[PATCH 01/14] serial: tegra: add internal loopback functionality
From: Krishna Yarlagadda <hidden>
Date: 2019-08-12 11:28:44
Also in:
linux-serial, linux-tegra, lkml
Subsystem:
tegra serial driver, the rest, tty layer and serial drivers · Maintainers:
Laxman Dewangan, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Andreas Abel <redacted> Add the internal loopback functionality that can be enabled with TIOCM_LOOP. Signed-off-by: Andreas Abel <redacted> Signed-off-by: Krishna Yarlagadda <redacted> --- drivers/tty/serial/serial-tegra.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index d5269aa..19f4c24 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c@@ -4,7 +4,7 @@ * * High-speed serial driver for NVIDIA Tegra SoCs * - * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved. + * Copyright (c) 2012-2019, NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan <ldewangan@nvidia.com> */
@@ -192,16 +192,34 @@ static void set_dtr(struct tegra_uart_port *tup, bool active) } } +static void set_loopbk(struct tegra_uart_port *tup, bool active) +{ + unsigned long mcr = tup->mcr_shadow; + + if (active) + mcr |= UART_MCR_LOOP; + else + mcr &= ~UART_MCR_LOOP; + + if (mcr != tup->mcr_shadow) { + tegra_uart_write(tup, mcr, UART_MCR); + tup->mcr_shadow = mcr; + } +} + static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl) { struct tegra_uart_port *tup = to_tegra_uport(u); - int dtr_enable; + int enable; tup->rts_active = !!(mctrl & TIOCM_RTS); set_rts(tup, tup->rts_active); - dtr_enable = !!(mctrl & TIOCM_DTR); - set_dtr(tup, dtr_enable); + enable = !!(mctrl & TIOCM_DTR); + set_dtr(tup, enable); + + enable = !!(mctrl & TIOCM_LOOP); + set_loopbk(tup, enable); } static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
--
2.7.4