linux-kernel - Re: [PATCH v2 3/6] usb: typec: tcpci_rt1711h: Add regulator support when source vbus

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Date:   Fri, 22 Jul 2022 15:12:55 +0800
From:   Gene Chen <gene.chen.richtek@...il.com>
To:     Guenter Roeck <linux@...ck-us.net>
Cc:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Rob Herring <robh+dt@...nel.org>,
        krzysztof.kozlowski+dt@...aro.org, linux-usb@...r.kernel.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        devicetree <devicetree@...r.kernel.org>,
        Gene Chen <gene_chen@...htek.com>,
        ChiYuan Huang <cy_huang@...htek.com>
Subject: Re: [PATCH v2 3/6] usb: typec: tcpci_rt1711h: Add regulator support
 when source vbus

Guenter Roeck <linux@...ck-us.net> 於 2022年7月21日 週四 晚上10:28寫道：
>
> On 7/20/22 23:11, Gene Chen wrote:
> > From: Gene Chen <gene_chen@...htek.com>
> >
> > Add regulator support when source vbus
> >
> > Signed-off-by: Gene Chen <gene_chen@...htek.com>
> > ---
> >   drivers/usb/typec/tcpm/tcpci_rt1711h.c | 28 ++++++++++++++++++++++++++
> >   1 file changed, 28 insertions(+)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpci_rt1711h.c b/drivers/usb/typec/tcpm/tcpci_rt1711h.c
> > index 3309ceace2b2..52c9594e531d 100644
> > --- a/drivers/usb/typec/tcpm/tcpci_rt1711h.c
> > +++ b/drivers/usb/typec/tcpm/tcpci_rt1711h.c
> > @@ -10,6 +10,7 @@
> >   #include <linux/i2c.h>
> >   #include <linux/interrupt.h>
> >   #include <linux/gpio/consumer.h>
> > +#include <linux/regulator/consumer.h>
> >   #include <linux/usb/tcpm.h>
> >   #include <linux/regmap.h>
> >   #include "tcpci.h"
> > @@ -40,6 +41,8 @@ struct rt1711h_chip {
> >       struct tcpci_data data;
> >       struct tcpci *tcpci;
> >       struct device *dev;
> > +     struct regulator *vbus;
> > +     bool src_en;
> >   };
> >
> >   static int rt1711h_read16(struct rt1711h_chip *chip, unsigned int reg, u16 *val)
> > @@ -103,6 +106,26 @@ static int rt1711h_init(struct tcpci *tcpci, struct tcpci_data *tdata)
> >
> >       /* dcSRC.DRP : 33% */
> >       return rt1711h_write16(chip, RT1711H_RTCTRL16, 330);
> > +
> > +}
> > +
> > +static int rt1711h_set_vbus(struct tcpci *tcpci, struct tcpci_data *tdata,
> > +                         bool src, bool snk)
> > +{
> > +     struct rt1711h_chip *chip = tdata_to_rt1711h(tdata);
> > +     int ret;
> > +
> > +     if (chip->src_en == src)
> > +             return 1;
> > +
> > +     if (src)
> > +             ret = regulator_enable(chip->vbus);
> > +     else
> > +             ret = regulator_disable(chip->vbus);
> > +
> > +     if (!ret)
> > +             chip->src_en = src;
> > +     return ret ? ret : 1;
>
> Are you sure this is what you want ? Returning 1 bypasses the code setting
> the vbus registers in tcpci.c. If that is on purpose it might make sense
> to explain it.
>

ACK, return 0 is more compatible with next generation chip,
and writing tcpci vbus command won't affect to ic if not supported.

> >   }
> >
> >   static int rt1711h_set_vconn(struct tcpci *tcpci, struct tcpci_data *tdata,
> > @@ -246,7 +269,12 @@ static int rt1711h_probe(struct i2c_client *client,
> >       if (ret < 0)
> >               return ret;
> >
> > +     chip->vbus = devm_regulator_get(&client->dev, "vbus");
> > +     if (IS_ERR(chip->vbus))
> > +             return PTR_ERR(chip->vbus);
> > +
>
> This makes regulator support mandatory, which so far was not the case.
> That warrants an explanation why it is not a problem for existing users.
>

We verified ic behavior as SNK only, because we couldn't add tcpci set
vbus callback and external boost otg vbus.
And we use our own type-c state machine and pd policy engine for mass
production to user.

> Thanks,
> Guenter
>
> >       chip->data.init = rt1711h_init;
> > +     chip->data.set_vbus = rt1711h_set_vbus;
> >       chip->data.set_vconn = rt1711h_set_vconn;
> >       chip->data.start_drp_toggling = rt1711h_start_drp_toggling;
> >       chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
>