Re: [PATCH 1/4] power: supply: max17040: Add IRQ handler for low SOC alert

Krzysztof Kozlowski
2018-07-25T10:27:22Z

On 23 July 2018 at 06:08, Matheus Castello <matheus@castello.eng.br> wrote:
> According datasheet max17040 has a pin for alert host for low SOC.
> This pin can be used as external interrupt, so we need to check for
> interrupts assigned for device and handle it.
>
> In hadler we are checking and storing fuel gauge registers values
> and send an uevent to notificate user space, so user space can decide
> save work or turn off since the alert demonstrate that the battery may
> no have the power to keep the system turned on for much longer.
>
> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
> ---
> drivers/power/supply/max17040_battery.c | 51 +++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
> index 33c40f79d23d..6e54e58814a9 100644
> --- a/drivers/power/supply/max17040_battery.c
> +++ b/drivers/power/supply/max17040_battery.c
> @@ -17,6 +17,7 @@
> #include <linux/err.h>
> #include <linux/i2c.h>
> #include <linux/delay.h>
> +#include <linux/interrupt.h>
> #include <linux/power_supply.h>
> #include <linux/max17040_battery.h>
> #include <linux/slab.h>
> @@ -179,6 +180,24 @@ static void max17040_work(struct work_struct *work)
> MAX17040_DELAY);
> }
>
> +static irqreturn_t max17040_thread_handler(int id, void *dev)
> +{
> + struct max17040_chip *chip = dev;
> + struct i2c_client *client = chip->client;
> +
> + dev_warn(&client->dev, "IRQ: Alert battery low level");
> + /* read registers */
> + max17040_get_vcell(chip->client);

You just stored chip->client in client...

> + max17040_get_soc(chip->client);
> + max17040_get_online(chip->client);
> + max17040_get_status(chip->client);

This duplicates max17040_work(). Can you split common part?

> +
> + /* send uevent */
> + power_supply_changed(chip->battery);
> +
> + return IRQ_HANDLED;
> +}
> +
> static enum power_supply_property max17040_battery_props[] = {
> POWER_SUPPLY_PROP_STATUS,
> POWER_SUPPLY_PROP_ONLINE,
> @@ -200,6 +219,8 @@ static int max17040_probe(struct i2c_client *client,
> struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> struct power_supply_config psy_cfg = {};
> struct max17040_chip *chip;
> + int ret;
> + unsigned int flags;

Define them in scope using them.

>
> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
> return -EIO;
> @@ -221,6 +242,24 @@ static int max17040_probe(struct i2c_client *client,
> return PTR_ERR(chip->battery);
> }
>
> + /* check interrupt */
> + if (client->irq) {
> + 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);

Please indent it to parenthesis.

> + if (ret) {
> + client->irq = 0;
> + if (ret != -EBUSY)
> + dev_warn(&client->dev,
> + "Failed to get IRQ err %d \n", ret);
> + }
> + }
> +
> max17040_reset(client);
> max17040_get_version(client);
>
> @@ -248,6 +287,12 @@ static int max17040_suspend(struct device *dev)
> struct max17040_chip *chip = i2c_get_clientdata(client);
>
> cancel_delayed_work(&chip->work);
> +
> + if (chip->client->irq) {

I think this should use device wakeup properties (e.g.
device_init_wakeup(), device_may_wakeup()) coming from pdata.

It would be nice to CC users of this driver. We have it on some of
boards. Unfortunately get_maintainer will not point it automatically
so:
scripts/get_maintainer.pl -f drivers/mfd/max14577.c

Best regards,
Krzysztof

> + disable_irq(chip->client->irq);
> + enable_irq_wake(chip->client->irq);
> + }
> +
> return 0;
> }
>
> @@ -258,6 +303,12 @@ static int max17040_resume(struct device *dev)
>
> queue_delayed_work(system_power_efficient_wq, &chip->work,
> MAX17040_DELAY);
> +
> + if (chip->client->irq) {
> + disable_irq_wake(chip->client->irq);
> + enable_irq(chip->client->irq);
> + }
> +
> return 0;
> }
>
> --
> 2.13.3
>