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	int i, ret = 0;
 30
 31	mdev = dev->priv;
 32
 33	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
 34	for (i = 0; i < val_len; i++) {
 35		int tmp = reg + i;
 36
 37		ret = __mdiobus_read(mdev->bus, ((tmp & 0xE0) >> 5) |
 38				     SMI_KSZ88XX_READ_PHY, tmp);
 39		if (ret < 0)
 40			goto out;
 41
 42		val[i] = ret;
 43	}
 44	ret = 0;
 45
 46 out:
 47	mutex_unlock(&mdev->bus->mdio_lock);
 48
 49	return ret;
 50}
 51
 52static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
 53{
 54	struct ksz_device *dev = ctx;
 55	struct mdio_device *mdev;
 56	int i, ret = 0;
 57	u32 reg;
 58	u8 *val;
 59
 60	mdev = dev->priv;
 61
 62	val = (u8 *)(data + 4);
 63	reg = *(u32 *)data;
 64
 65	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
 66	for (i = 0; i < (count - 4); i++) {
 67		int tmp = reg + i;
 68
 69		ret = __mdiobus_write(mdev->bus, ((tmp & 0xE0) >> 5),
 70				      tmp, val[i]);
 71		if (ret < 0)
 72			goto out;
 73	}
 74
 75 out:
 76	mutex_unlock(&mdev->bus->mdio_lock);
 77
 78	return ret;
 79}
 80
 81static const struct regmap_bus regmap_smi[] = {
 82	{
 83		.read = ksz8863_mdio_read,
 84		.write = ksz8863_mdio_write,
 85		.max_raw_read = 1,
 86		.max_raw_write = 1,
 87	},
 88	{
 89		.read = ksz8863_mdio_read,
 90		.write = ksz8863_mdio_write,
 91		.val_format_endian_default = REGMAP_ENDIAN_BIG,
 92		.max_raw_read = 2,
 93		.max_raw_write = 2,
 94	},
 95	{
 96		.read = ksz8863_mdio_read,
 97		.write = ksz8863_mdio_write,
 98		.val_format_endian_default = REGMAP_ENDIAN_BIG,
 99		.max_raw_read = 4,
100		.max_raw_write = 4,
101	}
102};
103
104static const struct regmap_config ksz8863_regmap_config[] = {
105	{
106		.name = "#8",
107		.reg_bits = 8,
108		.pad_bits = 24,
109		.val_bits = 8,
110		.cache_type = REGCACHE_NONE,
111		.use_single_read = 1,
112		.lock = ksz_regmap_lock,
113		.unlock = ksz_regmap_unlock,
114	},
115	{
116		.name = "#16",
117		.reg_bits = 8,
118		.pad_bits = 24,
119		.val_bits = 16,
120		.cache_type = REGCACHE_NONE,
121		.use_single_read = 1,
122		.lock = ksz_regmap_lock,
123		.unlock = ksz_regmap_unlock,
124	},
125	{
126		.name = "#32",
127		.reg_bits = 8,
128		.pad_bits = 24,
129		.val_bits = 32,
130		.cache_type = REGCACHE_NONE,
131		.use_single_read = 1,
132		.lock = ksz_regmap_lock,
133		.unlock = ksz_regmap_unlock,
134	}
135};
136
137static int ksz8863_smi_probe(struct mdio_device *mdiodev)
138{
139	struct regmap_config rc;
140	struct ksz_device *dev;
141	int ret;
142	int i;
143
144	dev = ksz_switch_alloc(&mdiodev->dev, mdiodev);
145	if (!dev)
146		return -ENOMEM;
147
148	for (i = 0; i < ARRAY_SIZE(ksz8863_regmap_config); i++) {
149		rc = ksz8863_regmap_config[i];
150		rc.lock_arg = &dev->regmap_mutex;
151		dev->regmap[i] = devm_regmap_init(&mdiodev->dev,
152						  &regmap_smi[i], dev,
153						  &rc);
154		if (IS_ERR(dev->regmap[i])) {
155			return dev_err_probe(&mdiodev->dev,
156					     PTR_ERR(dev->regmap[i]),
157					     "Failed to initialize regmap%i\n",
158					     ksz8863_regmap_config[i].val_bits);
159		}
160	}
161
162	if (mdiodev->dev.platform_data)
163		dev->pdata = mdiodev->dev.platform_data;
164
165	ret = ksz_switch_register(dev);
166
167	/* Main DSA driver may not be started yet. */
168	if (ret)
169		return ret;
170
171	dev_set_drvdata(&mdiodev->dev, dev);
172
173	return 0;
174}
175
176static void ksz8863_smi_remove(struct mdio_device *mdiodev)
177{
178	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
179
180	if (dev)
181		ksz_switch_remove(dev);
182}
183
184static void ksz8863_smi_shutdown(struct mdio_device *mdiodev)
185{
186	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
187
188	if (dev)
189		dsa_switch_shutdown(dev->ds);
190
191	dev_set_drvdata(&mdiodev->dev, NULL);
192}
193
194static const struct of_device_id ksz8863_dt_ids[] = {
195	{
196		.compatible = "microchip,ksz8863",
197		.data = &ksz_switch_chips[KSZ8830]
198	},
199	{
200		.compatible = "microchip,ksz8873",
201		.data = &ksz_switch_chips[KSZ8830]
202	},
203	{ },
204};
205MODULE_DEVICE_TABLE(of, ksz8863_dt_ids);
206
207static struct mdio_driver ksz8863_driver = {
208	.probe	= ksz8863_smi_probe,
209	.remove	= ksz8863_smi_remove,
210	.shutdown = ksz8863_smi_shutdown,
211	.mdiodrv.driver = {
212		.name	= "ksz8863-switch",
213		.of_match_table = ksz8863_dt_ids,
214	},
215};
216
217mdio_module_driver(ksz8863_driver);
218
219MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
220MODULE_DESCRIPTION("Microchip KSZ8863 SMI Switch driver");
221MODULE_LICENSE("GPL v2");