From: Wolfram Sang <wsa@kernel.org>
To: Dinh Nguyen <dinguyen@kernel.org>
Cc: jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com,
mika.westerberg@linux.intel.com, robh+dt@kernel.org,
krzk+dt@kernel.org, linux-i2c@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCHv6 1/2] i2c: designware: introduce a custom scl recovery for SoCFPGA platforms
Date: Wed, 22 Jun 2022 22:07:51 +0200 [thread overview]
Message-ID: <YrN2lxvlP4cWfelY@kunai> (raw)
In-Reply-To: <928b2996-b2e7-d847-0e20-7e19df3cbf03@kernel.org>
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> From the original code, the first mechanism to a recovery is to acquire a
> GPIO for the SCL line and send the 9 SCL pulses, after that, it does a reset
> of the I2C module. For the SOCFPGA part, there is no GPIO line for the SCL,
> thus the I2C module cannot even get a reset. This code allows the function
> to reset the I2C module for SOCFPGA, which is the 2nd part of the recovery
> process.
The second part is totally useless if the client device is holding SDA
low. Which is exactly the situation that recovery tries to fix. As I
said, if you can't control SCL, you don't have recovery.
> > See, this function is named scl_recovery, but there is no SCL involved.
> > This is why I think there is the misunderstanding here.
> >
>
> I understand your point here. Perhaps just call it i2c_socfpga_recovery()?
No. adap->bus_recovery_info should be NULL.
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next prev parent reply other threads:[~2022-06-22 20:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 23:01 [PATCHv6 1/2] i2c: designware: introduce a custom scl recovery for SoCFPGA platforms Dinh Nguyen
2022-06-20 23:01 ` [PATCHv6 2/2] dt-bindings: i2c: dw: Add Intel's SoCFPGA I2C controller Dinh Nguyen
2022-06-21 14:14 ` [PATCHv6 1/2] i2c: designware: introduce a custom scl recovery for SoCFPGA platforms Jarkko Nikula
2022-06-21 21:37 ` Wolfram Sang
2022-06-22 13:45 ` Dinh Nguyen
2022-06-22 20:07 ` Wolfram Sang [this message]
2022-07-12 12:41 ` Dinh Nguyen
2022-07-12 12:52 ` Dinh Nguyen
2022-07-12 13:29 ` Wolfram Sang
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