1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Microchip KSZ8863 series register access through SMI
  4 *
  5 * Copyright (C) 2019 Pengutronix, Michael Grzeschik <kernel@pengutronix.de>
  6 */
  7
  8#include "ksz8.h"
  9#include "ksz_common.h"
 10
 11/* Serial Management Interface (SMI) uses the following frame format:
 12 *
 13 *       preamble|start|Read/Write|  PHY   |  REG  |TA|   Data bits      | Idle
 14 *               |frame| OP code  |address |address|  |                  |
 15 * read | 32x1´s | 01  |    00    | 1xRRR  | RRRRR |Z0| 00000000DDDDDDDD |  Z
 16 * write| 32x1´s | 01  |    00    | 0xRRR  | RRRRR |10| xxxxxxxxDDDDDDDD |  Z
 17 *
 18 */
 19
 20#define SMI_KSZ88XX_READ_PHY	BIT(4)
 21
 22static int ksz8863_mdio_read(void *ctx, const void *reg_buf, size_t reg_len,
 23			     void *val_buf, size_t val_len)
 24{
 25	struct ksz_device *dev = ctx;
 26	struct mdio_device *mdev;
 27	u8 reg = *(u8 *)reg_buf;
 28	u8 *val = val_buf;
 29	struct ksz8 *ksz8;
 30	int i, ret = 0;
 31
 32	ksz8 = dev->priv;
 33	mdev = ksz8->priv;
 34
 35	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
 36	for (i = 0; i < val_len; i++) {
 37		int tmp = reg + i;
 38
 39		ret = __mdiobus_read(mdev->bus, ((tmp & 0xE0) >> 5) |
 40				     SMI_KSZ88XX_READ_PHY, tmp);
 41		if (ret < 0)
 42			goto out;
 43
 44		val[i] = ret;
 45	}
 46	ret = 0;
 47
 48 out:
 49	mutex_unlock(&mdev->bus->mdio_lock);
 50
 51	return ret;
 52}
 53
 54static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
 55{
 56	struct ksz_device *dev = ctx;
 57	struct mdio_device *mdev;
 58	struct ksz8 *ksz8;
 59	int i, ret = 0;
 60	u32 reg;
 61	u8 *val;
 62
 63	ksz8 = dev->priv;
 64	mdev = ksz8->priv;
 65
 66	val = (u8 *)(data + 4);
 67	reg = *(u32 *)data;
 68
 69	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
 70	for (i = 0; i < (count - 4); i++) {
 71		int tmp = reg + i;
 72
 73		ret = __mdiobus_write(mdev->bus, ((tmp & 0xE0) >> 5),
 74				      tmp, val[i]);
 75		if (ret < 0)
 76			goto out;
 77	}
 78
 79 out:
 80	mutex_unlock(&mdev->bus->mdio_lock);
 81
 82	return ret;
 83}
 84
 85static const struct regmap_bus regmap_smi[] = {
 86	{
 87		.read = ksz8863_mdio_read,
 88		.write = ksz8863_mdio_write,
 89		.max_raw_read = 1,
 90		.max_raw_write = 1,
 91	},
 92	{
 93		.read = ksz8863_mdio_read,
 94		.write = ksz8863_mdio_write,
 95		.val_format_endian_default = REGMAP_ENDIAN_BIG,
 96		.max_raw_read = 2,
 97		.max_raw_write = 2,
 98	},
 99	{
100		.read = ksz8863_mdio_read,
101		.write = ksz8863_mdio_write,
102		.val_format_endian_default = REGMAP_ENDIAN_BIG,
103		.max_raw_read = 4,
104		.max_raw_write = 4,
105	}
106};
107
108static const struct regmap_config ksz8863_regmap_config[] = {
109	{
110		.name = "#8",
111		.reg_bits = 8,
112		.pad_bits = 24,
113		.val_bits = 8,
114		.cache_type = REGCACHE_NONE,
115		.use_single_read = 1,
116		.lock = ksz_regmap_lock,
117		.unlock = ksz_regmap_unlock,
118	},
119	{
120		.name = "#16",
121		.reg_bits = 8,
122		.pad_bits = 24,
123		.val_bits = 16,
124		.cache_type = REGCACHE_NONE,
125		.use_single_read = 1,
126		.lock = ksz_regmap_lock,
127		.unlock = ksz_regmap_unlock,
128	},
129	{
130		.name = "#32",
131		.reg_bits = 8,
132		.pad_bits = 24,
133		.val_bits = 32,
134		.cache_type = REGCACHE_NONE,
135		.use_single_read = 1,
136		.lock = ksz_regmap_lock,
137		.unlock = ksz_regmap_unlock,
138	}
139};
140
141static int ksz8863_smi_probe(struct mdio_device *mdiodev)
142{
143	struct regmap_config rc;
144	struct ksz_device *dev;
145	struct ksz8 *ksz8;
146	int ret;
147	int i;
148
149	ksz8 = devm_kzalloc(&mdiodev->dev, sizeof(struct ksz8), GFP_KERNEL);
150	if (!ksz8)
151		return -ENOMEM;
152
153	ksz8->priv = mdiodev;
154
155	dev = ksz_switch_alloc(&mdiodev->dev, ksz8);
156	if (!dev)
157		return -ENOMEM;
158
159	for (i = 0; i < ARRAY_SIZE(ksz8863_regmap_config); i++) {
160		rc = ksz8863_regmap_config[i];
161		rc.lock_arg = &dev->regmap_mutex;
162		dev->regmap[i] = devm_regmap_init(&mdiodev->dev,
163						  &regmap_smi[i], dev,
164						  &rc);
165		if (IS_ERR(dev->regmap[i])) {
166			ret = PTR_ERR(dev->regmap[i]);
167			dev_err(&mdiodev->dev,
168				"Failed to initialize regmap%i: %d\n",
169				ksz8863_regmap_config[i].val_bits, ret);
170			return ret;
171		}
172	}
173
174	if (mdiodev->dev.platform_data)
175		dev->pdata = mdiodev->dev.platform_data;
176
177	ret = ksz8_switch_register(dev);
178
179	/* Main DSA driver may not be started yet. */
180	if (ret)
181		return ret;
182
183	dev_set_drvdata(&mdiodev->dev, dev);
184
185	return 0;
186}
187
188static void ksz8863_smi_remove(struct mdio_device *mdiodev)
189{
190	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
191
192	if (dev)
193		ksz_switch_remove(dev);
194}
195
196static const struct of_device_id ksz8863_dt_ids[] = {
197	{ .compatible = "microchip,ksz8863" },
198	{ .compatible = "microchip,ksz8873" },
199	{ },
200};
201MODULE_DEVICE_TABLE(of, ksz8863_dt_ids);
202
203static struct mdio_driver ksz8863_driver = {
204	.probe	= ksz8863_smi_probe,
205	.remove	= ksz8863_smi_remove,
206	.mdiodrv.driver = {
207		.name	= "ksz8863-switch",
208		.of_match_table = ksz8863_dt_ids,
209	},
210};
211
212mdio_module_driver(ksz8863_driver);
213
214MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
215MODULE_DESCRIPTION("Microchip KSZ8863 SMI Switch driver");
216MODULE_LICENSE("GPL v2");