Re: [PATCH v1 1/1] usb: typec: tps6598x: Export some power supply properties

From: Guido Günther
Date: Thu Nov 26 2020 - 12:05:51 EST


Hi Heikki,
On Thu, Nov 26, 2020 at 02:35:52PM +0200, Heikki Krogerus wrote:
> On Wed, Nov 25, 2020 at 06:55:46PM +0100, Guido Günther wrote:
> > This allows downstream supplies and userspace to detect
> > whether external power is supplied.
> >
> > Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>
>
> This look OK to me, but I have one request below.

Thanks for having look!

> Btw. Are you sure that this works when the power supply class is not
> enabled? If I remember correctly, there are no stubs for the power
> supply functions.

You remember correctly - i've added a 'select POWER_SUPPLY' in v2.
>
> > ---
> > drivers/usb/typec/tps6598x.c | 97 ++++++++++++++++++++++++++++++++++++
> > 1 file changed, 97 insertions(+)
> >
> > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c
> > index 3db33bb622c3..ea72957602d8 100644
> > --- a/drivers/usb/typec/tps6598x.c
> > +++ b/drivers/usb/typec/tps6598x.c
> > @@ -9,6 +9,7 @@
> > #include <linux/i2c.h>
> > #include <linux/acpi.h>
> > #include <linux/module.h>
> > +#include <linux/power_supply.h>
> > #include <linux/regmap.h>
> > #include <linux/interrupt.h>
> > #include <linux/usb/typec.h>
> > @@ -55,6 +56,7 @@ enum {
> > };
> >
> > /* TPS_REG_POWER_STATUS bits */
> > +#define TPS_POWER_STATUS_CONNECTION BIT(0)
> > #define TPS_POWER_STATUS_SOURCESINK BIT(1)
> > #define TPS_POWER_STATUS_PWROPMODE(p) (((p) & GENMASK(3, 2)) >> 2)
> >
> > @@ -96,8 +98,24 @@ struct tps6598x {
> > struct typec_partner *partner;
> > struct usb_pd_identity partner_identity;
> > struct usb_role_switch *role_sw;
> > + struct typec_capability typec_cap;
> > +
> > + struct power_supply *psy;
> > + struct power_supply_desc psy_desc;
> > + enum power_supply_usb_type usb_type;
> > +};
> > +
> > +static enum power_supply_property tps6598x_psy_props[] = {
> > + POWER_SUPPLY_PROP_USB_TYPE,
> > + POWER_SUPPLY_PROP_ONLINE,
> > +};
> > +
> > +static enum power_supply_usb_type tps6598x_psy_usb_types[] = {
> > + POWER_SUPPLY_USB_TYPE_C,
> > };
> >
> > +static const char *tps6598x_psy_name_prefix = "tps6598x-source-psy-";
> > +
> > /*
> > * Max data bytes for Data1, Data2, and other registers. See ch 1.3.2:
> > * https://www.ti.com/lit/ug/slvuan1a/slvuan1a.pdf
> > @@ -248,6 +266,8 @@ static int tps6598x_connect(struct tps6598x *tps, u32 status)
> > if (desc.identity)
> > typec_partner_set_identity(tps->partner);
> >
> > + power_supply_changed(tps->psy);
> > +
> > return 0;
> > }
> >
> > @@ -260,6 +280,7 @@ static void tps6598x_disconnect(struct tps6598x *tps, u32 status)
> > typec_set_pwr_role(tps->port, TPS_STATUS_PORTROLE(status));
> > typec_set_vconn_role(tps->port, TPS_STATUS_VCONN(status));
> > tps6598x_set_data_role(tps, TPS_STATUS_DATAROLE(status), false);
> > + power_supply_changed(tps->psy);
> > }
> >
> > static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
> > @@ -467,6 +488,78 @@ static const struct regmap_config tps6598x_regmap_config = {
> > .max_register = 0x7F,
> > };
> >
> > +static int tps6598x_psy_get_online(struct tps6598x *tps,
> > + union power_supply_propval *val)
> > +{
> > + int ret;
> > + u16 pwr_status;
> > +
> > + ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &pwr_status);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (!(pwr_status & TPS_POWER_STATUS_CONNECTION) ||
> > + !(pwr_status & TPS_POWER_STATUS_SOURCESINK)) {
> > + val->intval = 0;
> > + } else {
> > + val->intval = 1;
> > + }
> > + return 0;
> > +}
> > +
> > +static int tps6598x_psy_get_prop(struct power_supply *psy,
> > + enum power_supply_property psp,
> > + union power_supply_propval *val)
> > +{
> > + struct tps6598x *tps = power_supply_get_drvdata(psy);
> > + int ret = 0;
> > +
> > + switch (psp) {
> > + case POWER_SUPPLY_PROP_USB_TYPE:
> > + val->intval = POWER_SUPPLY_USB_TYPE_C;
>
> It shouldn't be a problem to already check if there is PD contract in
> place by reading the Power Status register:
>
> ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &pwr_status);
> if (ret < 0)
> ...
>
> if (TPS_POWER_STATUS_PWROPMODE(pwr_status) == TYPEC_PWR_MODE_PD)
> val->intval = POWER_SUPPLY_USB_TYPE_PD;
> else
> val->intval = POWER_SUPPLY_USB_TYPEC_C;

