From b543c301c2c5fbf24ed160a0c227122f09f38e5f Mon Sep 17 00:00:00 2001 From: Robert Baldyga Date: Wed, 10 Dec 2014 12:49:27 +0100 Subject: serial: samsung: add DMA support for RX Add RX DMA transfers support for samsung serial driver. It's enabled when DMA controller for RX channel is specified in device-tree. DMA transactions are started when number of bytes in RX FIFO reaches trigger level, otherwise PIO mode is used. DMA transfer size is always PAGE_SIZE which can cause large latency when smaller data amount is transferred, so we always terminate DMA transaction on RX timeout interrupt. Timeout interval is set to 64 frame times. Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski. Signed-off-by: Robert Baldyga Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/samsung.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/tty/serial/samsung.h') diff --git a/drivers/tty/serial/samsung.h b/drivers/tty/serial/samsung.h index e60011c591e8..d275032aa68d 100644 --- a/drivers/tty/serial/samsung.h +++ b/drivers/tty/serial/samsung.h @@ -88,6 +88,7 @@ struct s3c24xx_uart_port { unsigned int tx_in_progress; unsigned int tx_mode; + unsigned int rx_mode; struct s3c24xx_uart_info *info; struct clk *clk; -- cgit v1.2.1