Re: [PATCH v2 3/4] hwmon/ltc2990: Add platform_data support

Guenter Roeck
2019-08-13T13:25:01Z

On 8/13/19 3:10 AM, Max Staudt wrote:
> On 08/13/2019 10:02 AM, Guenter Roeck 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 ?
>
> The driver does have DT support implemented right above my new platform_data code, and DT takes precedence. However, I can't set DT data programatically when instantiating the client using i2c_new_device() - hence the platform_data support.
>

Sorry, I don't understand. Why exactly can't you replace of_property_read_u32_array()
with device_property_read_u32_array() and use fwnode_create_software_node()
in the calling code to set the properties ?

Guenter