On Thu, 24 May 2018, Steve Twiss wrote:
> Thanks Marek,
>
> On 23 May 2018 12:42 Marek Vasut wrote,
>
> > To: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>; Geert Uytterhoeven <geert+renesas@xxxxxxxxx>; Lee Jones <lee.jones@xxxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; Steve Twiss <stwiss.opensource@xxxxxxxxxxx>; Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; linux-renesas-soc@xxxxxxxxxxxxxxx
> > Subject: [PATCH 4/6] mfd: da9063: Disallow RTC on DA9063L
> >
> > The DA9063L does not contain RTC block, unlike the full DA9063.
> > Do not allow binding RTC driver on this variant of the chip.
> >
> > Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
> > Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> > Cc: Mark Brown <broonie@xxxxxxxxxx>
> > Cc: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>
> > Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> > Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> > ---
> > drivers/mfd/da9063-core.c | 18 +++++++++++-------
> > 1 file changed, 11 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/mfd/da9063-core.c b/drivers/mfd/da9063-core.c index 7360b76b4f72..263c83006413 100644
> > --- a/drivers/mfd/da9063-core.c
> > +++ b/drivers/mfd/da9063-core.c
> > @@ -101,14 +101,14 @@ static const struct mfd_cell da9063_devs[] = {
> > .of_compatible = "dlg,da9063-onkey",
> > },
> > {
> > + .name = DA9063_DRVNAME_VIBRATION,
> > + },
> > + { /* Only present on DA9063 , not on DA9063L */
> > .name = DA9063_DRVNAME_RTC,
> > .num_resources = ARRAY_SIZE(da9063_rtc_resources),
> > .resources = da9063_rtc_resources,
> > .of_compatible = "dlg,da9063-rtc",
> > },
> > - {
> > - .name = DA9063_DRVNAME_VIBRATION,
> > - },
> > };
> >
> > static int da9063_clear_fault_log(struct da9063 *da9063) @@ -163,7 +163,7 @@ int da9063_device_init(struct da9063 *da9063, unsigned int irq) {
> > struct da9063_pdata *pdata = da9063->dev->platform_data;
> > int model, variant_id, variant_code;
> > - int ret;
> > + int da9063_devs_len, ret;
> >
> > ret = da9063_clear_fault_log(da9063);
> > if (ret < 0)
> > @@ -225,9 +225,13 @@ int da9063_device_init(struct da9063 *da9063, unsigned int irq)
> >
> > da9063->irq_base = regmap_irq_chip_get_base(da9063->regmap_irq);
> >
> > - ret = mfd_add_devices(da9063->dev, -1, da9063_devs,
> > - ARRAY_SIZE(da9063_devs), NULL, da9063->irq_base,
> > - NULL);
> > + da9063_devs_len = ARRAY_SIZE(da9063_devs);
> > + /* RTC, the last device in the list, is only present on DA9063 */
> > + if (da9063->type == PMIC_TYPE_DA9063L)
> > + da9063_devs_len -= 1;
> > +
> > + ret = mfd_add_devices(da9063->dev, -1, da9063_devs, da9063_devs_len,
> > + NULL, da9063->irq_base, NULL);
> > if (ret)
> > dev_err(da9063->dev, "Cannot add MFD cells\n");
> >
>
> MFD cells definitely has less impact than regmap_range and regmap_irq.
> I agree, there's no point in having a completely new
> static const struct mfd_cell da9063l_devs[] = { ... } for DA9063L
This solution is fragile.
I agree that a new MFD cell is not required in its entirety. It
would however, be better to split out the RTC entry into a new one and
only register it when (da9063->type == PMIC_TYPE_DA9063). This is a
better solution than messing around with passed struct sizes.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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