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serial: pl011: Add device tree support for RX DMA polling 

Add equivalent attributes to those provided in the platform data
for use when RX DMA is enabled.

Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andrew Jackson 2014-11-07 14:14:23 +00:00 committed by Greg Kroah-Hartman
parent 2d3b7d6e7d
commit 98267d33e2
2 changed files with 30 additions and 9 deletions
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5
Documentation/devicetree/bindings/serial/pl011.txt
View File

@ -13,5 +13,10 @@ Optional properties:
- dmas: When present, may have one or two dma channels.
The first one must be named "rx", the second one
must be named "tx".
- auto-poll: Enables polling when using RX DMA.
- poll-rate-ms: Rate at which poll occurs when auto-poll is set,
default 100ms.
- poll-timeout-ms: Poll timeout when auto-poll is set, default
3000ms.
See also bindings/arm/primecell.txt

20
drivers/tty/serial/amba-pl011.c
View File

@ -341,6 +341,7 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
dmaengine_slave_config(chan, &rx_conf);
uap->dmarx.chan = chan;
uap->dmarx.auto_poll_rate = false;
if (plat && plat->dma_rx_poll_enable) {
/* Set poll rate if specified. */
if (plat->dma_rx_poll_rate) {
@ -361,9 +362,24 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
plat->dma_rx_poll_timeout;
else
uap->dmarx.poll_timeout = 3000;
} else
uap->dmarx.auto_poll_rate = false;
} else if (!plat && dev->of_node) {
uap->dmarx.auto_poll_rate = of_property_read_bool(
dev->of_node, "auto-poll");
if (uap->dmarx.auto_poll_rate) {
u32 x;
if (0 == of_property_read_u32(dev->of_node,
"poll-rate-ms", &x))
uap->dmarx.poll_rate = x;
else
uap->dmarx.poll_rate = 100;
if (0 == of_property_read_u32(dev->of_node,
"poll-timeout-ms", &x))
uap->dmarx.poll_timeout = x;
else
uap->dmarx.poll_timeout = 3000;
}
}
dev_info(uap->port.dev, "DMA channel RX %s\n",
dma_chan_name(uap->dmarx.chan));
}