From mboxrd@z Thu Jan  1 00:00:00 1970
From: Guenter Roeck <linux@roeck-us.net>
Subject: Re: [PATCH v2 3/4] hwmon/ltc2990: Add platform_data support
Date: Tue, 13 Aug 2019 06:27:52 -0700
Message-ID: <1aff162f-f548-954c-b9d4-c6207a6c5875@roeck-us.net>
References: <20190812235237.21797-1-max@enpas.org>
 <20190812235237.21797-3-max@enpas.org> <20190813080237.GA29986@roeck-us.net>
 <CAMuHMdXHbjfrdusGB3qvcu1a=W65Ef1-NrvcCv1h9E9uicknLg@mail.gmail.com>
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To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Max Staudt <max@enpas.org>, Linux I2C <linux-i2c@vger.kernel.org>, linux-hwmon@vger.kernel.org, Wolfram Sang <wsa+renesas@sang-engineering.com>, Jean Delvare <jdelvare@suse.com>, Linux/m68k <linux-m68k@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
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On 8/13/19 1:27 AM, Geert Uytterhoeven wrote:
> Hi Günter,
> 
> On Tue, Aug 13, 2019 at 10:02 AM Guenter Roeck <linux@roeck-us.net> wrote:
>> On Tue, Aug 13, 2019 at 01:52:36AM +0200, Max Staudt wrote:
>>> This allows code using i2c_new_device() to specify a measurement mode.
>>>
>>> Signed-off-by: Max Staudt <max@enpas.org>
>>> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>> ---
>>>   drivers/hwmon/ltc2990.c               |  9 +++++++++
>>>   include/linux/platform_data/ltc2990.h | 11 +++++++++++
>>>   2 files changed, 20 insertions(+)
>>>   create mode 100644 include/linux/platform_data/ltc2990.h
>>>
>>> diff --git a/drivers/hwmon/ltc2990.c b/drivers/hwmon/ltc2990.c
>>> index f9431ad43..f19b9c50c 100644
>>> --- a/drivers/hwmon/ltc2990.c
>>> +++ b/drivers/hwmon/ltc2990.c
>>> @@ -14,6 +14,7 @@
>>>   #include <linux/kernel.h>
>>>   #include <linux/module.h>
>>>   #include <linux/of.h>
>>> +#include <linux/platform_data/ltc2990.h>
>>>
>>>   #define LTC2990_STATUS       0x00
>>>   #define LTC2990_CONTROL      0x01
>>> @@ -206,6 +207,7 @@ static int ltc2990_i2c_probe(struct i2c_client *i2c,
>>>        int ret;
>>>        struct device *hwmon_dev;
>>>        struct ltc2990_data *data;
>>> +     struct ltc2990_platform_data *pdata = dev_get_platdata(&i2c->dev);
>>>        struct device_node *of_node = i2c->dev.of_node;
>>>
>>>        if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
>>> @@ -227,6 +229,13 @@ static int ltc2990_i2c_probe(struct i2c_client *i2c,
>>>                if (data->mode[0] & ~LTC2990_MODE0_MASK ||
>>>                    data->mode[1] & ~LTC2990_MODE1_MASK)
>>>                        return -EINVAL;
>>> +     } else if (pdata) {
>>> +             data->mode[0] = pdata->meas_mode[0];
>>> +             data->mode[1] = pdata->meas_mode[1];
>>> +
>>> +             if (data->mode[0] & ~LTC2990_MODE0_MASK ||
>>> +                 data->mode[1] & ~LTC2990_MODE1_MASK)
>>> +                     return -EINVAL;
>>
>> I would prefer if the driver was modified to accept device
>> properties, and if those were set using the appropriate
>> fwnode function. Any reason for not doing that ?
> 
> That was my first thought as well, but isn't that limited to DT and ACPI
> properties (for now)?
> 

tcpm and, for example, the wcove driver don't seem to have a problem using
it, I don't see acpi involved there. Also, the code resides in the core driver
code and is always enabled unless I am missing something. What am I missing ?

Guenter