| Message ID | 20220208031944.3444-1-bjorn.andersson@linaro.org |
|---|---|
| Headers | show |
| Series | typec: mux: Introduce support for multiple TypeC muxes | expand |
On Tue, Feb 8, 2022 at 1:26 PM Bjorn Andersson <bjorn.andersson@linaro.org> wrote: > > The ON Semiconductor FSA4480 is a USB Type-C port multimedia switch with > support for analog audio headsets. It allows sharing a common USB Type-C > port to pass USB2.0 signal, analog audio, sideband use wires and analog > microphone signal. > > Due to lacking upstream audio support for testing, the audio muxing is > left untouched, but implementation of muxing the SBU lines is provided > as a pair of TypeC mux and switch devices. This provides the necessary > support for enabling the DisplayPort altmode on devices with this > circuit. ... > +config TYPEC_MUX_FSA4480 > + tristate "ON Semi FSA4480 Analog Audio Switch driver" > + depends on I2C > + select REGMAP_I2C > + help > + Driver for the ON Semiconductor FSA4480 Analog Audio Switch, which > + provides support for muxing analog audio and sideband signals on a > + common USB Type-C connector. What would be the module name? ... > +/* > + * Copyright (C) 2021 Linaro Ltd. 2021-2022 ? > + * Copyright (C) 2018-2020 The Linux Foundation > + */ ... Missed mod_devicetable.h ? ... > +#define FSA4480_ENABLE_DEVICE BIT(7) > +#define FSA4480_ENABLE_SBU GENMASK(6, 5) > +#define FSA4480_ENABLE_USB GENMASK(4, 3) Don't forget to include bits.h ... > + /* used to serialize concurrect change requests */ concurrent ... > +static const struct regmap_config fsa4480_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = FSA4480_RESET, I would create a specific macro, to avoid confusion in case if there will be more hw revisions with slightly different register layouts. > +}; ... > + fsa->regmap = devm_regmap_init_i2c(client, &fsa4480_regmap_config); > + if (IS_ERR(fsa->regmap)) { > + dev_err(dev, "failed to initialize regmap\n"); > + return PTR_ERR(fsa->regmap); return dev_err_probe(); > + } ... > + fsa->sw = typec_switch_register(dev, &sw_desc); > + if (IS_ERR(fsa->sw)) { > + dev_err(dev, "failed to register typec switch: %ld\n", PTR_ERR(fsa->sw)); > + return PTR_ERR(fsa->sw); Ditto. > + } ... > + mux_desc.fwnode = dev->fwnode; Please, avoid dereferencing fwnode, use dev_fwnode() instead. ... > + fsa->mux = typec_mux_register(dev, &mux_desc); > + if (IS_ERR(fsa->mux)) { > + typec_switch_unregister(fsa->sw); > + dev_err(dev, "failed to register typec mux: %ld\n", PTR_ERR(fsa->mux)); > + return PTR_ERR(fsa->mux); return dev_err_probe(); > + } ... > +static struct i2c_driver fsa4480_driver = { > + .driver = { > + .name = "fsa4480", > + .of_match_table = fsa4480_of_table, > + }, > + .probe_new = fsa4480_probe, > + .remove = fsa4480_remove, > + .id_table = fsa4480_table, > +}; > + Redundant blank line. > +module_i2c_driver(fsa4480_driver);
On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: > In some cases multiple connections with the same connection id > needs to be resolved from a fwnode graph. > > One such example is when separate hardware is used for performing muxing > and/or orientation switching of the SuperSpeed and SBU lines in a USB-C USB Type-C ? > connector. In this case the connector needs to belong to a graph with > multiple matching remote endpoints, and the TypeC controller needs to be Type-C ? > able to resolve them both. > > Add a new API that allows this kind of lookup. > > Given that the match() callback returns an opaque reference to something > provided by the client it's not possible for the implementation to > release the returned object and as such it's not possible to handle > errors, which in turn means that it's not possible to query the number > of elements or dynamically grow the results array. It's however expected > that the number of matches will be reasonably low and that the worst > case is known by the caller before hand. ... > + fwnode_graph_for_each_endpoint(fwnode, ep) { > + if (count >= matches_len) { > + fwnode_handle_put(ep); > + return count; > + } > + > + node = fwnode_graph_get_remote_port_parent(ep); > + if (!fwnode_device_is_available(node)) { > + fwnode_handle_put(node); > + continue; > + } > + > + ret = match(node, con_id, data); > + fwnode_handle_put(node); > + Redundant blank line (it seems the current style w/o this). Ditto for the below function. > + if (ret) > + matches[count++] = ret; > + } ... > +/** > + * fwnode_connection_find_matches - Find connections from a device node > + * @fwnode: Device node with the connection > + * @con_id: Identifier for the connection > + * @data: Data for the match function > + * @match: Function to check and convert the connection description > + * @matches: Array of pointers to fill with matches > + * @matches_len: Length of @matches > + * > + * Find up to @matches_len connections with unique identifier @con_id between > + * @fwnode and other device nodes. @match will be used to convert the > + * connection description to data the caller is expecting to be returned > + * through the @matches array. > + * > + * Return: Number of matches resolved, of negative errno. s/of/or/ ? > + */ > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > + const char *con_id, void *data, > + devcon_match_fn_t match, > + void **matches, unsigned int matches_len) > +{ > + unsigned int count; > + > + if (!fwnode || !match || !matches) !matches case may be still useful to get the count and allocate memory by caller. Please, consider this case. > + return -EINVAL; > + > + count = fwnode_graph_devcon_matches(fwnode, con_id, data, match, > + matches, matches_len); > + > + return count + fwnode_devcon_matches(fwnode, con_id, data, match, > + matches + count, > + matches_len - count); I haven't found any explanation what the difference between two counts. Also can you define two count variables with distinct names and do something like count_A = ... matches += count; matches_len -= count; count_B = ... return count_A + count_B; ? > +}
