rtc: rv8803: set VDETOFF and SWOFF via device tree

There might be designs where the power supply circuit is designed
in a way that VDETOFF and SWOFF is required to be set. Otherwise the
RTC detects a power loss. Add a device tree interface for this.

Signed-off-by: Carsten Resch <Carsten.Resch@de.bosch.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@de.bosch.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index 9a2f6a95d5a7cf5757308c3ce6668e2f78d20c35..f9277e536f7e8754120da35b17581b9f1492c632 100644 (file)
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -52,11 +52,21 @@
 #define RV8803_CTRL_TIE                        BIT(4)
 #define RV8803_CTRL_UIE                        BIT(5)
 
+#define RX8900_BACKUP_CTRL             0x18
+#define RX8900_FLAG_SWOFF              BIT(2)
+#define RX8900_FLAG_VDETOFF            BIT(3)
+
+enum rv8803_type {
+       rv_8803,
+       rx_8900
+};
+
 struct rv8803_data {
        struct i2c_client *client;
        struct rtc_device *rtc;
        struct mutex flags_lock;
        u8 ctrl;
+       enum rv8803_type type;
 };
 
 static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
@@ -497,6 +507,35 @@ static struct rtc_class_ops rv8803_rtc_ops = {
        .ioctl = rv8803_ioctl,
 };
 
+static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
+{
+       struct i2c_client *client = rv8803->client;
+       struct device_node *node = client->dev.of_node;
+       int err;
+       u8 flags;
+
+       if (!node)
+               return 0;
+
+       if (rv8803->type != rx_8900)
+               return 0;
+
+       err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
+       if (err < 0)
+               return err;
+
+       flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
+
+       if (of_property_read_bool(node, "epson,vdet-disable"))
+               flags |= RX8900_FLAG_VDETOFF;
+
+       if (of_property_read_bool(node, "trickle-diode-disable"))
+               flags |= RX8900_FLAG_SWOFF;
+
+       return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
+                                        flags);
+}
+
 static int rv8803_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -517,6 +556,7 @@ static int rv8803_probe(struct i2c_client *client,
 
        mutex_init(&rv8803->flags_lock);
        rv8803->client = client;
+       rv8803->type = id->driver_data;
        i2c_set_clientdata(client, rv8803);
 
        flags = rv8803_read_reg(client, RV8803_FLAG);
@@ -558,6 +598,12 @@ static int rv8803_probe(struct i2c_client *client,
        if (err)
                return err;
 
+       err = rx8900_trickle_charger_init(rv8803);
+       if (err) {
+               dev_err(&client->dev, "failed to init charger\n");
+               return err;
+       }
+
        err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
        if (err)
                return err;
@@ -575,8 +621,8 @@ static int rv8803_remove(struct i2c_client *client)
 }
 
 static const struct i2c_device_id rv8803_id[] = {
-       { "rv8803", 0 },
-       { "rx8900", 0 },
+       { "rv8803", rv_8803 },
+       { "rx8900", rx_8900 },
        { }
 };
 MODULE_DEVICE_TABLE(i2c, rv8803_id);