Hi Mathieu
On 5/14/20 10:40 PM, Mathieu Poirier wrote: > After adding support for rpmsg device name extension, this patch > provides a function that returns the extension portion of an rpmsg > device name. That way users of the name extension functionality don't > have to write the same boiler plate code to extract the information. > > Suggested-by: Suman Anna <s-a...@ti.com>; > Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org> Probably what is missing now it is an upstreamed client. :) If a client is mandatory sample/rpmsg/rpmsg_client_sample.c could be a good candidate, using extension to construct the "Hello" message... Acked-by: Arnaud Pouliquen <arnaud.pouliq...@st.com> Regards, Arnaud > --- > drivers/rpmsg/rpmsg_core.c | 95 ++++++++++++++++++++++++++++++++++++++ > include/linux/rpmsg.h | 13 ++++++ > 2 files changed, 108 insertions(+) > > diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c > index 5e01e8dede6b..9583eb936607 100644 > --- a/drivers/rpmsg/rpmsg_core.c > +++ b/drivers/rpmsg/rpmsg_core.c > @@ -439,6 +439,101 @@ static int rpmsg_dev_match(struct device *dev, struct > device_driver *drv) > return of_driver_match_device(dev, drv); > } > > +/** > + * rpmsg_device_get_name_extension() - get the name extension of a rpmsg > device > + * @rpdev: the rpmsg device to work with > + * @skip: how many characters in the extension should be skipped over > + * > + * With function rpmsg_id_match() allowing for extension of the base driver > name > + * in order to differentiate services, this function returns the extension > part > + * of an rpmsg device name. As such and with the following rpmsg driver > device > + * id table and rpmsg device names: > + * > + * static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = { > + * { .name = "rpmsg-client-sample" }, > + * { }, > + * } > + * > + * rpdev1->id.name == "rpmsg-client-sample"; > + * rpdev2->id.name == "rpmsg-client-sample_instance0"; > + * > + * Calling rpmsg_device_get_name_extension() will yields the following: > + * > + * rpmsg_device_get_name_extension(rpdev1, 0) == NULL; > + * rpmsg_device_get_name_extension(rpdev2, 0) == "_instance0"; > + * rpmsg_device_get_name_extension(rpdev2, 1) == "instance0"; > + * > + * > + * Return: The name extension if found, NULL if the name of the RPMSG device > + * equals the name of the RPMSG driver and an error if no match is > + * found or a validation problem has occurred. > + */ > +const char *rpmsg_device_get_name_extension(struct rpmsg_device *rpdev, > + unsigned int skip) > +{ > + const char *drv_name, *dev_name, *extension; > + const struct rpmsg_device_id *ids; > + struct device *dev = &rpdev->dev; > + struct rpmsg_driver *rpdrv; > + bool match = false; > + unsigned int i; > + > + if (!dev->driver) > + return ERR_PTR(-EINVAL); > + > + rpdrv = to_rpmsg_driver(dev->driver); > + > + /* > + * No point in going further if the device doesn't have name or > + * the driver doesn't have a table to work with. > + */ > + if (!rpdev->id.name[0] || !rpdrv->id_table) > + return ERR_PTR(-EINVAL); > + > + ids = rpdrv->id_table; > + dev_name = rpdev->id.name; > + > + /* > + * See if any name in the driver's table match the beginning > + * of the rpmsg device's name. > + */ > + for (i = 0; ids[i].name[0]; i++) { > + drv_name = ids[i].name; > + if (strncmp(drv_name, > + dev_name, strlen(drv_name)) == 0) { > + match = true; > + break; > + } > + } > + > + /* > + * A match was not found, return an error to differentiate with cases > + * where a match was found but the name has no extension (see below). > + */ > + if (!match) > + return ERR_PTR(-ENOENT); > + > + /* No name extension to return if device and driver are the same */ > + if (strlen(dev_name) == strlen(drv_name)) > + return NULL; > + > + /* > + * Make sure we were not requested to skip past the end > + * of the device name. > + */ > + if (strlen(drv_name) + skip >= strlen(dev_name)) > + return ERR_PTR(-EINVAL); > + > + /* > + * Move past the base name published by the driver and > + * skip any extra characters if needed. > + */ > + extension = dev_name + strlen(drv_name) + skip; > + > + return extension; > +} > +EXPORT_SYMBOL(rpmsg_device_get_name_extension); > + > static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) > { > struct rpmsg_device *rpdev = to_rpmsg_device(dev); > diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h > index 9fe156d1c018..9537b95ad30a 100644 > --- a/include/linux/rpmsg.h > +++ b/include/linux/rpmsg.h > @@ -135,6 +135,9 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, > u32 src, u32 dst, > __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, > poll_table *wait); > > +const char *rpmsg_device_get_name_extension(struct rpmsg_device *dev, > + unsigned int skip); > + > #else > > static inline int register_rpmsg_device(struct rpmsg_device *dev) > @@ -242,6 +245,16 @@ static inline __poll_t rpmsg_poll(struct rpmsg_endpoint > *ept, > return 0; > } > > +static inline > +const char *rpmsg_device_get_name_extension(struct rpmsg_device *dev, > + unsigned int skip) > +{ > + /* This shouldn't be possible */ > + WARN_ON(1); > + > + return NULL; > +} > + > #endif /* IS_ENABLED(CONFIG_RPMSG) */ > > /* use a macro to avoid include chaining to get THIS_MODULE */ >