Hi, On 2/8/22 04:19, Bjorn Andersson wrote: > This series introduces a level of indirection between the controller's view of > a typec_mux/switch and the implementation and then expands that to support > multiple drivers. > > This is needed in order to support devices such as the Qualcomm Snapdragon 888 > HDK, which does muxing and orientation handling in the QMP (USB+DP) PHY and SBU > muxing in the external FSA4480 chip. > > Included in the series is a the new FSA4480 driver. This is done to deal with > the renaming of the driver-side typec_mux -> typec_mux_dev. I have tested patches 1-4 on a GPD win which uses a fusb302 TCPM with a pi3usb30532 mux and superspeed orientation switching as well as DP over Type-C still works fine there, so you may add my: Tested-by: Hans de Goede <hdegoede@redhat.com> Regards, Hans > > Changes since v1: > - Omitted QMP changes from this series, as the muxing implementation needs a > little bit more debugging. > > Bjorn Andersson (6): > device property: Helper to match multiple connections > device property: Use multi-connection matchers for single case > typec: mux: Introduce indirection > typec: mux: Allow multiple mux_devs per mux > dt-bindings: usb: Add binding for fcs,fsa4480 > usb: typec: mux: Add On Semi fsa4480 driver > > .../devicetree/bindings/usb/fcs,fsa4480.yaml | 72 +++++ > drivers/base/property.c | 85 ++++-- > drivers/usb/typec/bus.c | 2 +- > drivers/usb/typec/mux.c | 261 +++++++++++++----- > drivers/usb/typec/mux.h | 12 +- > drivers/usb/typec/mux/Kconfig | 9 + > drivers/usb/typec/mux/Makefile | 1 + > drivers/usb/typec/mux/fsa4480.c | 220 +++++++++++++++ > drivers/usb/typec/mux/intel_pmc_mux.c | 8 +- > drivers/usb/typec/mux/pi3usb30532.c | 8 +- > include/linux/property.h | 5 + > include/linux/usb/typec_mux.h | 22 +- > 12 files changed, 595 insertions(+), 110 deletions(-) > create mode 100644 Documentation/devicetree/bindings/usb/fcs,fsa4480.yaml > create mode 100644 drivers/usb/typec/mux/fsa4480.c >
On Mon, Feb 07, 2022 at 07:19:41PM -0800, Bjorn Andersson wrote: > Rather than directly exposing the implementation's representation of the > typec muxes to the controller/clients, introduce an indirection object. > > This enables the introduction of turning this relationship into a > one-to-many in the following patch. > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > > Changes sice v1: > - None > > drivers/usb/typec/bus.c | 2 +- > drivers/usb/typec/mux.c | 189 ++++++++++++++++---------- > drivers/usb/typec/mux.h | 12 +- > drivers/usb/typec/mux/intel_pmc_mux.c | 8 +- > drivers/usb/typec/mux/pi3usb30532.c | 8 +- > include/linux/usb/typec_mux.h | 22 +-- > 6 files changed, 146 insertions(+), 95 deletions(-) > > diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c > index 78e0e78954f2..26ea2fdec17d 100644 > --- a/drivers/usb/typec/bus.c > +++ b/drivers/usb/typec/bus.c > @@ -24,7 +24,7 @@ typec_altmode_set_mux(struct altmode *alt, unsigned long conf, void *data) > state.mode = conf; > state.data = data; > > - return alt->mux->set(alt->mux, &state); > + return typec_mux_set(alt->mux, &state); > } > > static int typec_altmode_set_state(struct typec_altmode *adev, > diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c > index c8340de0ed49..d0b42c297aca 100644 > --- a/drivers/usb/typec/mux.c > +++ b/drivers/usb/typec/mux.c > @@ -17,9 +17,13 @@ > #include "class.h" > #include "mux.h" > > +struct typec_switch { > + struct typec_switch_dev *sw_dev; > +}; > + > static int switch_fwnode_match(struct device *dev, const void *fwnode) > { > - if (!is_typec_switch(dev)) > + if (!is_typec_switch_dev(dev)) > return 0; > > return dev_fwnode(dev) == fwnode; > @@ -49,7 +53,7 @@ static void *typec_switch_match(struct fwnode_handle *fwnode, const char *id, > dev = class_find_device(&typec_mux_class, NULL, fwnode, > switch_fwnode_match); > > - return dev ? to_typec_switch(dev) : ERR_PTR(-EPROBE_DEFER); > + return dev ? to_typec_switch_dev(dev) : ERR_PTR(-EPROBE_DEFER); > } > > /** > @@ -63,12 +67,23 @@ static void *typec_switch_match(struct fwnode_handle *fwnode, const char *id, > */ > struct typec_switch *fwnode_typec_switch_get(struct fwnode_handle *fwnode) > { > + struct typec_switch_dev *sw_dev; > struct typec_switch *sw; > > - sw = fwnode_connection_find_match(fwnode, "orientation-switch", NULL, > - typec_switch_match); > - if (!IS_ERR_OR_NULL(sw)) > - WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); > + sw = kzalloc(sizeof(*sw), GFP_KERNEL); > + if (!sw) > + return ERR_PTR(-ENOMEM); > + > + sw_dev = fwnode_connection_find_match(fwnode, "orientation-switch", NULL, > + typec_switch_match); > + if (IS_ERR_OR_NULL(sw_dev)) { > + kfree(sw); > + return ERR_CAST(sw_dev); > + } > + > + WARN_ON(!try_module_get(sw_dev->dev.parent->driver->owner)); > + > + sw->sw_dev = sw_dev; > > return sw; > } > @@ -82,16 +97,22 @@ EXPORT_SYMBOL_GPL(fwnode_typec_switch_get); > */ > void typec_switch_put(struct typec_switch *sw) > { > - if (!IS_ERR_OR_NULL(sw)) { > - module_put(sw->dev.parent->driver->owner); > - put_device(&sw->dev); > - } > + struct typec_switch_dev *sw_dev; > + > + if (IS_ERR_OR_NULL(sw)) > + return; > + > + sw_dev = sw->sw_dev; > + > + module_put(sw_dev->dev.parent->driver->owner); > + put_device(&sw_dev->dev); > + kfree(sw); > } > EXPORT_SYMBOL_GPL(typec_switch_put); > > static void typec_switch_release(struct device *dev) > { > - kfree(to_typec_switch(dev)); > + kfree(to_typec_switch_dev(dev)); > } > > const struct device_type typec_switch_dev_type = { > @@ -109,82 +130,90 @@ const struct device_type typec_switch_dev_type = { > * connector to the USB controllers. USB Type-C plugs can be inserted > * right-side-up or upside-down. > */ > -struct typec_switch * > +struct typec_switch_dev * > typec_switch_register(struct device *parent, > const struct typec_switch_desc *desc) > { > - struct typec_switch *sw; > + struct typec_switch_dev *sw_dev; > int