[PATCH] drivers: pmic: Add sysreset driver to da9063 pmic device

[Alexandre Ghiti]

On Tue, Sep 21, 2021 at 9:23 AM Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
>
>
> On 9/20/21 5:48 PM, Alexandre Ghiti wrote:
> > This pmic device is present on the SiFive Unmatched board and this
> > new driver adds the possibility to reset it.
> >
> > Signed-off-by: Alexandre Ghiti <alexandre.ghiti at canonical.com>
> > ---
> >   configs/sifive_unmatched_defconfig |  2 ++
> >   drivers/power/pmic/da9063.c        | 49 ++++++++++++++++++++++++++++++
> >   2 files changed, 51 insertions(+)
> >
> > diff --git a/configs/sifive_unmatched_defconfig b/configs/sifive_unmatched_defconfig
> > index 978818b688..9ab058be39 100644
> > --- a/configs/sifive_unmatched_defconfig
> > +++ b/configs/sifive_unmatched_defconfig
> > @@ -43,3 +43,5 @@ CONFIG_DM_USB=y
> >   CONFIG_USB_XHCI_HCD=y
> >   CONFIG_USB_XHCI_PCI=y
> >   CONFIG_BOARD_EARLY_INIT_F=y
> > +CONFIG_DM_PMIC=y
> > +CONFIG_DM_PMIC_DA9063=y
> > diff --git a/drivers/power/pmic/da9063.c b/drivers/power/pmic/da9063.c
> > index 25101d18f7..b04879d9c5 100644
> > --- a/drivers/power/pmic/da9063.c
> > +++ b/drivers/power/pmic/da9063.c
> > @@ -10,6 +10,7 @@
> >   #include <dm.h>
> >   #include <i2c.h>
> >   #include <log.h>
> > +#include <dm/lists.h>
> >   #include <power/pmic.h>
> >   #include <power/regulator.h>
> >   #include <power/da9063_pmic.h>
> > @@ -87,6 +88,7 @@ static int da9063_bind(struct udevice *dev)
> >   {
> >       ofnode regulators_node;
> >       int children;
> > +     int ret;
> >
> >       regulators_node = dev_read_subnode(dev, "regulators");
> >       if (!ofnode_valid(regulators_node)) {
> > @@ -101,6 +103,14 @@ static int da9063_bind(struct udevice *dev)
> >       if (!children)
> >               debug("%s: %s - no child found\n", __func__, dev->name);
> >
> > +     if (CONFIG_IS_ENABLED(SYSRESET)) {
>
> Thank you for addressing the missing reset driver for the SiFive
> Unmatched board.
>
> I imagine some existing or future boards using the DA9063 will have a
> GPIO for system reset. Should all boards having a DA9063 PMIC implement
> system reset via the power management IC?
>
> We could instead use the devicetree to identify if a board shall use the
> DA9063 for system reset.

Indeed, with this patch, any board with this chip may use this reset
handler, I'm not sure in which order the sysreset drivers are called
though.
We could add a new device like the rtc/watchdog ones, I'll give it a
try, that sounds way cleaner.

>
> > +             ret = device_bind_driver(dev, "da9063-sysreset",
> > +                                      "da9063-sysreset", NULL);
> > +             if (ret)
> > +                     debug("%s: %s - failed to bind sysreset driver\n",
> > +                           __func__, dev->name);
> > +     }
> > +
> >       /* Always return success for this device */
> >       return 0;
> >   }
> > @@ -129,3 +139,42 @@ U_BOOT_DRIVER(pmic_da9063) = {
> >       .probe = da9063_probe,
> >       .ops = &da9063_ops,
> >   };
> > +
> > +#ifdef CONFIG_SYSRESET
>
> The linker will remove functions that are not used automatically. We
> have tended to not enclose functions in #ifdef but instead allow the
> compiler to check the code.
>

Ok thanks!


> > +#include <sysreset.h>
>
> Please, keep includes at the top of the code.
>
> > +
>
> Even though this is a static function I would add a Sphinx style comment
> here. Cf.
> https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation
>
> Best regards
>
> Heinrich
>
> > +static int da9063_sysreset_request(struct udevice *dev, enum sysreset_t type)
> > +{
> > +     struct udevice *pmic_dev = dev->parent;
> > +     uint ret;
> > +
> > +     if (type != SYSRESET_WARM && type != SYSRESET_COLD)
> > +             return -EPROTONOSUPPORT;
> > +
> > +     ret = pmic_reg_write(pmic_dev, DA9063_REG_PAGE_CON, 0x00);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     /* Sets the WAKE_UP bit */
> > +     ret = pmic_reg_write(pmic_dev, DA9063_REG_CONTROL_F, 0x04);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     /* Powerdown! */
> > +     ret = pmic_reg_write(pmic_dev, DA9063_REG_CONTROL_A, 0x68);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     return -EINPROGRESS;
> > +}
> > +
> > +static struct sysreset_ops da9063_sysreset_ops = {
> > +     .request = da9063_sysreset_request,
> > +};
> > +
> > +U_BOOT_DRIVER(da9063_sysreset) = {
> > +     .name = "da9063-sysreset",
> > +     .id = UCLASS_SYSRESET,
> > +     .ops = &da9063_sysreset_ops,
> > +};
> > +#endif
> >

Alex