diff options
| -rw-r--r-- | drivers/spi/spi-offload.c | 281 | ||||
| -rw-r--r-- | include/linux/spi/offload/consumer.h | 12 | ||||
| -rw-r--r-- | include/linux/spi/offload/provider.h | 28 | ||||
| -rw-r--r-- | include/linux/spi/offload/types.h | 37 |
4 files changed, 358 insertions, 0 deletions
diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c index 3a40ef30debf0..43582e50e279c 100644 --- a/drivers/spi/spi-offload.c +++ b/drivers/spi/spi-offload.c @@ -19,7 +19,11 @@ #include <linux/cleanup.h> #include <linux/device.h> #include <linux/export.h> +#include <linux/kref.h> +#include <linux/list.h> #include <linux/mutex.h> +#include <linux/of.h> +#include <linux/property.h> #include <linux/spi/offload/consumer.h> #include <linux/spi/offload/provider.h> #include <linux/spi/offload/types.h> @@ -31,6 +35,23 @@ struct spi_controller_and_offload { struct spi_offload *offload; }; +struct spi_offload_trigger { + struct list_head list; + struct kref ref; + struct fwnode_handle *fwnode; + /* synchronizes calling ops and driver registration */ + struct mutex lock; + /* + * If the provider goes away while the consumer still has a reference, + * ops and priv will be set to NULL and all calls will fail with -ENODEV. + */ + const struct spi_offload_trigger_ops *ops; + void *priv; +}; + +static LIST_HEAD(spi_offload_triggers); +static DEFINE_MUTEX(spi_offload_triggers_lock); + /** * devm_spi_offload_alloc() - Allocate offload instance * @dev: Device for devm purposes and assigned to &struct spi_offload.provider_dev @@ -112,3 +133,263 @@ struct spi_offload *devm_spi_offload_get(struct device *dev, return resource->offload; } EXPORT_SYMBOL_GPL(devm_spi_offload_get); + +static void spi_offload_trigger_free(struct kref *ref) +{ + struct spi_offload_trigger *trigger = + container_of(ref, struct spi_offload_trigger, ref); + + mutex_destroy(&trigger->lock); + fwnode_handle_put(trigger->fwnode); + kfree(trigger); +} + +static void spi_offload_trigger_put(void *data) +{ + struct spi_offload_trigger *trigger = data; + + scoped_guard(mutex, &trigger->lock) + if (trigger->ops && trigger->ops->release) + trigger->ops->release(trigger); + + kref_put(&trigger->ref, spi_offload_trigger_free); +} + +static struct spi_offload_trigger +*spi_offload_trigger_get(enum spi_offload_trigger_type type, + struct fwnode_reference_args *args) +{ + struct spi_offload_trigger *trigger; + bool match = false; + int ret; + + guard(mutex)(&spi_offload_triggers_lock); + + list_for_each_entry(trigger, &spi_offload_triggers, list) { + if (trigger->fwnode != args->fwnode) + continue; + + match = trigger->ops->match(trigger, type, args->args, args->nargs); + if (match) + break; + } + + if (!match) + return ERR_PTR(-EPROBE_DEFER); + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return ERR_PTR(-ENODEV); + + if (trigger->ops->request) { + ret = trigger->ops->request(trigger, type, args->args, args->nargs); + if (ret) + return ERR_PTR(ret); + } + + kref_get(&trigger->ref); + + return trigger; +} + +/** + * devm_spi_offload_trigger_get() - Get an offload trigger instance + * @dev: Device for devm purposes. + * @offload: Offload instance connected to a trigger. + * @type: Trigger type to get. + * + * Return: Offload trigger instance or error on failure. + */ +struct spi_offload_trigger +*devm_spi_offload_trigger_get(struct device *dev, + struct spi_offload *offload, + enum spi_offload_trigger_type type) +{ + struct spi_offload_trigger *trigger; + struct fwnode_reference_args args; + int ret; + + ret = fwnode_property_get_reference_args(dev_fwnode(offload->provider_dev), + "trigger-sources", + "#trigger-source-cells", 0, 0, + &args); + if (ret) + return ERR_PTR(ret); + + trigger = spi_offload_trigger_get(type, &args); + fwnode_handle_put(args.fwnode); + if (IS_ERR(trigger)) + return trigger; + + ret = devm_add_action_or_reset(dev, spi_offload_trigger_put, trigger); + if (ret) + return ERR_PTR(ret); + + return trigger; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_trigger_get); + +/** + * spi_offload_trigger_validate - Validate the requested