diff options
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/isil,isl12057.txt | 78 | ||||
| -rw-r--r-- | drivers/rtc/rtc-isl12057.c | 45 |
2 files changed, 117 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/rtc/isil,isl12057.txt b/Documentation/devicetree/bindings/rtc/isil,isl12057.txt new file mode 100644 index 000000000000..501c39ceae79 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/isil,isl12057.txt @@ -0,0 +1,78 @@ +Intersil ISL12057 I2C RTC/Alarm chip + +ISL12057 is a trivial I2C device (it has simple device tree bindings, +consisting of a compatible field, an address and possibly an interrupt +line). + +Nonetheless, it also supports an option boolean property +("isil,irq2-can-wakeup-machine") to handle the specific use-case found +on at least three in-tree users of the chip (NETGEAR ReadyNAS 102, 104 +and 2120 ARM-based NAS); On those devices, the IRQ#2 pin of the chip +(associated with the alarm supported by the driver) is not connected +to the SoC but to a PMIC. It allows the device to be powered up when +RTC alarm rings. In order to mark the device has a wakeup source and +get access to the 'wakealarm' sysfs entry, this specific property can +be set when the IRQ#2 pin of the chip is not connected to the SoC but +can wake up the device. + +Required properties supported by the device: + + - "compatible": must be "isil,isl12057" + - "reg": I2C bus address of the device + +Optional properties: + + - "isil,irq2-can-wakeup-machine": mark the chip as a wakeup source, + independently of the availability of an IRQ line connected to the + SoC. + + - "interrupt-parent", "interrupts": for passing the interrupt line + of the SoC connected to IRQ#2 of the RTC chip. + + +Example isl12057 node without IRQ#2 pin connected (no alarm support): + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + }; + + +Example isl12057 node with IRQ#2 pin connected to main SoC via MPP6 (note +that the pinctrl-related properties below are given for completeness and +may not be required or may be different depending on your system or +SoC, and the main function of the MPP used as IRQ line, i.e. +"interrupt-parent" and "interrupts" are usually sufficient): + + pinctrl { + ... + + rtc_alarm_pin: rtc_alarm_pin { + marvell,pins = "mpp6"; + marvell,function = "gpio"; + }; + + ... + + }; + + ... + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + pinctrl-0 = <&rtc_alarm_pin>; + pinctrl-names = "default"; + interrupt-parent = <&gpio0>; + interrupts = <6 IRQ_TYPE_EDGE_FALLING>; + }; + + +Example isl12057 node without IRQ#2 pin connected to the SoC but to a +PMIC, allowing the device to be started based on configured alarm: + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + isil,irq2-can-wakeup-machine; + }; diff --git a/drivers/rtc/rtc-isl12057.c b/drivers/rtc/rtc-isl12057.c index 3ec73ad7f2d8..bd76c5e35fa5 100644 --- a/drivers/rtc/rtc-isl12057.c +++ b/drivers/rtc/rtc-isl12057.c @@ -457,6 +457,40 @@ static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap) return 0; } +#ifdef CONFIG_OF +/* + * One would expect the device to be marked as a wakeup source only + * when an IRQ pin of the RTC is routed to an interrupt line of the + * CPU. In practice, such an IRQ pin can be connected to a PMIC and + * this allows the device to be powered up when RTC alarm rings. This + * is for instance the case on ReadyNAS 102, 104 and 2120. On those + * devices with no IRQ driectly connected to the SoC, the RTC chip + * can be forced as a wakeup source by stating that explicitly in + * the device's .dts file using the "isil,irq2-can-wakeup-machine" + * boolean property. This will guarantee 'wakealarm' sysfs entry is + * available on the device. + * + * The function below returns 1, i.e. the capability of the chip to + * wakeup the device, based on IRQ availability or if the boolean + * property has been set in the .dts file. Otherwise, it returns 0. + */ + +static bool isl12057_can_wakeup_machine(struct device *dev) +{ + struct isl12057_rtc_data *data = dev_get_drvdata(dev); + + return (data->irq || of_property_read_bool(dev->of_node, + "isil,irq2-can-wakeup-machine")); +} +#else +static bool isl12057_can_wakeup_machine(struct device *dev) +{ + struct isl12057_rtc_data *data = dev_get_drvdata(dev); + + return !!data->irq; +} +#endif + static int isl12057_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) { @@ -555,7 +589,8 @@ static int isl12057_probe(struct i2c_client *client, client->irq, ret); } - device_init_wakeup(dev, !!data->irq); + if (isl12057_can_wakeup_machine(dev)) + device_init_wakeup(dev, true); data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops, THIS_MODULE); @@ -576,9 +611,7 @@ err: static int isl12057_remove(struct i2c_client *client) { - struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev); - - if (rtc_data->irq) + if (isl12057_can_wakeup_machine(&client->dev)) device_init_wakeup(&client->dev, false); return 0; @@ -589,7 +622,7 @@ static int isl12057_rtc_suspend(struct device *dev) { struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev); - if (device_may_wakeup(dev)) + if (rtc_data->irq && device_may_wakeup(dev)) return enable_irq_wake(rtc_data->irq); return 0; @@ -599,7 +632,7 @@ static int isl12057_rtc_resume(struct device *dev) { struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev); - if (device_may_wakeup(dev)) + if (rtc_data->irq && device_may_wakeup(dev)) return disable_irq_wake(rtc_data->irq); return 0; |