diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/firmware/arm_scmi/bus.c | 30 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 5 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 310 |
3 files changed, 311 insertions, 34 deletions
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index aadf2da21561..784cf0027da3 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -51,6 +51,31 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv) return 0; } +static int scmi_match_by_id_table(struct device *dev, void *data) +{ + struct scmi_device *sdev = to_scmi_dev(dev); + struct scmi_device_id *id_table = data; + + return sdev->protocol_id == id_table->protocol_id && + !strcmp(sdev->name, id_table->name); +} + +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; + + id_table.protocol_id = prot_id; + id_table.name = name; + + dev = device_find_child(parent, &id_table, scmi_match_by_id_table); + if (!dev) + return NULL; + + return to_scmi_dev(dev); +} + const struct scmi_protocol *scmi_protocol_get(int protocol_id) { const struct scmi_protocol *proto; @@ -114,6 +139,10 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner, { int retval; + retval = scmi_protocol_device_request(driver->id_table); + if (retval) + return retval; + driver->driver.bus = &scmi_bus_type; driver->driver.name = driver->name; driver->driver.owner = owner; @@ -130,6 +159,7 @@ EXPORT_SYMBOL_GPL(scmi_driver_register); void scmi_driver_unregister(struct scmi_driver *driver) { driver_unregister(&driver->driver); + scmi_protocol_device_unrequest(driver->id_table); } EXPORT_SYMBOL_GPL(scmi_driver_unregister); diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 762dd5419700..228bf4a71d23 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -309,6 +309,11 @@ struct scmi_transport_ops { bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); }; +int scmi_protocol_device_request(const struct scmi_device_id *id_table); +void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table); +struct scmi_device *scmi_child_dev_find(struct device *parent, + int prot_id, const char *name); + /** * struct scmi_desc - Description of SoC integration * diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index c25c20c150dc..66eb3f0e5daf 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -21,6 +21,7 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/ktime.h> +#include <linux/list.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_device.h> @@ -56,6 +57,14 @@ static DEFINE_MUTEX(scmi_list_mutex); /* Track the unique id for the transfers for debug & profiling purpose */ static atomic_t transfer_last_id; +static DEFINE_IDR(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; +}; + /** * struct scmi_xfers_info - Structure to manage transfer information * @@ -113,6 +122,8 @@ struct scmi_protocol_instance { * @protocols_mtx: A mutex to protect protocols instances initialization. * @protocols_imp: List of protocols implemented, currently maximum of * MAX_PROTOCOLS_IMP elements allocated by the base protocol + * @active_protocols: IDR storing device_nodes for protocols actually defined + * in the DT and confirmed as implemented by fw. * @notify_priv: Pointer to private data structure specific to notifications. * @node: List head * @users: Number of users of this instance @@ -130,6 +141,7 @@ struct scmi_info { /* Ensure mutual exclusive access to protocols instance array */ struct mutex protocols_mtx; u8 *protocols_imp; + struct idr active_protocols; void *notify_priv; struct list_head node; int users; @@ -935,6 +947,13 @@ static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id) WARN_ON(ret); } +static inline +struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info) +{ + info->users++; + return &info->handle; +} + /** * scmi_handle_get() - Get the SCMI handle for a device * @@ -956,8 +975,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev) list_for_each(p, &scmi_list) { info = list_entry(p, struct scmi_info, node); if (dev->parent == info->dev) { - handle = &info->handle; - info->users++; + handle = scmi_handle_get_from_info_unlocked(info); break; } } @@ -1100,63 +1118,268 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) return ret; } -static inline void -scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, - int prot_id, const char *name) +/** + * scmi_get_protocol_device - Helper to get/create an SCMI device. + * + * @np: A device node representing a valid active protocols for the referred + * SCMI instance. + * @info: The referred SCMI instance for which we are getting/creating this + * device. + * @prot_id: The protocol ID. + * @name: The device name. + * + * Referring to the specific SCMI instance identified by @info, this helper + * takes care to return a properly initialized device matching the requested + * @proto_id and @name: if device was still not existent it is created as a + * child of the specified SCMI instance @info and its transport properly + * initialized as usual. + */ +static inline struct scmi_device * +scmi_get_protocol_device(struct device_node *np, struct scmi_info *info, + int prot_id, const char *name) { struct scmi_device *sdev; + /* Already created for this parent SCMI instance ? */ + sdev = scmi_child_dev_find(info->dev, prot_id, name); + if (sdev) + return sdev; + + pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id); + sdev = scmi_device_create(np, info->dev, prot_id, name); if (!sdev) { dev_err(info->dev, "failed to create %d protocol device\n", prot_id); - return; + return NULL; } if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { dev_err(&sdev->dev, "failed to setup transport\n"); scmi_device_destroy(sdev); - return; + return NULL; } + return sdev; +} + +static inline void +scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, + int prot_id, const char *name) +{ + struct scmi_device *sdev; + + sdev = scmi_get_protocol_device(np, info, prot_id, name); + if (!sdev) + return; + /* setup handle now as the transport is ready */ scmi_set_handle(sdev); } -#define MAX_SCMI_DEV_PER_PROTOCOL 2 -struct scmi_prot_devnames { - int