC_CORR_DIVIDEND / 2)
+               return -ERANGE;
+
+       mr = at91_rtc_read(AT91_RTC_MR);
+       mr &= ~(AT91_RTC_NEGPPM | AT91_RTC_CORRECTION | AT91_RTC_HIGHPPM);
+
+       if (offset > 0)
+               mr |= AT91_RTC_NEGPPM;
+       else
+               offset = -offset;
+
+       /* offset less than 764 ppb, disable correction*/
+       if (offset < 764) {
+               at91_rtc_write(AT91_RTC_MR, mr & ~AT91_RTC_NEGPPM);
+
+               return 0;
+       }
+
+       /*
+        * 29208 ppb is the perfect cutoff between low range and high range
+        * low range values are never better than high range value after that.
+        */
+       if (offset < 29208) {
+               corr = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, offset * AT91_RTC_CORR_LOW_RATIO);
+       } else {
+               corr = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, offset);
+               mr |= AT91_RTC_HIGHPPM;
+       }
+
+       if (corr > 128)
+               corr = 128;
+
+       mr |= FIELD_PREP(AT91_RTC_CORRECTION, corr - 1);
+
+       at91_rtc_write(AT91_RTC_MR, mr);
+
+       return 0;
+}
+
 /*
  * IRQ handler for the RTC
  */
@@ -343,6 +420,10 @@ static const struct at91_rtc_config at91sam9x5_config = {
        .use_shadow_imr = true,
 };
 
+static const struct at91_rtc_config sama5d4_config = {
+       .has_correction = true,
+};
+
 static const struct of_device_id at91_rtc_dt_ids[] = {
        {
                .compatible = "atmel,at91rm9200-rtc",
@@ -352,10 +433,13 @@ static const struct of_device_id at91_rtc_dt_ids[] = {
                .data = &at91sam9x5_config,
        }, {
                .compatible = "atmel,sama5d4-rtc",
-               .data = &at91rm9200_config,
+               .data = &sama5d4_config,
        }, {
                .compatible = "atmel,sama5d2-rtc",
-               .data = &at91rm9200_config,
+               .data = &sama5d4_config,
+       }, {
+               .compatible = "microchip,sam9x60-rtc",
+               .data = &sama5d4_config,
        }, {
                /* sentinel */
        }
@@ -370,6 +454,16 @@ static const struct rtc_class_ops at91_rtc_ops = {
        .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 };
 
+static const struct rtc_class_ops sama5d4_rtc_ops = {
+       .read_time      = at91_rtc_readtime,
+       .set_time       = at91_rtc_settime,
+       .read_alarm     = at91_rtc_readalarm,
+       .set_alarm      = at91_rtc_setalarm,
+       .alarm_irq_enable = at91_rtc_alarm_irq_enable,
+       .set_offset     = at91_rtc_setoffset,
+       .read_offset    = at91_rtc_readoffset,
+};
+
 /*
  * Initialize and install RTC driver
  */
@@ -416,7 +510,7 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
        }
 
        at91_rtc_write(AT91_RTC_CR, 0);
-       at91_rtc_write(AT91_RTC_MR, 0);         /* 24 hour mode */
+       at91_rtc_write(AT91_RTC_MR, at91_rtc_read(AT91_RTC_MR) & ~AT91_RTC_HRMOD);
 
        /* Disable all interrupts */
        at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
@@ -437,10 +531,14 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
        if (!device_can_wakeup(&pdev->dev))
                device_init_wakeup(&pdev->dev, 1);
 
-       rtc->ops = &at91_rtc_ops;
+       if (at91_rtc_config->has_correction)
+               rtc->ops = &sama5d4_rtc_ops;
+       else
+               rtc->ops = &at91_rtc_ops;
+
        rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
        rtc->range_max = RTC_TIMESTAMP_END_2099;
-       ret = rtc_register_device(rtc);
+       ret = devm_rtc_register_device(rtc);
        if (ret)
                goto err_clk;