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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-27 21:04:49 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-27 21:04:49 +0300
commit11c70529983e8136ea1bd5c32e4f9cd14503c644 (patch)
tree8e36f8397a68a4906fd49b72de8c7efb9b0e2a0d /drivers/firmware/arm_scmi/bus.c
parentd40b2f4c94f221bd5aab205f945e6f88d3df0929 (diff)
parent524af30c931382726b6a46ee4f392fb6e60f8a03 (diff)
downloadlinux-11c70529983e8136ea1bd5c32e4f9cd14503c644.tar.xz
Merge tag 'soc-drivers-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Arnd Bergmann: "As usual, there are lots of minor driver changes across SoC platforms from NXP, Amlogic, AMD Zynq, Mediatek, Qualcomm, Apple and Samsung. These usually add support for additional chip variations in existing drivers, but also add features or bugfixes. The SCMI firmware subsystem gains a unified raw userspace interface through debugfs, which can be used for validation purposes. Newly added drivers include: - New power management drivers for StarFive JH7110, Allwinner D1 and Renesas RZ/V2M - A driver for Qualcomm battery and power supply status - A SoC device driver for identifying Nuvoton WPCM450 chips - A regulator coupler driver for Mediatek MT81xxv" * tag 'soc-drivers-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (165 commits) power: supply: Introduce Qualcomm PMIC GLINK power supply soc: apple: rtkit: Do not copy the reg state structure to the stack soc: sunxi: SUN20I_PPU should depend on PM memory: renesas-rpc-if: Remove redundant division of dummy soc: qcom: socinfo: Add IDs for IPQ5332 and its variant dt-bindings: arm: qcom,ids: Add IDs for IPQ5332 and its variant dt-bindings: power: qcom,rpmpd: add RPMH_REGULATOR_LEVEL_LOW_SVS_L1 firmware: qcom_scm: Move qcom_scm.h to include/linux/firmware/qcom/ MAINTAINERS: Update qcom CPR maintainer entry dt-bindings: firmware: document Qualcomm SM8550 SCM dt-bindings: firmware: qcom,scm: add qcom,scm-sa8775p compatible soc: qcom: socinfo: Add Soc IDs for IPQ8064 and variants dt-bindings: arm: qcom,ids: Add Soc IDs for IPQ8064 and variants soc: qcom: socinfo: Add support for new field in revision 17 soc: qcom: smd-rpm: Add IPQ9574 compatible soc: qcom: pmic_glink: remove redundant calculation of svid soc: qcom: stats: Populate all subsystem debugfs files dt-bindings: soc: qcom,rpmh-rsc: Update to allow for generic nodes soc: qcom: pmic_glink: add CONFIG_NET/CONFIG_OF dependencies soc: qcom: pmic_glink: Introduce altmode support ...
Diffstat (limited to 'drivers/firmware/arm_scmi/bus.c')
-rw-r--r--drivers/firmware/arm_scmi/bus.c395
1 files changed, 302 insertions, 93 deletions
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index cc2eba067575..73140b854b31 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -7,8 +7,10 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/atomic.h>
#include <linux/types.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
@@ -16,9 +18,174 @@
#include "common.h"
+BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh);
+EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
+
static DEFINE_IDA(scmi_bus_id);
-static DEFINE_IDR(scmi_protocols);
-static DEFINE_SPINLOCK(protocol_lock);
+
+static DEFINE_IDR(scmi_requested_devices);
+/* Protect access to scmi_requested_devices */
+static DEFINE_MUTEX(scmi_requested_devices_mtx);
+
+struct scmi_requested_dev {
+ const struct scmi_device_id *id_table;
+ struct list_head node;
+};
+
+/* Track globally the creation of SCMI SystemPower related devices */
+static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
+
+/**
+ * scmi_protocol_device_request - Helper to request a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be created.
+ *
+ * This helper let an SCMI driver request specific devices identified by the
+ * @id_table to be created for each active SCMI instance.
+ *
+ * The requested device name MUST NOT be already existent for any protocol;
+ * at first the freshly requested @id_table is annotated in the IDR table
+ * @scmi_requested_devices and then the requested device is advertised to any
+ * registered party via the @scmi_requested_devices_nh notification chain.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
+{
+ int ret = 0;
+ unsigned int id = 0;
+ struct list_head *head, *phead = NULL;
+ struct scmi_requested_dev *rdev;
+
+ pr_debug("Requesting SCMI device (%s) for protocol %x\n",
+ id_table->name, id_table->protocol_id);
+
+ if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) &&
+ !IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX)) {
+ pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+ id_table->name, id_table->protocol_id);
+ return -EINVAL;
+ }
+
+ /*
+ * Search for the matching protocol rdev list and then search
+ * of any existent equally named device...fails if any duplicate found.
