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

[Krzysztof Kozlowski <krzk@kernel.org>]

On Fri, Nov 01, 2019 at 01:52:13PM -0300, Matheus Castello wrote:
> 
> 
> 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.

I still do not get why this change is here and how is related to this
commit.


Best regards,
Krzysztof