ret; > > if (!desc || !desc->set) > return ERR_PTR(-EINVAL); > > - sw = kzalloc(sizeof(*sw), GFP_KERNEL); > - if (!sw) > + sw_dev = kzalloc(sizeof(*sw_dev), GFP_KERNEL); > + if (!sw_dev) > return ERR_PTR(-ENOMEM); > > - sw->set = desc->set; > + sw_dev->set = desc->set; > > - device_initialize(&sw->dev); > - sw->dev.parent = parent; > - sw->dev.fwnode = desc->fwnode; > - sw->dev.class = &typec_mux_class; > - sw->dev.type = &typec_switch_dev_type; > - sw->dev.driver_data = desc->drvdata; > - dev_set_name(&sw->dev, "%s-switch", > + device_initialize(&sw_dev->dev); > + sw_dev->dev.parent = parent; > + sw_dev->dev.fwnode = desc->fwnode; > + sw_dev->dev.class = &typec_mux_class; > + sw_dev->dev.type = &typec_switch_dev_type; > + sw_dev->dev.driver_data = desc->drvdata; > + dev_set_name(&sw_dev->dev, "%s-switch", > desc->name ? desc->name : dev_name(parent)); > > - ret = device_add(&sw->dev); > + ret = device_add(&sw_dev->dev); > if (ret) { > dev_err(parent, "failed to register switch (%d)\n", ret); > - put_device(&sw->dev); > + put_device(&sw_dev->dev); > return ERR_PTR(ret); > } > > - return sw; > + return sw_dev; > } > EXPORT_SYMBOL_GPL(typec_switch_register); > > int typec_switch_set(struct typec_switch *sw, > enum typec_orientation orientation) > { > + struct typec_switch_dev *sw_dev; > + > if (IS_ERR_OR_NULL(sw)) > return 0; > > - return sw->set(sw, orientation); > + sw_dev = sw->sw_dev; > + > + return sw_dev->set(sw_dev, orientation); > } > EXPORT_SYMBOL_GPL(typec_switch_set); > > /** > * typec_switch_unregister - Unregister USB Type-C orientation switch > - * @sw: USB Type-C orientation switch > + * @sw_dev: USB Type-C orientation switch > * > * Unregister switch that was registered with typec_switch_register(). > */ > -void typec_switch_unregister(struct typec_switch *sw) > +void typec_switch_unregister(struct typec_switch_dev *sw_dev) > { > - if (!IS_ERR_OR_NULL(sw)) > - device_unregister(&sw->dev); > + if (!IS_ERR_OR_NULL(sw_dev)) > + device_unregister(&sw_dev->dev); > } > EXPORT_SYMBOL_GPL(typec_switch_unregister); > > -void typec_switch_set_drvdata(struct typec_switch *sw, void *data) > +void typec_switch_set_drvdata(struct typec_switch_dev *sw_dev, void *data) > { > - dev_set_drvdata(&sw->dev, data); > + dev_set_drvdata(&sw_dev->dev, data); > } > EXPORT_SYMBOL_GPL(typec_switch_set_drvdata); > > -void *typec_switch_get_drvdata(struct typec_switch *sw) > +void *typec_switch_get_drvdata(struct typec_switch_dev *sw_dev) > { > - return dev_get_drvdata(&sw->dev); > + return dev_get_drvdata(&sw_dev->dev); > } > EXPORT_SYMBOL_GPL(typec_switch_get_drvdata); > > /* ------------------------------------------------------------------------- */ > > +struct typec_mux { > + struct typec_mux_dev *mux_dev; > +}; > + > static int mux_fwnode_match(struct device *dev, const void *fwnode) > { > - if (!is_typec_mux(dev)) > + if (!is_typec_mux_dev(dev)) > return 0; > > return dev_fwnode(dev) == fwnode; > @@ -246,7 +275,7 @@ static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id, > dev = class_find_device(&typec_mux_class, NULL, fwnode, > mux_fwnode_match); > > - return dev ? to_typec_mux(dev) : ERR_PTR(-EPROBE_DEFER); > + return dev ? to_typec_mux_dev(dev) : ERR_PTR(-EPROBE_DEFER); > } > > /** > @@ -262,12 +291,23 @@ static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id, > struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode, > const struct typec_altmode_desc *desc) > { > + struct typec_mux_dev *mux_dev; > struct typec_mux *mux; > > - mux = fwnode_connection_find_match(fwnode, "mode-switch", (void *)desc, > - typec_mux_match); > - if (!IS_ERR_OR_NULL(mux)) > - WARN_ON(!try_module_get(mux->dev.parent->driver->owner)); > + mux = kzalloc(sizeof(*mux), GFP_KERNEL); > + if (!mux) > + return ERR_PTR(-ENOMEM); > + > + mux_dev = fwnode_connection_find_match(fwnode, "mode-switch", (void *)desc, > + typec_mux_match); > + if (IS_ERR_OR_NULL(mux_dev)) { > + kfree(mux); > + return ERR_CAST(mux_dev); > + } > + > + WARN_ON(!try_module_get(mux_dev->dev.parent->driver->owner)); > + > + mux->mux_dev = mux_dev; > > return mux; > } > @@ -281,25 +321,34 @@ EXPORT_SYMBOL_GPL(fwnode_typec_mux_get); > */ > void typec_mux_put(struct typec_mux *mux) > { > - if (!IS_ERR_OR_NULL(mux)) { > - module_put(mux->dev.parent->driver->owner); > - put_device(&mux->dev); > - } > + struct typec_mux_dev *mux_dev; > + > + if (IS_ERR_OR_NULL(mux)) > + return; > + > + mux_dev = mux->mux_dev; > + module_put(mux_dev->dev.parent->driver->owner); > + put_device(&mux_dev->dev); > + kfree(mux); > } > EXPORT_SYMBOL_GPL(typec_mux_put); > > int typec_mux_set(struct typec_mux *mux, struct typec_mux_state *state) > { > + struct typec_mux_dev *mux_dev; > + > if (IS_ERR_OR_NULL(mux)) > return 0; > > - return mux->set(mux, state); > + mux_dev = mux->mux_dev; > + > + return mux_dev->set(mux_dev, state); > } > EXPORT_SYMBOL_GPL(typec_mux_set); > > static void typec_mux_release(struct device *dev) > { > - kfree(to_typec_mux(dev)); > + kfree(to_typec_mux_dev(dev)); > } > > const struct device_type typec_mux_dev_type = { > @@ -317,63 +366,63 @@ const struct device_type typec_mux_dev_type = { > * the pins on the connector need to be reconfigured. This function registers > * multiplexer switches routing the pins on the connector. > */ > -struct typec_mux * > +struct typec_mux_dev * > typec_mux_register(struct device *parent, const struct typec_mux_desc *desc) > { > - struct typec_mux *mux; > + struct typec_mux_dev *mux_dev; > int ret; > > if (!desc || !desc->set) > return ERR_PTR(-EINVAL); > > - mux = kzalloc(sizeof(*mux), GFP_KERNEL); > - if (!mux) > + mux_dev = kzalloc(sizeof(*mux_dev), GFP_KERNEL); > + if (!mux_dev) > return ERR_PTR(-ENOMEM); > > - mux->set = desc->set; > + mux_dev->set = desc->set; > > - device_initialize(&mux->dev); > - mux->dev.parent = parent; > - mux->dev.fwnode = desc->fwnode; > - mux->dev.class = &typec_mux_class; > - mux->dev.type = &typec_mux_dev_type; > - mux->dev.driver_data = desc->drvdata; > - dev_set_name(&mux->dev, "%s-mux", > + device_initialize(&mux_dev->dev); > + mux_dev->dev.parent = parent; > + mux_dev->dev.fwnode = desc->fwnode; > + mux_dev->dev.class = &typec_mux_class; > + mux_dev->dev.type = &typec_mux_dev_type; > + mux_dev->dev.driver_data = desc->drvdata; > + dev_set_name(&mux_dev->dev, "%s-mux", > desc->name ? desc->name : dev_name(parent)); > > - ret = device_add(&mux->dev); > + ret = device_add(&mux_dev->dev); > if (ret) { > dev_err(parent, "failed to register mux (%d)\n", ret); > - put_device(&mux->dev); > + put_device(&mux_dev->dev); > return ERR_PTR(ret); > } > > - return mux; > + return mux_dev; > } > EXPORT_SYMBOL_GPL(typec_mux_register); > > /** > * typec_mux_unregister - Unregister Multiplexer Switch > - * @mux: USB Type-C Connector Multiplexer/DeMultiplexer > + * @mux_dev: USB Type-C Connector Multiplexer/DeMultiplexer > * > * Unregister mux that was registered with typec_mux_register(). > */ > -void typec_mux_unregister(struct typec_mux *mux) > +void typec_mux_unregister(struct typec_mux_dev *mux_dev) > { > - if (!IS_ERR_OR_NULL(mux)) > - device_unregister(&mux->dev); > + if (!IS_ERR_OR_NULL(mux_dev)) > + device_unregister(&mux_dev->dev); > } > EXPORT_SYMBOL_GPL(typec_mux_unregister); > > -void typec_mux_set_drvdata(struct typec_mux *mux, void *data) > +void typec_mux_set_drvdata(struct typec_mux_dev *mux_dev, void *data) > { > - dev_set_drvdata(&mux->dev, data); > + dev_set_drvdata(&mux_dev->dev, data); > } > EXPORT_SYMBOL_GPL(typec_mux_set_drvdata); > > -void *typec_mux_get_drvdata(struct typec_mux *mux) > +void *typec_mux_get_drvdata(struct typec_mux_dev *mux_dev) > { > - return dev_get_drvdata(&mux->dev); > + return dev_get_drvdata(&mux_dev->dev); > } > EXPORT_SYMBOL_GPL(typec_mux_get_drvdata); > > diff --git a/drivers/usb/typec/mux.h b/drivers/usb/typec/mux.h > index b1d6e837cb74..58f0f28b6dc8 100644 > --- a/drivers/usb/typec/mux.h > +++ b/drivers/usb/typec/mux.h > @@ -5,23 +5,23 @@ > > #include <linux/usb/typec_mux.h> > > -struct typec_switch { > +struct typec_switch_dev { > struct device dev; > typec_switch_set_fn_t set; > }; > > -struct typec_mux { > +struct typec_mux_dev { > struct device dev; > typec_mux_set_fn_t set; > }; > > -#define to_typec_switch(_dev_) container_of(_dev_, struct typec_switch, dev) > -#define to_typec_mux(_dev_) container_of(_dev_, struct typec_mux, dev) > +#define to_typec_switch_dev(_dev_) container_of(_dev_, struct typec_switch_dev, dev) > +#define to_typec_mux_dev(_dev_) container_of(_dev_, struct typec_mux_dev, dev) > > extern const struct device_type typec_switch_dev_type; > extern const struct device_type typec_mux_dev_type; > > -#define is_typec_switch(dev) ((dev)->type == &typec_switch_dev_type) > -#define is_typec_mux(dev) ((dev)->type == &typec_mux_dev_type) > +#define is_typec_switch_dev(dev) ((dev)->type == &typec_switch_dev_type) > +#define is_typec_mux_dev(dev) ((dev)->type == &typec_mux_dev_type) > > #endif /* __USB_TYPEC_MUX__ */ > diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c > index 2cdd22130834..51d8f3b88128 100644 > --- a/drivers/usb/typec/mux/intel_pmc_mux.c > +++ b/drivers/usb/typec/mux/intel_pmc_mux.c > @@ -121,8 +121,8 @@ struct pmc_usb_port { > int num; > u32 iom_status; > struct pmc_usb *pmc; > - struct typec_mux *typec_mux; > - struct typec_switch *typec_sw; > + struct typec_mux_dev *typec_mux; > + struct typec_switch_dev *typec_sw; > struct usb_role_switch *usb_sw; > > enum typec_orientation orientation; > @@ -416,7 +416,7 @@ static int pmc_usb_connect(struct pmc_usb_port *port, enum usb_role role) > } > > static int > -pmc_usb_mux_set(struct typec_mux *mux, struct typec_mux_state *state) > +pmc_usb_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state) > { > struct pmc_usb_port *port = typec_mux_get_drvdata(mux); > > @@ -452,7 +452,7 @@ pmc_usb_mux_set(struct typec_mux *mux, struct typec_mux_state *state) > return -EOPNOTSUPP; > } > > -static int pmc_usb_set_orientation(struct typec_switch *sw, > +static int pmc_usb_set_orientation(struct typec_switch_dev *sw, > enum typec_orientation orientation) > { > struct pmc_usb_port *port = typec_switch_get_drvdata(sw); > diff --git a/drivers/usb/typec/mux/pi3usb30532.c b/drivers/usb/typec/mux/pi3usb30532.c > index 7afe275b17d0..6ce9f282594e 100644 > --- a/drivers/usb/typec/mux/pi3usb30532.c > +++ b/drivers/usb/typec/mux/pi3usb30532.c > @@ -23,8 +23,8 @@ > struct pi3usb30532 { > struct i2c_client *client; > struct mutex lock; /* protects the cached conf register */ > - struct typec_switch *sw; > - struct typec_mux *mux; > + struct typec_switch_dev *sw; > + struct typec_mux_dev *mux; > u8 conf; > }; > > @@ -45,7 +45,7 @@ static int pi3usb30532_set_conf(struct pi3usb30532 *pi, u8 new_conf) > return 0; > } > > -static int pi3usb30532_sw_set(struct typec_switch *sw, > +static int pi3usb30532_sw_set(struct typec_switch_dev *sw, > enum typec_orientation orientation) > { > struct pi3usb30532 *pi = typec_switch_get_drvdata(sw); > @@ -74,7 +74,7 @@ static int pi3usb30532_sw_set(struct typec_switch *sw, > } > > static int > -pi3usb30532_mux_set(struct typec_mux *mux, struct typec_mux_state *state) > +pi3usb30532_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state) > { > struct pi3usb30532 *pi = typec_mux_get_drvdata(mux); > u8 new_conf; > diff --git a/include/linux/usb/typec_mux.h b/include/linux/usb/typec_mux.h > index a9d9957933dc..ee57781dcf28 100644 > --- a/include/linux/usb/typec_mux.h > +++ b/include/linux/usb/typec_mux.h > @@ -8,11 +8,13 @@ > > struct device; > struct typec_mux; > +struct typec_mux_dev; > struct typec_switch; > +struct typec_switch_dev; > struct typec_altmode; > struct fwnode_handle; > > -typedef int (*typec_switch_set_fn_t)(struct typec_switch *sw, > +typedef int (*typec_switch_set_fn_t)(struct typec_switch_dev *sw, > enum typec_orientation orientation); > > struct typec_switch_desc { > @@ -32,13 +34,13 @@ static inline struct