Re: [PATCH V2 4/5] usb: serial: f81534: add H/W disable port support
From: Johan Hovold
Date: Tue Jan 09 2018 - 06:30:10 EST
On Thu, Jan 04, 2018 at 10:29:20AM +0800, Ji-Ze Hong (Peter Hong) wrote:
> The F81532/534 can be disable port by manufacturer with
> following H/W design.
> 1: Connect DCD/DSR/CTS/RI pin to ground.
> 2: Connect RX pin to ground.
>
> In driver, we'll implements some detect method likes following:
> 1: Read MSR.
> 2: Turn MCR LOOP bit on, off and read LSR after delay with 60ms.
> It'll contain BREAK status in LSR.
>
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx>
> ---
> V2:
> 1: f81534_check_port_hw_disabled() change return type from int to bool.
> 2: Add help function f81534_set_phy_port_register() /
> f81534_get_phy_port_register() for f81534_check_port_hw_disabled()
> to read register without port.
> 3: Re-write f81534_calc_num_ports() & f81534_attach() to reduce the
> f81534_check_port_hw_disabled() repeatedly called.
This looks good, but please split up the config-data-readout refactoring
and f81534_check_port_hw_disabled() changes in two patches.
Johan