rtc: pcf85363: add alarm support

Handle alarms, currently only on INTA

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 3c5e5e1..3fa5bda 100644 (file)
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -73,6 +73,39 @@
 #define CTRL_RESETS    0x2f
 #define CTRL_RAM       0x40
 
+#define ALRM_SEC_A1E   BIT(0)
+#define ALRM_MIN_A1E   BIT(1)
+#define ALRM_HR_A1E    BIT(2)
+#define ALRM_DAY_A1E   BIT(3)
+#define ALRM_MON_A1E   BIT(4)
+#define ALRM_MIN_A2E   BIT(5)
+#define ALRM_HR_A2E    BIT(6)
+#define ALRM_DAY_A2E   BIT(7)
+
+#define INT_WDIE       BIT(0)
+#define INT_BSIE       BIT(1)
+#define INT_TSRIE      BIT(2)
+#define INT_A2IE       BIT(3)
+#define INT_A1IE       BIT(4)
+#define INT_OIE                BIT(5)
+#define INT_PIE                BIT(6)
+#define INT_ILP                BIT(7)
+
+#define FLAGS_TSR1F    BIT(0)
+#define FLAGS_TSR2F    BIT(1)
+#define FLAGS_TSR3F    BIT(2)
+#define FLAGS_BSF      BIT(3)
+#define FLAGS_WDF      BIT(4)
+#define FLAGS_A1F      BIT(5)
+#define FLAGS_A2F      BIT(6)
+#define FLAGS_PIF      BIT(7)
+
+#define PIN_IO_INTAPM  GENMASK(1, 0)
+#define PIN_IO_INTA_CLK        0
+#define PIN_IO_INTA_BAT        1
+#define PIN_IO_INTA_OUT        2
+#define PIN_IO_INTA_HIZ        3
+
 #define NVRAM_SIZE     0x40
 
 static struct i2c_driver pcf85363_driver;
@@ -131,11 +164,123 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
                                 buf, len);
 }
 
+static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+       unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
+       unsigned int val;
+       int ret;
+
+       ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf,
+                              sizeof(buf));
+       if (ret)
+               return ret;
+
+       alrm->time.tm_sec = bcd2bin(buf[0]);
+       alrm->time.tm_min = bcd2bin(buf[1]);
+       alrm->time.tm_hour = bcd2bin(buf[2]);
+       alrm->time.tm_mday = bcd2bin(buf[3]);
+       alrm->time.tm_mon = bcd2bin(buf[4]) - 1;
+
+       ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val);
+       if (ret)
+               return ret;
+
+       alrm->enabled =  !!(val & INT_A1IE);
+
+       return 0;
+}
+
+static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned
+                                         int enabled)
+{
+       unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E |
+                                  ALRM_DAY_A1E | ALRM_MON_A1E;
+       int ret;
+
+       ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags,
+                                enabled ? alarm_flags : 0);
+       if (ret)
+               return ret;
+
+       ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN,
+                                INT_A1IE, enabled ? INT_A1IE : 0);
+
+       if (ret || enabled)
+               return ret;
+
+       /* clear current flags */
+       return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
+}
+
+static int pcf85363_rtc_alarm_irq_enable(struct device *dev,
+                                        unsigned int enabled)
+{
+       struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+
+       return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled);
+}
+
+static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+       unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
+       int ret;
+
+       buf[0] = bin2bcd(alrm->time.tm_sec);
+       buf[1] = bin2bcd(alrm->time.tm_min);
+       buf[2] = bin2bcd(alrm->time.tm_hour);
+       buf[3] = bin2bcd(alrm->time.tm_mday);
+       buf[4] = bin2bcd(alrm->time.tm_mon + 1);
+
+       /*
+        * Disable the alarm interrupt before changing the value to avoid
+        * spurious interrupts
+        */
+       ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0);
+       if (ret)
+               return ret;
+
+       ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf,
+                               sizeof(buf));
+       if (ret)
+               return ret;
+
+       return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled);
+}
+
+static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id)
+{
+       struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id);
+       unsigned int flags;
+       int err;
+
+       err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags);
+       if (err)
+               return IRQ_NONE;
+
+       if (flags & FLAGS_A1F) {
+               rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF);
+               regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
+               return IRQ_HANDLED;
+       }
+
+       return IRQ_NONE;
+}
+
 static const struct rtc_class_ops rtc_ops = {
        .read_time      = pcf85363_rtc_read_time,
        .set_time       = pcf85363_rtc_set_time,
 };
 
+static const struct rtc_class_ops rtc_ops_alarm = {
+       .read_time      = pcf85363_rtc_read_time,
+       .set_time       = pcf85363_rtc_set_time,
+       .read_alarm     = pcf85363_rtc_read_alarm,
+       .set_alarm      = pcf85363_rtc_set_alarm,
+       .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
+};
+
 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
                               size_t bytes)
 {
@@ -197,6 +342,20 @@ static int pcf85363_probe(struct i2c_client *client,
 
        pcf85363->rtc->ops = &rtc_ops;
 
+       if (client->irq > 0) {
+               regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
+               regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
+                                  PIN_IO_INTA_OUT, PIN_IO_INTAPM);
+               ret = devm_request_threaded_irq(pcf85363->dev, client->irq,
+                                               NULL, pcf85363_rtc_handle_irq,
+                                               IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                               "pcf85363", client);
+               if (ret)
+                       dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
+               else
+                       pcf85363->rtc->ops = &rtc_ops_alarm;
+       }
+
        ret = rtc_register_device(pcf85363->rtc);
 
        nvmem_cfg.priv = pcf85363;