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From: Dmitry Osipenko <digetx@gmail.com>
To: Akhil R <akhilrajeev@nvidia.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"thierry.reding@gmail.com" <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Mikko Perttunen <mperttunen@nvidia.com>,
	Laxman Dewangan <ldewangan@nvidia.com>,
	"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Petlozu Pravareshwar <petlozup@nvidia.com>
Subject: Re: [PATCH 1/6] i2c: tegra: Add support for Tegra234 I2C
Date: Wed, 19 Jan 2022 15:20:35 +0300	[thread overview]
Message-ID: <a7a33c29-427d-5e82-f327-aa4701d51898@gmail.com> (raw)
In-Reply-To: <DM5PR12MB1850237ECA6C115AD776635EC0599@DM5PR12MB1850.namprd12.prod.outlook.com>

19.01.2022 11:20, Akhil R пишет:
>> 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.

From where those T194 parameters specified in the Tegra I2C driver came
from?

I'm now looking at T194 TRM (Xavier_TRM_DP09253002_v1.3p 10.2.3.1.1
Example Settings for Various I2C Speeds) and see that all the values
should match T234. Please check whether T194 configuration is correct
and fix it if needed.

  reply	other threads:[~2022-01-19 12:20 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-13 13:30 [PATCH 0/6] Add I2C and PWM support for T234 Akhil R
2022-01-13 13:30 ` [PATCH 1/6] i2c: tegra: Add support for Tegra234 I2C Akhil R
2022-01-18 20:54   ` Dmitry Osipenko
2022-01-19  8:20     ` Akhil R
2022-01-19 12:20       ` Dmitry Osipenko [this message]
2022-01-20 14:23         ` Akhil R
2022-01-13 13:30 ` [PATCH 2/6] dt-bindings: i2c: tegra: Add Tegra234 details Akhil R
2022-02-09  2:17   ` Rob Herring
2022-02-09  3:54     ` Akhil R
2022-01-13 13:30 ` [PATCH 3/6] dt-bindings: Add headers for Tegra234 I2C Akhil R
2022-01-13 13:30 ` [PATCH 4/6] arm64: tegra: Add Tegra234 I2C devicetree nodes Akhil R
2022-01-13 13:30 ` [PATCH 5/6] dt-bindings: Add headers for Tegra234 PWM Akhil R
2022-01-13 13:30 ` [PATCH 6/6] arm64: tegra: Add Tegra234 PWM devicetree nodes Akhil R

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