Re: [PATCH v4 3/4] power: supply: max17040: Config alert SOC low level threshold from FDT

[Matheus Castello <matheus@castello.eng.br>]

Em 11/1/19 12:27 PM, Krzysztof Kozlowski escreveu:
> On Thu, Oct 31, 2019 at 03:41:33PM -0300, Matheus Castello wrote:
>> For configuration of fuel gauge alert for a low level state of charge
>> interrupt we add a function to config level threshold and a device tree
>> binding property to set it in flatned device tree node.
>>
>> Now we can use "maxim,alert-low-soc-level" property with the values from
>> 1% up to 32% to configure alert interrupt threshold.
>>
>> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
>> ---
>>   drivers/power/supply/max17040_battery.c | 88 +++++++++++++++++++++----
>>   1 file changed, 74 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
>> index 75459f76d02c..802575342c72 100644
>> --- a/drivers/power/supply/max17040_battery.c
>> +++ b/drivers/power/supply/max17040_battery.c
>> @@ -29,6 +29,9 @@
>>   #define MAX17040_DELAY		1000
>>   #define MAX17040_BATTERY_FULL	95
>>
>> +#define MAX17040_ATHD_MASK		0xFFC0
>> +#define MAX17040_ATHD_DEFAULT_POWER_UP	4
>> +
>>   struct max17040_chip {
>>   	struct i2c_client		*client;
>>   	struct delayed_work		work;
>> @@ -43,6 +46,8 @@ struct max17040_chip {
>>   	int soc;
>>   	/* State Of Charge */
>>   	int status;
>> +	/* Low alert threshold from 32% to 1% of the State of Charge */
>> +	u32 low_soc_alert_threshold;
>>   };
>>
>>   static int max17040_get_property(struct power_supply *psy,
>> @@ -99,6 +104,22 @@ static void max17040_reset(struct i2c_client *client)
>>   	max17040_write_reg(client, MAX17040_CMD, 0x0054);
>>   }
>>
>> +static int max17040_set_low_soc_threshold_alert(struct i2c_client *client,
>> +	u32 level)
>> +{
>> +	int ret;
>> +	u16 data;
>> +
>> +	level = 32 - level;
>> +	data = max17040_read_reg(client, MAX17040_RCOMP);
>> +	/* clear the alrt bit and set LSb 5 bits */
>> +	data &= MAX17040_ATHD_MASK;
>> +	data |= level;
>> +	ret = max17040_write_reg(client, MAX17040_RCOMP, data);
>> +
>> +	return ret;
>> +}
>> +
>>   static void max17040_get_vcell(struct i2c_client *client)
>>   {
>>   	struct max17040_chip *chip = i2c_get_clientdata(client);
>> @@ -115,7 +136,6 @@ static void max17040_get_soc(struct i2c_client *client)
>>   	u16 soc;
>>
>>   	soc = max17040_read_reg(client, MAX17040_SOC);
>> -
>>   	chip->soc = (soc >> 8);
>>   }
>>
>> @@ -161,6 +181,24 @@ static void max17040_get_status(struct i2c_client *client)
>>   		chip->status = POWER_SUPPLY_STATUS_FULL;
>>   }
>>
>> +static int max17040_get_of_data(struct max17040_chip *chip)
>> +{
>> +	struct device *dev = &chip->client->dev;
>> +	struct device_node *np = dev->of_node;
>> +	int ret = 0;
>> +
>> +	if (of_property_read_u32(np, "maxim,alert-low-soc-level",
>> +			&chip->low_soc_alert_threshold)) {
> 
> Please align the line break with line above. checkpatch --strict might
> give you hints about this.
> >> +		chip->low_soc_alert_threshold = MAX17040_ATHD_DEFAULT_POWER_UP;
>> +	/* check if low_soc_alert_threshold is between 1% and 32% */
> 
> The comment looks misleading here, like it belongs to previous block.
> Maybe put it inside else if {} block?
> 
>> +	} else if (chip->low_soc_alert_threshold <= 0 ||
