[PATCH v4] Input: sun4i-lradc-keys - Add wakup support

From: Samuel Holland
Date: Thu Nov 18 2021 - 21:54:24 EST


From: Ondrej Jirman <megous@xxxxxxxxxx>

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 <megous@xxxxxxxxxx>
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>

---

Changes since v3:
- Only mark device as wakeup capable if setting the wakeirq succeeds
- An entirely different, but equivalent, DT binding patch was merged,
so there is only one patch left

Changes since v2:
- Dropped unnecessary pr_err in platform_get_irq() error path
- Dropped patch 3 (DT update) as it was merged
- Added Acked-by/Reviewed-by tags

Changes since v1:
- Add requisite DT binding change
- Only add wakeup capability if "wakeup-source" is present
- Warn but do not error out if setting the wake IRQ fails
- Add "wakeup-source" property to PinePhone device tree
---
drivers/input/keyboard/sun4i-lradc-keys.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
index 4a796bed48ac..781f9b053115 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 +273,11 @@ 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)
+ return irq;
+
+ error = devm_request_irq(dev, irq, sun4i_lradc_irq, 0,
"sun4i-a10-lradc-keys", lradc);
if (error)
return error;
@@ -282,6 +286,14 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
if (error)
return error;

+ if (device_property_read_bool(dev, "wakeup-source")) {
+ error = dev_pm_set_wake_irq(dev, irq);
+ if (error)
+ dev_warn(dev, "Failed to set wake IRQ\n");
+ else
+ device_set_wakeup_capable(dev, true);
+ }
+
return 0;
}

--
2.32.0