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- From cc252ee4f3948d12a878c93cbdb0505a9ee7bc03 Mon Sep 17 00:00:00 2001
- From: Michael Lange <linuxstuff@milaw.biz>
- Date: Thu, 21 Jan 2016 18:10:16 +0100
- Subject: [PATCH] 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>
- ---
- drivers/rtc/rtc-ds1307.c | 29 +++++++++++++++++++++++++++--
- 1 file changed, 27 insertions(+), 2 deletions(-)
- --- a/drivers/rtc/rtc-ds1307.c
- +++ b/drivers/rtc/rtc-ds1307.c
- @@ -860,6 +860,7 @@ static int ds1307_probe(struct i2c_clien
- 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;
- @@ -907,6 +908,20 @@ static int ds1307_probe(struct i2c_clien
- 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:
- @@ -925,11 +940,13 @@ static int ds1307_probe(struct i2c_clien
- 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);
- @@ -1144,6 +1161,14 @@ 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,
|