Fixed in v2.
Cheers,
-- Guido

>
> Something like that.
>
> > + break;
> > + case POWER_SUPPLY_PROP_ONLINE:
> > + ret = tps6598x_psy_get_online(tps, val);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int devm_tps6598_psy_register(struct tps6598x *tps)
> > +{
> > + struct power_supply_config psy_cfg = {};
> > + const char *port_dev_name = dev_name(tps->dev);
> > + size_t psy_name_len = strlen(tps6598x_psy_name_prefix) +
> > + strlen(port_dev_name) + 1;
> > + char *psy_name;
> > +
> > + psy_cfg.drv_data = tps;
> > + psy_cfg.fwnode = dev_fwnode(tps->dev);
> > + psy_name = devm_kzalloc(tps->dev, psy_name_len, GFP_KERNEL);
> > + if (!psy_name)
> > + return -ENOMEM;
> > +
> > + snprintf(psy_name, psy_name_len, "%s%s", tps6598x_psy_name_prefix,
> > + port_dev_name);
> > + tps->psy_desc.name = psy_name;
> > + tps->psy_desc.type = POWER_SUPPLY_TYPE_USB;
> > + tps->psy_desc.usb_types = tps6598x_psy_usb_types;
> > + tps->psy_desc.num_usb_types = ARRAY_SIZE(tps6598x_psy_usb_types);
> > + tps->psy_desc.properties = tps6598x_psy_props;
> > + tps->psy_desc.num_properties = ARRAY_SIZE(tps6598x_psy_props);
> > + tps->psy_desc.get_property = tps6598x_psy_get_prop;
> > +
> > + tps->usb_type = POWER_SUPPLY_USB_TYPE_C;
> > +
> > + tps->psy = devm_power_supply_register(tps->dev, &tps->psy_desc,
> > + &psy_cfg);
> > + return PTR_ERR_OR_ZERO(tps->psy);
> > +}
> > +
> > static int tps6598x_probe(struct i2c_client *client)
> > {
> > struct typec_capability typec_cap = { };
> > @@ -560,6 +653,10 @@ static int tps6598x_probe(struct i2c_client *client)
> > goto err_role_put;
> > }
> >
> > + ret = devm_tps6598_psy_register(tps);
> > + if (ret)
> > + return ret;
> > +
> > tps->port = typec_register_port(&client->dev, &typec_cap);
> > if (IS_ERR(tps->port)) {
> > ret = PTR_ERR(tps->port);
> > --
> > 2.29.2
>
> thanks,
>
> --
> heikki
>