net/mdio/of_mdio.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * OF helpers for the MDIO (Ethernet PHY) API
0004  *
0005  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
0006  *
0007  * This file provides helper functions for extracting PHY device information
0008  * out of the OpenFirmware device tree and using it to populate an mii_bus.
0009  */
0010
0011 #include <linux/device.h>
0012 #include <linux/err.h>
0013 #include <linux/fwnode_mdio.h>
0014 #include <linux/kernel.h>
0015 #include <linux/module.h>
0016 #include <linux/netdevice.h>
0017 #include <linux/of.h>
0018 #include <linux/of_irq.h>
0019 #include <linux/of_mdio.h>
0020 #include <linux/of_net.h>
0021 #include <linux/phy.h>
0022 #include <linux/phy_fixed.h>
0023
0024 #define DEFAULT_GPIO_RESET_DELAY    10  /* in microseconds */
0025
0026 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
0027 MODULE_LICENSE("GPL");
0028
0029 /* Extract the clause 22 phy ID from the compatible string of the form
0030  * ethernet-phy-idAAAA.BBBB */
0031 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
0032 {
0033     return fwnode_get_phy_id(of_fwnode_handle(device), phy_id);
0034 }
0035
0036 int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
0037                    struct device_node *child, u32 addr)
0038 {
0039     return fwnode_mdiobus_phy_device_register(mdio, phy,
0040                           of_fwnode_handle(child),
0041                           addr);
0042 }
0043 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
0044
0045 static int of_mdiobus_register_phy(struct mii_bus *mdio,
0046                     struct device_node *child, u32 addr)
0047 {
0048     return fwnode_mdiobus_register_phy(mdio, of_fwnode_handle(child), addr);
0049 }
0050
0051 static int of_mdiobus_register_device(struct mii_bus *mdio,
0052                       struct device_node *child, u32 addr)
0053 {
0054     struct fwnode_handle *fwnode = of_fwnode_handle(child);
0055     struct mdio_device *mdiodev;
0056     int rc;
0057
0058     mdiodev = mdio_device_create(mdio, addr);
0059     if (IS_ERR(mdiodev))
0060         return PTR_ERR(mdiodev);
0061
0062     /* Associate the OF node with the device structure so it
0063      * can be looked up later.
0064      */
0065     fwnode_handle_get(fwnode);
0066     device_set_node(&mdiodev->dev, fwnode);
0067
0068     /* All data is now stored in the mdiodev struct; register it. */
0069     rc = mdio_device_register(mdiodev);
0070     if (rc) {
0071         mdio_device_free(mdiodev);
0072         of_node_put(child);
0073         return rc;
0074     }
0075
0076     dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
0077         child, addr);
0078     return 0;
0079 }
0080
0081 /* The following is a list of PHY compatible strings which appear in
0082  * some DTBs. The compatible string is never matched against a PHY
0083  * driver, so is pointless. We only expect devices which are not PHYs
0084  * to have a compatible string, so they can be matched to an MDIO
0085  * driver.  Encourage users to upgrade their DT blobs to remove these.
0086  */
0087 static const struct of_device_id whitelist_phys[] = {
0088     { .compatible = "brcm,40nm-ephy" },
0089     { .compatible = "broadcom,bcm5241" },
0090     { .compatible = "marvell,88E1111", },
0091     { .compatible = "marvell,88e1116", },
0092     { .compatible = "marvell,88e1118", },
0093     { .compatible = "marvell,88e1145", },
0094     { .compatible = "marvell,88e1149r", },
0095     { .compatible = "marvell,88e1310", },
0096     { .compatible = "marvell,88E1510", },
0097     { .compatible = "marvell,88E1514", },
0098     { .compatible = "moxa,moxart-rtl8201cp", },
0099     {}
0100 };
0101
0102 /*
0103  * Return true if the child node is for a phy. It must either:
0104  * o Compatible string of "ethernet-phy-idX.X"
0105  * o Compatible string of "ethernet-phy-ieee802.3-c45"
0106  * o Compatible string of "ethernet-phy-ieee802.3-c22"
0107  * o In the white list above (and issue a warning)
0108  * o No compatibility string
0109  *
0110  * A device which is not a phy is expected to have a compatible string
0111  * indicating what sort of device it is.
0112  */
0113 bool of_mdiobus_child_is_phy(struct device_node *child)
0114 {
0115     u32 phy_id;
0116
0117     if (of_get_phy_id(child, &phy_id) != -EINVAL)
0118         return true;
0119
0120     if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
0121         return true;
0122
0123     if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
0124         return true;
0125
0126     if (of_match_node(whitelist_phys, child)) {
0127         pr_warn(FW_WARN
0128             "%pOF: Whitelisted compatible string. Please remove\n",
0129             child);
0130         return true;
0131     }
0132
0133     if (!of_find_property(child, "compatible", NULL))
0134         return true;
0135
0136     return false;
0137 }
0138 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
0139
0140 /**
0141  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
0142  * @mdio: pointer to mii_bus structure
0143  * @np: pointer to device_node of MDIO bus.
0144  *
0145  * This function registers the mii_bus structure and registers a phy_device
0146  * for each child node of @np.