+ */
+ mutex_lock(&scmi_requested_devices_mtx);
+ idr_for_each_entry(&scmi_requested_devices, head, id) {
+ if (!phead) {
+ /* A list found registered in the IDR is never empty */
+ rdev = list_first_entry(head, struct scmi_requested_dev,
+ node);
+ if (rdev->id_table->protocol_id ==
+ id_table->protocol_id)
+ phead = head;
+ }
+ list_for_each_entry(rdev, head, node) {
+ if (!strcmp(rdev->id_table->name, id_table->name)) {
+ pr_err("Ignoring duplicate request [%d] %s\n",
+ rdev->id_table->protocol_id,
+ rdev->id_table->name);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ }
+
+ /*
+ * No duplicate found for requested id_table, so let's create a new
+ * requested device entry for this new valid request.
+ */
+ rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+ if (!rdev) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ rdev->id_table = id_table;
+
+ /*
+ * Append the new requested device table descriptor to the head of the
+ * related protocol list, eventually creating such head if not already
+ * there.
+ */
+ if (!phead) {
+ phead = kzalloc(sizeof(*phead), GFP_KERNEL);
+ if (!phead) {
+ kfree(rdev);
+ ret = -ENOMEM;
+ goto out;
+ }
+ INIT_LIST_HEAD(phead);
+
+ ret = idr_alloc(&scmi_requested_devices, (void *)phead,
+ id_table->protocol_id,
+ id_table->protocol_id + 1, GFP_KERNEL);
+ if (ret != id_table->protocol_id) {
+ pr_err("Failed to save SCMI device - ret:%d\n", ret);
+ kfree(rdev);
+ kfree(phead);
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = 0;
+ }
+ list_add(&rdev->node, phead);
+
+out:
+ mutex_unlock(&scmi_requested_devices_mtx);
+
+ if (!ret)
+ blocking_notifier_call_chain(&scmi_requested_devices_nh,
+ SCMI_BUS_NOTIFY_DEVICE_REQUEST,
+ (void *)rdev->id_table);
+
+ return ret;
+}
+
+/**
+ * scmi_protocol_device_unrequest - Helper to unrequest a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be unrequested.
+ *
+ * The unrequested device, described by the provided id_table, is at first
+ * removed from the IDR @scmi_requested_devices and then the removal is
+ * advertised to any registered party via the @scmi_requested_devices_nh
+ * notification chain.
+ */
+static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
+{
+ struct list_head *phead;
+
+ pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
+ id_table->name, id_table->protocol_id);
+
+ mutex_lock(&scmi_requested_devices_mtx);
+ phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+ if (phead) {
+ struct scmi_requested_dev *victim, *tmp;
+
+ list_for_each_entry_safe(victim, tmp, phead, node) {
+ if (!strcmp(victim->id_table->name, id_table->name)) {
+ list_del(&victim->node);
+
+ mutex_unlock(&scmi_requested_devices_mtx);
+ blocking_notifier_call_chain(&scmi_requested_devices_nh,
+ SCMI_BUS_NOTIFY_DEVICE_UNREQUEST,
+ (void *)victim->id_table);
+ kfree(victim);
+ mutex_lock(&scmi_requested_devices_mtx);
+ break;
+ }
+ }
+
+ if (list_empty(phead)) {
+ idr_remove(&scmi_requested_devices,
+ id_table->protocol_id);
+ kfree(phead);
+ }
+ }
+ mutex_unlock(&scmi_requested_devices_mtx);
+}
static const struct scmi_device_id *
scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
@@ -58,11 +225,11 @@ static int scmi_match_by_id_table(struct device *dev, void *data)
struct scmi_device_id *id_table = data;
return sdev->protocol_id == id_table->protocol_id &&
- !strcmp(sdev->name, id_table->name);
+ (id_table->name && !strcmp(sdev->name, id_table->name));
}
-struct scmi_device *scmi_child_dev_find(struct device *parent,
- int prot_id, const char *name)
+static struct scmi_device *scmi_child_dev_find(struct device *parent,
+ int prot_id, const char *name)
{
struct scmi_device_id id_table;
struct device *dev;
@@ -77,30 +244,6 @@ struct scmi_device *scmi_child_dev_find(struct device *parent,
return to_scmi_dev(dev);
}
-const struct scmi_protocol *scmi_protocol_get(int protocol_id)
-{
- const struct scmi_protocol *proto;
-
- proto = idr_find(&scmi_protocols, protocol_id);
- if (!proto || !try_module_get(proto->owner)) {
- pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
- return NULL;
- }
-
- pr_debug("Found SCMI Protocol 0x%x\n", protocol_id);
