diff options
Diffstat (limited to 'drivers/slimbus/core.c')
| -rw-r--r-- | drivers/slimbus/core.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c new file mode 100644 index 000000000..219483b79 --- /dev/null +++ b/drivers/slimbus/core.c @@ -0,0 +1,550 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2011-2017, The Linux Foundation + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/idr.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/pm_runtime.h> +#include <linux/slimbus.h> +#include "slimbus.h" + +static DEFINE_IDA(ctrl_ida); + +static const struct slim_device_id *slim_match(const struct slim_device_id *id, + const struct slim_device *sbdev) +{ + while (id->manf_id != 0 || id->prod_code != 0) { + if (id->manf_id == sbdev->e_addr.manf_id && + id->prod_code == sbdev->e_addr.prod_code && + id->dev_index == sbdev->e_addr.dev_index && + id->instance == sbdev->e_addr.instance) + return id; + id++; + } + return NULL; +} + +static int slim_device_match(struct device *dev, struct device_driver *drv) +{ + struct slim_device *sbdev = to_slim_device(dev); + struct slim_driver *sbdrv = to_slim_driver(drv); + + /* Attempt an OF style match first */ + if (of_driver_match_device(dev, drv)) + return 1; + + return !!slim_match(sbdrv->id_table, sbdev); +} + +static void slim_device_update_status(struct slim_device *sbdev, + enum slim_device_status status) +{ + struct slim_driver *sbdrv; + + if (sbdev->status == status) + return; + + sbdev->status = status; + if (!sbdev->dev.driver) + return; + + sbdrv = to_slim_driver(sbdev->dev.driver); + if (sbdrv->device_status) + sbdrv->device_status(sbdev, sbdev->status); +} + +static int slim_device_probe(struct device *dev) +{ + struct slim_device *sbdev = to_slim_device(dev); + struct slim_driver *sbdrv = to_slim_driver(dev->driver); + int ret; + + ret = sbdrv->probe(sbdev); + if (ret) + return ret; + + /* try getting the logical address after probe */ + ret = slim_get_logical_addr(sbdev); + if (!ret) { + slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP); + } else { + dev_err(&sbdev->dev, "Failed to get logical address\n"); + ret = -EPROBE_DEFER; + } + + return ret; +} + +static void slim_device_remove(struct device *dev) +{ + struct slim_device *sbdev = to_slim_device(dev); + struct slim_driver *sbdrv; + + if (dev->driver) { + sbdrv = to_slim_driver(dev->driver); + if (sbdrv->remove) + sbdrv->remove(sbdev); + } +} + +static int slim_device_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct slim_device *sbdev = to_slim_device(dev); + + return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev)); +} + +struct bus_type slimbus_bus = { + .name = "slimbus", + .match = slim_device_match, + .probe = slim_device_probe, + .remove = slim_device_remove, + .uevent = slim_device_uevent, +}; +EXPORT_SYMBOL_GPL(slimbus_bus); + +/* + * __slim_driver_register() - Client driver registration with SLIMbus + * + * @drv:Client driver to be associated with client-device. + * @owner: owning module/driver + * + * This API will register the client driver with the SLIMbus + * It is called from the driver's module-init function. + */ +int __slim_driver_register(struct slim_driver *drv, struct module *owner) +{ + /* ID table and probe are mandatory */ + if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe) + return -EINVAL; + + drv->driver.bus = &slimbus_bus; + drv->driver.owner = owner; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(__slim_driver_register); + +/* + * slim_driver_unregister() - Undo effect of slim_driver_register + * + * @drv: Client driver to be unregistered + */ +void slim_driver_unregister(struct slim_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(slim_driver_unregister); + +static void slim_dev_release(struct device *dev) +{ + struct slim_device *sbdev = to_slim_device(dev); + + kfree(sbdev); +} + +static int slim_add_device(struct slim_controller *ctrl, + struct slim_device *sbdev, + struct device_node *node) +{ + sbdev->dev.bus = &slimbus_bus; + sbdev->dev.parent = ctrl->dev; + sbdev->dev.release = slim_dev_release; + sbdev->dev.driver = NULL; + sbdev->ctrl = ctrl; + INIT_LIST_HEAD(&sbdev->stream_list); + spin_lock_init(&sbdev->stream_list_lock); + sbdev->dev.of_node = of_node_get(node); + sbdev->dev.fwnode = of_fwnode_handle(node); + + dev_set_name(&sbdev->dev, "%x:%x:%x:%x", + sbdev->e_addr.manf_id, + sbdev->e_addr.prod_code, + sbdev->e_addr.dev_index, + sbdev->e_addr.instance); + + return device_register(&sbdev->dev); +} + +static struct slim_device *slim_alloc_device(struct