0147  */
0148 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
0149 {
0150     struct device_node *child;
0151     bool scanphys = false;
0152     int addr, rc;
0153
0154     if (!np)
0155         return mdiobus_register(mdio);
0156
0157     /* Do not continue if the node is disabled */
0158     if (!of_device_is_available(np))
0159         return -ENODEV;
0160
0161     /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
0162      * the device tree are populated after the bus has been registered */
0163     mdio->phy_mask = ~0;
0164
0165     device_set_node(&mdio->dev, of_fwnode_handle(np));
0166
0167     /* Get bus level PHY reset GPIO details */
0168     mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
0169     of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
0170     mdio->reset_post_delay_us = 0;
0171     of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
0172
0173     /* Register the MDIO bus */
0174     rc = mdiobus_register(mdio);
0175     if (rc)
0176         return rc;
0177
0178     /* Loop over the child nodes and register a phy_device for each phy */
0179     for_each_available_child_of_node(np, child) {
0180         addr = of_mdio_parse_addr(&mdio->dev, child);
0181         if (addr < 0) {
0182             scanphys = true;
0183             continue;
0184         }
0185
0186         if (of_mdiobus_child_is_phy(child))
0187             rc = of_mdiobus_register_phy(mdio, child, addr);
0188         else
0189             rc = of_mdiobus_register_device(mdio, child, addr);
0190
0191         if (rc == -ENODEV)
0192             dev_err(&mdio->dev,
0193                 "MDIO device at address %d is missing.\n",
0194                 addr);
0195         else if (rc)
0196             goto unregister;
0197     }
0198
0199     if (!scanphys)
0200         return 0;
0201
0202     /* auto scan for PHYs with empty reg property */
0203     for_each_available_child_of_node(np, child) {
0204         /* Skip PHYs with reg property set */
0205         if (of_find_property(child, "reg", NULL))
0206             continue;
0207
0208         for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
0209             /* skip already registered PHYs */
0210             if (mdiobus_is_registered_device(mdio, addr))
0211                 continue;
0212
0213             /* be noisy to encourage people to set reg property */
0214             dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
0215                  child, addr);
0216
0217             if (of_mdiobus_child_is_phy(child)) {
0218                 /* -ENODEV is the return code that PHYLIB has
0219                  * standardized on to indicate that bus
0220                  * scanning should continue.
0221                  */
0222                 rc = of_mdiobus_register_phy(mdio, child, addr);
0223                 if (!rc)
0224                     break;
0225                 if (rc != -ENODEV)
0226                     goto unregister;
0227             }
0228         }
0229     }
0230
0231     return 0;
0232
0233 unregister:
0234     of_node_put(child);
0235     mdiobus_unregister(mdio);
0236     return rc;
0237 }
0238 EXPORT_SYMBOL(of_mdiobus_register);
0239
0240 /**
0241  * of_mdio_find_device - Given a device tree node, find the mdio_device
0242  * @np: pointer to the mdio_device's device tree node
0243  *
0244  * If successful, returns a pointer to the mdio_device with the embedded
0245  * struct device refcount incremented by one, or NULL on failure.
0246  * The caller should call put_device() on the mdio_device after its use
0247  */
0248 struct mdio_device *of_mdio_find_device(struct device_node *np)
0249 {
0250     return fwnode_mdio_find_device(of_fwnode_handle(np));
0251 }
0252 EXPORT_SYMBOL(of_mdio_find_device);
0253
0254 /**
0255  * of_phy_find_device - Give a PHY node, find the phy_device
0256  * @phy_np: Pointer to the phy's device tree node
0257  *
0258  * If successful, returns a pointer to the phy_device with the embedded
0259  * struct device refcount incremented by one, or NULL on failure.
0260  */
0261 struct phy_device *of_phy_find_device(struct device_node *phy_np)
0262 {
0263     return fwnode_phy_find_device(of_fwnode_handle(phy_np));
0264 }
0265 EXPORT_SYMBOL(of_phy_find_device);
0266
0267 /**
0268  * of_phy_connect - Connect to the phy described in the device tree
0269  * @dev: pointer to net_device claiming the phy
0270  * @phy_np: Pointer to device tree node for the PHY
0271  * @hndlr: Link state callback for the network device
0272  * @flags: flags to pass to the PHY
0273  * @iface: PHY data interface type
0274  *
0275  * If successful, returns a pointer to the phy_device with the embedded
0276  * struct device refcount incremented by one, or NULL on failure. The
0277  * refcount must be dropped by calling phy_disconnect() or phy_detach().
