From: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
To: linux-kernel@vger.kernel.org
Cc: linux-riscv@lists.infradead.org, linux-i2c@vger.kernel.org,
peter@korsgaard.com, andrew@lunn.ch, paul.walmsley@sifive.com,
palmer@dabbelt.com, aou@eecs.berkeley.edu,
Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Subject: [PATCH v3 0/1] fix i2c polling mode workaround for FU540-C000 SoC
Date: Thu, 15 Oct 2020 07:08:26 -0700 [thread overview]
Message-ID: <1602770907-61852-1-git-send-email-sagar.kadam@sifive.com> (raw)
The polling mode workaround for the FU540-C000 on HiFive Unleashed A00
board was added earlier. The logic for this seems to work only in case
the interrupt property was missing/not added into the i2c0 device node.
Here we address this issue by identifying the SOC based on compatibility
string and set the master xfer's to polling mode if it's the FU540-C000
SoC.
The fix has been tested on Linux 5.9.0-rc8 with a PMOD based RTCC sensor
connected to I2C pins J1 header of the board. Log for reference
# uname -a
Linux buildroot 5.9.0-rc8-00001-g9da7791 #1 SMP Fri Oct 9 07:56:13 PDT 2020 riscv64 GNU/Linux
# i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 6f
70: -- -- -- -- -- -- -- --
# i2cget 0 0x57 0 b -y
0xa5
# i2cset 0 0x57 0 0x9f b -y
# i2cget 0 0x57 0 b -y
0x9f
# i2cget 0 0x57 1 b -y
0xff
# i2cset 0 0x57 1 0xa9 b -y
# i2cget 0 0x57 1 b -y
0xa9
# i2cget 0 0x6f 0x20 b -y
0x98
# i2cset 0 0x6f 0x20 0xa5 b -y
# i2cget 0 0x6f 0x20 b -y
0xa5
# i2cget 0 0x6f 0x5f b -y
0x55
# i2cset 0 0x6f 0x5f 0x5a b -y
# i2cget 0 0x6f 0x5f b -y
0x5a
#
Without the fix here, it's observed that "i2cdetect -y 0"
turns the system unresponsive, with CPU stall messages.
Patch History:
===============================
V3:
-Rectified typo as suggested here:
https://lkml.org/lkml/2020/10/9/902
V2:
-Incorporated changes as suggested by Peter Kosgaard
https://lkml.org/lkml/2020/10/8/663
V1: Base version
Sagar Shrikant Kadam (1):
i2c: ocores: fix polling mode workaround on FU540-C000 SoC
drivers/i2c/busses/i2c-ocores.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
--
2.7.4
next reply other threads:[~2020-10-15 14:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-15 14:08 Sagar Shrikant Kadam [this message]
2020-10-15 14:08 ` [PATCH v3 1/1] i2c: ocores: fix polling mode workaround on FU540-C000 SoC Sagar Shrikant Kadam
2020-10-15 14:49 ` Peter Korsgaard
2020-10-16 4:23 ` Sagar Kadam
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1602770907-61852-1-git-send-email-sagar.kadam@sifive.com \
--to=sagar.kadam@sifive.com \
--cc=andrew@lunn.ch \
--cc=aou@eecs.berkeley.edu \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=peter@korsgaard.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).