slim_controller *ctrl, + struct slim_eaddr *eaddr, + struct device_node *node) +{ + struct slim_device *sbdev; + int ret; + + sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL); + if (!sbdev) + return NULL; + + sbdev->e_addr = *eaddr; + ret = slim_add_device(ctrl, sbdev, node); + if (ret) { + put_device(&sbdev->dev); + return NULL; + } + + return sbdev; +} + +static void of_register_slim_devices(struct slim_controller *ctrl) +{ + struct device *dev = ctrl->dev; + struct device_node *node; + + if (!ctrl->dev->of_node) + return; + + for_each_child_of_node(ctrl->dev->of_node, node) { + struct slim_device *sbdev; + struct slim_eaddr e_addr; + const char *compat = NULL; + int reg[2], ret; + int manf_id, prod_code; + + compat = of_get_property(node, "compatible", NULL); + if (!compat) + continue; + + ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code); + if (ret != 2) { + dev_err(dev, "Manf ID & Product code not found %s\n", + compat); + continue; + } + + ret = of_property_read_u32_array(node, "reg", reg, 2); + if (ret) { + dev_err(dev, "Device and Instance id not found:%d\n", + ret); + continue; + } + + e_addr.dev_index = reg[0]; + e_addr.instance = reg[1]; + e_addr.manf_id = manf_id; + e_addr.prod_code = prod_code; + + sbdev = slim_alloc_device(ctrl, &e_addr, node); + if (!sbdev) + continue; + } +} + +/* + * slim_register_controller() - Controller bring-up and registration. + * + * @ctrl: Controller to be registered. + * + * A controller is registered with the framework using this API. + * If devices on a controller were registered before controller, + * this will make sure that they get probed when controller is up + */ +int slim_register_controller(struct slim_controller *ctrl) +{ + int id; + + id = ida_alloc(&ctrl_ida, GFP_KERNEL); + if (id < 0) + return id; + + ctrl->id = id; + + if (!ctrl->min_cg) + ctrl->min_cg = SLIM_MIN_CLK_GEAR; + if (!ctrl->max_cg) + ctrl->max_cg = SLIM_MAX_CLK_GEAR; + + ida_init(&ctrl->laddr_ida); + idr_init(&ctrl->tid_idr); + mutex_init(&ctrl->lock); + mutex_init(&ctrl->sched.m_reconf); + init_completion(&ctrl->sched.pause_comp); + spin_lock_init(&ctrl->txn_lock); + + dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n", + ctrl->name, ctrl->dev); + + of_register_slim_devices(ctrl); + + return 0; +} +EXPORT_SYMBOL_GPL(slim_register_controller); + +/* slim_remove_device: Remove the effect of slim_add_device() */ +static void slim_remove_device(struct slim_device *sbdev) +{ + of_node_put(sbdev->dev.of_node); + device_unregister(&sbdev->dev); +} + +static int slim_ctrl_remove_device(struct device *dev, void *null) +{ + slim_remove_device(to_slim_device(dev)); + return 0; +} + +/** + * slim_unregister_controller() - Controller tear-down. + * + * @ctrl: Controller to tear-down. + */ +int slim_unregister_controller(struct slim_controller *ctrl) +{ + /* Remove all clients */ + device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device); + ida_free(&ctrl_ida, ctrl->id); + + return 0; +} +EXPORT_SYMBOL_GPL(slim_unregister_controller); + +/** + * slim_report_absent() - Controller calls this function when a device + * reports absent, OR when the device cannot be communicated with + * + * @sbdev: Device that cannot be reached, or sent report absent + */ +void slim_report_absent(struct slim_device *sbdev) +{ + struct slim_controller *ctrl = sbdev->ctrl; + + if (!ctrl) + return; + + /* invalidate logical addresses */ + mutex_lock(&ctrl->lock); + sbdev->is_laddr_valid = false; + mutex_unlock(&ctrl->lock); + if (!ctrl->get_laddr) + ida_free(&ctrl->laddr_ida, sbdev->laddr); + slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN); +} +EXPORT_SYMBOL_GPL(slim_report_absent); + +static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b) +{ + return (a->manf_id == b->manf_id && + a->prod_code == b->prod_code && + a->dev_index == b->dev_index && + a->instance == b->instance); +} + +static int slim_match_dev(struct device *dev, void *data) +{ + struct slim_eaddr *e_addr = data; + struct slim_device *sbdev = to_slim_device(dev); + + return slim_eaddr_equal(&sbdev->e_addr, e_addr); +} + +static struct slim_device *find_slim_device(struct slim_controller *ctrl, + struct slim_eaddr *eaddr) +{ + struct slim_device *sbdev; + struct device *dev; + + dev = device_find_child(ctrl->dev, eaddr, slim_match_dev); + if (dev) { + sbdev = to_slim_device(dev); + return sbdev; + } + + return NULL; +} + +/** + * slim_get_device() - get handle to a device. + * + * @ctrl: Controller on which this device will be added/queried + * @e_addr: Enumeration