typec_switch *typec_switch_get(struct device *dev) > return fwnode_typec_switch_get(dev_fwnode(dev)); > } > > -struct typec_switch * > +struct typec_switch_dev * > typec_switch_register(struct device *parent, > const struct typec_switch_desc *desc); > -void typec_switch_unregister(struct typec_switch *sw); > +void typec_switch_unregister(struct typec_switch_dev *sw); > > -void typec_switch_set_drvdata(struct typec_switch *sw, void *data); > -void *typec_switch_get_drvdata(struct typec_switch *sw); > +void typec_switch_set_drvdata(struct typec_switch_dev *sw, void *data); > +void *typec_switch_get_drvdata(struct typec_switch_dev *sw); > > struct typec_mux_state { > struct typec_altmode *alt; > @@ -46,7 +48,7 @@ struct typec_mux_state { > void *data; > }; > > -typedef int (*typec_mux_set_fn_t)(struct typec_mux *mux, > +typedef int (*typec_mux_set_fn_t)(struct typec_mux_dev *mux, > struct typec_mux_state *state); > > struct typec_mux_desc { > @@ -67,11 +69,11 @@ typec_mux_get(struct device *dev, const struct typec_altmode_desc *desc) > return fwnode_typec_mux_get(dev_fwnode(dev), desc); > } > > -struct typec_mux * > +struct typec_mux_dev * > typec_mux_register(struct device *parent, const struct typec_mux_desc *desc); > -void typec_mux_unregister(struct typec_mux *mux); > +void typec_mux_unregister(struct typec_mux_dev *mux); > > -void typec_mux_set_drvdata(struct typec_mux *mux, void *data); > -void *typec_mux_get_drvdata(struct typec_mux *mux); > +void typec_mux_set_drvdata(struct typec_mux_dev *mux, void *data); > +void *typec_mux_get_drvdata(struct typec_mux_dev *mux); > > #endif /* __USB_TYPEC_MUX */ > -- > 2.33.1
On Mon, Feb 07, 2022 at 07:19:42PM -0800, Bjorn Andersson wrote: > In the Qualcomm platforms the USB/DP PHY handles muxing and orientation > switching of the SuperSpeed lines, but the SBU lines needs to be > connected and switched by external (to the SoC) hardware. > > It's therefor necessary to be able to have the TypeC controller operate > multiple TypeC muxes and switches. Use the newly introduced indirection > object to handle this, to avoid having to taint the TypeC controllers > with knowledge about the downstream hardware configuration. > > The max number of devs per indirection is set to 3, which account for > being able to mux/switch the USB HS, SS and SBU lines, as per defined > defined in the usb-c-connector binding. This number could be grown if > need arrises at a later point in time. > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > > Changes since v1: > - Improved the motivation for the 3 in the commit message. > - kfree sw and mux in error paths > > drivers/usb/typec/mux.c | 128 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 102 insertions(+), 26 deletions(-) > > diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c > index d0b42c297aca..cf2347dd1663 100644 > --- a/drivers/usb/typec/mux.c > +++ b/drivers/usb/typec/mux.c > @@ -17,8 +17,11 @@ > #include "class.h" > #include "mux.h" > > +#define TYPEC_MUX_MAX_DEVS 3 > + > struct typec_switch { > - struct typec_switch_dev *sw_dev; > + struct typec_switch_dev *sw_devs[TYPEC_MUX_MAX_DEVS]; > + unsigned int num_sw_devs; > }; > > static int switch_fwnode_match(struct device *dev, const void *fwnode) > @@ -67,25 +70,50 @@ static void *typec_switch_match(struct fwnode_handle *fwnode, const char *id, > */ > struct typec_switch *fwnode_typec_switch_get(struct fwnode_handle *fwnode) > { > - struct typec_switch_dev *sw_dev; > + struct typec_switch_dev *sw_devs[TYPEC_MUX_MAX_DEVS]; > struct typec_switch *sw; > + int count; > + int err; > + int i; > > sw = kzalloc(sizeof(*sw), GFP_KERNEL); > if (!sw) > return ERR_PTR(-ENOMEM); > > - sw_dev = fwnode_connection_find_match(fwnode, "orientation-switch", NULL, > - typec_switch_match); > - if (IS_ERR_OR_NULL(sw_dev)) { > + count = fwnode_connection_find_matches(fwnode, "orientation-switch", NULL, > + typec_switch_match, > + (void **)sw_devs, > + ARRAY_SIZE(sw_devs)); > + if (count <= 0) { > kfree(sw); > - return ERR_CAST(sw_dev); > + return NULL; > } > > - WARN_ON(!try_module_get(sw_dev->dev.parent->driver->owner)); > + for (i = 0; i < count; i++) { > + if (IS_ERR(sw_devs[i])) { > + err = PTR_ERR(sw_devs[i]); > + goto put_sw_devs; > + } > + } > > - sw->sw_dev = sw_dev; > + for (i = 0; i < count; i++) { > + WARN_ON(!try_module_get(sw_devs[i]->dev.parent->driver->owner)); > + sw->sw_devs[i] = sw_devs[i]; > + } > + > + sw->num_sw_devs = count; > > return sw; > + > +put_sw_devs: > + for (i = 0; i < count; i++) { > + if (!IS_ERR(sw_devs[i])) > + put_device(&sw_devs[i]->dev); > + } > + > + kfree(sw); > + > + return ERR_PTR(err); > } > EXPORT_SYMBOL_GPL(fwnode_typec_switch_get); > > @@ -98,14 +126,17 @@ EXPORT_SYMBOL_GPL(fwnode_typec_switch_get); > void typec_switch_put(struct typec_switch *sw) > { > struct typec_switch_dev *sw_dev; > + unsigned int i; > > if (IS_ERR_OR_NULL(sw)) > return; > > - sw_dev = sw->sw_dev; > + for (i = 0; i < sw->num_sw_devs; i++) { > + sw_dev = sw->sw_devs[i]; > > - module_put(sw_dev->dev.parent->driver->owner); > - put_device(&sw_dev->dev); > + module_put(sw_dev->dev.parent->driver->owner); > + put_device(&sw_dev->dev); > + } > kfree(sw); > } > EXPORT_SYMBOL_GPL(typec_switch_put); > @@ -170,13 +201,21 @@ int typec_switch_set(struct typec_switch *sw, > enum typec_orientation orientation) > { > struct typec_switch_dev *sw_dev; > + unsigned int i; > + int ret; > > if (IS_ERR_OR_NULL(sw)) > return 0; > > - sw_dev = sw->sw_dev; > + for (i = 0; i < sw->num_sw_devs; i++) { > + sw_dev = sw->sw_devs[i]; > + > + ret = sw_dev->set(sw_dev, orientation); > + if (ret) > + return ret; > + } > > - return sw_dev->set(sw_dev, orientation); > + return 0; > } > EXPORT_SYMBOL_GPL(typec_switch_set); > > @@ -208,7 +247,8 @@ EXPORT_SYMBOL_GPL(typec_switch_get_drvdata); > /* ------------------------------------------------------------------------- */ > > struct typec_mux { > - struct typec_mux_dev *mux_dev; > + struct