lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20180801133512.12276-1-tudor.ambarus@microchip.com>
Date:   Wed, 1 Aug 2018 16:35:10 +0300
From:   Tudor Ambarus <tudor.ambarus@...rochip.com>
To:     <wsa@...-dreams.de>, <linux-i2c@...r.kernel.org>,
        <ludovic.desroches@...rochip.com>, <nicolas.ferre@...rochip.com>,
        <alexandre.belloni@...tlin.com>
CC:     <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <linus.walleij@...aro.org>,
        Tudor Ambarus <tudor.ambarus@...rochip.com>
Subject: [PATCH 0/2] i2c: enable buses to save their clock frequency in adapter

The clock-frequency property is not mandatory for the i2c buses. If it's
not present in the device tree, the buses __usually__ assume it's 100kHZ
(see altera, at91, axxia, etc.). Broadcom uses a 375kHZ default
clock-frequency, so the default clock frequency varies from bus to bus.

There are i2c clients that need to know the bus clock frequency in order to
compute their wake token (see atecc508a i2c client).

The clock-frequency value has to be propagated to the i2c clients, otherwise,
if they will not find the i2c bus clock frequency in the device tree, they
will have to make their own assumption of the clock frequency.

Spare the i2c clients of making wrong assumptions of the i2c bus clock
frequency and enable the buses to save their clock frequency in adapter.

since rfc:
- reword commit messages

Tudor Ambarus (2):
  i2c: enable buses to save their clock frequency in adapter
  i2c: at91: Save the bus clock frequency in adapter

 drivers/i2c/busses/i2c-at91.c | 1 +
 include/linux/i2c.h           | 1 +
 2 files changed, 2 insertions(+)

-- 
2.9.4

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