trigger + * @trigger: Offload trigger instance + * @config: Trigger config to validate + * + * On success, @config may be modifed to reflect what the hardware can do. + * For example, the frequency of a periodic trigger may be adjusted to the + * nearest supported value. + * + * Callers will likely need to do additional validation of the modified trigger + * parameters. + * + * Return: 0 on success, negative error code on failure. + */ +int spi_offload_trigger_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return -ENODEV; + + if (!trigger->ops->validate) + return -EOPNOTSUPP; + + return trigger->ops->validate(trigger, config); +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_validate); + +/** + * spi_offload_trigger_enable - enables trigger for offload + * @offload: Offload instance + * @trigger: Offload trigger instance + * @config: Trigger config to validate + * + * There must be a prepared offload instance with the specified ID (i.e. + * spi_optimize_message() was called with the same offload assigned to the + * message). This will also reserve the bus for exclusive use by the offload + * instance until the trigger is disabled. Any other attempts to send a + * transfer or lock the bus will fail with -EBUSY during this time. + * + * Calls must be balanced with spi_offload_trigger_disable(). + * + * Context: can sleep + * Return: 0 on success, else a negative error code. + */ +int spi_offload_trigger_enable(struct spi_offload *offload, + struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + int ret; + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return -ENODEV; + + if (offload->ops && offload->ops->trigger_enable) { + ret = offload->ops->trigger_enable(offload); + if (ret) + return ret; + } + + if (trigger->ops->enable) { + ret = trigger->ops->enable(trigger, config); + if (ret) { + if (offload->ops->trigger_disable) + offload->ops->trigger_disable(offload); + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_enable); + +/** + * spi_offload_trigger_disable - disables hardware trigger for offload + * @offload: Offload instance + * @trigger: Offload trigger instance + * + * Disables the hardware trigger for the offload instance with the specified ID + * and releases the bus for use by other clients. + * + * Context: can sleep + */ +void spi_offload_trigger_disable(struct spi_offload *offload, + struct spi_offload_trigger *trigger) +{ + if (offload->ops && offload->ops->trigger_disable) + offload->ops->trigger_disable(offload); + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return; + + if (trigger->ops->disable) + trigger->ops->disable(trigger); +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_disable); + +/* Triggers providers */ + +static void spi_offload_trigger_unregister(void *data) +{ + struct spi_offload_trigger *trigger = data; + + scoped_guard(mutex, &spi_offload_triggers_lock) + list_del(&trigger->list); + + scoped_guard(mutex, &trigger->lock) { + trigger->priv = NULL; + trigger->ops = NULL; + } + + kref_put(&trigger->ref, spi_offload_trigger_free); +} + +/** + * devm_spi_offload_trigger_register() - Allocate and register an offload trigger + * @dev: Device for devm purposes. + * @info: Provider-specific trigger info. + * + * Return: 0 on success, else a negative error code. + */ +int devm_spi_offload_trigger_register(struct device *dev, + struct spi_offload_trigger_info *info) +{ + struct spi_offload_trigger *trigger; + + if (!info->fwnode || !info->ops) + return -EINVAL; + + trigger = kzalloc(sizeof(*trigger), GFP_KERNEL); + if (!trigger) + return -ENOMEM; + + kref_init(&trigger->ref); + mutex_init(&trigger->lock); + trigger->fwnode = fwnode_handle_get(info->fwnode); + trigger->ops = info->ops; + trigger->priv = info->priv; + + scoped_guard(mutex, &spi_offload_triggers_lock) + list_add_tail(&trigger->list, &spi_offload_triggers); + + return devm_add_action_or_reset(dev, spi_offload_trigger_unregister, trigger); +} +EXPORT_SYMBOL_GPL(devm_spi_offload_trigger_register); + +/** + * spi_offload_trigger_get_priv() - Get the private data for the