0278  */
0279 struct phy_device *of_phy_connect(struct net_device *dev,
0280                   struct device_node *phy_np,
0281                   void (*hndlr)(struct net_device *), u32 flags,
0282                   phy_interface_t iface)
0283 {
0284     struct phy_device *phy = of_phy_find_device(phy_np);
0285     int ret;
0286
0287     if (!phy)
0288         return NULL;
0289
0290     phy->dev_flags |= flags;
0291
0292     ret = phy_connect_direct(dev, phy, hndlr, iface);
0293
0294     /* refcount is held by phy_connect_direct() on success */
0295     put_device(&phy->mdio.dev);
0296
0297     return ret ? NULL : phy;
0298 }
0299 EXPORT_SYMBOL(of_phy_connect);
0300
0301 /**
0302  * of_phy_get_and_connect
0303  * - Get phy node and connect to the phy described in the device tree
0304  * @dev: pointer to net_device claiming the phy
0305  * @np: Pointer to device tree node for the net_device claiming the phy
0306  * @hndlr: Link state callback for the network device
0307  *
0308  * If successful, returns a pointer to the phy_device with the embedded
0309  * struct device refcount incremented by one, or NULL on failure. The
0310  * refcount must be dropped by calling phy_disconnect() or phy_detach().
0311  */
0312 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
0313                       struct device_node *np,
0314                       void (*hndlr)(struct net_device *))
0315 {
0316     phy_interface_t iface;
0317     struct device_node *phy_np;
0318     struct phy_device *phy;
0319     int ret;
0320
0321     ret = of_get_phy_mode(np, &iface);
0322     if (ret)
0323         return NULL;
0324     if (of_phy_is_fixed_link(np)) {
0325         ret = of_phy_register_fixed_link(np);
0326         if (ret < 0) {
0327             netdev_err(dev, "broken fixed-link specification\n");
0328             return NULL;
0329         }
0330         phy_np = of_node_get(np);
0331     } else {
0332         phy_np = of_parse_phandle(np, "phy-handle", 0);
0333         if (!phy_np)
0334             return NULL;
0335     }
0336
0337     phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
0338
0339     of_node_put(phy_np);
0340
0341     return phy;
0342 }
0343 EXPORT_SYMBOL(of_phy_get_and_connect);
0344
0345 /*
0346  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
0347  * support two DT bindings:
0348  * - the old DT binding, where 'fixed-link' was a property with 5
0349  *   cells encoding various information about the fixed PHY
0350  * - the new DT binding, where 'fixed-link' is a sub-node of the
0351  *   Ethernet device.
0352  */
0353 bool of_phy_is_fixed_link(struct device_node *np)
0354 {
0355     struct device_node *dn;
0356     int len, err;
0357     const char *managed;
0358
0359     /* New binding */
0360     dn = of_get_child_by_name(np, "fixed-link");
0361     if (dn) {
0362         of_node_put(dn);
0363         return true;
0364     }
0365
0366     err = of_property_read_string(np, "managed", &managed);
0367     if (err == 0 && strcmp(managed, "auto") != 0)
0368         return true;
0369
0370     /* Old binding */
0371     if (of_get_property(np, "fixed-link", &len) &&
0372         len == (5 * sizeof(__be32)))
0373         return true;
0374
0375     return false;
0376 }
0377 EXPORT_SYMBOL(of_phy_is_fixed_link);
0378
0379 int of_phy_register_fixed_link(struct device_node *np)
0380 {
0381     struct fixed_phy_status status = {};
0382     struct device_node *fixed_link_node;
0383     u32 fixed_link_prop[5];
0384     const char *managed;
0385
0386     if (of_property_read_string(np, "managed", &managed) == 0 &&
0387         strcmp(managed, "in-band-status") == 0) {
0388         /* status is zeroed, namely its .link member */
0389         goto register_phy;
0390     }
0391
0392     /* New binding */
0393     fixed_link_node = of_get_child_by_name(np, "fixed-link");
0394     if (fixed_link_node) {
0395         status.link = 1;
0396         status.duplex = of_property_read_bool(fixed_link_node,
0397                               "full-duplex");
0398         if (of_property_read_u32(fixed_link_node, "speed",
0399                      &status.speed)) {
0400             of_node_put(fixed_link_node);
0401             return -EINVAL;
0402         }
0403         status.pause = of_property_read_bool(fixed_link_node, "pause");
0404         status.asym_pause = of_property_read_bool(fixed_link_node,
0405                               "asym-pause");
0406         of_node_put(fixed_link_node);
0407
0408         goto register_phy;
0409     }
0410
0411     /* Old binding */
0412     if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
0413                        ARRAY_SIZE(fixed_link_prop)) == 0) {
0414         status.link = 1;
0415         status.duplex = fixed_link_prop[1];
0416         status.speed  = fixed_link_prop[2];
0417         status.pause  = fixed_link_prop[3];
0418         status.asym_pause = fixed_link_prop[4];
0419         goto register_phy;
0420     }
0421
0422     return -ENODEV;
0423
0424 register_phy:
0425     return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
0426 }
0427 EXPORT_SYMBOL(of_phy_register_fixed_link);
0428
0429 void of_phy_deregister_fixed_link(struct device_node *np)
0430 {
0431     struct phy_device *phydev;
0432
0433     phydev = of_phy_find_device(np);
0434     if (!phydev)
0435         return;
0436
0437     fixed_phy_unregister(phydev);
0438
0439     put_device(&phydev->mdio.dev);  /* of_phy_find_device() */
0440     phy_device_free(phydev);    /* fixed_phy_register() */
0441 }
0442 EXPORT_SYMBOL(of_phy_deregister_fixed_link);