linux-kernel - [PATCH v2 v2 0/3] Extend dt bindings to support I2C on sifive devices and a fix broken IRQ in polling mode.

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  7 May 2019 20:45:05 +0530
From:   Sagar Shrikant Kadam <sagar.kadam@...ive.com>
To:     robh+dt@...nel.org, mark.rutland@....com, peter@...sgaard.com,
        andrew@...n.ch, palmer@...ive.com, paul.walmsley@...ive.com,
        sagar.kadam@...ive.com, linux-i2c@...r.kernel.org,
        devicetree@...r.kernel.org, linux-riscv@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 v2 0/3] Extend dt bindings to support I2C on sifive devices and a fix broken IRQ in polling mode.

The patch is based on mainline v5.1 and extends DT-bindings for Opencore based I2C device in FU540 
SoC, available on HiFive unleashed board (Rev A00), and also provides a workaround for broken IRQ
which affect I2C polling mode interface on FU540 chipsets. 

The polling mode workaround patch fixes the CPU stall issue, when-ever i2c transfer are initiated.

This workaround checks if it's a FU540 chipset based on device tree information, and check's for open
core's IF(interrupt flag) and TIP flags to break from the polling loop upon completion of transfer.

To test the patch, a PMOD-AD2 sensor is connected to HiFive Unleashed board over J1 connector, and 
appropriate device node is added into board specific device tree as per the information provided in 
dt-bindings in Documentation/devicetree/bindings/i2c/i2c-sifive.txt.
Without this workaround, the CPU stall's infinitely.

Busybox i2c utilities used to verify workaround : i2cdetect, i2cdump, i2cset, i2cget

Patch History:

V0<->V1:
-Incorporate review comments from Andrew
-Extend dt bindings into i2c-ocores.txt instead of adding new file
-Rename SIFIVE_FLAG_POLL to OCORES_FLAG_BROKEN_IRQ

V0:
-Update dt bindings for sifive i2c devices
-Fix broken IRQ affecting i2c polling mode interface.

Sagar Shrikant Kadam (3):
  dt-bindings: i2c: extend existing opencore bindings.
  i2c-ocore: sifive: add support for i2c device on FU540-c000 SoC.
  i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC.

 .../devicetree/bindings/i2c/i2c-ocores.txt         | 20 +++++++++++++
 drivers/i2c/busses/i2c-ocores.c                    | 33 +++++++++++++++++++---
 2 files changed, 49 insertions(+), 4 deletions(-)

-- 
1.9.1

-- 
The information transmitted is intended only for the person or entity to 
which it is addressed and may contain confidential and/or privileged 
material. If you are not the intended recipient of this message please do 
not read, copy, use or disclose this communication and notify the sender 
immediately. It should be noted that any review, retransmission, 
dissemination or other use of, or taking action or reliance upon, this 
information by persons or entities other than the intended recipient is 
prohibited.