trigger + * + * @trigger: Offload trigger instance. + * + * Return: Private data for the trigger. + */ +void *spi_offload_trigger_get_priv(struct spi_offload_trigger *trigger) +{ + return trigger->priv; +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_get_priv); diff --git a/include/linux/spi/offload/consumer.h b/include/linux/spi/offload/consumer.h index 05543dbedf308..5a0ec5303d600 100644 --- a/include/linux/spi/offload/consumer.h +++ b/include/linux/spi/offload/consumer.h @@ -19,4 +19,16 @@ struct spi_device; struct spi_offload *devm_spi_offload_get(struct device *dev, struct spi_device *spi, const struct spi_offload_config *config); +struct spi_offload_trigger +*devm_spi_offload_trigger_get(struct device *dev, + struct spi_offload *offload, + enum spi_offload_trigger_type type); +int spi_offload_trigger_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); +int spi_offload_trigger_enable(struct spi_offload *offload, + struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); +void spi_offload_trigger_disable(struct spi_offload *offload, + struct spi_offload_trigger *trigger); + #endif /* __LINUX_SPI_OFFLOAD_CONSUMER_H */ diff --git a/include/linux/spi/offload/provider.h b/include/linux/spi/offload/provider.h index 278c4edfcdb7b..76c7cf6510924 100644 --- a/include/linux/spi/offload/provider.h +++ b/include/linux/spi/offload/provider.h @@ -8,12 +8,40 @@ #define __LINUX_SPI_OFFLOAD_PROVIDER_H #include <linux/module.h> +#include <linux/spi/offload/types.h> #include <linux/types.h> MODULE_IMPORT_NS("SPI_OFFLOAD"); struct device; +struct spi_offload_trigger; struct spi_offload *devm_spi_offload_alloc(struct device *dev, size_t priv_size); +struct spi_offload_trigger_ops { + bool (*match)(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, u64 *args, u32 nargs); + int (*request)(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, u64 *args, u32 nargs); + void (*release)(struct spi_offload_trigger *trigger); + int (*validate)(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); + int (*enable)(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); + void (*disable)(struct spi_offload_trigger *trigger); +}; + +struct spi_offload_trigger_info { + /** @fwnode: Provider fwnode, used to match to consumer. */ + struct fwnode_handle *fwnode; + /** @ops: Provider-specific callbacks. */ + const struct spi_offload_trigger_ops *ops; + /** Provider-specific state to be used in callbacks. */ + void *priv; +}; + +int devm_spi_offload_trigger_register(struct device *dev, + struct spi_offload_trigger_info *info); +void *spi_offload_trigger_get_priv(struct spi_offload_trigger *trigger); + #endif /* __LINUX_SPI_OFFLOAD_PROVIDER_H */ diff --git a/include/linux/spi/offload/types.h b/include/linux/spi/offload/types.h index a74f8d84541b1..7476f2073b02e 100644 --- a/include/linux/spi/offload/types.h +++ b/include/linux/spi/offload/types.h @@ -38,6 +38,43 @@ struct spi_offload { struct device *provider_dev; /** @priv: provider driver private data */ void *priv; + /** @ops: callbacks for offload support */ + const struct spi_offload_ops *ops; +}; + +enum spi_offload_trigger_type { + /* Indication from SPI peripheral that data is read to read. */ + SPI_OFFLOAD_TRIGGER_DATA_READY, + /* Trigger comes from a periodic source such as a clock. */ + SPI_OFFLOAD_TRIGGER_PERIODIC, +}; + +struct spi_offload_trigger_periodic { + u64 frequency_hz; +}; + +struct spi_offload_trigger_config { + /** @type: type discriminator for union */ + enum spi_offload_trigger_type type; + union { + struct spi_offload_trigger_periodic periodic; + }; +}; + +/** + * struct spi_offload_ops - callbacks implemented by offload providers + */ +struct spi_offload_ops { + /** + * @trigger_enable: Optional callback to enable the trigger for the + * given offload instance. + */ + int (*trigger_enable)(struct spi_offload *offload); + /** + * @trigger_disable: Optional callback to disable the trigger for the + * given offload instance. + */ + void (*trigger_disable)(struct spi_offload *offload); }; #endif /* __LINUX_SPI_OFFLOAD_TYPES_H */ |