-
- return proto;
-}
-
-void scmi_protocol_put(int protocol_id)
-{
- const struct scmi_protocol *proto;
-
- proto = idr_find(&scmi_protocols, protocol_id);
- if (proto)
- module_put(proto->owner);
-}
-
static int scmi_dev_probe(struct device *dev)
{
struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
@@ -121,12 +264,13 @@ 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)
@@ -147,7 +291,7 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
retval = driver_register(&driver->driver);
if (!retval)
- pr_debug("registered new scmi driver %s\n", driver->name);
+ pr_debug("Registered new scmi driver %s\n", driver->name);
return retval;
}
@@ -165,13 +309,53 @@ static void scmi_device_release(struct device *dev)
kfree(to_scmi_dev(dev));
}
-struct scmi_device *
-scmi_device_create(struct device_node *np, struct device *parent, int protocol,
- const char *name)
+static void __scmi_device_destroy(struct scmi_device *scmi_dev)
+{
+ pr_debug("(%s) Destroying SCMI device '%s' for protocol 0x%x (%s)\n",
+ of_node_full_name(scmi_dev->dev.parent->of_node),
+ dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+ scmi_dev->name);
+
+ if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
+ atomic_set(&scmi_syspower_registered, 0);
+
+ kfree_const(scmi_dev->name);
+ ida_free(&scmi_bus_id, scmi_dev->id);
+ device_unregister(&scmi_dev->dev);
+}
+
+static struct scmi_device *
+__scmi_device_create(struct device_node *np, struct device *parent,
+ int protocol, const char *name)
{
int id, retval;
struct scmi_device *scmi_dev;
+ /*
+ * If the same protocol/name device already exist under the same parent
+ * (i.e. SCMI instance) just return the existent device.
+ * This avoids any race between the SCMI driver, creating devices for
+ * each DT defined protocol at probe time, and the concurrent
+ * registration of SCMI drivers.
+ */
+ scmi_dev = scmi_child_dev_find(parent, protocol, name);
+ if (scmi_dev)
+ return scmi_dev;
+
+ /*
+ * Ignore any possible subsequent failures while creating the device
+ * since we are doomed anyway at that point; not using a mutex which
+ * spans across this whole function to keep things simple and to avoid
+ * to serialize all the __scmi_device_create calls across possibly
+ * different SCMI server instances (parent)
+ */
+ if (protocol == SCMI_PROTOCOL_SYSTEM &&
+ atomic_cmpxchg(&scmi_syspower_registered, 0, 1)) {
+ dev_warn(parent,
+ "SCMI SystemPower protocol device must be unique !\n");
+ return NULL;
+ }
+
scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
if (!scmi_dev)
return NULL;
@@ -201,6 +385,10 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol,
if (retval)
goto put_dev;
+ pr_debug("(%s) Created SCMI device '%s' for protocol 0x%x (%s)\n",
+ of_node_full_name(parent->of_node),
+ dev_name(&scmi_dev->dev), protocol, name);
+
return scmi_dev;
put_dev:
kfree_const(scmi_dev->name);
@@ -209,77 +397,85 @@ put_dev:
return NULL;
}
-void scmi_device_destroy(struct scmi_device *scmi_dev)
-{
- kfree_const(scmi_dev->name);
- scmi_handle_put(scmi_dev->handle);
- ida_free(&scmi_bus_id, scmi_dev->id);
- device_unregister(&scmi_dev->dev);
-}
-
-void scmi_device_link_add(struct device *consumer, struct device *supplier)
-{
- struct device_link *link;
-
- link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER);
-
- WARN_ON(!link);
-}
-
-void scmi_set_handle(struct scmi_device *scmi_dev)
-{
- scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
- if (scmi_dev->handle)
- scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev);
-}
-
-int scmi_protocol_register(const struct scmi_protocol *proto)
+/**
+ * scmi_device_create - A method to create one or more SCMI devices
+ *
+ * @np: A reference to the device node to use for the new device(s)
+ * @parent: The parent device to use identifying a specific SCMI instance
+ * @protocol: The SCMI protocol to be associated with this device
+ * @name: The requested-name of the device to be created; this is optional
+ * and if no @name is provided, all the devices currently known to
+ * be requested on the SCMI bus for @protocol will be created.
