rtc: ds1672: move oscillator handling to .read_time

Return -EINVAL when trying to read an invalid time instead of just probe
because this is a useful information for userspace.

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

diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c
index b9860820cc908dbb597202a759462cdcd1b12a14..71645f009e04149f7e1aec8d0b5b5f52b62faf9a 100644 (file)
--- a/drivers/rtc/rtc-ds1672.c
+++ b/drivers/rtc/rtc-ds1672.c
@@ -29,7 +29,7 @@
 static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
        unsigned long time;
-       unsigned char addr = DS1672_REG_CNT_BASE;
+       unsigned char addr = DS1672_REG_CONTROL;
        unsigned char buf[4];
 
        struct i2c_msg msgs[] = {
@@ -41,11 +41,25 @@ static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
                {/* read date */
                        .addr = client->addr,
                        .flags = I2C_M_RD,
-                       .len = 4,
+                       .len = 1,
                        .buf = buf
                },
        };
 
+       /* read control register */
+       if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
+               dev_warn(&client->dev, "Unable to read the control register\n");
+               return -EIO;
+       }
+
+       if (buf[0] & DS1672_REG_CONTROL_EOSC) {
+               dev_warn(&client->dev, "Oscillator not enabled. Set time to enable.\n");
+               return -EINVAL;
+       }
+
+       addr = DS1672_REG_CNT_BASE;
+       msgs[1].len = 4;
+
        /* read date registers */
        if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
                dev_err(&client->dev, "%s: read error\n", __func__);
@@ -154,7 +168,6 @@ static int ds1672_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
        int err = 0;
-       u8 control;
        struct rtc_device *rtc;
 
        dev_dbg(&client->dev, "%s\n", __func__);
@@ -178,16 +191,6 @@ static int ds1672_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, rtc);
 
-       /* read control register */
-       err = ds1672_get_control(client, &control);
-       if (err) {
-               dev_warn(&client->dev, "Unable to read the control register\n");
-       }
-
-       if (control & DS1672_REG_CONTROL_EOSC)
-               dev_warn(&client->dev, "Oscillator not enabled. "
-                        "Set time to enable.\n");
-
        /* Register sysfs hooks */
        err = device_create_file(&client->dev, &dev_attr_control);
        if (err)