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NVIDIA: SAUCE: dmaengine: tegra: Get slave channel based on DT

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BugLink: https://bugs.launchpad.net/bugs/2072591

Add option for DMA clients to provide channel number and
stream-id in device tree. dma-cells need to be increased to 3
for accommodating additional details.

This is required in a virtualized environment where all channels
and clients are not allowed use the same stream id.

The channel number read from device tree is modified to match with
the hardware channel number in the driver. This is done to avoid
ABI breakage. Otherwise, it would require updating all the device
trees that provide this information

http://nvbugs/200761027

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Abhilash G <abhilashg@nvidia.com>
Tested-by: Abhilash G <abhilashg@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jacob Martin <jacob.martin@canonical.com>
Acked-by: Noah Wager <noah.wager@canonical.com>
Signed-off-by: Noah Wager <noah.wager@canonical.com>
This commit is contained in:
Akhil R
2022-11-04 15:47:29 +05:30
committed by Noah Wager
parent ab20bafd58
commit 38d7bf773f
1 changed files with 61 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/dma/tegra186-gpc-dma.c
+61 -17
View File
@@ -1288,10 +1288,54 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
vchan_free_chan_resources(&tdc->vc);
}
static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
static int tegra_dma_program_sid(struct tegra_dma_channel *tdc, int stream_id)
{
unsigned int reg_val = tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID0_MASK);
reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID1_MASK);
reg_val |= FIELD_PREP(TEGRA_GPCDMA_MCSEQ_STREAM_ID0_MASK, stream_id);
reg_val |= FIELD_PREP(TEGRA_GPCDMA_MCSEQ_STREAM_ID1_MASK, stream_id);
tdc_write(tdc, TEGRA_GPCDMA_CHAN_MCSEQ, reg_val);
return 0;
}
static struct dma_chan *tegra_dma_get_slave_channel(struct tegra_dma *tdma,
struct of_phandle_args *dma_spec)
{
struct tegra_dma_channel *tdc;
struct dma_chan *chan;
unsigned int chan_id;
chan_id = dma_spec->args[1];
if (chan_id > hweight_long(tdma->chan_mask))
return NULL;
/* Adjust the chan_id as channel id from
* DT is starting from an offset
*/
chan_id += (ffs(tdma->chan_mask) - 1);
chan = dma_get_slave_channel(&tdma->channels[chan_id].vc.chan);
if (!chan)
return NULL;
tdc = to_tegra_dma_chan(chan);
tdc->slave_id = dma_spec->args[0];
tdc->stream_id = dma_spec->args[2];
/* Re-program stream-id for this channel */
tegra_dma_program_sid(tdc, tdc->stream_id);
return chan;
}
static struct dma_chan *tegra_dma_get_any_slave_channel(struct tegra_dma *tdma,
struct of_phandle_args *dma_spec)
{
struct tegra_dma *tdma = ofdma->of_dma_data;
struct tegra_dma_channel *tdc;
struct dma_chan *chan;
@@ -1305,6 +1349,20 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
return chan;
}
static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct tegra_dma *tdma = ofdma->of_dma_data;
/* Check if channel no and stream-id are specified in devicetree.
* Get any channel and program default stream-id otherwise
*/
if (dma_spec->args_count == 3)
return tegra_dma_get_slave_channel(tdma, dma_spec);
return tegra_dma_get_any_slave_channel(tdma, dma_spec);
}
static const struct tegra_dma_chip_data tegra186_dma_chip_data = {
.nr_channels = 32,
.channel_reg_size = SZ_64K,
@@ -1344,20 +1402,6 @@ static const struct of_device_id tegra_dma_of_match[] = {
};
MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
static int tegra_dma_program_sid(struct tegra_dma_channel *tdc, int stream_id)
{
unsigned int reg_val = tdc_read(tdc, TEGRA_GPCDMA_CHAN_MCSEQ);
reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID0_MASK);
reg_val &= ~(TEGRA_GPCDMA_MCSEQ_STREAM_ID1_MASK);
reg_val |= FIELD_PREP(TEGRA_GPCDMA_MCSEQ_STREAM_ID0_MASK, stream_id);
reg_val |= FIELD_PREP(TEGRA_GPCDMA_MCSEQ_STREAM_ID1_MASK, stream_id);
tdc_write(tdc, TEGRA_GPCDMA_CHAN_MCSEQ, reg_val);
return 0;
}
static int tegra_dma_probe(struct platform_device *pdev)
{
const struct tegra_dma_chip_data *cdata = NULL;