[1/2] dmaengine: sh: rz-dmac: Add device_synchronize callback

Commit Message

Biju Das July 19, 2022, 2:48 p.m. UTC

Some on-chip peripheral modules(for eg:- rspi) on RZ/G2L SoC
use the same signal for both interrupt and DMA transfer requests.
The signal works as a DMA transfer request signal by setting
DMARS, and subsequent interrupt requests to the interrupt controller
are masked.

We can enable the interrupt by clearing the DMARS.

This patch adds device_synchronize callback for clearing
DMARS and thereby allowing DMA consumers to switch to
interrupt mode.

Signed-off-by: Biju Das <[e-mail]>
---
 drivers/dma/sh/rz-dmac.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index ee2872e7d64c..675e6d5319d7 100644
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -630,6 +630,14 @@  static void rz_dmac_virt_desc_free(struct virt_dma_desc *vd)
 	 */
 }
 
+static void rz_dmac_device_synchronize(struct dma_chan *chan)
+{
+	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
+	struct rz_dmac *dmac = to_rz_dmac(chan->device);
+
+	rz_dmac_set_dmars_register(dmac, channel->index, 0);
+}
+
 /*
  * -----------------------------------------------------------------------------
  * IRQ handling
@@ -909,6 +917,7 @@  static int rz_dmac_probe(struct platform_device *pdev)
 	engine->device_config = rz_dmac_config;
 	engine->device_terminate_all = rz_dmac_terminate_all;
 	engine->device_issue_pending = rz_dmac_issue_pending;
+	engine->device_synchronize = rz_dmac_device_synchronize;
 
 	engine->copy_align = DMAENGINE_ALIGN_1_BYTE;
 	dma_set_max_seg_size(engine->dev, U32_MAX);