>> +			chip->low_soc_alert_threshold >= 33){
> 
> Missing space before {.
> 
>> +		ret = -EINVAL;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   static void max17040_check_changes(struct i2c_client *client)
>>   {
>>   	max17040_get_vcell(client);
>> @@ -192,6 +230,10 @@ static irqreturn_t max17040_thread_handler(int id, void *dev)
>>   	/* send uevent */
>>   	power_supply_changed(chip->battery);
>>
>> +	/* reset alert bit */
>> +	max17040_set_low_soc_threshold_alert(client,
>> +		chip->low_soc_alert_threshold);
> 
> Unless the continuation exceeds 80 character limit, please align it with
> previous line.
> 
>> +
>>   	return IRQ_HANDLED;
>>   }
>>
>> @@ -216,6 +258,7 @@ static int max17040_probe(struct i2c_client *client,
>>   	struct i2c_adapter *adapter = client->adapter;
>>   	struct power_supply_config psy_cfg = {};
>>   	struct max17040_chip *chip;
>> +	int ret;
>>
>>   	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
>>   		return -EIO;
>> @@ -226,6 +269,12 @@ static int max17040_probe(struct i2c_client *client,
>>
>>   	chip->client = client;
>>   	chip->pdata = client->dev.platform_data;
>> +	ret = max17040_get_of_data(chip);
>> +	if (ret) {
>> +		dev_err(&client->dev,
>> +			"failed: low SOC alert OF data out of bounds\n");
>> +		return ret;
>> +	}
>>
>>   	i2c_set_clientdata(client, chip);
>>   	psy_cfg.drv_data = chip;
>> @@ -242,20 +291,31 @@ static int max17040_probe(struct i2c_client *client,
>>
>>   	/* check interrupt */
>>   	if (client->irq) {
>> -		int ret;
>> -		unsigned int flags;
>> -
>> -		dev_info(&client->dev, "IRQ: enabled\n");
>> -		flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
>> -		ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
>> -						max17040_thread_handler, flags,
>> -						chip->battery->desc->name,
>> -						chip);
>> -
>> -		if (ret) {
>> -			client->irq = 0;
>> +		if (of_device_is_compatible(client->dev.of_node,
>> +			"maxim,max77836-battery")) {
> 
> Alignment.
> 
>> +			ret = max17040_set_low_soc_threshold_alert(client,
>> +				chip->low_soc_alert_threshold);
> 
> Ditto.
> 
>> +			if (ret) {
>> +				dev_err(&client->dev,
>> +					"Failed to set low SOC alert: err %d\n",
>> +					ret);
>> +				return ret;
>> +			}
>> +
>> +			dev_info(&client->dev, "IRQ: enabled\n");
>> +			ret = devm_request_threaded_irq(&client->dev,
>> +				client->irq, NULL, max17040_thread_handler,
>> +				(client->flags | IRQF_ONESHOT),
> 
> This looks unrelated. Befor ethis were IRQF_TRIGGER_FALLING |
> IRQF_ONESHOT, now you use client->flags. There is no reason why this
> commit should change >

I am using client->flags here to not overwrite the flag passed in device 
tree. Let me know what you think about it: if I should leave it as in 
the previous commit, or should I modify the previous commit too.

>> +				chip->battery->desc->name, chip);
> 
> This breaks alignment which was here before.
> 
> Best regards,
> Krzysztof
> 
> 

Thanks for the review i will work on it.

>> +
>> +			if (ret) {
>> +				client->irq = 0;
>> +				dev_warn(&client->dev,
>> +					"Failed to get IRQ err %d\n", ret);
>> +			}
>> +		} else {
>>   			dev_warn(&client->dev,
>> -				"Failed to get IRQ err %d\n", ret);
>> +				"Device not compatible for IRQ");
>>   		}
>>   	}
>>
>> --
>> 2.24.0.rc2
>>