linux-kernel - Re: [PATCH v12 4/6] i2c: tegra: Add HS mode support

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Message-ID: <f173a987-dafd-4bc7-9905-745f855e12bf@nvidia.com>
Date: Tue, 18 Nov 2025 12:16:57 +0000
From: Jon Hunter <jonathanh@...dia.com>
To: Akhil R <akhilrajeev@...dia.com>
Cc: andi.shyti@...nel.org, digetx@...il.com, kkartik@...dia.com,
 ldewangan@...dia.com, linux-i2c@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org,
 smangipudi@...dia.com, thierry.reding@...il.com,
 wsa+renesas@...g-engineering.com, wsa@...nel.org
Subject: Re: [PATCH v12 4/6] i2c: tegra: Add HS mode support


On 18/11/2025 11:09, Akhil R wrote:
> On Mon, 17 Nov 2025 11:07:07 +0000, Jon Hunter wrote:
>> On 15/11/2025 04:26, Akhil R wrote:
>>> Add support for HS (High Speed) mode transfers, which is supported by
>>> Tegra194 onwards. Also adjust the bus frequency such that it uses the
>>> fast plus mode when HS mode is not supported.
>>>
>>> Signed-off-by: Akhil R <akhilrajeev@...dia.com>
>>> Signed-off-by: Kartik Rajput <kkartik@...dia.com>
>>> ---
>>> v10 -> v12:
>>> 	* Update bus_freq_hz to max supported freq and updates to
>>> 	  accomodate the changes from Patch 2/6.
>>> v10 -> v11:
>>> 	* Update the if condition as per the comments received on:
>>> 	  https://lore.kernel.org/linux-tegra/20251110080502.865953-1-kkartik@nvidia.com/T/#t
>>> v9 -> v10:
>>>           * Change switch block to an if-else block.
>>> v5 -> v9:
>>>           * In the switch block, handle the case when hs mode is not
>>>             supported. Also update it to use Fast mode for master code
>>>             byte as per the I2C spec for HS mode.
>>> v3 -> v5:
>>>           * Set has_hs_mode_support to false for unsupported SoCs.
>>> v2 -> v3:
>>>           * Document tlow_hs_mode and thigh_hs_mode.
>>> v1 -> v2:
>>>           * Document has_hs_mode_support.
>>>           * Add a check to set the frequency to fastmode+ if the device
>>>             does not support HS mode but the requested frequency is more
>>>             than fastmode+.
>>> ---
>>>    drivers/i2c/busses/i2c-tegra.c | 59 ++++++++++++++++++++++++++++++++--
>>>    1 file changed, 57 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>>> index 8a696c88882e..9ebeb6a2eaf5 100644
>>> --- a/drivers/i2c/busses/i2c-tegra.c
>>> +++ b/drivers/i2c/busses/i2c-tegra.c
>>> @@ -91,6 +91,7 @@
>>>    #define I2C_HEADER_IE_ENABLE			BIT(17)
>>>    #define I2C_HEADER_REPEAT_START			BIT(16)
>>>    #define I2C_HEADER_CONTINUE_XFER		BIT(15)
>>> +#define I2C_HEADER_HS_MODE			BIT(22)
>>
>> This should be ordered according to the value. So place this above
>> I2C_HEADER_CONT_ON_NAK.
> 
> Agree.
> 
> Do we need a new version with this change or would it be possible to
> update while applying?

Given we need another minor fix to 3/6 you might as well send a new version.

Jon
-- 
nvpublic