diff options
Diffstat (limited to 'drivers/hsi/hsi.c')
| -rw-r--r-- | drivers/hsi/hsi.c | 772 |
1 files changed, 772 insertions, 0 deletions
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c new file mode 100644 index 000000000..fe9371271 --- /dev/null +++ b/drivers/hsi/hsi.c @@ -0,0 +1,772 @@ +/* + * HSI core. + * + * Copyright (C) 2010 Nokia Corporation. All rights reserved. + * + * Contact: Carlos Chinea <carlos.chinea@nokia.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ +#include <linux/hsi/hsi.h> +#include <linux/compiler.h> +#include <linux/list.h> +#include <linux/kobject.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include "hsi_core.h" + +static ssize_t modalias_show(struct device *dev, + struct device_attribute *a __maybe_unused, char *buf) +{ + return sprintf(buf, "hsi:%s\n", dev_name(dev)); +} +static DEVICE_ATTR_RO(modalias); + +static struct attribute *hsi_bus_dev_attrs[] = { + &dev_attr_modalias.attr, + NULL, +}; +ATTRIBUTE_GROUPS(hsi_bus_dev); + +static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev)); + + return 0; +} + +static int hsi_bus_match(struct device *dev, struct device_driver *driver) +{ + if (of_driver_match_device(dev, driver)) + return true; + + if (strcmp(dev_name(dev), driver->name) == 0) + return true; + + return false; +} + +static struct bus_type hsi_bus_type = { + .name = "hsi", + .dev_groups = hsi_bus_dev_groups, + .match = hsi_bus_match, + .uevent = hsi_bus_uevent, +}; + +static void hsi_client_release(struct device *dev) +{ + struct hsi_client *cl = to_hsi_client(dev); + + kfree(cl->tx_cfg.channels); + kfree(cl->rx_cfg.channels); + kfree(cl); +} + +struct hsi_client *hsi_new_client(struct hsi_port *port, + struct hsi_board_info *info) +{ + struct hsi_client *cl; + size_t size; + + cl = kzalloc(sizeof(*cl), GFP_KERNEL); + if (!cl) + return NULL; + + cl->tx_cfg = info->tx_cfg; + if (cl->tx_cfg.channels) { + size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels); + cl->tx_cfg.channels = kzalloc(size , GFP_KERNEL); + memcpy(cl->tx_cfg.channels, info->tx_cfg.channels, size); + } + + cl->rx_cfg = info->rx_cfg; + if (cl->rx_cfg.channels) { + size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels); + cl->rx_cfg.channels = kzalloc(size , GFP_KERNEL); + memcpy(cl->rx_cfg.channels, info->rx_cfg.channels, size); + } + + cl->device.bus = &hsi_bus_type; + cl->device.parent = &port->device; + cl->device.release = hsi_client_release; + dev_set_name(&cl->device, "%s", info->name); + cl->device.platform_data = info->platform_data; + if (info->archdata) + cl->device.archdata = *info->archdata; + if (device_register(&cl->device) < 0) { + pr_err("hsi: failed to register client: %s\n", info->name); + put_device(&cl->device); + } + + return cl; +} +EXPORT_SYMBOL_GPL(hsi_new_client); + +static void hsi_scan_board_info(struct hsi_controller *hsi) +{ + struct hsi_cl_info *cl_info; + struct hsi_port *p; + + list_for_each_entry(cl_info, &hsi_board_list, list) + if (cl_info->info.hsi_id == hsi->id) { + p = hsi_find_port_num(hsi, cl_info->info.port); + if (!p) + continue; + hsi_new_client(p, &cl_info->info); + } +} + +#ifdef CONFIG_OF +static struct hsi_board_info hsi_char_dev_info = { + .name = "hsi_char", +}; + +static int hsi_of_property_parse_mode(struct device_node *client, char *name, + unsigned int *result) +{ + const char *mode; + int err; + + err = of_property_read_string(client, name, &mode); + if (err < 0) + return err; + + if (strcmp(mode, "stream") == 0) + *result = HSI_MODE_STREAM; + else if (strcmp(mode, "frame") == 0) + *result = HSI_MODE_FRAME; + else + return -EINVAL; + + return 0; +} + +static int hsi_of_property_parse_flow(struct device_node *client, char *name, + unsigned int *result) +{ + const char *flow; + int err; + + err = of_property_read_string(client, name, &flow); + if (err < 0) + return err; + + if (strcmp(flow, "synchronized") == 0) + *result = HSI_FLOW_SYNC; + else if (strcmp(flow, "pipeline") == 0) + *result = HSI_FLOW_PIPE; + else + return -EINVAL; + + return 0; +} + +static int hsi_of_property_parse_arb_mode(struct device_node *client, + char *name, unsigned int *result) +{ + const char *arb_mode; + int err; + + err = of_property_read_string(client, name, &arb_mode); + if (err < 0) + return err; + + if (strcmp(arb_mode, "round-robin") == 0) + *result = HSI_ARB_RR; + else if (strcmp(arb_mode, "priority") == 0) + *result = HSI_ARB_PRIO; + else + return -EINVAL; + + return 0; +} + +static void hsi_add_client_from_dt(struct hsi_port *port, + struct device_node *client) +{ + struct hsi_client *cl; + struct hsi_channel channel; + struct property *prop; + char name[32]; + int length, cells, err, i, max_chan, mode; + + cl = kzalloc(sizeof(*cl), GFP_KERNEL); + if (!cl) + return; + + err = of_modalias_node(client, name, sizeof(name)); + if (err) + goto err; + + dev_set_name(&cl->device, "%s", name); + + err = hsi_of_property_parse_mode(client, "hsi-mode", &mode); + if (err) { + err = hsi_of_property_parse_mode(client, "hsi-rx-mode", + &cl->rx_cfg.mode); + if (err) + goto err; + + err = hsi_of_property_parse_mode(client, "hsi-tx-mode", + &cl->tx_cfg.mode); + if (err) + goto err; + } else { + cl->rx_cfg.mode = mode; + cl->tx_cfg.mode = mode; + } + + err = of_property_read_u32(client, "hsi-speed-kbps", + &cl->tx_cfg.speed); + if (err) + goto err; + cl->rx_cfg.speed = cl->tx_cfg.speed; + + err = hsi_of_property_parse_flow(client, "hsi-flow", + &cl->rx_cfg.flow); + if (err) + goto err; + + err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode", + &cl->rx_cfg.arb_mode); + if (err) + goto err; + + prop = of_find_property(client, "hsi-channel-ids", &length); + if (!prop) { + err = -EINVAL; + goto err; + } + + cells = length / sizeof(u32); + + cl->rx_cfg.num_channels = cells; + cl->tx_cfg.num_channels = cells; + + cl->rx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL); + if (!cl->rx_cfg.channels) { + err = -ENOMEM; + goto err; + } + + cl->tx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL); + if (!cl->tx_cfg.channels) { + err = -ENOMEM; + goto err2; + } + + max_chan = 0; + for (i = 0; i < cells; i++) { + err = of_property_read_u32_index(client, "hsi-channel-ids", i, + &channel.id); + if (err) + goto err3; + + err = of_property_read_string_index(client, "hsi-channel-names", + i, &channel.name); + if (err) + channel.name = NULL; + + if (channel.id > max_chan) + max_chan = channel.id; + + cl->rx_cfg.channels[i] = channel; + cl->tx_cfg.channels[i] = channel; + } + + cl->rx_cfg.num_hw_channels = max_chan + 1; + cl->tx_cfg.num_hw_channels = max_chan + 1; + + cl->device.bus = &hsi_bus_type; + cl->device.parent = &port->device; + cl->device.release = hsi_client_release; + cl->device.of_node = client; + + if (device_register(&cl->device) < 0) { + pr_err("hsi: failed to register client: %s\n", name); + put_device(&cl->device); + goto err3; + } + + return; + +err3: + kfree(cl->tx_cfg.channels); +err2: + kfree(cl->rx_cfg.channels); +err: + kfree(cl); + pr_err("hsi client: missing or incorrect of property: err=%d\n", err); +} + +void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients) +{ + struct device_node *child; + + /* register hsi-char device */ + hsi_new_client(port, &hsi_char_dev_info); + + for_each_available_child_of_node(clients, child) + hsi_add_client_from_dt(port, child); +} +EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt); +#endif + +int hsi_remove_client(struct device *dev, void *data __maybe_unused) +{ + device_unregister(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(hsi_remove_client); + +static int hsi_remove_port(struct device *dev, void *data __maybe_unused) +{ + device_for_each_child(dev, NULL, hsi_remove_client); + device_unregister(dev); + + return 0; +} + +static void hsi_controller_release(struct device *dev) +{ + struct hsi_controller *hsi = to_hsi_controller(dev); + + kfree(hsi->port); + kfree(hsi); +} + +static void hsi_port_release(struct device *dev) +{ + kfree(to_hsi_port(dev)); +} + +/** + * hsi_unregister_port - Unregister an HSI port + * @port: The HSI port to unregister + */ +void hsi_port_unregister_clients(struct hsi_port *port) +{ + device_for_each_child(&port->device, NULL, hsi_remove_client); +} +EXPORT_SYMBOL_GPL(hsi_port_unregister_clients); + +/** + * hsi_unregister_controller - Unregister an HSI controller + * @hsi: The HSI controller to register + */ +void hsi_unregister_controller(struct hsi_controller *hsi) +{ + device_for_each_child(&hsi->device, NULL, hsi_remove_port); + device_unregister(&hsi->device); +} +EXPORT_SYMBOL_GPL(hsi_unregister_controller); + +/** + * hsi_register_controller - Register an HSI controller and its ports + * @hsi: The HSI controller to register + * + * Returns -errno on failure, 0 on success. + */ +int hsi_register_controller(struct hsi_controller *hsi) +{ + unsigned int i; + int err; + + err = device_add(&hsi->device); + if (err < 0) + return err; + for (i = 0; i < hsi->num_ports; i++) { + hsi->port[i]->device.parent = &hsi->device; + err = device_add(&hsi->port[i]->device); + if (err < 0) + goto out; + } + /* Populate HSI bus with HSI clients */ + hsi_scan_board_info(hsi); + + return 0; +out: + while (i-- > 0) + device_del(&hsi->port[i]->device); + device_del(&hsi->device); + + return err; +} +EXPORT_SYMBOL_GPL(hsi_register_controller); + +/** + * hsi_register_client_driver - Register an HSI client to the HSI bus + * @drv: HSI client driver to register + * + * Returns -errno on failure, 0 on success. + */ +int hsi_register_client_driver(struct hsi_client_driver *drv) +{ + drv->driver.bus = &hsi_bus_type; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(hsi_register_client_driver); + +static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused) +{ + return 0; +} + +static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused) +{ + return 0; +} + +/** + * hsi_put_controller - Free an HSI controller + * + * @hsi: Pointer to the HSI controller to freed + * + * HSI controller drivers should only use this function if they need + * to free their allocated hsi_controller structures before a successful + * call to hsi_register_controller. Other use is not allowed. + */ +void hsi_put_controller(struct hsi_controller *hsi) +{ + unsigned int i; + + if (!hsi) + return; + + for (i = 0; i < hsi->num_ports; i++) + if (hsi->port && hsi->port[i]) + put_device(&hsi->port[i]->device); + put_device(&hsi->device); +} +EXPORT_SYMBOL_GPL(hsi_put_controller); + +/** + * hsi_alloc_controller - Allocate an HSI controller and its ports + * @n_ports: Number of ports on the HSI controller + * @flags: Kernel allocation flags + * + * Return NULL on failure or a pointer to an hsi_controller on success. + */ +struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags) +{ + struct hsi_controller *hsi; + struct hsi_port **port; + unsigned int i; + + if (!n_ports) + return NULL; + + hsi = kzalloc(sizeof(*hsi), flags); + if (!hsi) + return NULL; + port = kzalloc(sizeof(*port)*n_ports, flags); + if (!port) { + kfree(hsi); + return NULL; + } + hsi->num_ports = n_ports; + hsi->port = port; + hsi->device.release = hsi_controller_release; + device_initialize(&hsi->device); + + for (i = 0; i < n_ports; i++) { + port[i] = kzalloc(sizeof(**port), flags); + if (port[i] == NULL) + goto out; + port[i]->num = i; + port[i]->async = hsi_dummy_msg; + port[i]->setup = hsi_dummy_cl; + port[i]->flush = hsi_dummy_cl; + port[i]->start_tx = hsi_dummy_cl; + port[i]->stop_tx = hsi_dummy_cl; + port[i]->release = hsi_dummy_cl; + mutex_init(&port[i]->lock); + ATOMIC_INIT_NOTIFIER_HEAD(&port[i]->n_head); + dev_set_name(&port[i]->device, "port%d", i); + hsi->port[i]->device.release = hsi_port_release; + device_initialize(&hsi->port[i]->device); + } + + return hsi; +out: + hsi_put_controller(hsi); + + return NULL; +} +EXPORT_SYMBOL_GPL(hsi_alloc_controller); + +/** + * hsi_free_msg - Free an HSI message + * @msg: Pointer to the HSI message + * + * Client is responsible to free the buffers pointed by the scatterlists. + */ +void hsi_free_msg(struct hsi_msg *msg) +{ + if (!msg) + return; + sg_free_table(&msg->sgt); + kfree(msg); +} +EXPORT_SYMBOL_GPL(hsi_free_msg); + +/** + * hsi_alloc_msg - Allocate an HSI message + * @nents: Number of memory entries + * @flags: Kernel allocation flags + * + * nents can be 0. This mainly makes sense for read transfer. + * In that case, HSI drivers will call the complete callback when + * there is data to be read without consuming it. + * + * Return NULL on failure or a pointer to an hsi_msg on success. + */ +struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags) +{ + struct hsi_msg *msg; + int err; + + msg = kzalloc(sizeof(*msg), flags); + if (!msg) + return NULL; + + if (!nents) + return msg; + + err = sg_alloc_table(&msg->sgt, nents, flags); + if (unlikely(err)) { + kfree(msg); + msg = NULL; + } + + return msg; +} +EXPORT_SYMBOL_GPL(hsi_alloc_msg); + +/** + * hsi_async - Submit an HSI transfer to the controller + * @cl: HSI client sending the transfer + * @msg: The HSI transfer passed to controller + * + * The HSI message must have the channel, ttype, complete and destructor + * fields set beforehand. If nents > 0 then the client has to initialize + * also the scatterlists to point to the buffers to write to or read from. + * + * HSI controllers relay on pre-allocated buffers from their clients and they + * do not allocate buffers on their own. + * + * Once the HSI message transfer finishes, the HSI controller calls the + * complete callback with the status and actual_len fields of the HSI message + * updated. The complete callback can be called before returning from + * hsi_async. + * + * Returns -errno on failure or 0 on success + */ +int hsi_async(struct hsi_client *cl, struct hsi_msg *msg) +{ + struct hsi_port *port = hsi_get_port(cl); + + if (!hsi_port_claimed(cl)) + return -EACCES; + + WARN_ON_ONCE(!msg->destructor || !msg->complete); + msg->cl = cl; + + return port->async(msg); +} +EXPORT_SYMBOL_GPL(hsi_async); + +/** + * hsi_claim_port - Claim the HSI client's port + * @cl: HSI client that wants to claim its port + * @share: Flag to indicate if the client wants to share the port or not. + * + * Returns -errno on failure, 0 on success. + */ +int hsi_claim_port(struct hsi_client *cl, unsigned int share) +{ + struct hsi_port *port = hsi_get_port(cl); + int err = 0; + + mutex_lock(&port->lock); + if ((port->claimed) && (!port->shared || !share)) { + err = -EBUSY; + goto out; + } + if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) { + err = -ENODEV; + goto out; + } + port->claimed++; + port->shared = !!share; + cl->pclaimed = 1; +out: + mutex_unlock(&port->lock); + + return err; +} +EXPORT_SYMBOL_GPL(hsi_claim_port); + +/** + * hsi_release_port - Release the HSI client's port + * @cl: HSI client which previously claimed its port + */ +void hsi_release_port(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + + mutex_lock(&port->lock); + /* Allow HW driver to do some cleanup */ + port->release(cl); + if (cl->pclaimed) + port->claimed--; + BUG_ON(port->claimed < 0); + cl->pclaimed = 0; + if (!port->claimed) + port->shared = 0; + module_put(to_hsi_controller(port->device.parent)->owner); + mutex_unlock(&port->lock); +} +EXPORT_SYMBOL_GPL(hsi_release_port); + +static int hsi_event_notifier_call(struct notifier_block *nb, + unsigned long event, void *data __maybe_unused) +{ + struct hsi_client *cl = container_of(nb, struct hsi_client, nb); + + (*cl->ehandler)(cl, event); + + return 0; +} + +/** + * hsi_register_port_event - Register a client to receive port events + * @cl: HSI client that wants to receive port events + * @handler: Event handler callback + * + * Clients should register a callback to be able to receive + * events from the ports. Registration should happen after + * claiming the port. + * The handler can be called in interrupt context. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_register_port_event(struct hsi_client *cl, + void (*handler)(struct hsi_client *, unsigned long)) +{ + struct hsi_port *port = hsi_get_port(cl); + + if (!handler || cl->ehandler) + return -EINVAL; + if (!hsi_port_claimed(cl)) + return -EACCES; + cl->ehandler = handler; + cl->nb.notifier_call = hsi_event_notifier_call; + + return atomic_notifier_chain_register(&port->n_head, &cl->nb); +} +EXPORT_SYMBOL_GPL(hsi_register_port_event); + +/** + * hsi_unregister_port_event - Stop receiving port events for a client + * @cl: HSI client that wants to stop receiving port events + * + * Clients should call this function before releasing their associated + * port. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_unregister_port_event(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + int err; + + WARN_ON(!hsi_port_claimed(cl)); + + err = atomic_notifier_chain_unregister(&port->n_head, &cl->nb); + if (!err) + cl->ehandler = NULL; + + return err; +} +EXPORT_SYMBOL_GPL(hsi_unregister_port_event); + +/** + * hsi_event - Notifies clients about port events + * @port: Port where the event occurred + * @event: The event type + * + * Clients should not be concerned about wake line behavior. However, due + * to a race condition in HSI HW protocol, clients need to be notified + * about wake line changes, so they can implement a workaround for it. + * + * Events: + * HSI_EVENT_START_RX - Incoming wake line high + * HSI_EVENT_STOP_RX - Incoming wake line down + * + * Returns -errno on error, or 0 on success. + */ +int hsi_event(struct hsi_port *port, unsigned long event) +{ + return atomic_notifier_call_chain(&port->n_head, event, NULL); +} +EXPORT_SYMBOL_GPL(hsi_event); + +/** + * hsi_get_channel_id_by_name - acquire channel id by channel name + * @cl: HSI client, which uses the channel + * @name: name the channel is known under + * + * Clients can call this function to get the hsi channel ids similar to + * requesting IRQs or GPIOs by name. This function assumes the same + * channel configuration is used for RX and TX. + * + * Returns -errno on error or channel id on success. + */ +int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name) +{ + int i; + + if (!cl->rx_cfg.channels) + return -ENOENT; + + for (i = 0; i < cl->rx_cfg.num_channels; i++) + if (!strcmp(cl->rx_cfg.channels[i].name, name)) + return cl->rx_cfg.channels[i].id; + + return -ENXIO; +} +EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name); + +static int __init hsi_init(void) +{ + return bus_register(&hsi_bus_type); +} +postcore_initcall(hsi_init); + +static void __exit hsi_exit(void) +{ + bus_unregister(&hsi_bus_type); +} +module_exit(hsi_exit); + +MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>"); +MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework"); +MODULE_LICENSE("GPL v2"); |