diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/rtc-m41t80.txt | 9 | ||||
| -rw-r--r-- | drivers/rtc/rtc-m41t80.c | 12 |
2 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt b/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt index c746cb221210..cdd196b1e9bd 100644 --- a/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt +++ b/Documentation/devicetree/bindings/rtc/rtc-m41t80.txt @@ -21,10 +21,19 @@ Optional properties: clock name - wakeup-source: Enables wake up of host system on alarm +Optional child node: +- clock: Provide this if the square wave pin is used as boot-enabled fixed clock. + Example: rtc@68 { compatible = "st,m41t80"; reg = <0x68>; interrupt-parent = <&UIC0>; interrupts = <0x9 0x8>; + + clock { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <32768>; + }; }; diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index 89128fc29ccc..b3ece42b6f90 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -544,10 +544,22 @@ static struct clk *m41t80_sqw_register_clk(struct m41t80_data *m41t80) { struct i2c_client *client = m41t80->client; struct device_node *node = client->dev.of_node; + struct device_node *fixed_clock; struct clk *clk; struct clk_init_data init; int ret; + fixed_clock = of_get_child_by_name(node, "clock"); + if (fixed_clock) { + /* + * skip registering square wave clock when a fixed + * clock has been registered. The fixed clock is + * registered automatically when being referenced. + */ + of_node_put(fixed_clock); + return 0; + } + /* First disable the clock */ ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); if (ret < 0) |