From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
This series adds MCTRL_GPIO support to 8250 driver. In order to do so
following changes had to be made:
* read/write calls to MCR register were put into new routines:
serial8250_out_MCR() and serial8250_in_MCR(). These new routines
now access both UARTs MCR register as also read/write GPIO pins
for RTS/DTR
* MCTRL_GPIO framwork had routines to set MCR and to read MSR, reading
MCR related GPIO signals was missing, hence mctrl_gpio_get_outputs()
routine was implemented
Issues:
* when 8250 driver is used with GPIOLIB disabled, mctrl_gpio_init()
return errors. This would render console unusable. Solution: ignore
mctrl_gpio_init() return value, if GPIOLIB is disabled.
* when 8250 driver is used as console, it sets DTR signale before
MCTL_GPIO API is initialized. This produces a kernel crash. Solution:
return from API calls, if mctrl_gpio structure is NULL i.e. not
initialized. Also rework mctrl_gpio_init() to alwasy return NULL in case
of an error.
Yegor Yefremov (4):
tty/serial/8250: make UART_MCR register access consistent
serial: mctrl_gpio: add modem control read routine
serial: mctrl_gpio: enable API usage only for initialized mctrl_gpios
struct
tty/serial/8250: use mctrl_gpio helpers
Documentation/devicetree/bindings/serial/8250.txt | 19 ++++++++
drivers/tty/serial/8250/8250.h | 43 ++++++++++++++++++
drivers/tty/serial/8250/8250_core.c | 4 ++
drivers/tty/serial/8250/8250_omap.c | 35 ++++++++-------
drivers/tty/serial/8250/8250_port.c | 54 ++++++++++++-----------
drivers/tty/serial/8250/Kconfig | 1 +
drivers/tty/serial/serial_mctrl_gpio.c | 42 ++++++++++++++++--
drivers/tty/serial/serial_mctrl_gpio.h | 17 ++++++-
include/linux/serial_8250.h | 1 +
9 files changed, 171 insertions(+), 45 deletions(-)
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
