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From: Hans de Goede <hdegoede@redhat.com>
To: Daniel Scally <djrscally@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Mark Gross <markgross@kernel.org>,
	Andy Shevchenko <andy@infradead.org>,
	Wolfram Sang <wsa@the-dreams.de>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>, Len Brown <lenb@kernel.org>,
	linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Kate Hsuan <hpa@redhat.com>,
	linux-media@vger.kernel.org, linux-clk@vger.kernel.org,
	Andy Shevchenko <andy.shevchenko@gmail.com>
Subject: Re: [PATCH v6 07/15] platform/x86: int3472: Enable I2c daisy chain
Date: Fri, 3 Dec 2021 11:21:16 +0100	[thread overview]
Message-ID: <724ab9d5-7ba1-dae6-49b9-831bafca5b84@redhat.com> (raw)
In-Reply-To: <2fd5400e-e587-54d2-1071-ad8df49a8a68@redhat.com>

Hi,

On 11/26/21 12:45, Hans de Goede wrote:
> Hi,
> 
> On 11/26/21 12:39, Daniel Scally wrote:
>> Hello
>>
>> On 26/11/2021 11:30, Hans de Goede wrote:
>>> Hi,
>>>
>>> On 11/26/21 00:39, Laurent Pinchart wrote:
>>>> Hi Hans,
>>>>
>>>> Thank you for the patch.
>>>>
>>>> On Thu, Nov 25, 2021 at 05:54:04PM +0100, Hans de Goede wrote:
>>>>> From: Daniel Scally <djrscally@gmail.com>
>>>>>
>>>>> The TPS68470 PMIC has an I2C passthrough mode through which I2C traffic
>>>>> can be forwarded to a device connected to the PMIC as though it were
>>>>> connected directly to the system bus. Enable this mode when the chip
>>>>> is initialised.
>>>> Is there any drawback doing this unconditionally, if nothing is
>>>> connected to the bus on the other side (including no pull-ups) ?
>>> I actually never took a really close look at this patch, I just
>>> sorta inherited it from Daniel.
>>>
>>> Now that I have taken a close look, I see that it is setting the
>>> exact same bits as which get set when enabling the VSIO regulator.
>>>
>>> The idea here is that the I2C-passthrough only gets enabled when
>>> the VSIO regulator is turned on, because some sensors end up
>>> shorting the I2C pins to ground when the sensor is not powered.
>>>
>>> Since we set these bits when powering up the VSIO regulator
>>> and since we do that before trying to talk to the sensor
>>> I don't think that we need this (hack) anymore.
>>>
>>> I will give things a try without this change and if things
>>> still work I will drop this patch from the set.
>>>
>>> Daniel, what do you think?
>>
>>
>> Humm, we're only using the VSIO regulator with the VCM though right?
> 
> Nope, there is a mapping from VSIO to dovdd for the ov8865 in the
> board_data; and I'm pretty sure I copied that from your earlier
> attempts at getting regulator lookups registered :)
> 
> And even if the VSIO regulator was only used by the VCM, then it would
> get turned off after probing the VCM, clearing the 2 bits which this
> commit sets. Which would break things if we did not re-enable it when
> the ov8865 needs it.
> 
>> Which might not be on when the ov8865 tries to probe. I haven't tried
>> without this patch to be honest; I set it because that was what Windows
>> does when powering on the PMIC.
> 
> See above, I'm pretty sure we can do without this patch which means
> that the INT3472 code will no longer be poking at the PMIC directly
> itself, which is good :)
> 
> Anyways I'll give this a try sometime next week and then drop the
> patch.

I can confirm that this patch indeed is no longer necessary with
the current regulator code already taking care of this.

I will post version 7 of this patch-set soon, with this patch dropped.