typec_mux_dev *mux_devs[TYPEC_MUX_MAX_DEVS]; > + unsigned int num_mux_devs; > }; > > static int mux_fwnode_match(struct device *dev, const void *fwnode) > @@ -291,25 +331,50 @@ static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id, > struct typec_mux *fwnode_typec_mux_get(struct fwnode_handle *fwnode, > const struct typec_altmode_desc *desc) > { > - struct typec_mux_dev *mux_dev; > + struct typec_mux_dev *mux_devs[TYPEC_MUX_MAX_DEVS]; > struct typec_mux *mux; > + int count; > + int err; > + int i; > > mux = kzalloc(sizeof(*mux), GFP_KERNEL); > if (!mux) > return ERR_PTR(-ENOMEM); > > - mux_dev = fwnode_connection_find_match(fwnode, "mode-switch", (void *)desc, > - typec_mux_match); > - if (IS_ERR_OR_NULL(mux_dev)) { > + count = fwnode_connection_find_matches(fwnode, "mode-switch", > + (void *)desc, typec_mux_match, > + (void **)mux_devs, > + ARRAY_SIZE(mux_devs)); > + if (count <= 0) { > kfree(mux); > - return ERR_CAST(mux_dev); > + return NULL; > } > > - WARN_ON(!try_module_get(mux_dev->dev.parent->driver->owner)); > + for (i = 0; i < count; i++) { > + if (IS_ERR(mux_devs[i])) { > + err = PTR_ERR(mux_devs[i]); > + goto put_mux_devs; > + } > + } > + > + for (i = 0; i < count; i++) { > + WARN_ON(!try_module_get(mux_devs[i]->dev.parent->driver->owner)); > + mux->mux_devs[i] = mux_devs[i]; > + } > > - mux->mux_dev = mux_dev; > + mux->num_mux_devs = count; > > return mux; > + > +put_mux_devs: > + for (i = 0; i < count; i++) { > + if (!IS_ERR(mux_devs[i])) > + put_device(&mux_devs[i]->dev); > + } > + > + kfree(mux); > + > + return ERR_PTR(err); > } > EXPORT_SYMBOL_GPL(fwnode_typec_mux_get); > > @@ -322,13 +387,16 @@ EXPORT_SYMBOL_GPL(fwnode_typec_mux_get); > void typec_mux_put(struct typec_mux *mux) > { > struct typec_mux_dev *mux_dev; > + unsigned int i; > > if (IS_ERR_OR_NULL(mux)) > return; > > - mux_dev = mux->mux_dev; > - module_put(mux_dev->dev.parent->driver->owner); > - put_device(&mux_dev->dev); > + for (i = 0; i < mux->num_mux_devs; i++) { > + mux_dev = mux->mux_devs[i]; > + module_put(mux_dev->dev.parent->driver->owner); > + put_device(&mux_dev->dev); > + } > kfree(mux); > } > EXPORT_SYMBOL_GPL(typec_mux_put); > @@ -336,13 +404,21 @@ EXPORT_SYMBOL_GPL(typec_mux_put); > int typec_mux_set(struct typec_mux *mux, struct typec_mux_state *state) > { > struct typec_mux_dev *mux_dev; > + unsigned int i; > + int ret; > > if (IS_ERR_OR_NULL(mux)) > return 0; > > - mux_dev = mux->mux_dev; > + for (i = 0; i < mux->num_mux_devs; i++) { > + mux_dev = mux->mux_devs[i]; > + > + ret = mux_dev->set(mux_dev, state); > + if (ret) > + return ret; > + } > > - return mux_dev->set(mux_dev, state); > + return 0; > } > EXPORT_SYMBOL_GPL(typec_mux_set); > > -- > 2.33.1
On Wed 09 Feb 04:30 PST 2022, Andy Shevchenko wrote: > On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: > > In some cases multiple connections with the same connection id > > needs to be resolved from a fwnode graph. > > > > One such example is when separate hardware is used for performing muxing > > and/or orientation switching of the SuperSpeed and SBU lines in a USB-C > > USB Type-C ? > > > connector. In this case the connector needs to belong to a graph with > > multiple matching remote endpoints, and the TypeC controller needs to be > > Type-C ? > > > able to resolve them both. > > > > Add a new API that allows this kind of lookup. > > > > Given that the match() callback returns an opaque reference to something > > provided by the client it's not possible for the implementation to > > release the returned object and as such it's not possible to handle > > errors, which in turn means that it's not possible to query the number > > of elements or dynamically grow the results array. It's however expected > > that the number of matches will be reasonably low and that the worst > > case is known by the caller before hand. > > ... > > > + fwnode_graph_for_each_endpoint(fwnode, ep) { > > + if (count >= matches_len) { > > + fwnode_handle_put(ep); > > + return count; > > + } > > + > > + node = fwnode_graph_get_remote_port_parent(ep); > > + if (!fwnode_device_is_available(node)) { > > + fwnode_handle_put(node); > > + continue; > > + } > > + > > + ret = match(node, con_id, data); > > + fwnode_handle_put(node); > > > + > > Redundant blank line (it seems the current style w/o this). > Ditto for the below function. > > > + if (ret) > > + matches[count++] = ret; > > + } > > ... > > > +/** > > + * fwnode_connection_find_matches - Find connections from a device node > > + * @fwnode: Device node with the connection > > + * @con_id: Identifier for the connection > > + * @data: Data for the match function > > + * @match: Function to check and convert the connection description > > + * @matches: Array of pointers to fill with matches > > + * @matches_len: Length of @matches > > + * > > + * Find up to @matches_len connections with unique identifier @con_id between > > + * @fwnode and other device nodes. @match will be used to convert the > > + * connection description to data the caller is expecting to be returned > > + * through the @matches array. > > + * > > + * Return: Number of matches resolved, of negative errno. > > s/of/or/ ? > > > + */ > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > + const char *con_id, void *data, > > + devcon_match_fn_t match, > > + void **matches, unsigned int matches_len) > > +{ > > + unsigned int count; > > + > > + if (!fwnode || !match || !matches) > > !matches case may be still useful to get the count and allocate memory by > caller. Please, consider this case. > As discussed in previous version, and described in the commit message, the returned value of "match" is a opaque pointer to something which has to be passed back to the caller in order to be cleaned up. E.g. the typec mux code returns a pointer to a typec_mux/switch object with a refcounted struct device within, or an ERR_PTR(). So unfortunately we can must gather the results into matches and pass it back to the caller to take consume or clean up. Thanks for your review, I'll update the patches according to the other feedback. Regards, Bjorn > > + return -EINVAL; > > + > > + count = fwnode_graph_devcon_matches(fwnode, con_id, data, match, > > + matches, matches_len); > > + > > + return count + fwnode_devcon_matches(fwnode, con_id, data, match, > > + matches + count, > > + matches_len - count); > > I haven't found any explanation what the difference between two counts. Also > can you define two count variables with distinct names and do something like > > count_A = ... > > matches += count; > matches_len -= count; > > count_B = ... > > return count_A + count_B; > > ? > > > +} > > -- > With Best Regards, > Andy Shevchenko > >
