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[176.247.78.218]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47f85c532d4sm45965701f8f.22.2026.07.27.01.07.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jul 2026 01:07:10 -0700 (PDT) Message-ID: <7d9d7bfac46269c1a66b6aff25a28d12354cc3c3.camel@baylibre.com> Subject: Re: [PATCH v4] i2c: Add FTDI FT4222H USB I2C adapter From: Francesco Lavra To: Andi Shyti , linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Date: Mon, 27 Jul 2026 10:07:08 +0200 In-Reply-To: References: <20260225112046.2394231-1-flavra@baylibre.com> Organization: BayLibre Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.4-2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Another friendly ping On Thu, 2026-04-30 at 17:40 +0200, Francesco Lavra wrote: > Friendly ping >=20 > On Wed, 2026-02-25 at 12:20 +0100, Francesco Lavra wrote: > > FT4222H exports a USB interface to operate as I2C bus master when set > > up > > (via the DCNF pins) in configuration mode 0 or 3. > > The USB communication protocol implemented by the FT4222 chip is not > > publicly documented, therefore the name assigned to the various defines > > used in the USB communication code is a semi-educated guess after > > sniffing > > USB traffic generated with the FTDI FT4222 userspace library. > >=20 > > Signed-off-by: Francesco Lavra >=20