Merge tag 'rtc-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Core:
   - Fix rtctest error path

  New drivers:
   - Microcrystal RV8803

  Subsystem wide cleanups:
   - remove misuse of IRQF_NO_SUSPEND flag

  Drivers:
   - at91rm9200: clear RTC alarm status flag prior to suspending
   - davinci: remove incorrect reference to probe function
   - ds1307: Fix alarm programming for mcp794xx
   - ds1390: trickle charger support, fix ds1390_get_reg
   - isl1208: Pass the IRQF_ONESHOT flag
   - opal: fix type of token
   - pcf2127: fix RTC_READ_VL, remove useless driver version
   - pcf85063: return an error when date is invalid
   - pcf8563: add CLKOUT to common clock framework
   - rx8025: remove unnecessary braces
   - s3c: Set year, month, day value for setting alarm
   - stmp3xxx: unify register access macros
   - License fixes: pcf2127, da9063
   - wakeup-source support for isl12057 and opal"

* tag 'rtc-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (23 commits)
  rtc: Add a driver for Micro Crystal RV8803
  rtc: s3c: Set year, month, day value for setting alarm
  rtc: ds1307: Fix alarm programming for mcp794xx
  rtc: isl12057: enable support for the standard "wakeup-source" property
  rtc: opal: enable support for the stardard "wakeup-source" property
  rtc: isl1208: Pass the IRQF_ONESHOT flag
  rtc: pcf8563: add CLKOUT to common clock framework
  rtc: davinci: remove incorrect reference to probe function
  rtc: at91rm9200: clear RTC alarm status flag prior to suspending
  rtc: pcf2127: remove useless driver version
  rtc: pcf2127: fix reading uninitialized value on RTC_READ_VL ioctl
  rtc: stmp3xxx: unify register access macros
  rtc: da9063: GPL copyright inconsistency fix
  rtc: pcf85063: return an error when date is invalid
  rtc: rx8025: remove unnecessary braces
  rtc: ds1343: remove misuse of IRQF_NO_SUSPEND flag
  rtc: ab8500: remove misuse of IRQF_NO_SUSPEND flag
  rtc: pl031: remove misuse of IRQF_NO_SUSPEND flag
  rtc: opal: fix type of token
  rtc: ds1390: Add trickle charger device tree binding
  ...

drivers/rtc/rtc-ds1390.c

@@ -20,6 +20,7 @@
 #include <linux/spi/spi.h>
 #include <linux/bcd.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #define DS1390_REG_100THS		0x00
 #define DS1390_REG_SECONDS		0x01
@@ -40,11 +41,31 @@
 #define DS1390_REG_STATUS		0x0E
 #define DS1390_REG_TRICKLE		0x0F
 
+#define DS1390_TRICKLE_CHARGER_ENABLE	0xA0
+#define DS1390_TRICKLE_CHARGER_250_OHM	0x01
+#define DS1390_TRICKLE_CHARGER_2K_OHM	0x02
+#define DS1390_TRICKLE_CHARGER_4K_OHM	0x03
+#define DS1390_TRICKLE_CHARGER_NO_DIODE	0x04
+#define DS1390_TRICKLE_CHARGER_DIODE	0x08
+
 struct ds1390 {
 	struct rtc_device *rtc;
 	u8 txrx_buf[9];	/* cmd + 8 registers */
 };
 
+static void ds1390_set_reg(struct device *dev, unsigned char address,
+			   unsigned char data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned char buf[2];
+
+	/* MSB must be '1' to write */
+	buf[0] = address | 0x80;
+	buf[1] = data;
+
+	spi_write(spi, buf, 2);
+}
+
 static int ds1390_get_reg(struct device *dev, unsigned char address,
 				unsigned char *data)
 {
@@ -62,11 +83,50 @@ static int ds1390_get_reg(struct device *dev, unsigned char address,
 	if (status != 0)
 		return status;
 
-	*data = chip->txrx_buf[1];
+	*data = chip->txrx_buf[0];
 
 	return 0;
 }
 
+static void ds1390_trickle_of_init(struct spi_device *spi)
+{
+	u32 ohms = 0;
+	u8 value;
+
+	if (of_property_read_u32(spi->dev.of_node, "trickle-resistor-ohms",
+				 &ohms))
+		goto out;
+
+	/* Enable charger */
+	value = DS1390_TRICKLE_CHARGER_ENABLE;
+	if (of_property_read_bool(spi->dev.of_node, "trickle-diode-disable"))
+		value |= DS1390_TRICKLE_CHARGER_NO_DIODE;
+	else
+		value |= DS1390_TRICKLE_CHARGER_DIODE;
+
+	/* Resistor select */
+	switch (ohms) {
+	case 250:
+		value |= DS1390_TRICKLE_CHARGER_250_OHM;
+		break;
+	case 2000:
+		value |= DS1390_TRICKLE_CHARGER_2K_OHM;
+		break;
+	case 4000:
+		value |= DS1390_TRICKLE_CHARGER_4K_OHM;
+		break;
+	default:
+		dev_warn(&spi->dev,
+			 "Unsupported ohm value %02ux in dt\n", ohms);
+		return;
+	}
+
+	ds1390_set_reg(&spi->dev, DS1390_REG_TRICKLE, value);
+
+out:
+	return;
+}
+
 static int ds1390_read_time(struct device *dev, struct rtc_time *dt)
 {
 	struct spi_device *spi = to_spi_device(dev);
@@ -143,6 +203,9 @@ static int ds1390_probe(struct spi_device *spi)
 		return res;
 	}
 
+	if (spi->dev.of_node)
+		ds1390_trickle_of_init(spi);
+
 	chip->rtc = devm_rtc_device_register(&spi->dev, "ds1390",
 					&ds1390_rtc_ops, THIS_MODULE);
 	if (IS_ERR(chip->rtc)) {