From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH 0/2] serial: 8250_dw: add fractional divisor support Date: Mon, 02 Jul 2018 13:18:42 +0300 Message-ID: References: <20180702180428.331b36c5@xhacker.debian> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180702180428.331b36c5@xhacker.debian> Sender: linux-kernel-owner@vger.kernel.org To: Jisheng Zhang , Greg Kroah-Hartman , Jiri Slaby Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-serial@vger.kernel.org On Mon, 2018-07-02 at 18:04 +0800, Jisheng Zhang wrote: > For Synopsys DesignWare 8250 uart which version >= 4.00a, there's a > valid divisor latch fraction register. The fractional divisor width is > 4bits ~ 6bits. > There are several serial IPs that have fractional divider built-in. None is using any specific hooks. Why do you need in your case, esp. taking into consideration that we have a custom ->set_termios() callback? > patch1 introduces necessary hooks to 8250 core. > patch2 implement the fractional divisor support for Synopsys DW 8250. > > Jisheng Zhang (2): > serial: 8250: introduce get_divisor() and set_divisor() hook > serial: 8250_dw: add fractional divisor support > > drivers/tty/serial/8250/8250_core.c | 4 +++ > drivers/tty/serial/8250/8250_dw.c | 54 > +++++++++++++++++++++++++++++ > drivers/tty/serial/8250/8250_port.c | 8 +++++ > include/linux/serial_8250.h | 7 ++++ > 4 files changed, 73 insertions(+) > -- Andy Shevchenko Intel Finland Oy