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
 29struct lan9303_mdio {
 30	struct mdio_device *device;
 31	struct lan9303 chip;
 32};
 33
 34static 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
 39static 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
 52static 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
 57static 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
 70static 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
 78static 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
 85static 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
 90static 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
108static 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
142static 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
154static const struct of_device_id lan9303_mdio_of_match[] = {
155	{ .compatible = "smsc,lan9303-mdio" },
156	{ /* sentinel */ },
157};
158MODULE_DEVICE_TABLE(of, lan9303_mdio_of_match);
159
160static 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};
168mdio_module_driver(lan9303_mdio_driver);
169
170MODULE_AUTHOR("Stefan Roese <sr@denx.de>, Juergen Borleis <kernel@pengutronix.de>");
171MODULE_DESCRIPTION("Driver for SMSC/Microchip LAN9303 three port ethernet switch in MDIO managed mode");
172MODULE_LICENSE("GPL v2");