Subject: [PATCH-v4 2/3] mfd: 88pm800: Set default interrupt clear method

From: [email-masked] (Vaibhav Hiremath)
Date: Thu, 25 Jun 2015 16:49:50 +0530

On Thursday 25 June 2015 03:56 PM, Lee Jones wrote:
> On Thu, 25 Jun 2015, Vaibhav Hiremath wrote:
>
>> As per the spec, bit 1 (INT_CLEAR_MODE) of reg addr 0xe
>> (page 0) controls the method of clearing interrupt
>> status of 88pm800 family of devices;
>>
>>    0: clear on read
>>    1: clear on write
>>
>> If pdata is not coming from board file, then set the
>> default irq clear method to "irq clear on write"
>>
>> Also, as suggested by "Lee Jones" renaming variable field
>> to appropriate name.
>>
>> Signed-off-by: Zhao Ye <[email-masked]>
>> Signed-off-by: Vaibhav Hiremath <[email-masked]>
>> ---
>>   drivers/mfd/88pm800.c       | 15 ++++++++++-----
>>   include/linux/mfd/88pm80x.h |  6 ++++--
>>   2 files changed, 14 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/mfd/88pm800.c b/drivers/mfd/88pm800.c
>> index 40fd014..e0cd7ad 100644
>> --- a/drivers/mfd/88pm800.c
>> +++ b/drivers/mfd/88pm800.c
>> @@ -376,7 +376,7 @@ static int device_irq_init_800(struct pm80x_chip *chip)
>>   {
>>   	struct regmap *map = chip->regmap;
>>   	unsigned long flags = IRQF_ONESHOT;
>> -	int data, mask, ret = -EINVAL;
>> +	int irq_clr_mode, mask, ret = -EINVAL;
>>
>>   	if (!map || !chip->irq) {
>>   		dev_err(chip->dev, "incorrect parameters\n");
>> @@ -384,15 +384,16 @@ static int device_irq_init_800(struct pm80x_chip *chip)
>>   	}
>>
>>   	/*
>> -	 * irq_mode defines the way of clearing interrupt. it's read-clear by
>> -	 * default.
>> +	 * irq_clr_on_wr defines the way of clearing interrupt by
>> +	 * read/write(0/1).  It's read-clear by default.
>>   	 */
>>   	mask =
>>   	    PM800_WAKEUP2_INV_INT | PM800_WAKEUP2_INT_CLEAR |
>>   	    PM800_WAKEUP2_INT_MASK;
>>
>> -	data = PM800_WAKEUP2_INT_CLEAR;
>> -	ret = regmap_update_bits(map, PM800_WAKEUP2, mask, data);
>> +	irq_clr_mode = (chip->irq_clr_on_wr) ?
>
> Drop the brackets.
>

Ok

>> +		PM800_WAKEUP2_INT_WRITE_CLEAR : PM800_WAKEUP2_INT_READ_CLEAR;
>> +	ret = regmap_update_bits(map, PM800_WAKEUP2, mask, irq_clr_mode);
>>
>>   	if (ret < 0)
>>   		goto out;
>> @@ -514,6 +515,7 @@ static int device_800_init(struct pm80x_chip *chip,
>>   	}
>>
>>   	chip->regmap_irq_chip = &pm800_irq_chip;
>> +	chip->irq_clr_on_wr = pdata->irq_clr_on_wr;
>
> You have protection around pdata everywhere else in the file, I
> suggest you supply some here too.
>

Actually it is not really needed, as the PATCH 1/1 introduces

         if (!pdata && !np) {
                 dev_err(&client->dev,
                         "pm80x requires platform data or of_node\n");
                 return -EINVAL;
         }

         if (!pdata && !np) {
                 dev_err(&client->dev,
                         "pm80x requires platform data or of_node\n");
                 return -EINVAL;
         }

So there is no way you can have pdata = NULL beyond this point.

>>   	ret = device_irq_init_800(chip);
>>   	if (ret < 0) {
>> @@ -566,6 +568,9 @@ static int pm800_probe(struct i2c_client *client,
>>   		pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
>>   		if (!pdata)
>>   			return -ENOMEM;
>> +
>> +		/* by default, set irq clear method on write */
>> +		pdata->irq_clr_on_wr = true;
>
> You can save yourself some memory here, by removing this seemingly
> pointless allocation and do this above:
>
>          chip->irq_clr_on_wr = pdata ? pdata->irq_clr_on_wr : true;
>

Yes certainly better way of doing it :)
I will change it.

>>   	}
>>
>>   	ret = pm80x_init(client);
>> diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
>> index 97cb283..94b3dcd 100644
>> --- a/include/linux/mfd/88pm80x.h
>> +++ b/include/linux/mfd/88pm80x.h
>> @@ -77,6 +77,8 @@ enum {
>>   #define PM800_WAKEUP2		(0x0E)
>>   #define PM800_WAKEUP2_INV_INT		(1 << 0)
>>   #define PM800_WAKEUP2_INT_CLEAR		(1 << 1)
>> +#define PM800_WAKEUP2_INT_READ_CLEAR		(0 << 1)
>> +#define PM800_WAKEUP2_INT_WRITE_CLEAR		(1 << 1)
>>   #define PM800_WAKEUP2_INT_MASK		(1 << 2)
>
> Use the BIT() macro.
>

I thought about this, but the whole file doesn't use it, so I also
chose not to.

>>   #define PM800_POWER_UP_LOG	(0x10)
>> @@ -300,7 +302,7 @@ struct pm80x_chip {
>>   	struct regmap_irq_chip_data *irq_data;
>>   	int type;
>>   	int irq;
>> -	int irq_mode;
>> +	int irq_clr_on_wr;	/* '1': Clear on write, '0': Clear on read*/
>
> Whitespace issue.
>

Didn't see any...and I also ran checkpatch.

> Shouldn't this be a bool?
>

Just was not sure about any older board file interface.
Ideally it should be bool only.

> Actually even better, I would define; CLR_ON_WRITE and CLR_ON_READ,
> and call the variable irq_clear_method, or something.
>
> Much clearer that way I think.
>

We have slowly decided to almost hardcode it to one value if there is
no board file. I feel we should just keep it to simple.

If you still insist, I can implement.

Thanks,
Vaibhav