[PATCH 4.19 172/220] mfd: ti_am335x_tscadc: Keep ADC interface on if child is wakeup capable

Greg Kroah-Hartman
2019-11-22T11:06:02Z

From: Vignesh R <vigneshr@ti.com>

[ Upstream commit c974ac771479327b5424f60d58845e31daddadea ]

If a child device like touchscreen is wakeup capable, then keep ADC
interface on, so that a touching resistive screen will generate wakeup
event to the system.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mfd/ti_am335x_tscadc.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index fe8d335a4d74d..4660ad90ef556 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -295,11 +295,24 @@ static int ti_tscadc_remove(struct platform_device *pdev)
return 0;
}

+static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data)
+{
+ return device_may_wakeup(dev);
+}
+
static int __maybe_unused tscadc_suspend(struct device *dev)
{
struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);

regmap_write(tscadc->regmap, REG_SE, 0x00);
+ if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) {
+ u32 ctrl;
+
+ regmap_read(tscadc->regmap, REG_CTRL, &ctrl);
+ ctrl &= ~(CNTRLREG_POWERDOWN);
+ ctrl |= CNTRLREG_TSCSSENB;
+ regmap_write(tscadc->regmap, REG_CTRL, ctrl);
+ }
pm_runtime_put_sync(dev);

return 0;
--
2.20.1