drivers/net/dsa/lan9303_mdio.c

   1 /*
   2  * Copyright (C) 2017 Pengutronix, Juergen Borleis <kernel@pengutronix.de>
   3  *
   4  * Partially based on a patch from
   5  * Copyright (c) 2014 Stefan Roese <sr@denx.de>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mdio.h>
  20 #include <linux/phy.h>
  21 #include <linux/of.h>
  22
  23 #include "lan9303.h"
  24
  25 /* Generate phy-addr and -reg from the input address */
  26 #define PHY_ADDR(x) ((((x) >> 6) + 0x10) & 0x1f)
  27 #define PHY_REG(x) (((x) >> 1) & 0x1f)
  28
  29 struct lan9303_mdio {
  30         struct mdio_device *device;
  31         struct lan9303 chip;
  32 };
  33
  34 static void lan9303_mdio_real_write(struct mdio_device *mdio, int reg, u16 val)
  35 {
  36         mdio->bus->write(mdio->bus, PHY_ADDR(reg), PHY_REG(reg), val);
  37 }
  38
  39 static int lan9303_mdio_write(void *ctx, uint32_t reg, uint32_t val)
  40 {
  41         struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
  42
  43         reg <<= 2; /* reg num to offset */
  44         mutex_lock(&sw_dev->device->bus->mdio_lock);
  45         lan9303_mdio_real_write(sw_dev->device, reg, val & 0xffff);
  46         lan9303_mdio_real_write(sw_dev->device, reg + 2, (val >> 16) & 0xffff);
  47         mutex_unlock(&sw_dev->device->bus->mdio_lock);
  48
  49         return 0;
  50 }
  51
  52 static u16 lan9303_mdio_real_read(struct mdio_device *mdio, int reg)
  53 {
  54         return mdio->bus->read(mdio->bus, PHY_ADDR(reg), PHY_REG(reg));
  55 }
  56
  57 static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
  58 {
  59         struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
  60
  61         reg <<= 2; /* reg num to offset */
  62         mutex_lock(&sw_dev->device->bus->mdio_lock);
  63         *val = lan9303_mdio_real_read(sw_dev->device, reg);
  64         *val |= (lan9303_mdio_real_read(sw_dev->device, reg + 2) << 16);
  65         mutex_unlock(&sw_dev->device->bus->mdio_lock);
  66
  67         return 0;
  68 }
  69
  70 static int lan9303_mdio_phy_write(struct lan9303 *chip, int phy, int reg,
  71                                   u16 val)
  72 {
  73         struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
  74
  75         return mdiobus_write_nested(sw_dev->device->bus, phy, reg, val);
  76 }
  77
  78 static int lan9303_mdio_phy_read(struct lan9303 *chip, int phy,  int reg)
  79 {
  80         struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
  81
  82         return mdiobus_read_nested(sw_dev->device->bus, phy, reg);
  83 }
  84
  85 static const struct lan9303_phy_ops lan9303_mdio_phy_ops = {
  86         .phy_read = lan9303_mdio_phy_read,
  87         .phy_write = lan9303_mdio_phy_write,
  88 };
  89
  90 static const struct regmap_config lan9303_mdio_regmap_config = {
  91         .reg_bits = 8,
  92         .val_bits = 32,
  93         .reg_stride = 1,
  94         .can_multi_write = true,
  95         .max_register = 0x0ff, /* address bits 0..1 are not used */
  96         .reg_format_endian = REGMAP_ENDIAN_LITTLE,
  97
  98         .volatile_table = &lan9303_register_set,
  99         .wr_table = &lan9303_register_set,
 100         .rd_table = &lan9303_register_set,
 101
 102         .reg_read = lan9303_mdio_read,
 103         .reg_write = lan9303_mdio_write,
 104
 105         .cache_type = REGCACHE_NONE,
 106 };
 107
 108 static int lan9303_mdio_probe(struct mdio_device *mdiodev)
 109 {
 110         struct lan9303_mdio *sw_dev;
 111         int ret;
 112
 113         sw_dev = devm_kzalloc(&mdiodev->dev, sizeof(struct lan9303_mdio),
 114                               GFP_KERNEL);
 115         if (!sw_dev)
 116                 return -ENOMEM;
 117
 118         sw_dev->chip.regmap = devm_regmap_init(&mdiodev->dev, NULL, sw_dev,
 119                                                &lan9303_mdio_regmap_config);
 120         if (IS_ERR(sw_dev->chip.regmap)) {
 121                 ret = PTR_ERR(sw_dev->chip.regmap);
 122                 dev_err(&mdiodev->dev, "regmap init failed: %d\n", ret);
 123                 return ret;
 124         }
 125
 126         /* link forward and backward */
 127         sw_dev->device = mdiodev;
 128         dev_set_drvdata(&mdiodev->dev, sw_dev);
 129         sw_dev->chip.dev = &mdiodev->dev;
 130
 131         sw_dev->chip.ops = &lan9303_mdio_phy_ops;
 132
 133         ret = lan9303_probe(&sw_dev->chip, mdiodev->dev.of_node);
 134         if (ret != 0)
 135                 return ret;
 136
 137         dev_info(&mdiodev->dev, "LAN9303 MDIO driver loaded successfully\n");
 138
 139         return 0;
 140 }
 141
 142 static void lan9303_mdio_remove(struct mdio_device *mdiodev)
 143 {
 144         struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);
 145
 146         if (!sw_dev)
 147                 return;
 148
 149         lan9303_remove(&sw_dev->chip);
 150 }
 151
 152 /*-------------------------------------------------------------------------*/
 153
 154 static const struct of_device_id lan9303_mdio_of_match[] = {
 155         { .compatible = "smsc,lan9303-mdio" },
 156         { /* sentinel */ },
 157 };
 158 MODULE_DEVICE_TABLE(of, lan9303_mdio_of_match);
 159
 160 static struct mdio_driver lan9303_mdio_driver = {
 161         .mdiodrv.driver = {
 162                 .name = "LAN9303_MDIO",
 163                 .of_match_table = of_match_ptr(lan9303_mdio_of_match),
 164         },
 165         .probe  = lan9303_mdio_probe,
 166         .remove = lan9303_mdio_remove,
 167 };
 168 mdio_module_driver(lan9303_mdio_driver);
 169
 170 MODULE_AUTHOR("Stefan Roese <sr@denx.de>, Juergen Borleis <kernel@pengutronix.de>");
 171 MODULE_DESCRIPTION("Driver for SMSC/Microchip LAN9303 three port ethernet switch in MDIO managed mode");
 172 MODULE_LICENSE("GPL v2");