[PATCH 5/5] serial: pl011: Add device tree support for RX DMA polling

From: Andrew Jackson
Date: Fri Nov 07 2014 - 09:16:18 EST



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

Signed-off-by: Andrew Jackson <Andrew.Jackson@xxxxxxx>
---
Documentation/devicetree/bindings/serial/pl011.txt | 19 ++++++++++------
drivers/tty/serial/amba-pl011.c | 22 +++++++++++++++++--
2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/serial/pl011.txt b/Documentation/devicetree/bindings/serial/pl011.txt
index 5d2e840..0e05340 100644
--- a/Documentation/devicetree/bindings/serial/pl011.txt
+++ b/Documentation/devicetree/bindings/serial/pl011.txt
@@ -6,12 +6,17 @@ Required properties:
- interrupts: exactly one interrupt specifier

Optional properties:
-- pinctrl: When present, must have one state named "sleep"
- and one state named "default"
-- clocks: When present, must refer to exactly one clock named
- "apb_pclk"
-- dmas: When present, may have one or two dma channels.
- The first one must be named "rx", the second one
- must be named "tx".
+- pinctrl: When present, must have one state named "sleep"
+ and one state named "default"
+- clocks: When present, must refer to exactly one clock named
+ "apb_pclk"
+- 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
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 79b9c93..767711b 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -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));
}
--
1.7.1

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