linux-kernel - RE: [PATCH 1/6] i2c: tegra: Add support for Tegra234 I2C

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

Message-ID: <DM5PR12MB1850237ECA6C115AD776635EC0599@DM5PR12MB1850.namprd12.prod.outlook.com>
Date:   Wed, 19 Jan 2022 08:20:36 +0000
From:   Akhil R <akhilrajeev@...dia.com>
To:     Dmitry Osipenko <digetx@...il.com>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "thierry.reding@...il.com" <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mikko Perttunen <mperttunen@...dia.com>,
        Laxman Dewangan <ldewangan@...dia.com>,
        "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-tegra@...r.kernel.org" <linux-tegra@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Petlozu Pravareshwar <petlozup@...dia.com>
Subject: RE: [PATCH 1/6] i2c: tegra: Add support for Tegra234 I2C

> 13.01.2022 16:30, Akhil R пишет:
> > +static const struct tegra_i2c_hw_feature tegra234_i2c_hw = {
> > +     .has_continue_xfer_support = true,
> > +     .has_per_pkt_xfer_complete_irq = true,
> > +     .clk_divisor_hs_mode = 0x2,
> > +     .clk_divisor_std_mode = 0x4f,
> > +     .clk_divisor_fast_mode = 0x58,
> > +     .clk_divisor_fast_plus_mode = 0x24,
> > +     .has_config_load_reg = true,
> > +     .has_multi_master_mode = true,
> > +     .has_slcg_override_reg = true,
> > +     .has_mst_fifo = true,
> > +     .quirks = &tegra194_i2c_quirks,
> > +     .supports_bus_clear = true,
> > +     .has_apb_dma = false,
> > +     .tlow_std_mode = 0x8,
> > +     .thigh_std_mode = 0x7,
> > +     .tlow_fast_fastplus_mode = 0x1,
> > +     .thigh_fast_fastplus_mode = 0x1,
> > +     .setup_hold_time_std_mode = 0x08080808,
> > +     .setup_hold_time_fast_fast_plus_mode = 0x02020202,
> > +     .setup_hold_time_hs_mode = 0x090909,
> > +     .has_interface_timing_reg = true, };
> 
> Why tegra194_i2c_hw can't be reused by T234? Looks like I2C h/w hasn't
> changed and somebody just made a minor tuning of the timing parameters, does
> it really matter in practice?
The timing parameters are important to get the desired data rate for I2C. The values,
unfortunately, cannot be reused from Tegra194.

Thanks,
Akhil

--
nvpublic