diff options
| author | Andreas Abel <aabel@nvidia.com> | 2019-08-12 16:58:10 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 12:43:54 +0200 |
| commit | 6300b140c29fdcd45e84fb551196a6e38dadddcc (patch) | |
| tree | 2885d023ddd0f2c0583e20f40bfa318f73974b62 /drivers/tty | |
| parent | d2ace81bf902a9f11d52e59e5d232d2255a0e353 (diff) | |
serial: tegra: add internal loopback functionality
Add the internal loopback functionality that can be enabled with
TIOCM_LOOP.
Signed-off-by: Andreas Abel <aabel@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/1565609303-27000-2-git-send-email-kyarlagadda@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/serial-tegra.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index 76ffbc7826ae..83cc8dca58d4 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) |