On Fri, Feb 18, 2022 at 11:00:45AM -0800, Bjorn Andersson wrote: > On Wed 09 Feb 04:30 PST 2022, Andy Shevchenko wrote: > > On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: ... > > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > > + const char *con_id, void *data, > > > + devcon_match_fn_t match, > > > + void **matches, unsigned int matches_len) > > > +{ > > > + unsigned int count; > > > + > > > + if (!fwnode || !match || !matches) > > > > !matches case may be still useful to get the count and allocate memory by > > caller. Please, consider this case. > > > > As discussed in previous version, and described in the commit message, > the returned value of "match" is a opaque pointer to something which > has to be passed back to the caller in order to be cleaned up. > > E.g. the typec mux code returns a pointer to a typec_mux/switch object > with a refcounted struct device within, or an ERR_PTR(). > > So unfortunately we can must gather the results into matches and pass it > back to the caller to take consume or clean up. It's fine. You have **matches, means pointer of an opaque pointer. What I'm talking about is memory allocation for and array of _pointers_. That's what caller very much aware of and can allocate on heap. So, please consider this case.
On Sun 20 Feb 03:16 PST 2022, Andy Shevchenko wrote: > On Fri, Feb 18, 2022 at 11:00:45AM -0800, Bjorn Andersson wrote: > > On Wed 09 Feb 04:30 PST 2022, Andy Shevchenko wrote: > > > On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: > > ... > > > > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > > > + const char *con_id, void *data, > > > > + devcon_match_fn_t match, > > > > + void **matches, unsigned int matches_len) > > > > +{ > > > > + unsigned int count; > > > > + > > > > + if (!fwnode || !match || !matches) > > > > > > !matches case may be still useful to get the count and allocate memory by > > > caller. Please, consider this case. > > > > > > > As discussed in previous version, and described in the commit message, > > the returned value of "match" is a opaque pointer to something which > > has to be passed back to the caller in order to be cleaned up. > > > > E.g. the typec mux code returns a pointer to a typec_mux/switch object > > with a refcounted struct device within, or an ERR_PTR(). > > > > So unfortunately we can must gather the results into matches and pass it > > back to the caller to take consume or clean up. > > > It's fine. You have **matches, means pointer of an opaque pointer. > What I'm talking about is memory allocation for and array of _pointers_. > That's what caller very much aware of and can allocate on heap. So, please > consider this case. > I'm sorry, but I'm not sure what you're looking for. I still interpret your comment as that it would be nice to be able to do something like: count = fwnode_connection_find_matches(fwnode, "orientation-switch", NULL, typec_switch_match, NULL, 0); based on the returned value the caller could allocate an array of "count" pointers and then call the function again to actually fill out the count elements. The problem with this is that, typec_switch_match() does: void *typec_switch_match(fwnode, id, data) { struct device *dev = find_struct_device(fwnode, id); if (!dev) return NULL; get_device(dev); return container_of(dev, struct typec_switch, dev); } So if we call the match function and if that finds a "dev" it will return a struct typec_switch with a refcounted struct device within. We can see if that's NULL or not and will be able to return a "count", but we have no way of releasing the reference acquired - we must return the void pointer back to the client, so that it can release it. My claim is that this is not a problem, because this works fine with any reasonable size of fwnode graphs we might run into - and the client will in general have a sense of the worst case number of matches (in this series its 3, as there's 3 types of lanes that can be switched/muxed coming out of a USB connector). But that's perhaps not what you're referring to? Or perhaps I'm missing something else? Regards, Bjorn
On Sun, Feb 20, 2022 at 08:55:10PM -0800, Bjorn Andersson wrote: > On Sun 20 Feb 03:16 PST 2022, Andy Shevchenko wrote: > > On Fri, Feb 18, 2022 at 11:00:45AM -0800, Bjorn Andersson wrote: > > > On Wed 09 Feb 04:30 PST 2022, Andy Shevchenko wrote: > > > > On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: ... > > > > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > > > > + const char *con_id, void *data, > > > > > + devcon_match_fn_t match, > > > > > + void **matches, unsigned int matches_len) > > > > > +{ > > > > > + unsigned int count; > > > > > + > > > > > + if (!fwnode || !match || !matches) > > > > > > > > !matches case may be still useful to get the count and allocate memory by > > > > caller. Please, consider this case. > > > > > > As discussed in previous version, and described in the commit message, > > > the returned value of "match" is a opaque pointer to something which > > > has to be passed back to the caller in order to be cleaned up. > > > > > > E.g. the typec mux code returns a pointer to a typec_mux/switch object > > > with a refcounted struct