Re: [PATCH 2/4] mfd: simple-mfd-i2c: Adds Ampere's Altra SMpro support

From: Quan Nguyen <quan@os.amperecomputing.com>
To: Lee Jones <lee.jones@linaro.org>
Cc: Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Rob Herring <robh+dt@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org,
	Open Source Submission <patches@amperecomputing.com>,
	Phong Vo <phong@os.amperecomputing.com>,
	"Thang Q . Nguyen" <thang@os.amperecomputing.com>
Subject: Re: [PATCH 2/4] mfd: simple-mfd-i2c: Adds Ampere's Altra SMpro support
Date: Mon, 1 Mar 2021 19:46:08 +0700	[thread overview]
Message-ID: <f4b00f4c-6e6c-810d-d16d-5d01ebf4d36d@os.amperecomputing.com> (raw)
In-Reply-To: <20210226083114.GE641347@dell>

On 26/02/2021 15:31, Lee Jones wrote:
> On Thu, 25 Feb 2021, Quan Nguyen wrote:
> 
>> Adds an MFD driver for SMpro found on the Mt.Jade hardware reference
>> platform with Ampere's Altra processor family.
>>
>> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
>> ---
>>   drivers/mfd/Kconfig          | 10 ++++++++++
>>   drivers/mfd/simple-mfd-i2c.c | 15 +++++++++++++--
>>   2 files changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index b74efa469e90..5414371bdea1 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -77,6 +77,16 @@ config MFD_AS3711
>>   	help
>>   	  Support for the AS3711 PMIC from AMS
>>   
>> +config MFD_SMPRO
>> +	tristate "Ampere Computing MFD SMpro core driver"
>> +	select MFD_SIMPLE_MFD_I2C
> 
> Nice to see another user here.
> 
>> +	help
>> +	  Say yes here to enable SMpro driver support for Ampere's Altra
>> +	  processor family.
>> +
>> +	  Ampere's Altra SMpro exposes an I2C regmap interface that can
>> +	  be accessed by child devices.
>> +
>>   config MFD_AS3722
>>   	tristate "ams AS3722 Power Management IC"
>>   	select MFD_CORE
>> diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
>> index 87f684cff9a1..0459a9fbd3f5 100644
>> --- a/drivers/mfd/simple-mfd-i2c.c
>> +++ b/drivers/mfd/simple-mfd-i2c.c
>> @@ -21,14 +21,24 @@ static const struct regmap_config simple_regmap_config = {
>>   	.val_bits = 8,
>>   };
>>   
>> +static const struct regmap_config simple_word_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 16,
>> +};
>> +
>>   static int simple_mfd_i2c_probe(struct i2c_client *i2c)
>>   {
>>   	const struct regmap_config *config;
>>   	struct regmap *regmap;
>>   
>>   	config = device_get_match_data(&i2c->dev);
>> -	if (!config)
>> -		config = &simple_regmap_config;
>> +	if (!config) {
>> +		if (of_device_is_compatible(i2c->dev.of_node,
>> +						"ampere,ac01-smpro"))
> 
> Could you use 'struct of_device_id's .data attribute instead please?
> 
Thank you, but I'm not sure if I got it right.

Do you mean we could use .data attribute to get the expected 
reg_bits/val_bits values and translate them to simple_word_regmap_config 
without the need to match the compatible string ?

>> +			config = &simple_word_regmap_config;
>> +		else
>> +			config = &simple_regmap_config;
>> +	}
>>   
>>   	regmap = devm_regmap_init_i2c(i2c, config);
>>   	if (IS_ERR(regmap))
>> @@ -39,6 +49,7 @@ static int simple_mfd_i2c_probe(struct i2c_client *i2c)
>>   
>>   static const struct of_device_id simple_mfd_i2c_of_match[] = {
>>   	{ .compatible = "kontron,sl28cpld" },
>> +	{ .compatible = "ampere,ac01-smpro" },
>>   	{}
>>   };
>>   MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
> 