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authorJon Hunter <jon-hunter@ti.com>2011-11-09 16:04:49 +0400
committerKevin Hilman <khilman@ti.com>2011-12-15 04:05:24 +0400
commita9e210e0b7a344c0e44aa6bf6888176bbc635c42 (patch)
treee24466ff2fd9c2f10979d5fce32a870c451448ff /arch/arm/plat-omap
parentc86845db77ce220f77e6645b18800744684946ac (diff)
downloadlinux-a9e210e0b7a344c0e44aa6bf6888176bbc635c42.tar.xz
ARM: OMAP2+: UART: Make the RX_TIMEOUT for DMA configurable for each UART
When using DMA there are two timeouts defined. The first timeout, rx_timeout, is really a polling rate in which software polls the DMA status to see if the DMA has finished. This is necessary for the RX side because we do not know how much data we will receive. The secound timeout, RX_TIMEOUT, is a timeout after which the DMA will be stopped if no more data is received. To make this clearer, rename rx_timeout as rx_poll_rate and rename the function serial_omap_rx_timeout() to serial_omap_rxdma_poll(). The OMAP-Serial driver defines an RX_TIMEOUT of 3 seconds that is used to indicate when the DMA for UART can be stopped if no more data is received. The value is a global definition that is applied to all instances of the UART. Each UART may be used for a different purpose and so the timeout required may differ. Make this value configurable for each UART so that this value can be optimised for power savings. Signed-off-by: Jon Hunter <jon-hunter@ti.com> Signed-off-by: Govindraj.R <govindraj.raja@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes) Signed-off-by: Kevin Hilman <khilman@ti.com>
Diffstat (limited to 'arch/arm/plat-omap')
-rw-r--r--arch/arm/plat-omap/include/plat/omap-serial.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index a740a6c0e104..ea63b2bc761c 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -53,7 +53,6 @@
#define OMAP_UART_DMA_CH_FREE -1
-#define RX_TIMEOUT (3 * HZ)
#define OMAP_MAX_HSUART_PORTS 4
#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
@@ -69,6 +68,7 @@ struct omap_uart_port_info {
unsigned int dma_rx_buf_size;
unsigned int dma_rx_timeout;
unsigned int autosuspend_timeout;
+ unsigned int dma_rx_poll_rate;
int (*get_context_loss_count)(struct device *);
void (*set_forceidle)(struct platform_device *);
@@ -98,6 +98,7 @@ struct uart_omap_dma {
/* timer to poll activity on rx dma */
struct timer_list rx_timer;
unsigned int rx_buf_size;
+ unsigned int rx_poll_rate;
unsigned int rx_timeout;
};