From: Lars-Peter Clausen <lars@metafoo.de>
Date: Wed, 5 Nov 2014 12:35:16 +0000 (+0100)
Subject: tty: xuartps: Add support for setting modem control signals
X-Git-Tag: firefly_0821_release~176^2~2678^2~78
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=19038ad9f08c96dcff870b18af8fd5ae5141dec1;p=firefly-linux-kernel-4.4.55.git
tty: xuartps: Add support for setting modem control signals
Add support for setting the state of the DTR and RTS signals.
Acked-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 200c1af2141b..542bab37e502 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -132,6 +132,15 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
/* Goes in read_status_mask for break detection as the HW doesn't do it*/
#define CDNS_UART_IXR_BRK 0x80000000
+/*
+ * Modem Control register:
+ * The read/write Modem Control register controls the interface with the modem
+ * or data set, or a peripheral device emulating a modem.
+ */
+#define CDNS_UART_MODEMCR_FCM 0x00000020 /* Automatic flow control mode */
+#define CDNS_UART_MODEMCR_RTS 0x00000002 /* Request to send output control */
+#define CDNS_UART_MODEMCR_DTR 0x00000001 /* Data Terminal Ready */
+
/*
* Channel Status Register:
* The channel status register (CSR) is provided to enable the control logic
@@ -915,7 +924,18 @@ static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
- /* N/A */
+ u32 val;
+
+ val = cdns_uart_readl(CDNS_UART_MODEMCR_OFFSET);
+
+ val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR);
+
+ if (mctrl & TIOCM_RTS)
+ val |= CDNS_UART_MODEMCR_RTS;
+ if (mctrl & TIOCM_DTR)
+ val |= CDNS_UART_MODEMCR_DTR;
+
+ cdns_uart_writel(val, CDNS_UART_MODEMCR_OFFSET);
}
#ifdef CONFIG_CONSOLE_POLL