mirror/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

firmware: arm_scmi: Add common notifier helpers

Browse Source 
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>
This commit is contained in:
Cristian Marussi
2022-12-22 18:50:44 +00:00
committed by Sudeep Holla
parent 9115c20ac1
commit 53b8c25df7
3 changed files with 92 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/firmware/arm_scmi/bus.c
View File

@@ -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)

5
drivers/firmware/arm_scmi/common.h
View File

@@ -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);

83
drivers/firmware/arm_scmi/driver.c
View File

@@ -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);