Add runtime and system sleep power management operations to the RZ DMAC
driver. This enables proper handling of suspend and resume sequences,
including device reset and channel re-initialization, preparing the driver
for power state transitions.
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
---
drivers/dma/sh/rz-dmac.c | 47 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index 4ab6076f5499e..d849e313a7f79 100644
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -437,6 +437,24 @@ static int rz_dmac_xfer_desc(struct rz_dmac_chan *chan)
* DMA engine operations
*/
+static int rz_dmac_chan_init_all(struct rz_dmac *dmac)
+{
+ unsigned int i;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(dmac->dev);
+ if (ret < 0)
+ return ret;
+
+ rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_0_7_COMMON_BASE + DCTRL);
+ rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_8_15_COMMON_BASE + DCTRL);
+
+ for (i = 0; i < dmac->n_channels; i++)
+ rz_dmac_ch_writel(&dmac->channels[i], CHCTRL_DEFAULT, CHCTRL, 1);
+
+ return pm_runtime_put_sync(dmac->dev);
+}
+
static int rz_dmac_alloc_chan_resources(struct dma_chan *chan)
{
struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
@@ -1070,6 +1088,34 @@ static void rz_dmac_remove(struct platform_device *pdev)
platform_device_put(dmac->icu.pdev);
}
+static int rz_dmac_suspend(struct device *dev)
+{
+ struct rz_dmac *dmac = dev_get_drvdata(dev);
+
+ return reset_control_assert(dmac->rstc);
+}
+
+static int rz_dmac_resume(struct device *dev)
+{
+ struct rz_dmac *dmac = dev_get_drvdata(dev);
+ int ret;
+
+ ret = reset_control_deassert(dmac->rstc);
+ if (ret)
+ return ret;
+
+ return rz_dmac_chan_init_all(dmac);
+}
+
+static const struct dev_pm_ops rz_dmac_pm_ops = {
+ /*
+ * TODO for system sleep/resume:
+ * - Wait for the current transfer to complete and stop the device,
+ * - Resume transfers, if any.
+ */
+ SYSTEM_SLEEP_PM_OPS(rz_dmac_suspend, rz_dmac_resume)
+};
+
static const struct of_device_id of_rz_dmac_match[] = {
{ .compatible = "renesas,r9a09g057-dmac", },
{ .compatible = "renesas,rz-dmac", },
@@ -1079,6 +1125,7 @@ MODULE_DEVICE_TABLE(of, of_rz_dmac_match);
static struct platform_driver rz_dmac_driver = {
.driver = {
+ .pm = pm_sleep_ptr(&rz_dmac_pm_ops),
.name = "rz-dmac",
.of_match_table = of_rz_dmac_match,
},
--
2.43.0
