usb: renesas_usbhs: Revise the binding document about the dma-names
Since the DT should describe the hardware (not the driver limitation),
This patch revises the binding document about the dma-names to change
simple numbering as "ch%d" instead of "tx<n>" and "rx<n>".
Also this patch fixes the actual code of renesas_usbhs driver to handle
the new dma-names.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/Documentation/devicetree/bindings/usb/renesas_usbhs.txt b/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
index dc2a18f..ddbe304 100644
--- a/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
+++ b/Documentation/devicetree/bindings/usb/renesas_usbhs.txt
@@ -15,10 +15,8 @@
- phys: phandle + phy specifier pair
- phy-names: must be "usb"
- dmas: Must contain a list of references to DMA specifiers.
- - dma-names : Must contain a list of DMA names:
- - tx0 ... tx<n>
- - rx0 ... rx<n>
- - This <n> means DnFIFO in USBHS module.
+ - dma-names : named "ch%d", where %d is the channel number ranging from zero
+ to the number of channels (DnFIFOs) minus one.
Example:
usbhs: usb@e6590000 {
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 8597cf9..bc23b4a 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -1227,15 +1227,21 @@
{
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,