On Fri, Sep 29, 2017 at 03:08:54PM +0200, Ulrich Hecht wrote:
> HSCIF has facilities that allow moving the RX sampling point by between
> -8 and 7 sampling cycles (one sampling cycles equals 1/15 of a bit
> by default) to improve the error margin in case of slightly mismatched
> bit rates between sender and receiver.
>
> This patch allows changing the default (0, meaning center) using the
> sysfs attribute "rx_sampling_point".
>
> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@xxxxxxxxx>
> ---
> drivers/tty/serial/sh-sci.c | 62 +++++++++++++++++++++++++++++++++++++++++++--
> drivers/tty/serial/sh-sci.h | 4 +++
> 2 files changed, 64 insertions(+), 2 deletions(-)
Adding random sysfs files for random serial ports isn't good, especially
if you do not document them in Documentation/ABI.
I don't want to see this, but if you write sysfs files in the future,
here's some review comments:
> +static DEVICE_ATTR(rx_sampling_point, 0644,
> + rx_sampling_point_show,
> + rx_sampling_point_store);
DEVICE_ATTR_RW()
> + if (port->port.type == PORT_HSCIF) {
> + sysfs_remove_file(&dev->dev.kobj,
> + &dev_attr_rx_sampling_point.attr);
No driver code should ever call sysfs functions, this should be either:
device_create_file()
or properly use an attribute group.
thanks,
greg k-h
