diff options
Diffstat (limited to 'drivers/net/phy/mdio_bus.c')
| -rw-r--r-- | drivers/net/phy/mdio_bus.c | 762 |
1 files changed, 762 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c new file mode 100644 index 000000000..efdac68da --- /dev/null +++ b/drivers/net/phy/mdio_bus.c @@ -0,0 +1,762 @@ +/* MDIO Bus interface + * + * Author: Andy Fleming + * + * Copyright (c) 2004 Freescale Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/unistd.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/gpio.h> +#include <linux/gpio/consumer.h> +#include <linux/of_device.h> +#include <linux/of_mdio.h> +#include <linux/of_gpio.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/skbuff.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/mii.h> +#include <linux/ethtool.h> +#include <linux/phy.h> +#include <linux/io.h> +#include <linux/uaccess.h> +#include <linux/gpio/consumer.h> + +#include <asm/irq.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/mdio.h> + +#include "mdio-boardinfo.h" + +static int mdiobus_register_gpiod(struct mdio_device *mdiodev) +{ + struct gpio_desc *gpiod = NULL; + + /* Deassert the optional reset signal */ + if (mdiodev->dev.of_node) + gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode, + "reset-gpios", 0, GPIOD_OUT_LOW, + "PHY reset"); + if (IS_ERR(gpiod)) { + if (PTR_ERR(gpiod) == -ENOENT || PTR_ERR(gpiod) == -ENOSYS) + gpiod = NULL; + else + return PTR_ERR(gpiod); + } + + mdiodev->reset = gpiod; + + /* Assert the reset signal again */ + mdio_device_reset(mdiodev, 1); + + return 0; +} + +int mdiobus_register_device(struct mdio_device *mdiodev) +{ + int err; + + if (mdiodev->bus->mdio_map[mdiodev->addr]) + return -EBUSY; + + if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) { + err = mdiobus_register_gpiod(mdiodev); + if (err) + return err; + } + + mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev; + + return 0; +} +EXPORT_SYMBOL(mdiobus_register_device); + +int mdiobus_unregister_device(struct mdio_device *mdiodev) +{ + if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev) + return -EINVAL; + + mdiodev->bus->mdio_map[mdiodev->addr] = NULL; + + return 0; +} +EXPORT_SYMBOL(mdiobus_unregister_device); + +struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr) +{ + struct mdio_device *mdiodev = bus->mdio_map[addr]; + + if (!mdiodev) + return NULL; + + if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY)) + return NULL; + + return container_of(mdiodev, struct phy_device, mdio); +} +EXPORT_SYMBOL(mdiobus_get_phy); + +bool mdiobus_is_registered_device(struct mii_bus *bus, int addr) +{ + return bus->mdio_map[addr]; +} +EXPORT_SYMBOL(mdiobus_is_registered_device); + +/** + * mdiobus_alloc_size - allocate a mii_bus structure + * @size: extra amount of memory to allocate for private storage. + * If non-zero, then bus->priv is points to that memory. + * + * Description: called by a bus driver to allocate an mii_bus + * structure to fill in. + */ +struct mii_bus *mdiobus_alloc_size(size_t size) +{ + struct mii_bus *bus; + size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN); + size_t alloc_size; + int i; + + /* If we alloc extra space, it should be aligned */ + if (size) + alloc_size = aligned_size + size; + else + alloc_size = sizeof(*bus); + + bus = kzalloc(alloc_size, GFP_KERNEL); + if (!bus) + return NULL; + + bus->state = MDIOBUS_ALLOCATED; + if (size) + bus->priv = (void *)bus + aligned_size; + + /* Initialise the interrupts to polling */ + for (i = 0; i < PHY_MAX_ADDR; i++) + bus->irq[i] = PHY_POLL; + + return bus; +} +EXPORT_SYMBOL(mdiobus_alloc_size); + +static void _devm_mdiobus_free(struct device *dev, void *res) +{ + mdiobus_free(*(struct mii_bus **)res); +} + +static int devm_mdiobus_match(struct device *dev, void *res, void *data) +{ + struct mii_bus **r = res; + + if (WARN_ON(!r || !*r)) + return 0; + + return *r == data; +} + +/** + * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size() + * @dev: Device to allocate mii_bus for + * @sizeof_priv: Space to allocate for private structure. + * + * Managed mdiobus_alloc_size. mii_bus allocated with this function is + * automatically freed on driver detach. + * + * If an mii_bus allocated with this function needs to be freed separately, + * devm_mdiobus_free() must be used. + * + * RETURNS: + * Pointer to allocated mii_bus on success, NULL on failure. + */ +struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv) +{ + struct mii_bus **ptr, *bus; + + ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return NULL; + + /* use raw alloc_dr for kmalloc caller tracing */ + bus = mdiobus_alloc_size(sizeof_priv); + if (bus) { + *ptr = bus; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return bus; +} +EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size); + +/** + * devm_mdiobus_free - Resource-managed mdiobus_free() + * @dev: Device this mii_bus belongs to + * @bus: the mii_bus associated with the device + * + * Free mii_bus allocated with devm_mdiobus_alloc_size(). + */ +void devm_mdiobus_free(struct device *dev, struct mii_bus *bus) +{ + int rc; + + rc = devres_release(dev, _devm_mdiobus_free, + devm_mdiobus_match, bus); + WARN_ON(rc); +} +EXPORT_SYMBOL_GPL(devm_mdiobus_free); + +/** + * mdiobus_release - mii_bus device release callback + * @d: the target struct device that contains the mii_bus + * + * Description: called when the last reference to an mii_bus is + * dropped, to free the underlying memory. + */ +static void mdiobus_release(struct device *d) +{ + struct mii_bus *bus = to_mii_bus(d); + BUG_ON(bus->state != MDIOBUS_RELEASED && + /* for compatibility with error handling in drivers */ + bus->state != MDIOBUS_ALLOCATED); + kfree(bus); +} + +static struct class mdio_bus_class = { + .name = "mdio_bus", + .dev_release = mdiobus_release, +}; + +#if IS_ENABLED(CONFIG_OF_MDIO) +/* Helper function for of_mdio_find_bus */ +static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np) +{ + return dev->of_node == mdio_bus_np; +} +/** + * of_mdio_find_bus - Given an mii_bus node, find the mii_bus. + * @mdio_bus_np: Pointer to the mii_bus. + * + * Returns a reference to the mii_bus, or NULL if none found. The + * embedded struct device will have its reference count incremented, + * and this must be put once the bus is finished with. + * + * Because the association of a device_node and mii_bus is made via + * of_mdiobus_register(), the mii_bus cannot be found before it is + * registered with of_mdiobus_register(). + * + */ +struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np) +{ + struct device *d; + + if (!mdio_bus_np) + return NULL; + + d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np, + of_mdio_bus_match); + + return d ? to_mii_bus(d) : NULL; +} +EXPORT_SYMBOL(of_mdio_find_bus); + +/* Walk the list of subnodes of a mdio bus and look for a node that + * matches the mdio device's address with its 'reg' property. If + * found, set the of_node pointer for the mdio device. This allows + * auto-probed phy devices to be supplied with information passed in + * via DT. + */ +static void of_mdiobus_link_mdiodev(struct mii_bus *bus, + struct mdio_device *mdiodev) +{ + struct device *dev = &mdiodev->dev; + struct device_node *child; + + if (dev->of_node || !bus->dev.of_node) + return; + + for_each_available_child_of_node(bus->dev.of_node, child) { + int addr; + + addr = of_mdio_parse_addr(dev, child); + if (addr < 0) + continue; + + if (addr == mdiodev->addr) { + dev->of_node = child; + dev->fwnode = of_fwnode_handle(child); + return; + } + } +} +#else /* !IS_ENABLED(CONFIG_OF_MDIO) */ +static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio, + struct mdio_device *mdiodev) +{ +} +#endif + +/** + * mdiobus_create_device_from_board_info - create a full MDIO device given + * a mdio_board_info structure + * @bus: MDIO bus to create the devices on + * @bi: mdio_board_info structure describing the devices + * + * Returns 0 on success or < 0 on error. + */ +static int mdiobus_create_device(struct mii_bus *bus, + struct mdio_board_info *bi) +{ + struct mdio_device *mdiodev; + int ret = 0; + + mdiodev = mdio_device_create(bus, bi->mdio_addr); + if (IS_ERR(mdiodev)) + return -ENODEV; + + strncpy(mdiodev->modalias, bi->modalias, + sizeof(mdiodev->modalias)); + mdiodev->bus_match = mdio_device_bus_match; + mdiodev->dev.platform_data = (void *)bi->platform_data; + + ret = mdio_device_register(mdiodev); + if (ret) + mdio_device_free(mdiodev); + + return ret; +} + +/** + * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus + * @bus: target mii_bus + * @owner: module containing bus accessor functions + * + * Description: Called by a bus driver to bring up all the PHYs + * on a given bus, and attach them to the bus. Drivers should use + * mdiobus_register() rather than __mdiobus_register() unless they + * need to pass a specific owner module. MDIO devices which are not + * PHYs will not be brought up by this function. They are expected to + * to be explicitly listed in DT and instantiated by of_mdiobus_register(). + * + * Returns 0 on success or < 0 on error. + */ +int __mdiobus_register(struct mii_bus *bus, struct module *owner) +{ + struct