[PATCH v2 08/11] dmaengine: dw-axi-dmac: support dma-channel-mask

Jisheng Zhang
2023-04-15T10:49:09Z

Some dma channels may not be available, so we need to tell the driver
the available dma channels, use the general dt binding
"dma-channel-mask" for this purpose.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
.../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 19 +++++++++++++++++++
drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 1 +
2 files changed, 20 insertions(+)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index edb1c089a8eb..a6e46cb66000 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -216,6 +216,8 @@ static void axi_dma_hw_init(struct axi_dma_chip *chip)
u32 i;

for (i = 0; i < chip->dw->hdata->nr_channels; i++) {
+ if (!(chip->dw->hdata->channels_mask & (1 << i)))
+ continue;
axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
axi_chan_disable(&chip->dw->chan[i]);
}
@@ -1390,6 +1392,14 @@ static int parse_device_properties(struct axi_dma_chip *chip)
chip->dw->hdata->axi_rw_burst_len = tmp;
}

+ /*
+ * Use all channels if there's no dma-channel-mask property
+ */
+ ret = device_property_read_u32(dev, "dma-channel-mask", &tmp);
+ if (ret)
+ tmp = GENMASK(chip->dw->hdata->nr_channels - 1, 0);
+ chip->dw->hdata->channels_mask = tmp;
+
chip->dw->hdata->perch_irq = device_property_read_bool(dev, "snps,perch_irq");

return 0;
@@ -1450,6 +1460,10 @@ static int dw_probe(struct platform_device *pdev)
if (hdata->perch_irq) {
char irqname[8];
for (i = 0; i < hdata->nr_channels; i++) {
+ if (!(hdata->channels_mask & (1 << i))) {
+ dw->chan[i].irq = -1;
+ continue;
+ }
snprintf(irqname, sizeof(irqname), "ch%u", i);
dw->chan[i].irq = platform_get_irq_byname(pdev, irqname);
if (dw->chan[i].irq < 0)
@@ -1475,6 +1489,9 @@ static int dw_probe(struct platform_device *pdev)
for (i = 0; i < hdata->nr_channels; i++) {
struct axi_dma_chan *chan = &dw->chan[i];

+ if (!(hdata->channels_mask & (1 << i)))
+ continue;
+
chan->chip = chip;
chan->id = i;
chan->chan_regs = chip->regs + COMMON_REG_LEN + i * CHAN_REG_LEN;
@@ -1572,6 +1589,8 @@ static int dw_remove(struct platform_device *pdev)
clk_prepare_enable(chip->core_clk);
axi_dma_irq_disable(chip);
for (i = 0; i < dw->hdata->nr_channels; i++) {
+ if (!(dw->hdata->channels_mask & (1 << i)))
+ continue;
axi_chan_disable(&chip->dw->chan[i]);
axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
}
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index 83ac839b4394..f57961620d2d 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -30,6 +30,7 @@ struct dw_axi_dma_hcfg {
u32 priority[DMAC_MAX_CHANNELS];
/* maximum supported axi burst length */
u32 axi_rw_burst_len;
+ u32 channels_mask;
/* Register map for DMAX_NUM_CHANNELS <= 8 */
bool reg_map_8_channels;
bool restrict_axi_burst_len;
--
2.39.2