Messages in this thread |  | | Subject | Re: [PATCH 02/18] staging: typec: tcpm: Add extcon helper functions for USB2 current limit detect | From | Guenter Roeck <> | Date | Sun, 6 Aug 2017 07:07:52 -0700 |
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On 08/06/2017 05:35 AM, Hans de Goede wrote: > Some type-c port-controllers, such as the fusb302 port-controller, rely > on an external device doing USB2 charger-type detection. > > Existing PMIC (and charger) drivers already use extcon to communicate the > detected charger-type from the PMIC (extcon) driver to the charger driver. > > Rather then inventing a new API for USB2 charger-type detection > specifically for use with the tcpm code, lets simply re-use the existing > support. This will also allow re-using existing PMIC extcon drivers such > as the axp288 and Intel Whiskey Cove drivers as is on devices where these > are combined with a fusb302 (or in the future another port-controller > which relies on external USB2 charger-type detection). > > This commit adds a helper function which tcpc drivers can use to easily > hook into existing PMIC extcon drivers for USB2 charger-type detection: > > int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc); > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/staging/typec/tcpm.c | 40 ++++++++++++++++++++++++++++++++++++++++ > drivers/staging/typec/tcpm.h | 6 ++++++ > 2 files changed, 46 insertions(+) > > diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c > index 9f5adace4309..06bb0e640bcf 100644 > --- a/drivers/staging/typec/tcpm.c > +++ b/drivers/staging/typec/tcpm.c > @@ -16,6 +16,7 @@ > > #include <linux/completion.h> > #include <linux/debugfs.h> > +#include <linux/delay.h> > #include <linux/device.h> > #include <linux/kernel.h> > #include <linux/module.h> > @@ -3532,6 +3533,45 @@ void tcpm_unregister_port(struct tcpm_port *port) > } > EXPORT_SYMBOL_GPL(tcpm_unregister_port); > > +/* Generic (helper) implementations for some tcpc_dev callbacks */ > +int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc) > +{ > + struct extcon_dev *extcon = tcpc->usb2_extcon; > + int current_limit = 0; > + unsigned long timeout; > + > + if (!extcon) > + return 0; > + > + /* > + * USB2 Charger detection may still be in progress when we get here, > + * this can take upto 600ms, wait 800ms max. > + */ > + timeout = jiffies + msecs_to_jiffies(800); > + do { > + if (extcon_get_state(extcon, EXTCON_CHG_USB_SDP) == 1) { > + current_limit = 500; > + break; > + } > + > + if (extcon_get_state(extcon, EXTCON_CHG_USB_CDP) == 1 || > + extcon_get_state(extcon, EXTCON_CHG_USB_ACA) == 1) { > + current_limit = 1500; > + break; > + } > + > + if (extcon_get_state(extcon, EXTCON_CHG_USB_DCP) == 1) { > + current_limit = 2000; > + break; > + } > + > + msleep(50); > + } while (time_before(jiffies, timeout)); > + > + return current_limit; > +} > +EXPORT_SYMBOL_GPL(tcpm_get_usb2_current_limit_extcon); > +
Not really sure about this one. Should it be part of low level drivers ?
Guenter
> MODULE_AUTHOR("Guenter Roeck <groeck@chromium.org>"); > MODULE_DESCRIPTION("USB Type-C Port Manager"); > MODULE_LICENSE("GPL"); > diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h > index 01b7d89379a3..35e8c1e7dba0 100644 > --- a/drivers/staging/typec/tcpm.h > +++ b/drivers/staging/typec/tcpm.h > @@ -16,6 +16,7 @@ > #define __LINUX_USB_TCPM_H > > #include <linux/bitops.h> > +#include <linux/extcon.h> > #include <linux/usb/typec.h> > #include "pd.h" > > @@ -126,6 +127,8 @@ struct tcpc_dev { > int (*pd_transmit)(struct tcpc_dev *dev, enum tcpm_transmit_type type, > const struct pd_message *msg); > struct tcpc_mux_dev *mux; > + /* Used by tcpm_get_usb2_current_limit_extcon helpers */ > + struct extcon_dev *usb2_extcon; > }; > > struct tcpm_port; > @@ -151,4 +154,7 @@ void tcpm_pd_transmit_complete(struct tcpm_port *port, > void tcpm_pd_hard_reset(struct tcpm_port *port); > void tcpm_tcpc_reset(struct tcpm_port *port); > > +/* Generic (helper) implementations for some tcpc_dev callbacks */ > +int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc); > + > #endif /* __LINUX_USB_TCPM_H */ >
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