xref: /openbmc/linux/drivers/net/dsa/lan9303_mdio.c (revision be2b81b5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 Pengutronix, Juergen Borleis <kernel@pengutronix.de>
4  *
5  * Partially based on a patch from
6  * Copyright (c) 2014 Stefan Roese <sr@denx.de>
7  */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/mdio.h>
11 #include <linux/phy.h>
12 #include <linux/of.h>
13 
14 #include "lan9303.h"
15 
16 /* Generate phy-addr and -reg from the input address */
17 #define PHY_ADDR(x) ((((x) >> 6) + 0x10) & 0x1f)
18 #define PHY_REG(x) (((x) >> 1) & 0x1f)
19 
20 struct lan9303_mdio {
21 	struct mdio_device *device;
22 	struct lan9303 chip;
23 };
24 
25 static void lan9303_mdio_real_write(struct mdio_device *mdio, int reg, u16 val)
26 {
27 	mdio->bus->write(mdio->bus, PHY_ADDR(reg), PHY_REG(reg), val);
28 }
29 
30 static int lan9303_mdio_write(void *ctx, uint32_t reg, uint32_t val)
31 {
32 	struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
33 
34 	reg <<= 2; /* reg num to offset */
35 	mutex_lock(&sw_dev->device->bus->mdio_lock);
36 	lan9303_mdio_real_write(sw_dev->device, reg, val & 0xffff);
37 	lan9303_mdio_real_write(sw_dev->device, reg + 2, (val >> 16) & 0xffff);
38 	mutex_unlock(&sw_dev->device->bus->mdio_lock);
39 
40 	return 0;
41 }
42 
43 static u16 lan9303_mdio_real_read(struct mdio_device *mdio, int reg)
44 {
45 	return mdio->bus->read(mdio->bus, PHY_ADDR(reg), PHY_REG(reg));
46 }
47 
48 static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
49 {
50 	struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
51 
52 	reg <<= 2; /* reg num to offset */
53 	mutex_lock(&sw_dev->device->bus->mdio_lock);
54 	*val = lan9303_mdio_real_read(sw_dev->device, reg);
55 	*val |= (lan9303_mdio_real_read(sw_dev->device, reg + 2) << 16);
56 	mutex_unlock(&sw_dev->device->bus->mdio_lock);
57 
58 	return 0;
59 }
60 
61 static int lan9303_mdio_phy_write(struct lan9303 *chip, int phy, int reg,
62 				  u16 val)
63 {
64 	struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
65 
66 	return mdiobus_write_nested(sw_dev->device->bus, phy, reg, val);
67 }
68 
69 static int lan9303_mdio_phy_read(struct lan9303 *chip, int phy,  int reg)
70 {
71 	struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
72 
73 	return mdiobus_read_nested(sw_dev->device->bus, phy, reg);
74 }
75 
76 static const struct lan9303_phy_ops lan9303_mdio_phy_ops = {
77 	.phy_read = lan9303_mdio_phy_read,
78 	.phy_write = lan9303_mdio_phy_write,
79 };
80 
81 static const struct regmap_config lan9303_mdio_regmap_config = {
82 	.reg_bits = 8,
83 	.val_bits = 32,
84 	.reg_stride = 1,
85 	.can_multi_write = true,
86 	.max_register = 0x0ff, /* address bits 0..1 are not used */
87 	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
88 
89 	.volatile_table = &lan9303_register_set,
90 	.wr_table = &lan9303_register_set,
91 	.rd_table = &lan9303_register_set,
92 
93 	.reg_read = lan9303_mdio_read,
94 	.reg_write = lan9303_mdio_write,
95 
96 	.cache_type = REGCACHE_NONE,
97 };
98 
99 static int lan9303_mdio_probe(struct mdio_device *mdiodev)
100 {
101 	struct lan9303_mdio *sw_dev;
102 	int ret;
103 
104 	sw_dev = devm_kzalloc(&mdiodev->dev, sizeof(struct lan9303_mdio),
105 			      GFP_KERNEL);
106 	if (!sw_dev)
107 		return -ENOMEM;
108 
109 	sw_dev->chip.regmap = devm_regmap_init(&mdiodev->dev, NULL, sw_dev,
110 					       &lan9303_mdio_regmap_config);
111 	if (IS_ERR(sw_dev->chip.regmap)) {
112 		ret = PTR_ERR(sw_dev->chip.regmap);
113 		dev_err(&mdiodev->dev, "regmap init failed: %d\n", ret);
114 		return ret;
115 	}
116 
117 	/* link forward and backward */
118 	sw_dev->device = mdiodev;
119 	dev_set_drvdata(&mdiodev->dev, sw_dev);
120 	sw_dev->chip.dev = &mdiodev->dev;
121 
122 	sw_dev->chip.ops = &lan9303_mdio_phy_ops;
123 
124 	ret = lan9303_probe(&sw_dev->chip, mdiodev->dev.of_node);
125 	if (ret != 0)
126 		return ret;
127 
128 	dev_info(&mdiodev->dev, "LAN9303 MDIO driver loaded successfully\n");
129 
130 	return 0;
131 }
132 
133 static void lan9303_mdio_remove(struct mdio_device *mdiodev)
134 {
135 	struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);
136 
137 	if (!sw_dev)
138 		return;
139 
140 	lan9303_remove(&sw_dev->chip);
141 }
142 
143 static void lan9303_mdio_shutdown(struct mdio_device *mdiodev)
144 {
145 	struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);
146 
147 	if (!sw_dev)
148 		return;
149 
150 	lan9303_shutdown(&sw_dev->chip);
151 
152 	dev_set_drvdata(&mdiodev->dev, NULL);
153 }
154 
155 /*-------------------------------------------------------------------------*/
156 
157 static const struct of_device_id lan9303_mdio_of_match[] = {
158 	{ .compatible = "smsc,lan9303-mdio" },
159 	{ .compatible = "microchip,lan9354-mdio" },
160 	{ /* sentinel */ },
161 };
162 MODULE_DEVICE_TABLE(of, lan9303_mdio_of_match);
163 
164 static struct mdio_driver lan9303_mdio_driver = {
165 	.mdiodrv.driver = {
166 		.name = "LAN9303_MDIO",
167 		.of_match_table = of_match_ptr(lan9303_mdio_of_match),
168 	},
169 	.probe  = lan9303_mdio_probe,
170 	.remove = lan9303_mdio_remove,
171 	.shutdown = lan9303_mdio_shutdown,
172 };
173 mdio_module_driver(lan9303_mdio_driver);
174 
175 MODULE_AUTHOR("Stefan Roese <sr@denx.de>, Juergen Borleis <kernel@pengutronix.de>");
176 MODULE_DESCRIPTION("Driver for SMSC/Microchip LAN9303 three port ethernet switch in MDIO managed mode");
177 MODULE_LICENSE("GPL v2");
178