Re: [PATCH RESEND v6 1/5] hwmon: (pmbus/core): Add interrupt support

[Guenter Roeck <linux@roeck-us.net>]

On Wed, Dec 14, 2022 at 09:07:11AM +0100, Naresh Solanki wrote:
> From: Patrick Rudolph <patrick.rudolph@9elements.com>
> 
> Implement PMBUS irq handler.
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>

$ scripts/checkpatch.pl --strict index.html
CHECK: Blank lines aren't necessary after an open brace '{'
#131: FILE: drivers/hwmon/pmbus/pmbus_core.c:3088:
+	for (i = 0; i < data->info->pages; i++) {
+

CHECK: Alignment should match open parenthesis
#183: FILE: drivers/hwmon/pmbus/pmbus_core.c:3140:
+	ret = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler,
+			      0, "pmbus-irq", data);

CHECK: Please use a blank line after function/struct/union/enum declarations
#197: FILE: drivers/hwmon/pmbus/pmbus_core.c:3154:
 }
+static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)

total: 0 errors, 0 warnings, 3 checks, 109 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

index.html has style problems, please review.

Please run checkpatch --strict on your patches.
Also see Documentation/hwmon/submitting-patches.rst.

> ---
>  drivers/hwmon/pmbus/pmbus.h      |  2 +-
>  drivers/hwmon/pmbus/pmbus_core.c | 84 ++++++++++++++++++++++++++++++++
>  2 files changed, 85 insertions(+), 1 deletion(-)
> 
> 
> base-commit: 364ffd2537c44cb6914ff5669153f4a86fffad29
> 
> diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
> index 10fb17879f8e..6b2e6cf93b19 100644
> --- a/drivers/hwmon/pmbus/pmbus.h
> +++ b/drivers/hwmon/pmbus/pmbus.h
> @@ -26,7 +26,7 @@ enum pmbus_regs {
>  
>  	PMBUS_CAPABILITY		= 0x19,
>  	PMBUS_QUERY			= 0x1A,
> -
> +	PMBUS_SMBALERT_MASK		= 0x1B,
>  	PMBUS_VOUT_MODE			= 0x20,
>  	PMBUS_VOUT_COMMAND		= 0x21,
>  	PMBUS_VOUT_TRIM			= 0x22,
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 95e95783972a..244fd2597252 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -3072,11 +3072,89 @@ static int pmbus_regulator_register(struct pmbus_data *data)
>  
>  	return 0;
>  }
> +
> +static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
> +{
> +	return pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
> +}
> +
> +static irqreturn_t pmbus_fault_handler(int irq, void *pdata)
> +{
> +	struct pmbus_data *data = pdata;
> +	struct i2c_client *client = to_i2c_client(data->dev);
> +	int i, status;
> +
> +	for (i = 0; i < data->info->pages; i++) {
> +
> +		mutex_lock(&data->update_lock);
> +		status = pmbus_read_status_word(client, i);
> +		if (status < 0) {
> +			mutex_unlock(&data->update_lock);
> +			return status;
> +		}
> +
> +		if (status & ~(PB_STATUS_OFF | PB_STATUS_BUSY | PB_STATUS_POWER_GOOD_N))
> +			pmbus_clear_fault_page(client, i);
> +
> +		mutex_unlock(&data->update_lock);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
> +{
> +	struct device *dev = &client->dev;
> +	const struct pmbus_regulator_status_category *cat;
> +	const struct pmbus_regulator_status_assoc *bit;
> +	int i, j, err, ret, func;
> +	u8 mask;
> +
> +	for (i = 0; i < data->info->pages; i++) {
> +		func = data->info->func[i];
> +
> +		for (j = 0; j < ARRAY_SIZE(pmbus_regulator_flag_map); j++) {
> +			cat = &pmbus_regulator_flag_map[j];
> +			if (!(func & cat->func))
> +				continue;
> +			mask = 0;
> +			for (bit = cat->bits; bit->pflag; bit++)
> +				mask |= bit->pflag;
> +
> +			err = pmbus_write_smbalert_mask(client, i, cat->reg, ~mask);
> +			if (err)
> +				dev_err(dev, "Failed to set smbalert for reg 0x%02x\n",	cat->reg);

This concerns me. It might mean that the chip does not support
PMBUS_SMBALERT_MASK. If so, there would be lots of error messages.

> +		}
> +
> +		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_CML, 0xff);
> +		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_OTHER, 0xff);
> +		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_MFR_SPECIFIC, 0xff);

Why check the return value from pmbus_write_smbalert_mask above but not here ?

> +		if (data->info->func[i] & PMBUS_HAVE_FAN12)
> +			pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_FAN_12, 0xff);
> +		if (data->info->func[i] & PMBUS_HAVE_FAN34)
> +			pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_FAN_34, 0xff);
> +	}
> +
> +	/* Register notifiers - can fail if IRQ is not given */

The comment does not make sense. pmbus_irq_setup() is not called
if the interrupt "is not given".

> +	ret = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler,
> +			      0, "pmbus-irq", data);
> +	if (ret) {
> +		dev_warn(dev, "IRQ disabled %d\n", ret);

This is not a warning, it is an error.

> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  #else

This is still in regulator code. I said several times that this is not
acceptable.

>  static int pmbus_regulator_register(struct pmbus_data *data)
>  {
>  	return 0;
>  }
> +static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
> +{
> +	return 0;
> +}
>  #endif
>  
>  static struct dentry *pmbus_debugfs_dir;	/* pmbus debugfs directory */
> @@ -3441,6 +3519,12 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
>  	if (ret)
>  		return ret;
>  
> +	if (client->irq > 0) {
> +		ret = pmbus_irq_setup(client, data);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	ret = pmbus_init_debugfs(client, data);
>  	if (ret)
>  		dev_warn(dev, "Failed to register debugfs\n");