mdio_device *mdiodev; + int i, err; + struct gpio_desc *gpiod; + + if (NULL == bus || NULL == bus->name || + NULL == bus->read || NULL == bus->write) + return -EINVAL; + + BUG_ON(bus->state != MDIOBUS_ALLOCATED && + bus->state != MDIOBUS_UNREGISTERED); + + bus->owner = owner; + bus->dev.parent = bus->parent; + bus->dev.class = &mdio_bus_class; + bus->dev.groups = NULL; + dev_set_name(&bus->dev, "%s", bus->id); + + /* We need to set state to MDIOBUS_UNREGISTERED to correctly release + * the device in mdiobus_free() + * + * State will be updated later in this function in case of success + */ + bus->state = MDIOBUS_UNREGISTERED; + + err = device_register(&bus->dev); + if (err) { + pr_err("mii_bus %s failed to register\n", bus->id); + return -EINVAL; + } + + mutex_init(&bus->mdio_lock); + + /* de-assert bus level PHY GPIO reset */ + gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(gpiod)) { + dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n", + bus->id); + device_del(&bus->dev); + return PTR_ERR(gpiod); + } else if (gpiod) { + bus->reset_gpiod = gpiod; + + gpiod_set_value_cansleep(gpiod, 1); + udelay(bus->reset_delay_us); + gpiod_set_value_cansleep(gpiod, 0); + } + + if (bus->reset) + bus->reset(bus); + + for (i = 0; i < PHY_MAX_ADDR; i++) { + if ((bus->phy_mask & (1 << i)) == 0) { + struct phy_device *phydev; + + phydev = mdiobus_scan(bus, i); + if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) { + err = PTR_ERR(phydev); + goto error; + } + } + } + + mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device); + + bus->state = MDIOBUS_REGISTERED; + dev_dbg(&bus->dev, "probed\n"); + return 0; + +error: + while (--i >= 0) { + mdiodev = bus->mdio_map[i]; + if (!mdiodev) + continue; + + mdiodev->device_remove(mdiodev); + mdiodev->device_free(mdiodev); + } + + /* Put PHYs in RESET to save power */ + if (bus->reset_gpiod) + gpiod_set_value_cansleep(bus->reset_gpiod, 1); + + device_del(&bus->dev); + return err; +} +EXPORT_SYMBOL(__mdiobus_register); + +void mdiobus_unregister(struct mii_bus *bus) +{ + struct mdio_device *mdiodev; + int i; + + if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED)) + return; + bus->state = MDIOBUS_UNREGISTERED; + + for (i = 0; i < PHY_MAX_ADDR; i++) { + mdiodev = bus->mdio_map[i]; + if (!mdiodev) + continue; + + if (mdiodev->reset) + gpiod_put(mdiodev->reset); + + mdiodev->device_remove(mdiodev); + mdiodev->device_free(mdiodev); + } + + /* Put PHYs in RESET to save power */ + if (bus->reset_gpiod) + gpiod_set_value_cansleep(bus->reset_gpiod, 1); + + device_del(&bus->dev); +} +EXPORT_SYMBOL(mdiobus_unregister); + +/** + * mdiobus_free - free a struct mii_bus + * @bus: mii_bus to free + * + * This function releases the reference to the underlying device + * object in the mii_bus. If this is the last reference, the mii_bus + * will be freed. + */ +void mdiobus_free(struct mii_bus *bus) +{ + /* For compatibility with error handling in drivers. */ + if (bus->state == MDIOBUS_ALLOCATED) { + kfree(bus); + return; + } + + BUG_ON(bus->state != MDIOBUS_UNREGISTERED); + bus->state = MDIOBUS_RELEASED; + + put_device(&bus->dev); +} +EXPORT_SYMBOL(mdiobus_free); + +/** + * mdiobus_scan - scan a bus for MDIO devices. + * @bus: mii_bus to scan + * @addr: address on bus to scan + * + * This function scans the MDIO bus, looking for devices which can be + * identified using a vendor/product ID in registers 2 and 3. Not all + * MDIO devices have such registers, but PHY devices typically + * do. Hence this function assumes anything found is a PHY, or can be + * treated as a PHY. Other MDIO devices, such as switches, will + * probably not be found during the scan. + */ +struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) +{ + struct phy_device *phydev; + int err; + + phydev = get_phy_device(bus, addr, false); + if (IS_ERR(phydev)) + return phydev; + + /* + * For DT, see if the auto-probed phy has a correspoding child + * in the bus node, and set the of_node pointer in this case. + */ + of_mdiobus_link_mdiodev(bus, &phydev->mdio); + + err = phy_device_register(phydev); + if (err) { + phy_device_free(phydev); + return ERR_PTR(-ENODEV); + } + + return phydev; +} +EXPORT_SYMBOL(mdiobus_scan); + +/** + * __mdiobus_read - Unlocked version of the mdiobus_read function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to read + * + * Read a MDIO bus register. Caller must hold the mdio bus lock. + * + * NOTE: MUST NOT be called from interrupt context. + */ +int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) +{ + int retval; + + WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock)); + + retval = bus->read(bus, addr, regnum); + + trace_mdio_access(bus, 1, addr, regnum, retval, retval); + + return retval; +} +EXPORT_SYMBOL(__mdiobus_read); + +/** + * __mdiobus_write - Unlocked version of the mdiobus_write function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to write + * @val: value to write to @regnum + * + * Write a MDIO bus register. Caller must hold the mdio bus lock. + * + * NOTE: MUST NOT be called from interrupt context. + */ +int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) +{ + int err; + + WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock)); + + err = bus->write(bus, addr, regnum, val); + + trace_mdio_access(bus, 0, addr, regnum, val, err); + + return err; +} +EXPORT_SYMBOL(__mdiobus_write); + +/** + * mdiobus_read_nested - Nested version of the mdiobus_read function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to read + * + * In case of nested MDIO bus access avoid lockdep false positives by + * using mutex_lock_nested(). + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum) +{ + int retval; + + BUG_ON(in_interrupt()); + + mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED); + retval = __mdiobus_read(bus, addr, regnum); + mutex_unlock(&bus->mdio_lock); + + return retval; +} +EXPORT_SYMBOL(mdiobus_read_nested); + +/** + * mdiobus_read - Convenience function for reading a given MII mgmt register + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to read + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) +{ + int retval; + + BUG_ON(in_interrupt()); + + mutex_lock(&bus->mdio_lock); + retval = __mdiobus_read(bus, addr, regnum); + mutex_unlock(&bus->mdio_lock); + + return retval; +} +EXPORT_SYMBOL(mdiobus_read); + +/** + * mdiobus_write_nested - Nested version of the mdiobus_write function + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to write + * @val: value to write to @regnum + * + * In case of nested MDIO bus access avoid lockdep false positives by + * using mutex_lock_nested(). + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val) +{ + int err; + + BUG_ON(in_interrupt()); + + mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED); + err = __mdiobus_write(bus, addr, regnum, val); + mutex_unlock(&bus->mdio_lock); + + return err; +} +EXPORT_SYMBOL(mdiobus_write_nested); + +/** + * mdiobus_write - Convenience function for writing a given MII mgmt register + * @bus: the mii_bus struct + * @addr: the phy address + * @regnum: register number to write + * @val: value to write to @regnum + * + * NOTE: MUST NOT be called from interrupt context, + * because the bus read/write functions may wait for an interrupt + * to conclude the operation. + */ +int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) +{ + int err; + + BUG_ON(in_interrupt()); + + mutex_lock(&bus->mdio_lock); + err = __mdiobus_write(bus, addr, regnum, val); + mutex_unlock(&bus->mdio_lock); + + return err; +} +EXPORT_SYMBOL(mdiobus_write); + +/** + * mdio_bus_match - determine if given MDIO driver supports the given + * MDIO device + * @dev: target MDIO device + * @drv: given MDIO driver + * + * Description: Given a MDIO device, and a MDIO driver, return 1 if + * the driver supports the device. Otherwise, return 0. This may + * require calling the devices own match function, since different classes + * of MDIO devices have different match criteria. + */ +static int mdio_bus_match(struct device *dev, struct device_driver *drv) +{ + struct mdio_device *mdio = to_mdio_device(dev); + + if (of_driver_match_device(dev, drv)) + return 1; + + if (mdio->bus_match) + return mdio->bus_match(dev, drv); + + return 0; +} + +static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + int rc; + + /* Some devices have extra OF data and an OF-style MODALIAS */ + rc = of_device_uevent_modalias(dev, env); + if (rc != -ENODEV) + return rc; + + return 0; +} + +struct bus_type mdio_bus_type = { + .name = "mdio_bus", + .match = mdio_bus_match, + .uevent = mdio_uevent, +}; +EXPORT_SYMBOL(mdio_bus_type); + +int __init mdio_bus_init(void) +{ + int ret; + + ret = class_register(&mdio_bus_class); + if (!ret) { + ret = bus_register(&mdio_bus_type); + if (ret) + class_unregister(&mdio_bus_class); + } + + return ret; +} + +#if IS_ENABLED(CONFIG_PHYLIB) +void mdio_bus_exit(void) +{ + class_unregister(&mdio_bus_class); + bus_unregister(&mdio_bus_type); +} +EXPORT_SYMBOL_GPL(mdio_bus_exit); +#else +module_init(mdio_bus_init); +/* no module_exit, intentional */ +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("MDIO bus/device layer"); +#endif |