From 26b3c01f7debc1bbc3117bc9c9e016ca6f2e41d5 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Thu, 17 Dec 2009 15:27:23 -0800 Subject: rtc: set wakeup capability for I2C and SPI RTC drivers RTC core won't allow wakeup alarms to be set if RTC devices' parent (i.e. i2c_client or spi_device) isn't wakeup capable. For I2C devices there is I2C_CLIENT_WAKE flag exists that we can pass via board info, and if set, I2C core will initialize wakeup capability. For SPI devices there is no such flag at all. I believe that it's not platform code responsibility to allow or disallow wakeups, instead, drivers themselves should set the capability if a device can trigger wakeups. That's what drivers/base/power/sysfs.c says: * It is the responsibility of device drivers to enable (or disable) * wakeup signaling as part of changing device power states, respecting * the policy choices provided through the driver model. I2C and SPI RTC devices send wakeup events via interrupt lines, so we should set the wakeup capability if IRQ is routed. Ideally we should also check irq for wakeup capability before setting device's capability, i.e. if (can_irq_wake(irq)) device_set_wakeup_capable(&client->dev, 1); But there is no can_irq_wake() call exist, and it is not that trivial to implement it for all interrupts controllers and complex/cascaded setups. drivers/base/power/sysfs.c also covers these cases: * Devices may not be able to generate wakeup events from all power * states. Also, the events may be ignored in some configurations; * for example, they might need help from other devices that aren't * active So there is no guarantee that wakeup will actually work, and so I think there is no point in being pedantic wrt checking IRQ wakeup capability. Signed-off-by: Anton Vorontsov Cc: David Brownell Cc: Ben Dooks Cc: Jean Delvare Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1374.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/rtc/rtc-ds1374.c') diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c index 713f7bf5afb3..5317bbcbc7a0 100644 --- a/drivers/rtc/rtc-ds1374.c +++ b/drivers/rtc/rtc-ds1374.c @@ -383,6 +383,8 @@ static int ds1374_probe(struct i2c_client *client, dev_err(&client->dev, "unable to request IRQ\n"); goto out_free; } + + device_set_wakeup_capable(&client->dev, 1); } ds1374->rtc = rtc_device_register(client->name, &client->dev, -- cgit v1.2.2