1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020 NovaTech LLC
4  * George McCollister <george.mccollister@gmail.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/bits.h>
9 #include <linux/mdio.h>
10 #include <linux/module.h>
11 #include <linux/phy.h>
12 #include <linux/if_vlan.h>
13 #include <linux/of.h>
14 #include "xrs700x.h"
15 #include "xrs700x_reg.h"
16 
17 #define XRS_MDIO_IBA0	0x10
18 #define XRS_MDIO_IBA1	0x11
19 #define XRS_MDIO_IBD	0x14
20 
21 #define XRS_IB_READ	0x0
22 #define XRS_IB_WRITE	0x1
23 
24 static int xrs700x_mdio_reg_read(void *context, unsigned int reg,
25 				 unsigned int *val)
26 {
27 	struct mdio_device *mdiodev = context;
28 	struct device *dev = &mdiodev->dev;
29 	u16 uval;
30 	int ret;
31 
32 	uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
33 
34 	ret = mdiodev_write(mdiodev, XRS_MDIO_IBA1, uval);
35 	if (ret < 0) {
36 		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
37 		return ret;
38 	}
39 
40 	uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_READ);
41 
42 	ret = mdiodev_write(mdiodev, XRS_MDIO_IBA0, uval);
43 	if (ret < 0) {
44 		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
45 		return ret;
46 	}
47 
48 	ret = mdiodev_read(mdiodev, XRS_MDIO_IBD);
49 	if (ret < 0) {
50 		dev_err(dev, "xrs mdiobus_read returned %d\n", ret);
51 		return ret;
52 	}
53 
54 	*val = (unsigned int)ret;
55 
56 	return 0;
57 }
58 
59 static int xrs700x_mdio_reg_write(void *context, unsigned int reg,
60 				  unsigned int val)
61 {
62 	struct mdio_device *mdiodev = context;
63 	struct device *dev = &mdiodev->dev;
64 	u16 uval;
65 	int ret;
66 
67 	ret = mdiodev_write(mdiodev, XRS_MDIO_IBD, (u16)val);
68 	if (ret < 0) {
69 		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
70 		return ret;
71 	}
72 
73 	uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
74 
75 	ret = mdiodev_write(mdiodev, XRS_MDIO_IBA1, uval);
76 	if (ret < 0) {
77 		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
78 		return ret;
79 	}
80 
81 	uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_WRITE);
82 
83 	ret = mdiodev_write(mdiodev, XRS_MDIO_IBA0, uval);
84 	if (ret < 0) {
85 		dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
86 		return ret;
87 	}
88 
89 	return 0;
90 }
91 
92 static const struct regmap_config xrs700x_mdio_regmap_config = {
93 	.val_bits = 16,
94 	.reg_stride = 2,
95 	.reg_bits = 32,
96 	.pad_bits = 0,
97 	.write_flag_mask = 0,
98 	.read_flag_mask = 0,
99 	.reg_read = xrs700x_mdio_reg_read,
100 	.reg_write = xrs700x_mdio_reg_write,
101 	.max_register = XRS_VLAN(VLAN_N_VID - 1),
102 	.cache_type = REGCACHE_NONE,
103 	.reg_format_endian = REGMAP_ENDIAN_BIG,
104 	.val_format_endian = REGMAP_ENDIAN_BIG
105 };
106 
107 static int xrs700x_mdio_probe(struct mdio_device *mdiodev)
108 {
109 	struct xrs700x *priv;
110 	int ret;
111 
112 	priv = xrs700x_switch_alloc(&mdiodev->dev, mdiodev);
113 	if (!priv)
114 		return -ENOMEM;
115 
116 	priv->regmap = devm_regmap_init(&mdiodev->dev, NULL, mdiodev,
117 					&xrs700x_mdio_regmap_config);
118 	if (IS_ERR(priv->regmap)) {
119 		ret = PTR_ERR(priv->regmap);
120 		dev_err(&mdiodev->dev, "Failed to initialize regmap: %d\n", ret);
121 		return ret;
122 	}
123 
124 	dev_set_drvdata(&mdiodev->dev, priv);
125 
126 	ret = xrs700x_switch_register(priv);
127 
128 	/* Main DSA driver may not be started yet. */
129 	if (ret)
130 		return ret;
131 
132 	return 0;
133 }
134 
135 static void xrs700x_mdio_remove(struct mdio_device *mdiodev)
136 {
137 	struct xrs700x *priv = dev_get_drvdata(&mdiodev->dev);
138 
139 	if (!priv)
140 		return;
141 
142 	xrs700x_switch_remove(priv);
143 }
144 
145 static void xrs700x_mdio_shutdown(struct mdio_device *mdiodev)
146 {
147 	struct xrs700x *priv = dev_get_drvdata(&mdiodev->dev);
148 
149 	if (!priv)
150 		return;
151 
152 	xrs700x_switch_shutdown(priv);
153 
154 	dev_set_drvdata(&mdiodev->dev, NULL);
155 }
156 
157 static const struct of_device_id __maybe_unused xrs700x_mdio_dt_ids[] = {
158 	{ .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
159 	{ .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
160 	{ .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
161 	{ .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
162 	{},
163 };
164 MODULE_DEVICE_TABLE(of, xrs700x_mdio_dt_ids);
165 
166 static struct mdio_driver xrs700x_mdio_driver = {
167 	.mdiodrv.driver = {
168 		.name	= "xrs700x-mdio",
169 		.of_match_table = of_match_ptr(xrs700x_mdio_dt_ids),
170 	},
171 	.probe	= xrs700x_mdio_probe,
172 	.remove	= xrs700x_mdio_remove,
173 	.shutdown = xrs700x_mdio_shutdown,
174 };
175 
176 mdio_module_driver(xrs700x_mdio_driver);
177 
178 MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
179 MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA MDIO driver");
180 MODULE_LICENSE("GPL v2");
181