[PATCH v2 2/3] input: sun4i-lradc-keys - Add wakup support

[Samuel Holland]

From: Ondrej Jirman <meg...@megous.com>

Allow the driver to wake the system on key press if the "wakeup-source"
property is provided in the device tree. Using the LRADC as a wakeup
source requires keeping the AVCC domain active during sleep. Since this
has a nontrivial impact on power consumption (sometimes doubling it),
disable the LRADC wakeup source by default.

Signed-off-by: Ondrej Jirman <meg...@megous.com>
Signed-off-by: Samuel Holland <sam...@sholland.org>
---
 drivers/input/keyboard/sun4i-lradc-keys.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c 
b/drivers/input/keyboard/sun4i-lradc-keys.c
index 4a796bed48ac..a1eb2001c088 100644
--- a/drivers/input/keyboard/sun4i-lradc-keys.c
+++ b/drivers/input/keyboard/sun4i-lradc-keys.c
@@ -22,6 +22,8 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/pm_wakeup.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
@@ -226,8 +228,7 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
 {
        struct sun4i_lradc_data *lradc;
        struct device *dev = &pdev->dev;
-       int i;
-       int error;
+       int error, i, irq;
 
        lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
        if (!lradc)
@@ -272,8 +273,13 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
        if (IS_ERR(lradc->base))
                return PTR_ERR(lradc->base);
 
-       error = devm_request_irq(dev, platform_get_irq(pdev, 0),
-                                sun4i_lradc_irq, 0,
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "Failed to get IRQ\n");
+               return irq;
+       }
+
+       error = devm_request_irq(dev, irq, sun4i_lradc_irq, 0,
                                 "sun4i-a10-lradc-keys", lradc);
        if (error)
                return error;
@@ -282,6 +288,14 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
        if (error)
                return error;
 
+       if (device_property_read_bool(dev, "wakeup-source")) {
+               device_set_wakeup_capable(dev, true);
+
+               error = dev_pm_set_wake_irq(dev, irq);
+               if (error)
+                       dev_warn(dev, "Failed to set wake IRQ\n");
+       }
+
        return 0;
 }
 
-- 
2.26.2