media: hantro: add PM runtime resume callback

It seems that on i.MX8MQ the power domain controller does not propagate
resets to the VPU cores on resume. Add a callback to allow implementing
manual reset of the VPU cores after ungating the power domain.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/hantro/hantro.h

@@ -56,6 +56,7 @@ struct hantro_codec_ops;
  * @codec:			Supported codecs
  * @codec_ops:			Codec ops.
  * @init:			Initialize hardware.
+ * @runtime_resume:		reenable hardware after power gating
  * @vepu_irq:			encoder interrupt handler
  * @vdpu_irq:			decoder interrupt handler
  * @clk_names:			array of clock names
@@ -71,6 +72,7 @@ struct hantro_variant {
 	unsigned int codec;
 	const struct hantro_codec_ops *codec_ops;
 	int (*init)(struct hantro_dev *vpu);
+	int (*runtime_resume)(struct hantro_dev *vpu);
 	irqreturn_t (*vepu_irq)(int irq, void *priv);
 	irqreturn_t (*vdpu_irq)(int irq, void *priv);
 	const char *clk_names[HANTRO_MAX_CLOCKS];

drivers/staging/media/hantro/hantro_drv.c

@@ -832,9 +832,22 @@ static int hantro_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int hantro_runtime_resume(struct device *dev)
+{
+	struct hantro_dev *vpu = dev_get_drvdata(dev);
+
+	if (vpu->variant->runtime_resume)
+		return vpu->variant->runtime_resume(vpu);
+
+	return 0;
+}
+#endif
+
 static const struct dev_pm_ops hantro_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(NULL, hantro_runtime_resume, NULL)
 };
 
 static struct platform_driver hantro_driver = {