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>

diff --git a/Documentation/devicetree/bindings/serial/pl011.txt b/Documentation/devicetree/bindings/serial/pl011.txt
index 5d2e840..0e05340 100644 (file)
--- 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 d984a97..8d94c19 100644 (file)
--- 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));
        }