From c18b4c52c755175dc62aed7b409dca24f028ce76 Mon Sep 17 00:00:00 2001 From: Mirza Krak Date: Mon, 17 Oct 2016 15:53:31 +0200 Subject: [PATCH] rtc: pcf85063: do not register a RTC device if chip is not present Add a sanity check to see if chip is present. If we can not communicate with the chip there is no point in registering a RTC device. Signed-off-by: Mirza Krak Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-pcf85063.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c index efb0a08ac117..a06dff994c83 100644 --- a/drivers/rtc/rtc-pcf85063.c +++ b/drivers/rtc/rtc-pcf85063.c @@ -191,12 +191,19 @@ static int pcf85063_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct rtc_device *rtc; + int err; dev_dbg(&client->dev, "%s\n", __func__); if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; + err = i2c_smbus_read_byte_data(client, PCF85063_REG_CTRL1); + if (err < 0) { + dev_err(&client->dev, "RTC chip is not present\n"); + return err; + } + rtc = devm_rtc_device_register(&client->dev, pcf85063_driver.driver.name, &pcf85063_rtc_ops, THIS_MODULE); -- 2.39.5