Re: [PATCH v3 3/6] power: Add support for DA9150 Fuel-Gauge

[Sebastian Reichel <sre@kernel.org>]

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Hi Adam,

The driver looks mostly fine. I have a few comments, though:

On Tue, Jul 07, 2015 at 05:34:19PM +0100, Adam Thomson wrote:
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>

Please add a short description to the commit message.

> [...] 
>
> +config FG_DA9150

Please name the config entry BATTERY_DA9150 to be consistent with
the other fuel gauges.

> [...]
>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/power_supply.h>
> +#include <linux/list.h>
> +#include <asm/div64.h>
> +#include <linux/mfd/da9150/core.h>
> +#include <linux/mfd/da9150/registers.h>

I wonder if the "depends CHARGER_DA9150" in Kconfig should be
"depends MFD_DA9150" instead.

> [...]
> +
> +/* Power Supply attributes */
> +static int da9150_fg_capacity(struct da9150_fg *fg,
> +			      union power_supply_propval *val)
> +{
> +	da9150_fg_read_sync_start(fg);
> +	val->intval = da9150_fg_read_attr(fg, DA9150_QIF_SOC_PCT,
> +					  DA9150_QIF_SOC_PCT_SIZE);
> +	da9150_fg_read_sync_end(fg);

Create a wrapper function for this. Reading a single value
with sync guards is done multiple times.

da9150_fg_read_attr_sync(fg, ...) {
    da9150_fg_read_sync_start(fg);
    da9150_fg_read_attr(fg, ...);
    da9150_fg_read_sync_end(fg);
}

> +	if (val->intval > 100)
> +		val->intval = 100;
> +
> +	return 0;
> +}
> +
>
> [...]
> +					  DA9150_QIF_E_FG_STATUS_SIZE);
> +
> +	/* Handle warning/critical threhold events */
> +	if ((DA9150_FG_IRQ_LOW_SOC_MASK | DA9150_FG_IRQ_HIGH_SOC_MASK) &
> +	    e_fg_status)

Please make this (e_fg_status & CONSTANT_MASK).

> +		da9150_fg_soc_event_config(fg);
> +
> +	/* Clear any FG IRQs */
> +	da9150_fg_write_attr(fg, DA9150_QIF_E_FG_STATUS,
> +			     DA9150_QIF_E_FG_STATUS_SIZE, e_fg_status);
> +
> +	return IRQ_HANDLED;
> +}
> +
>
> [...]
>
> +static int da9150_fg_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct da9150 *da9150 = dev_get_drvdata(dev->parent);
> +	struct da9150_fg_pdata *fg_pdata = dev_get_platdata(dev);
> +	struct da9150_fg *fg;
> +	int ver, irq, ret;
> +
> +	fg = devm_kzalloc(dev, sizeof(*fg), GFP_KERNEL);
> +	if (fg == NULL)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, fg);
> +	fg->da9150 = da9150;
> +	fg->dev = dev;
> +
> +	mutex_init(&fg->io_lock);
> +
> +	/* Enable QIF */
> +	da9150_set_bits(da9150, DA9150_CORE2WIRE_CTRL_A, DA9150_FG_QIF_EN_MASK,
> +			DA9150_FG_QIF_EN_MASK);
> +
> +	fg->battery = power_supply_register(dev, &fg_desc, NULL);
> +	if (IS_ERR(fg->battery)) {
> +		ret = PTR_ERR(fg->battery);
> +		return ret;
> +	}

Please use devm_power_supply_register(...) to simplify the driver.

> +	ver = da9150_fg_read_attr(fg, DA9150_QIF_FW_MAIN_VER,
> +				  DA9150_QIF_FW_MAIN_VER_SIZE);
> +	dev_info(dev, "Version: 0x%x\n", ver);
> +
> +	/* Handle DT data if provided */
> +	if (dev->of_node) {
> +		fg_pdata = da9150_fg_dt_pdata(dev);
> +		dev->platform_data = fg_pdata;
> +	}
> +
> +	/* Handle any pdata provided */
> +	if (fg_pdata) {
> +		fg->interval = fg_pdata->update_interval;
> +
> +		if (fg_pdata->warn_soc_lvl > 100)
> +			dev_warn(dev, "Invalid SOC warning level provided, Ignoring");
> +		else
> +			fg->warn_soc = fg_pdata->warn_soc_lvl;
> +
> +		if ((fg_pdata->crit_soc_lvl > 100) ||
> +		    (fg_pdata->crit_soc_lvl >= fg_pdata->warn_soc_lvl))
> +			dev_warn(dev, "Invalid SOC critical level provided, Ignoring");
> +		else
> +			fg->crit_soc = fg_pdata->crit_soc_lvl;
> +
> +
> +	}
> +
> +	/* Configure initial SOC level events */
> +	da9150_fg_soc_event_config(fg);
> +
> +	/*
> +	 * If an interval period has been provided then setup repeating
> +	 * work for reporting data updates.
> +	 */
> +	if (fg->interval) {
> +		INIT_DELAYED_WORK(&fg->work, da9150_fg_work);
> +		schedule_delayed_work(&fg->work,
> +				      msecs_to_jiffies(fg->interval));
> +	}
> +
> +	/* Register IRQ */
> +	irq = platform_get_irq_byname(pdev, "FG");
> +	ret = request_threaded_irq(irq, NULL, da9150_fg_irq, IRQF_ONESHOT, "FG",
> +				   fg);
> +	if (ret)
> +		goto irq_fail;
> +
> +	return ret;
> +
> +irq_fail:
> +	cancel_delayed_work(&fg->work);
> +	power_supply_unregister(fg->battery);
> +
> +	return ret;
> +}
> +
> +static int da9150_fg_remove(struct platform_device *pdev)
> +{
> +	struct da9150_fg *fg = platform_get_drvdata(pdev);
> +	int irq;
> +
> +	irq = platform_get_irq_byname(pdev, "FG");
> +	free_irq(irq, fg);
> +
> +	if (fg->interval)
> +		cancel_delayed_work(&fg->work);

It looks like the order of irq freeing and canceling of the
delayed work is not important. In that case I suggest switching
to devm_request_threaded_irq(...).

> +	power_supply_unregister(fg->battery);
> +
> +	return 0;
> +}
> 
> [...]
>
> +
> +MODULE_DESCRIPTION("Fuel-Gauge Driver for DA9150");
> +MODULE_AUTHOR("Adam Thomson <Adam.Thomson.Opensource@diasemi.com>");
> +MODULE_LICENSE("GPL");

MODULE_LICENSE("GPL v2");

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