diff options
| author | Michael Lange <linuxstuff@milaw.biz> | 2016-01-21 18:10:16 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-02-04 23:44:17 +0100 |
| commit | 8bc2a40730ec74271a0573a6882871308d069f5d (patch) | |
| tree | 8b15ad190fd951a22b4e42fcbf4ecc70e15c3f2d /drivers/rtc | |
| parent | 04d3ba70a3c9c9ba593d3208531463c65f055526 (diff) | |
| download | linux-8bc2a40730ec74271a0573a6882871308d069f5d.tar.bz2 | |
rtc: ds1307: add support for the DT property 'wakeup-source'
For RTC chips with no IRQ directly 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 "wakeup-source" boolean property.
This will guarantee the 'wakealarm' sysfs entry is available on the
device, if supported by the RTC.
With these changes to the driver rtc-ds1307 and the necessary entries
in the .dts file, I get an working ds1337 RTC on the Witty Pi extension
board by UUGear for the Raspberry Pi.
An example for the entry in the .dts file:
rtc: ds1337@68 {
compatible = "dallas,ds1337";
reg = <0x68>;
wakeup-source;
If the "wakeup-source" property is set, do not request an IRQ.
Set also UIE mode to unsupported, to get a working 'hwclock' binary.
Signed-off-by: Michael Lange <linuxstuff@milaw.biz>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index cf685f67b391..bfedeb543bfd 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -851,6 +851,7 @@ static int ds1307_probe(struct i2c_client *client, struct chip_desc *chip = &chips[id->driver_data]; struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); bool want_irq = false; + bool ds1307_can_wakeup_device = false; unsigned char *buf; struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev); irq_handler_t irq_handler = ds1307_irq; @@ -898,6 +899,20 @@ static int ds1307_probe(struct i2c_client *client, ds1307->write_block_data = ds1307_write_block_data; } +#ifdef CONFIG_OF +/* + * For devices with no IRQ directly 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 "wakeup-source" boolean property. + * If the "wakeup-source" property is set, don't request an IRQ. + * This will guarantee the 'wakealarm' sysfs entry is available on the device, + * if supported by the RTC. + */ + if (of_property_read_bool(client->dev.of_node, "wakeup-source")) { + ds1307_can_wakeup_device = true; + } +#endif + switch (ds1307->type) { case ds_1337: case ds_1339: @@ -916,11 +931,13 @@ static int ds1307_probe(struct i2c_client *client, ds1307->regs[0] &= ~DS1337_BIT_nEOSC; /* - * Using IRQ? Disable the square wave and both alarms. + * Using IRQ or defined as wakeup-source? + * Disable the square wave and both alarms. * For some variants, be sure alarms can trigger when we're * running on Vbackup (BBSQI/BBSQW) */ - if (ds1307->client->irq > 0 && chip->alarm) { + if (chip->alarm && (ds1307->client->irq > 0 || + ds1307_can_wakeup_device)) { ds1307->regs[0] |= DS1337_BIT_INTCN | bbsqi_bitpos[ds1307->type]; ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE); @@ -1135,6 +1152,14 @@ read_rtc: return PTR_ERR(ds1307->rtc); } + if (ds1307_can_wakeup_device) { + /* Disable request for an IRQ */ + want_irq = false; + dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n"); + /* We cannot support UIE mode if we do not have an IRQ line */ + ds1307->rtc->uie_unsupported = 1; + } + if (want_irq) { err = devm_request_threaded_irq(&client->dev, client->irq, NULL, irq_handler, |