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

From: Sebastian Reichel
Date: Sat Jul 25 2015 - 13:27:32 EST


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@xxxxxxxxxxx>

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@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");

MODULE_LICENSE("GPL v2");

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