protocol_id; - char *names[MAX_SCMI_DEV_PER_PROTOCOL]; -}; +/** + * scmi_create_protocol_devices - Create devices for all pending requests for + * this SCMI instance. + * + * @np: The device node describing the protocol + * @info: The SCMI instance descriptor + * @prot_id: The protocol ID + * + * All devices previously requested for this instance (if any) are found and + * created by scanning the proper @&scmi_requested_devices entry. + */ +static void scmi_create_protocol_devices(struct device_node *np, + struct scmi_info *info, int prot_id) +{ + struct list_head *phead; -static struct scmi_prot_devnames devnames[] = { - { SCMI_PROTOCOL_POWER, { "genpd" },}, - { SCMI_PROTOCOL_SYSTEM, { "syspower" },}, - { SCMI_PROTOCOL_PERF, { "cpufreq" },}, - { SCMI_PROTOCOL_CLOCK, { "clocks" },}, - { SCMI_PROTOCOL_SENSOR, { "hwmon", "iiodev" },}, - { SCMI_PROTOCOL_RESET, { "reset" },}, - { SCMI_PROTOCOL_VOLTAGE, { "regulator" },}, -}; + mutex_lock(&scmi_requested_devices_mtx); + phead = idr_find(&scmi_requested_devices, prot_id); + if (phead) { + struct scmi_requested_dev *rdev; -static inline void -scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, - int prot_id) + list_for_each_entry(rdev, phead, node) + scmi_create_protocol_device(np, info, prot_id, + rdev->id_table->name); + } + mutex_unlock(&scmi_requested_devices_mtx); +} + +/** + * 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, then a matching device is created for each already + * active SCMI instance. (if any) + * + * This way the requested device is created straight-away for all the already + * initialized(probed) SCMI instances (handles) and it remains also annotated + * as pending creation if the requesting SCMI driver was loaded before some + * SCMI instance and related transports were available: when such late instance + * is probed, its probe will take care to scan the list of pending requested + * devices and create those on its own (see @scmi_create_protocol_devices and + * its enclosing loop) + * + * Return: 0 on Success + */ +int scmi_protocol_device_request(const struct scmi_device_id *id_table) { - int loop, cnt; + int ret = 0; + unsigned int id = 0; + struct list_head *head, *phead = NULL; + struct scmi_requested_dev *rdev; + struct scmi_info *info; - for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) { - if (devnames[loop].protocol_id != prot_id) - continue; + pr_debug("Requesting SCMI device (%s) for protocol %x\n", + id_table->name, id_table->protocol_id); + + /* + * 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); + + /* + * Now effectively create and initialize the requested device for every + * already initialized SCMI instance which has registered the requested + * protocol as a valid active one: i.e. defined in DT and supported by + * current platform FW. + */ + mutex_lock(&scmi_list_mutex); + list_for_each_entry(info, &scmi_list, node) { + struct device_node *child; + + child = idr_find(&info->active_protocols, + id_table->protocol_id); + if (child) { + struct scmi_device *sdev; + + sdev = scmi_get_protocol_device(child, info, + id_table->protocol_id, + id_table->name); + /* Set handle if not already set: device existed */ + if (sdev && !sdev->handle) + sdev->handle = + scmi_handle_get_from_info_unlocked(info); + } else { + dev_err(info->dev, + "Failed. SCMI protocol %d not active.\n", + id_table->protocol_id); + } + } + mutex_unlock(&scmi_list_mutex); + +out: + mutex_unlock(&scmi_requested_devices_mtx); - for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) { - const char *name = devnames[loop].names[cnt]; + return ret; +} - if (name) - scmi_create_protocol_device(np, info, prot_id, - name); +/** + * scmi_protocol_device_unrequest - Helper to unrequest a device + * + * @id_table: A protocol/name pair descriptor for the device to be unrequested. + * + * An helper to let an SCMI driver release its request about devices; note that + * devices are created and initialized once the first SCMI driver request them + * but they destroyed only on SCMI core unloading/unbinding. + * + * The current SCMI transport layer uses such devices as internal references and + * as such they could be shared as same transport between multiple drivers so + * that cannot be safely destroyed till the whole SCMI stack is removed. + * (unless adding further burden of refcounting.) + */ +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); + kfree(victim); + break; + } + } + + if (list_empty(phead)) { + idr_remove(&scmi_requested_devices, + id_table->protocol_id); + kfree(phead); } } + mutex_unlock(&scmi_requested_devices_mtx); } static int scmi_probe(struct platform_device *pdev) @@ -1181,6 +1404,7 @@ static int scmi_probe(struct platform_device *pdev) INIT_LIST_HEAD(&info->node); idr_init(&info->protocols); mutex_init(&info->protocols_mtx); + idr_init(&info->active_protocols); platform_set_drvdata(pdev, info); idr_init(&info->tx_idr); @@ -1233,6 +1457,19 @@ static int scmi_probe(struct platform_device *pdev) continue; } + /* + * Save this valid DT protocol descriptor amongst + * @active_protocols for this SCMI instance/ + */ + ret = idr_alloc(&info->active_protocols, child, + prot_id, prot_id + 1, GFP_KERNEL); + if (ret != prot_id) { + dev_err(dev, "SCMI protocol %d already activated. Skip\n", + prot_id); + continue; + } + + of_node_get(child); scmi_create_protocol_devices(child, info, prot_id); } @@ -1246,9 +1483,10 @@ void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) static int scmi_remove(struct platform_device *pdev) { - int ret = 0; + int ret = 0, id; struct scmi_info *info = platform_get_drvdata(pdev); struct idr *idr = &info->tx_idr; + struct device_node *child; mutex_lock(&scmi_list_mutex); if (info->users) @@ -1266,6 +1504,10 @@ static int scmi_remove(struct platform_device *pdev) idr_destroy(&info->protocols); mutex_unlock(&info->protocols_mtx); + idr_for_each_entry(&info->active_protocols, child, id) + of_node_put(child); + idr_destroy(&info->active_protocols); + /* Safe to free channels since no more users */ ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->tx_idr); |