dmaengine: xilinx_dpdma: stop using slave_id field

The display driver wants to pass a custom flag to the DMA engine driver,
which it started doing by using the slave_id field that was traditionally
used for a different purpose.

As there is no longer a correct use for the slave_id field, it should
really be removed, and the remaining users changed over to something
different.

The new mechanism for passing nonstandard settings is using the
.peripheral_config field, so use that to pass a newly defined structure
here, making it clear that this will not work in portable drivers.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211122222203.4103644-10-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
index ce5c66e6897d2ebb98563a760f3c048b4402a167..b0f4948b00a54f8bbd0cf70c17bb585d59ad9f91 100644 (file)
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -12,6 +12,7 @@
 #include <linux/clk.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
+#include <linux/dma/xilinx_dpdma.h>
 #include <linux/dmaengine.h>
 #include <linux/dmapool.h>
 #include <linux/interrupt.h>
@@ -1273,6 +1274,7 @@ static int xilinx_dpdma_config(struct dma_chan *dchan,
                               struct dma_slave_config *config)
 {
        struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+       struct xilinx_dpdma_peripheral_config *pconfig;
        unsigned long flags;
 
        /*
@@ -1282,15 +1284,18 @@ static int xilinx_dpdma_config(struct dma_chan *dchan,
         * fixed both on the DPDMA side and on the DP controller side.
         */
 
-       spin_lock_irqsave(&chan->lock, flags);
-
        /*
-        * Abuse the slave_id to indicate that the channel is part of a video
-        * group.
+        * Use the peripheral_config to indicate that the channel is part
+        * of a video group. This requires matching use of the custom
+        * structure in each driver.
         */
-       if (chan->id <= ZYNQMP_DPDMA_VIDEO2)
-               chan->video_group = config->slave_id != 0;
+       pconfig = config->peripheral_config;
+       if (WARN_ON(pconfig && config->peripheral_size != sizeof(*pconfig)))
+               return -EINVAL;
 
+       spin_lock_irqsave(&chan->lock, flags);
+       if (chan->id <= ZYNQMP_DPDMA_VIDEO2 && pconfig)
+               chan->video_group = pconfig->video_group;
        spin_unlock_irqrestore(&chan->lock, flags);
 
        return 0;

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index ff2b308d86517d213b77502c4f555f480102a79b..11c409cbc88e78e0e6de7723d09d30219c3f3c6a 100644 (file)
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -24,6 +24,7 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dma/xilinx_dpdma.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/module.h>
@@ -1058,14 +1059,18 @@ static void zynqmp_disp_layer_set_format(struct zynqmp_disp_layer *layer,
        zynqmp_disp_avbuf_set_format(layer->disp, layer, layer->disp_fmt);
 
        /*
-        * Set slave_id for each DMA channel to indicate they're part of a
+        * Set pconfig for each DMA channel to indicate they're part of a
         * video group.
         */
        for (i = 0; i < info->num_planes; i++) {
                struct zynqmp_disp_layer_dma *dma = &layer->dmas[i];
+               struct xilinx_dpdma_peripheral_config pconfig = {
+                       .video_group = true,
+               };
                struct dma_slave_config config = {
                        .direction = DMA_MEM_TO_DEV,
-                       .slave_id = 1,
+                       .peripheral_config = &pconfig,
+                       .peripheral_size = sizeof(pconfig),
                };
 
                dmaengine_slave_config(dma->chan, &config);

diff --git a/include/linux/dma/xilinx_dpdma.h b/include/linux/dma/xilinx_dpdma.h
new file mode 100644 (file)
index 0000000..83a1377
--- /dev/null
+++ b/include/linux/dma/xilinx_dpdma.h
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef __LINUX_DMA_XILINX_DPDMA_H
+#define __LINUX_DMA_XILINX_DPDMA_H
+
+#include <linux/types.h>
+
+struct xilinx_dpdma_peripheral_config {
+       bool video_group;
+};
+
+#endif /* __LINUX_DMA_XILINX_DPDMA_H */