Re: [PATCH 1/2] leds: Add support for Palmas LEDs

[Ian Lartey]

On 28/02/13 11:52, Ian Lartey wrote:
> On 28/02/13 05:44, Laxman Dewangan wrote:
> > On Wednesday 27 February 2013 06:43 PM, Ian Lartey wrote:
> > > The Palmas familly of chips has LED support. This is not always muxed
> > > to output pins so depending on the setting of the mux this driver
> > > will create the appropriate LED class devices.
> > >
> > > Signed-off-by: Graeme Gregory <gg@xxxxxxxxxxxxxxx>
> > > Signed-off-by: Ian Lartey <ian@xxxxxxxxxxxxxxx>
> > > ---
> >
> > Patch 1 and 2 can be merged together as this is makefile, Kconfig and
> > driver addition.
>
> This could cause a merge conflict for anyone adding files/drivers
> in drivers/leds so it's safer to separate the Kconfig and Makefile
> from the actual drver source code so that can go in conflict free.
>
> > > +
> > > +static int palmas_led_read(struct palmas_leds_data *leds, unsigned
> > > int reg,
> > > +               unsigned int *dest)
> > > +{
> > > +       unsigned int addr;
> > > +
> > > +       addr = PALMAS_BASE_TO_REG(PALMAS_LED_BASE, reg);
> > This is not require. Infact doing this will not work.
>
> Yes, of course, thanks for that.
> > palmas_read already take care of proper offset.
> >          unsigned int addr =  PALMAS_BASE_TO_REG(base, reg);
> >          int slave_id = PALMAS_BASE_TO_SLAVE(base);
> >
> >          return regmap_read(palmas->regmap[slave_id], addr, val);
> >
> >
> > same for other places also.
>
> ditto.
>
> > > +static void palmas_leds_work(struct work_struct *work)
> > > +{
> > > +       struct palmas_led *led = container_of(work, struct palmas_led,
> > > work);
> > > +       unsigned int period, ctrl;
> > > +       unsigned long flags;
> > > +
> > > +       mutex_lock(&led->mutex);
> > > +
> > > +       palmas_led_read(led->leds_data, PALMAS_LED_CTRL, &ctrl);
> > > +       palmas_led_read(led->leds_data, PALMAS_LED_PERIOD_CTRL,
> > > &period);
> > > +
> > > +       spin_lock_irqsave(&led->value_lock, flags);
> > > +
> > > +       switch (led->led_no) {
> > > +       case 1:
> > > +               ctrl &= ~PALMAS_LED_CTRL_LED_1_ON_TIME_MASK;
> > > +               period &= ~PALMAS_LED_PERIOD_CTRL_LED_1_PERIOD_MASK;
> > > +
> >
> > case 1,2,3 and 4 looks same, jus shift/mask are changed. I think this
> > can be rewritten here to reduce code size.
>
> Will do.

Hi Laxman,

Looking at this again I think the cose is as small as it can be
whilst maintaining readability.
Is is fairly compact as this is setting up the ctrl, period
led->blink, and led->brightness values  that are used in the
next section to actually write to the led control registers.

Ian
> > > +static int palmas_leds_probe(struct platform_device *pdev)
> > > +{
> > > +       struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
> > > +       struct palmas_leds_platform_data *pdata =
> > > pdev->dev.platform_data;
> > > +       struct palmas_leds_data *leds_data;
> > > +       struct device_node *node = pdev->dev.of_node;
> > > +       int ret, i;
> > > +       int offset = 0;
> > > +
> > > +       if (!palmas->led_muxed &&
> > > !is_palmas_charger(palmas->product_id)) {
> > > +               dev_err(&pdev->dev, "there are no LEDs muxed\n");
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       /* Palmas charger requires platform data */
> > > +       if (is_palmas_charger(palmas->product_id) && node && !pdata) {
> > > +               pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata),
> > > GFP_KERNEL);
> > > +
> > > +               if (!pdata)
> > > +                       return -ENOMEM;
> > > +
> > > +               ret = palmas_dt_to_pdata(&pdev->dev, node, pdata);
> > > +               if (ret)
> > > +                       return ret;
> > > +       }
> > > +
> > > +       if (is_palmas_charger(palmas->product_id) && !pdata)
> > > +               return -EINVAL;
> > > +
> > > +       leds_data = kzalloc(sizeof(*leds_data), GFP_KERNEL);
> >
> > Use devm_kzalloc().
>
> Noted.
>
> > > +
> > > +static int  palmas_leds_init(void)
> > > +{
> > > +       return platform_driver_register(&palmas_leds_driver);
> > > +}
> > > +module_init(palmas_leds_init);
> > > +
> > > +static void palmas_leds_exit(void)
> > > +{
> > > +       platform_driver_unregister(&palmas_leds_driver);
> > > +}
> > > +module_exit(palmas_leds_exit);
> >
> > use Module_platform_driver().
>
> Will do.
>
> >
>
>
> Thanks,
>
> Ian

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