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author | Cristian Marussi <cristian.marussi@arm.com> | 2022-12-22 18:50:44 +0000 |
---|---|---|
committer | Sudeep Holla <sudeep.holla@arm.com> | 2023-01-19 09:46:15 +0000 |
commit | 53b8c25df7082edd78a3fc63e359abee0f28fa70 (patch) | |
tree | 08dd92606f4dedd644d41be0983ff8ef8acdb46a /drivers/firmware | |
parent | 9115c20ac1ee9e92a3e751e352db818b7f95746a (diff) | |
download | linux-53b8c25df7082edd78a3fc63e359abee0f28fa70.tar.gz linux-53b8c25df7082edd78a3fc63e359abee0f28fa70.tar.bz2 linux-53b8c25df7082edd78a3fc63e359abee0f28fa70.zip |
firmware: arm_scmi: Add common notifier helpers
Add a pair of notifier chains and generic empty notifier callbacks.
Currently they are still unused but they will be used to act properly
on device request and creation events.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-5-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/arm_scmi/bus.c | 6 | ||||
-rw-r--r-- | drivers/firmware/arm_scmi/common.h | 5 | ||||
-rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 83 |
3 files changed, 92 insertions, 2 deletions
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index 089957f5fb9b..bed566f58029 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -15,6 +15,9 @@ #include "common.h" +BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh); +EXPORT_SYMBOL_GPL(scmi_requested_devices_nh); + static DEFINE_IDA(scmi_bus_id); static const struct scmi_device_id * @@ -94,12 +97,13 @@ static void scmi_dev_remove(struct device *dev) scmi_drv->remove(scmi_dev); } -static struct bus_type scmi_bus_type = { +struct bus_type scmi_bus_type = { .name = "scmi_protocol", .match = scmi_dev_match, .probe = scmi_dev_probe, .remove = scmi_dev_remove, }; +EXPORT_SYMBOL_GPL(scmi_bus_type); int scmi_driver_register(struct scmi_driver *driver, struct module *owner, const char *mod_name) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 6a38244494fd..7ddae90eb945 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -105,6 +105,11 @@ void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, int __init scmi_bus_init(void); void __exit scmi_bus_exit(void); +extern struct bus_type scmi_bus_type; + +#define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0 +#define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1 +extern struct blocking_notifier_head scmi_requested_devices_nh; int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index d1e32ea6d90a..62760bed1645 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -150,6 +150,9 @@ struct scmi_protocol_instance { * @notify_priv: Pointer to private data structure specific to notifications. * @node: List head * @users: Number of users of this instance + * @bus_nb: A notifier to listen for device bind/unbind on the scmi bus + * @dev_req_nb: A notifier to listen for device request/unrequest on the scmi + * bus */ struct scmi_info { struct device *dev; @@ -169,9 +172,13 @@ struct scmi_info { void *notify_priv; struct list_head node; int users; + struct notifier_block bus_nb; + struct notifier_block dev_req_nb; }; #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) +#define bus_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, bus_nb) +#define req_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, dev_req_nb) static const int scmi_linux_errmap[] = { /* better than switch case as long as return value is continuous */ @@ -2509,6 +2516,60 @@ static void scmi_cleanup_txrx_channels(struct scmi_info *info) scmi_cleanup_channels(info, &info->rx_idr); } +static int scmi_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct scmi_info *info = bus_nb_to_scmi_info(nb); + struct scmi_device *sdev = to_scmi_dev(data); + + /* Skip transport devices and devices of different SCMI instances */ + if (!strncmp(sdev->name, "__scmi_transport_device", 23) || + sdev->dev.parent != info->dev) + return NOTIFY_DONE; + + switch (action) { + case BUS_NOTIFY_BIND_DRIVER: + break; + case BUS_NOTIFY_UNBOUND_DRIVER: + break; + default: + return NOTIFY_DONE; + } + + dev_dbg(info->dev, "Device %s (%s) is now %s\n", dev_name(&sdev->dev), + sdev->name, action == BUS_NOTIFY_BIND_DRIVER ? + "about to be BOUND." : "UNBOUND."); + + return NOTIFY_OK; +} + +static int scmi_device_request_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device_node *np; + struct scmi_device_id *id_table = data; + struct scmi_info *info = req_nb_to_scmi_info(nb); + + np = idr_find(&info->active_protocols, id_table->protocol_id); + if (!np) + return NOTIFY_DONE; + + dev_dbg(info->dev, "%sRequested device (%s) for protocol 0x%x\n", + action == SCMI_BUS_NOTIFY_DEVICE_REQUEST ? "" : "UN-", + id_table->name, id_table->protocol_id); + + switch (action) { + case SCMI_BUS_NOTIFY_DEVICE_REQUEST: + break; + case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST: + break; + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + static int scmi_probe(struct platform_device *pdev) { int ret; @@ -2528,6 +2589,8 @@ static int scmi_probe(struct platform_device *pdev) info->dev = dev; info->desc = desc; + info->bus_nb.notifier_call = scmi_bus_notifier; + info->dev_req_nb.notifier_call = scmi_device_request_notifier; INIT_LIST_HEAD(&info->node); idr_init(&info->protocols); mutex_init(&info->protocols_mtx); @@ -2563,10 +2626,19 @@ static int scmi_probe(struct platform_device *pdev) if (ret) return ret; - ret = scmi_xfer_info_init(info); + ret = bus_register_notifier(&scmi_bus_type, &info->bus_nb); if (ret) goto clear_txrx_setup; + ret = blocking_notifier_chain_register(&scmi_requested_devices_nh, + &info->dev_req_nb); + if (ret) + goto clear_bus_notifier; + + ret = scmi_xfer_info_init(info); + if (ret) + goto clear_dev_req_notifier; + if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\n"); @@ -2624,6 +2696,11 @@ static int scmi_probe(struct platform_device *pdev) notification_exit: scmi_notification_exit(&info->handle); +clear_dev_req_notifier: + blocking_notifier_chain_unregister(&scmi_requested_devices_nh, + &info->dev_req_nb); +clear_bus_notifier: + bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); clear_txrx_setup: scmi_cleanup_txrx_channels(info); return ret; @@ -2652,6 +2729,10 @@ static int scmi_remove(struct platform_device *pdev) of_node_put(child); idr_destroy(&info->active_protocols); + blocking_notifier_chain_unregister(&scmi_requested_devices_nh, + &info->dev_req_nb); + bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); + /* Safe to free channels since no more users */ scmi_cleanup_txrx_channels(info); |