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path: root/drivers/usb/renesas_usbhs/fifo.c
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Diffstat (limited to 'drivers/usb/renesas_usbhs/fifo.c')
-rw-r--r--drivers/usb/renesas_usbhs/fifo.c24
1 files changed, 15 insertions, 9 deletions
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index fa126a2b0c33..c0f5c652d272 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -1239,15 +1239,21 @@ static void usbhsf_dma_init_dt(struct device *dev, struct usbhs_fifo *fifo,
{
char name[16];
- snprintf(name, sizeof(name), "tx%d", channel);
- fifo->tx_chan = dma_request_slave_channel_reason(dev, name);
- if (IS_ERR(fifo->tx_chan))
- fifo->tx_chan = NULL;
-
- snprintf(name, sizeof(name), "rx%d", channel);
- fifo->rx_chan = dma_request_slave_channel_reason(dev, name);
- if (IS_ERR(fifo->rx_chan))
- fifo->rx_chan = NULL;
+ /*
+ * To avoid complex handing for DnFIFOs, the driver uses each
+ * DnFIFO as TX or RX direction (not bi-direction).
+ * So, the driver uses odd channels for TX, even channels for RX.
+ */
+ snprintf(name, sizeof(name), "ch%d", channel);
+ if (channel & 1) {
+ fifo->tx_chan = dma_request_slave_channel_reason(dev, name);
+ if (IS_ERR(fifo->tx_chan))
+ fifo->tx_chan = NULL;
+ } else {
+ fifo->rx_chan = dma_request_slave_channel_reason(dev, name);
+ if (IS_ERR(fifo->rx_chan))
+ fifo->rx_chan = NULL;
+ }
}
static void usbhsf_dma_init(struct usbhs_priv *priv, struct usbhs_fifo *fifo,