mfd: ti_am335x_tscadc: Keep ADC interface on if child is wakeup capable

[ 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>

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index fe8d335a4d74dabcd2b012b9462a68aa0378d720..4660ad90ef556e52b57fd28bda959f2104937ba4 100644 (file)
--- 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;