device within, or an ERR_PTR(). > > > > > > So unfortunately we can must gather the results into matches and pass it > > > back to the caller to take consume or clean up. > > > > It's fine. You have **matches, means pointer of an opaque pointer. > > What I'm talking about is memory allocation for and array of _pointers_. > > That's what caller very much aware of and can allocate on heap. So, please > > consider this case. > > I'm sorry, but I'm not sure what you're looking for. > > > I still interpret your comment as that it would be nice to be able to do > something like: > > count = fwnode_connection_find_matches(fwnode, "orientation-switch", > NULL, typec_switch_match, NULL, 0); > > based on the returned value the caller could allocate an array of > "count" pointers and then call the function again to actually fill out > the count elements. Yes, that's what I want from the generic fwnode APIs. (Keyword: generic) > The problem with this is that, typec_switch_match() does: As you stated, the problem is in the typec_switch_match(). So, it's not related to the fwnode, but how you are using it. > void *typec_switch_match(fwnode, id, data) { > struct device *dev = find_struct_device(fwnode, id); > if (!dev) > return NULL; > get_device(dev); > return container_of(dev, struct typec_switch, dev); > } > > So if we call the match function and if that finds a "dev" it will > return a struct typec_switch with a refcounted struct device within. fwnode (as being an abstraction on top of the others) has no knowledge about this. And more important should not know that. > We can see if that's NULL or not and will be able to return a "count", > but we have no way of releasing the reference acquired - we must return > the void pointer back to the client, so that it can release it. The caller (if it wants to!) may create different callbacks for count and real matching, no? > My claim is that this is not a problem, because this works fine with any > reasonable size of fwnode graphs we might run into - and the client will > in general have a sense of the worst case number of matches (in this > series its 3, as there's 3 types of lanes that can be switched/muxed > coming out of a USB connector).
On Mon 21 Feb 09:19 PST 2022, Andy Shevchenko wrote: > On Sun, Feb 20, 2022 at 08:55:10PM -0800, Bjorn Andersson wrote: > > On Sun 20 Feb 03:16 PST 2022, Andy Shevchenko wrote: > > > On Fri, Feb 18, 2022 at 11:00:45AM -0800, Bjorn Andersson wrote: > > > > On Wed 09 Feb 04:30 PST 2022, Andy Shevchenko wrote: > > > > > On Mon, Feb 07, 2022 at 07:19:39PM -0800, Bjorn Andersson wrote: > > ... > > > > > > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > > > > > + const char *con_id, void *data, > > > > > > + devcon_match_fn_t match, > > > > > > + void **matches, unsigned int matches_len) > > > > > > +{ > > > > > > + unsigned int count; > > > > > > + > > > > > > + if (!fwnode || !match || !matches) > > > > > > > > > > !matches case may be still useful to get the count and allocate memory by > > > > > caller. Please, consider this case. > > > > > > > > As discussed in previous version, and described in the commit message, > > > > the returned value of "match" is a opaque pointer to something which > > > > has to be passed back to the caller in order to be cleaned up. > > > > > > > > E.g. the typec mux code returns a pointer to a typec_mux/switch object > > > > with a refcounted struct device within, or an ERR_PTR(). > > > > > > > > So unfortunately we can must gather the results into matches and pass it > > > > back to the caller to take consume or clean up. > > > > > > It's fine. You have **matches, means pointer of an opaque pointer. > > > What I'm talking about is memory allocation for and array of _pointers_. > > > That's what caller very much aware of and can allocate on heap. So, please > > > consider this case. > > > > I'm sorry, but I'm not sure what you're looking for. > > > > > > I still interpret your comment as that it would be nice to be able to do > > something like: > > > > count = fwnode_connection_find_matches(fwnode, "orientation-switch", > > NULL, typec_switch_match, NULL, 0); > > > > based on the returned value the caller could allocate an array of > > "count" pointers and then call the function again to actually fill out > > the count elements. > > Yes, that's what I want from the generic fwnode APIs. > (Keyword: generic) > > > The problem with this is that, typec_switch_match() does: > > As you stated, the problem is in the typec_switch_match(). So, it's not related > to the fwnode, but how you are using it. > > > void *typec_switch_match(fwnode, id, data) { > > struct device *dev = find_struct_device(fwnode, id); > > if (!dev) > > return NULL; > > get_device(dev); > > return container_of(dev, struct typec_switch, dev); > > } > > > > So if we call the match function and if that finds a "dev" it will > > return a struct typec_switch with a refcounted struct device within. > > fwnode (as being an abstraction on top of the others) has no knowledge > about this. And more important should not know that. > > > We can see if that's NULL or not and will be able to return a "count", > > but we have no way of releasing the reference acquired - we must return > > the void pointer back to the client, so that it can release it. > > The caller (if it wants to!) may create different callbacks for count and real > matching, no? > Ahh, yeah you're right, we can shift this responsibility onto the caller and thereby allow them to implement the count as well. Makes sense! Thanks, Bjorn > > My claim is that this is not a problem, because this works fine with any > > reasonable size of fwnode graphs we might run into - and the client will > > in general have a sense of the worst case number of matches (in this > > series its 3, as there's 3 types of lanes that can be switched/muxed > > coming out of a USB connector). > > -- > With Best Regards, > Andy Shevchenko > >