Re: [PATCH v2 1/1] iio: adc: meson: add separate config for axg SoC family

From: George Stark <gnstark@salutedevices.com>
To: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Cc: Jonathan Cameron <jic23@kernel.org>, <lars@metafoo.de>,
	<neil.armstrong@linaro.org>, <khilman@baylibre.com>,
	<jbrunet@baylibre.com>, <martin.blumenstingl@googlemail.com>,
	<andriy.shevchenko@linux.intel.com>, <nuno.sa@analog.com>,
	<u.kleine-koenig@pengutronix.de>, <linux-iio@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-amlogic@lists.infradead.org>, <kernel@salutedevices.com>
Subject: Re: [PATCH v2 1/1] iio: adc: meson: add separate config for axg SoC family
Date: Sat, 2 Dec 2023 03:05:13 +0300	[thread overview]
Message-ID: <2cd319fe-f1f8-4855-badb-cf7dd1f6160a@salutedevices.com> (raw)
In-Reply-To: <20231201180811.00002783@Huawei.com>

Hello Jonathan

On 12/1/23 21:08, Jonathan Cameron wrote:
> On Mon, 27 Nov 2023 22:17:33 +0300
> George Stark <gnstark@salutedevices.com> wrote:
> 
>> Hello Jonathan
>>
>> Thanks for the review.
>>
>> On 11/25/23 20:25, Jonathan Cameron wrote:
>>> On Wed, 22 Nov 2023 10:47:41 +0300
>>> George Stark <gnstark@salutedevices.com> wrote:
>>>    
>>>> According to Amlogic custom kernels ADC of axg SoC family has
>>>> vref_select and requires this setting to work nominally and thus
>>>> needs a separate config.
>>>>
>>>> Signed-off-by: George Stark <gnstark@salutedevices.com>
>>>> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>
>>> Is this a fix?  If so, please provide a fixes tag.
>> Actually yes, these changes could be done in the patch that introduced
>> new configuration parameters.
>>
>>> Or is it aligning with the vendor kernels and we don't know if
>>> it's strictly necessary or not?
>> I do know it's necessary if we want kernel driver to be independent from
>> ADC initialization in vendor u-boot code. I have Amlogic a113x device
>> (axg family) and can provide test results w and w/o this patch.
> 
> Definitely best to not rely on firmware.
> 
> So send a Fixes tag for this and I'll apply it as a fix
> (you get to figure out which patch it fixed :)

The patch is ready :)

https://lore.kernel.org/lkml/20231127235558.71995-1-gnstark@salutedevices.com/


> 
> Jonathan
> 
>>
>>>    
>>>> ---
>>>>    drivers/iio/adc/meson_saradc.c | 16 +++++++++++++++-
>>>>    1 file changed, 15 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
>>>> index db280da9edbf..34555a85f131 100644
>>>> --- a/drivers/iio/adc/meson_saradc.c
>>>> +++ b/drivers/iio/adc/meson_saradc.c
>>>> @@ -1242,6 +1242,20 @@ static const struct meson_sar_adc_param meson_sar_adc_gxl_param = {
>>>>    	.cmv_select = 1,
>>>>    };
>>>>    
>>>> +static const struct meson_sar_adc_param meson_sar_adc_axg_param = {
>>>> +	.has_bl30_integration = true,
>>>> +	.clock_rate = 1200000,
>>>> +	.bandgap_reg = MESON_SAR_ADC_REG11,
>>>> +	.regmap_config = &meson_sar_adc_regmap_config_gxbb,
>>>> +	.resolution = 12,
>>>> +	.disable_ring_counter = 1,
>>>> +	.has_reg11 = true,
>>>> +	.vref_volatge = 1,
>>>> +	.has_vref_select = true,
>>>> +	.vref_select = VREF_VDDA,
>>>> +	.cmv_select = 1,
>>>> +};
>>>> +
>>>>    static const struct meson_sar_adc_param meson_sar_adc_g12a_param = {
>>>>    	.has_bl30_integration = false,
>>>>    	.clock_rate = 1200000,
>>>> @@ -1286,7 +1300,7 @@ static const struct meson_sar_adc_data meson_sar_adc_gxm_data = {
>>>>    };
>>>>    
>>>>    static const struct meson_sar_adc_data meson_sar_adc_axg_data = {
>>>> -	.param = &meson_sar_adc_gxl_param,
>>>> +	.param = &meson_sar_adc_axg_param,
>>>>    	.name = "meson-axg-saradc",
>>>>    };
>>>>      
>>>    
>>
> 

-- 
Best regards
George

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