+ *
+ * This method can be invoked to create a single well-defined device (like
+ * a transport device or a device requested by an SCMI driver loaded after
+ * the core SCMI stack has been probed), or to create all the devices currently
+ * known to have been requested by the loaded SCMI drivers for a specific
+ * protocol (typically during SCMI core protocol enumeration at probe time).
+ *
+ * Return: The created device (or one of them if @name was NOT provided and
+ * multiple devices were created) or NULL if no device was created;
+ * note that NULL indicates an error ONLY in case a specific @name
+ * was provided: when @name param was not provided, a number of devices
+ * could have been potentially created for a whole protocol, unless no
+ * device was found to have been requested for that specific protocol.
+ */
+struct scmi_device *scmi_device_create(struct device_node *np,
+ struct device *parent, int protocol,
+ const char *name)
{
- int ret;
-
- if (!proto) {
- pr_err("invalid protocol\n");
- return -EINVAL;
- }
-
- if (!proto->instance_init) {
- pr_err("missing init for protocol 0x%x\n", proto->id);
- return -EINVAL;
+ struct list_head *phead;
+ struct scmi_requested_dev *rdev;
+ struct scmi_device *scmi_dev = NULL;
+
+ if (name)
+ return __scmi_device_create(np, parent, protocol, name);
+
+ mutex_lock(&scmi_requested_devices_mtx);
+ phead = idr_find(&scmi_requested_devices, protocol);
+ /* Nothing to do. */
+ if (!phead) {
+ mutex_unlock(&scmi_requested_devices_mtx);
+ return scmi_dev;
}
- spin_lock(&protocol_lock);
- ret = idr_alloc(&scmi_protocols, (void *)proto,
- proto->id, proto->id + 1, GFP_ATOMIC);
- spin_unlock(&protocol_lock);
- if (ret != proto->id) {
- pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n",
- proto->id, ret);
- return ret;
+ /* Walk the list of requested devices for protocol and create them */
+ list_for_each_entry(rdev, phead, node) {
+ struct scmi_device *sdev;
+
+ sdev = __scmi_device_create(np, parent,
+ rdev->id_table->protocol_id,
+ rdev->id_table->name);
+ /* Report errors and carry on... */
+ if (sdev)
+ scmi_dev = sdev;
+ else
+ pr_err("(%s) Failed to create device for protocol 0x%x (%s)\n",
+ of_node_full_name(parent->of_node),
+ rdev->id_table->protocol_id,
+ rdev->id_table->name);
}
+ mutex_unlock(&scmi_requested_devices_mtx);
- pr_debug("Registered SCMI Protocol 0x%x\n", proto->id);
-
- return 0;
+ return scmi_dev;
}
-EXPORT_SYMBOL_GPL(scmi_protocol_register);
+EXPORT_SYMBOL_GPL(scmi_device_create);
-void scmi_protocol_unregister(const struct scmi_protocol *proto)
+void scmi_device_destroy(struct device *parent, int protocol, const char *name)
{
- spin_lock(&protocol_lock);
- idr_remove(&scmi_protocols, proto->id);
- spin_unlock(&protocol_lock);
-
- pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id);
+ struct scmi_device *scmi_dev;
- return;
+ scmi_dev = scmi_child_dev_find(parent, protocol, name);
+ if (scmi_dev)
+ __scmi_device_destroy(scmi_dev);
}
-EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
+EXPORT_SYMBOL_GPL(scmi_device_destroy);
static int __scmi_devices_unregister(struct device *dev, void *data)
{
struct scmi_device *scmi_dev = to_scmi_dev(dev);
- scmi_device_destroy(scmi_dev);
+ __scmi_device_destroy(scmi_dev);
return 0;
}
@@ -288,20 +484,33 @@ static void scmi_devices_unregister(void)
bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister);
}
-int __init scmi_bus_init(void)
+static int __init scmi_bus_init(void)
{
int retval;
retval = bus_register(&scmi_bus_type);
if (retval)
- pr_err("scmi protocol bus register failed (%d)\n", retval);
+ pr_err("SCMI protocol bus register failed (%d)\n", retval);
+
+ pr_info("SCMI protocol bus registered\n");
return retval;
}
+subsys_initcall(scmi_bus_init);
-void __exit scmi_bus_exit(void)
+static void __exit scmi_bus_exit(void)
{
+ /*
+ * Destroy all remaining devices: just in case the drivers were
+ * manually unbound and at first and then the modules unloaded.
+ */
scmi_devices_unregister();
bus_unregister(&scmi_bus_type);
ida_destroy(&scmi_bus_id);
}
+module_exit(scmi_bus_exit);
+
+MODULE_ALIAS("scmi-core");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI protocol bus");
+MODULE_LICENSE("GPL");