Regards,

Hans



>>>>> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>>>>> Signed-off-by: Daniel Scally <djrscally@gmail.com>
>>>>> ---
>>>>>  .../x86/intel/int3472/intel_skl_int3472_tps68470.c         | 7 +++++++
>>>>>  1 file changed, 7 insertions(+)
>>>>>
>>>>> diff --git a/drivers/platform/x86/intel/int3472/intel_skl_int3472_tps68470.c b/drivers/platform/x86/intel/int3472/intel_skl_int3472_tps68470.c
>>>>> index c05b4cf502fe..42e688f4cad4 100644
>>>>> --- a/drivers/platform/x86/intel/int3472/intel_skl_int3472_tps68470.c
>>>>> +++ b/drivers/platform/x86/intel/int3472/intel_skl_int3472_tps68470.c
>>>>> @@ -45,6 +45,13 @@ static int tps68470_chip_init(struct device *dev, struct regmap *regmap)
>>>>>  		return ret;
>>>>>  	}
>>>>>  
>>>>> +	/* Enable I2C daisy chain */
>>>>> +	ret = regmap_write(regmap, TPS68470_REG_S_I2C_CTL, 0x03);
>>>>> +	if (ret) {
>>>>> +		dev_err(dev, "Failed to enable i2c daisy chain\n");
>>>>> +		return ret;
>>>>> +	}
>>>>> +
>>>>>  	dev_info(dev, "TPS68470 REVID: 0x%02x\n", version);
>>>>>  
>>>>>  	return 0;
>>


  parent reply	other threads:[~2021-12-03 10:21 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-25 16:53 [PATCH v6 00/15] Add support for X86/ACPI camera sensor/PMIC setup with clk and regulator platform data Hans de Goede
2021-11-25 16:53 ` [PATCH v6 01/15] ACPI: delay enumeration of devices with a _DEP pointing to an INT3472 device Hans de Goede
2021-11-25 16:53 ` [PATCH v6 02/15] i2c: acpi: Use acpi_dev_ready_for_enumeration() helper Hans de Goede
2021-11-26  7:16   ` Mika Westerberg
2021-11-25 16:54 ` [PATCH v6 03/15] i2c: acpi: Add i2c_acpi_new_device_by_fwnode() function Hans de Goede
2021-11-25 17:22   ` Andy Shevchenko
2021-11-26 11:19     ` Hans de Goede
2021-11-26  7:18   ` Mika Westerberg
2021-11-27 22:49   ` Wolfram Sang
2021-11-25 16:54 ` [PATCH v6 04/15] platform_data: Add linux/platform_data/tps68470.h file Hans de Goede
2021-11-25 16:54 ` [PATCH v6 05/15] regulator: Introduce tps68470-regulator driver Hans de Goede
2021-11-25 23:32   ` Laurent Pinchart
2021-11-26 11:22     ` Hans de Goede
2021-11-27 23:38       ` Laurent Pinchart
2021-11-29 12:08         ` Mark Brown
2021-11-29 15:35           ` Laurent Pinchart
2021-11-25 16:54 ` [PATCH v6 06/15] clk: Introduce clk-tps68470 driver Hans de Goede
2021-11-25 16:54 ` [PATCH v6 07/15] platform/x86: int3472: Enable I2c daisy chain Hans de Goede
2021-11-25 23:39   ` Laurent Pinchart
2021-11-26 11:30     ` Hans de Goede
2021-11-26 11:39       ` Daniel Scally
2021-11-26 11:45         ` Hans de Goede
2021-11-26 11:56           ` Daniel Scally
2021-12-03 10:21           ` Hans de Goede [this message]
2021-11-25 16:54 ` [PATCH v6 08/15] platform/x86: int3472: Split into 2 drivers Hans de Goede
2021-11-25 16:54 ` [PATCH v6 09/15] platform/x86: int3472: Add get_sensor_adev_and_name() helper Hans de Goede
2021-11-25 16:54 ` [PATCH v6 10/15] platform/x86: int3472: Pass tps68470_clk_platform_data to the tps68470-regulator MFD-cell Hans de Goede
2021-11-25 16:54 ` [PATCH v6 11/15] platform/x86: int3472: Pass tps68470_regulator_platform_data " Hans de Goede
2021-11-25 16:54 ` [PATCH v6 12/15] platform/x86: int3472: Deal with probe ordering issues Hans de Goede
2021-11-25 16:54 ` [PATCH v6 13/15] media: ipu3-cio2: Defer probing until the PMIC is fully setup Hans de Goede
2021-11-25 16:54 ` [PATCH v6 14/15] media: ipu3-cio2: Call cio2_bridge_init() before anything else Hans de Goede
2021-11-25 16:54 ` [PATCH v6 15/15] media: ipu3-cio2: Add support for instantiating i2c-clients for VCMs Hans de Goede

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