address of the device to be queried + * + * Return: pointer to a device if it has already reported. Creates a new + * device and returns pointer to it if the device has not yet enumerated. + */ +struct slim_device *slim_get_device(struct slim_controller *ctrl, + struct slim_eaddr *e_addr) +{ + struct slim_device *sbdev; + + sbdev = find_slim_device(ctrl, e_addr); + if (!sbdev) { + sbdev = slim_alloc_device(ctrl, e_addr, NULL); + if (!sbdev) + return ERR_PTR(-ENOMEM); + } + + return sbdev; +} +EXPORT_SYMBOL_GPL(slim_get_device); + +static int of_slim_match_dev(struct device *dev, void *data) +{ + struct device_node *np = data; + struct slim_device *sbdev = to_slim_device(dev); + + return (sbdev->dev.of_node == np); +} + +static struct slim_device *of_find_slim_device(struct slim_controller *ctrl, + struct device_node *np) +{ + struct slim_device *sbdev; + struct device *dev; + + dev = device_find_child(ctrl->dev, np, of_slim_match_dev); + if (dev) { + sbdev = to_slim_device(dev); + return sbdev; + } + + return NULL; +} + +/** + * of_slim_get_device() - get handle to a device using dt node. + * + * @ctrl: Controller on which this device will be added/queried + * @np: node pointer to device + * + * Return: pointer to a device if it has already reported. Creates a new + * device and returns pointer to it if the device has not yet enumerated. + */ +struct slim_device *of_slim_get_device(struct slim_controller *ctrl, + struct device_node *np) +{ + return of_find_slim_device(ctrl, np); +} +EXPORT_SYMBOL_GPL(of_slim_get_device); + +static int slim_device_alloc_laddr(struct slim_device *sbdev, + bool report_present) +{ + struct slim_controller *ctrl = sbdev->ctrl; + u8 laddr; + int ret; + + mutex_lock(&ctrl->lock); + if (ctrl->get_laddr) { + ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr); + if (ret < 0) + goto err; + } else if (report_present) { + ret = ida_simple_get(&ctrl->laddr_ida, + 0, SLIM_LA_MANAGER - 1, GFP_KERNEL); + if (ret < 0) + goto err; + + laddr = ret; + } else { + ret = -EINVAL; + goto err; + } + + if (ctrl->set_laddr) { + ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr); + if (ret) { + ret = -EINVAL; + goto err; + } + } + + sbdev->laddr = laddr; + sbdev->is_laddr_valid = true; + mutex_unlock(&ctrl->lock); + + slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP); + + dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n", + laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code, + sbdev->e_addr.dev_index, sbdev->e_addr.instance); + + return 0; + +err: + mutex_unlock(&ctrl->lock); + return ret; + +} + +/** + * slim_device_report_present() - Report enumerated device. + * + * @ctrl: Controller with which device is enumerated. + * @e_addr: Enumeration address of the device. + * @laddr: Return logical address (if valid flag is false) + * + * Called by controller in response to REPORT_PRESENT. Framework will assign + * a logical address to this enumeration address. + * Function returns -EXFULL to indicate that all logical addresses are already + * taken. + */ +int slim_device_report_present(struct slim_controller *ctrl, + struct slim_eaddr *e_addr, u8 *laddr) +{ + struct slim_device *sbdev; + int ret; + + ret = pm_runtime_get_sync(ctrl->dev); + + if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) { + dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n", + ctrl->sched.clk_state, ret); + goto slimbus_not_active; + } + + sbdev = slim_get_device(ctrl, e_addr); + if (IS_ERR(sbdev)) + return -ENODEV; + + if (sbdev->is_laddr_valid) { + *laddr = sbdev->laddr; + return 0; + } + + ret = slim_device_alloc_laddr(sbdev, true); + +slimbus_not_active: + pm_runtime_mark_last_busy(ctrl->dev); + pm_runtime_put_autosuspend(ctrl->dev); + return ret; +} +EXPORT_SYMBOL_GPL(slim_device_report_present); + +/** + * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device. + * + * @sbdev: client handle requesting the address. + * + * Return: zero if a logical address is valid or a new logical address + * has been assigned. error code in case of error. + */ +int slim_get_logical_addr(struct slim_device *sbdev) +{ + if (!sbdev->is_laddr_valid) + return slim_device_alloc_laddr(sbdev, false); + + return 0; +} +EXPORT_SYMBOL_GPL(slim_get_logical_addr); + +static void __exit slimbus_exit(void) +{ + bus_unregister(&slimbus_bus); +} +module_exit(slimbus_exit); + +static int __init slimbus_init(void) +{ + return bus_register(&slimbus_bus); +} +postcore_initcall(slimbus_init); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("SLIMbus core"); |