Re: [PATCH 1/2] hwmon: (lm90) Add power control

From: Wei Ni
Date: Wed Aug 07 2013 - 03:32:39 EST


On 08/07/2013 03:27 PM, Alexander Shiyan wrote:
>> The device lm90 can be controlled by the vdd rail.
>> Adding the power control support to power on/off the vdd rail.
>> And make sure that power is enabled before accessing the device.
>>
>> Signed-off-by: Wei Ni <wni@xxxxxxxxxx>
>> ---
>> drivers/hwmon/lm90.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++
> [...]
>> + if (!data->lm90_reg) {
>> + data->lm90_reg = regulator_get(&client->dev, "vdd");
>> + if (IS_ERR_OR_NULL(data->lm90_reg)) {
>> + if (PTR_ERR(data->lm90_reg) == -ENODEV)
>> + dev_info(&client->dev,
>> + "No regulator found for vdd. Assuming vdd is always powered.");
>> + else
>> + dev_warn(&client->dev,
>> + "Error [%ld] in getting the regulator handle for vdd.\n",
>> + PTR_ERR(data->lm90_reg));
>> + data->lm90_reg = NULL;
>> + mutex_unlock(&data->update_lock);
>> + return -ENODEV;
>> + }
>> + }
>> + if (is_enable) {
>> + ret = regulator_enable(data->lm90_reg);
>> + msleep(POWER_ON_DELAY);
>
> Can this delay be handled directly from regulator?

I think it should be handled in the device driver.
Because there have different delay time to wait devices stable.

>
> [...]
> ---
>

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