summaryrefslogtreecommitdiff
path: root/net/mdio-mux-uclass.c
blob: e425207d6e40044f4a8a9c8f807ac012cba633fc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2019
 * Alex Marginean, NXP
 */

#include <common.h>
#include <dm.h>
#include <miiphy.h>
#include <dm/device-internal.h>
#include <dm/uclass-internal.h>
#include <dm/lists.h>

#define MDIO_MUX_CHILD_DRV_NAME	"mdio-mux-bus-drv"

/**
 * struct mdio_mux_perdev_priv - Per-device class data for MDIO MUX DM
 *
 * @parent_mdio: Parent DM MDIO device, this is called for actual MDIO I/O after
 *               setting up the mux.  Typically this is a real MDIO device,
 *               unless there are cascaded muxes.
 * @selected:    Current child bus selection.  Defaults to -1
 */
struct mdio_mux_perdev_priv {
	struct udevice *mdio_parent;
	int selected;
};

/*
 * This source file uses three types of devices, as follows:
 * - mux is the hardware MDIO MUX which selects between the existing child MDIO
 * buses, this is the device relevant for MDIO MUX class of drivers.
 * - ch is a child MDIO bus, this is just a representation of a mux selection,
 * not a real piece of hardware.
 * - mdio_parent is the actual MDIO bus called to perform reads/writes after
 * the MUX is configured.  Typically this is a real MDIO device, unless there
 * are cascaded muxes.
 */

/**
 * struct mdio_mux_ch_data - Per-device data for child MDIOs
 *
 * @sel: Selection value used by the MDIO MUX to access this child MDIO bus
 */
struct mdio_mux_ch_data {
	int sel;
};

static struct udevice *mmux_get_parent_mdio(struct udevice *mux)
{
	struct mdio_mux_perdev_priv *pdata = dev_get_uclass_priv(mux);

	return pdata->mdio_parent;
}

static struct mdio_ops *mmux_get_mdio_parent_ops(struct udevice *mux)
{
	return mdio_get_ops(mmux_get_parent_mdio(mux));
}

/* call driver select function before performing MDIO r/w */
static int mmux_change_sel(struct udevice *ch, bool sel)
{
	struct udevice *mux = ch->parent;
	struct mdio_mux_perdev_priv *priv = dev_get_uclass_priv(mux);
	struct mdio_mux_ops *ops = mdio_mux_get_ops(mux);
	struct mdio_mux_ch_data *ch_data = dev_get_parent_platdata(ch);
	int err = 0;

	if (sel) {
		err = ops->select(mux, priv->selected, ch_data->sel);
		if (err)
			return err;

		priv->selected = ch_data->sel;
	} else {
		if (ops->deselect) {
			ops->deselect(mux, ch_data->sel);
			priv->selected = MDIO_MUX_SELECT_NONE;
		}
	}

	return 0;
}

/* Read wrapper, sets up the mux before issuing a read on parent MDIO bus */
static int mmux_read(struct udevice *ch, int addr, int devad,
		     int reg)
{
	struct udevice *mux = ch->parent;
	struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
	struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
	int err;

	err = mmux_change_sel(ch, true);
	if (err)
		return err;

	err = parent_ops->read(parent_mdio, addr, devad, reg);
	mmux_change_sel(ch, false);

	return err;
}

/* Write wrapper, sets up the mux before issuing a write on parent MDIO bus */
static int mmux_write(struct udevice *ch, int addr, int devad,
		      int reg, u16 val)
{
	struct udevice *mux = ch->parent;
	struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
	struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
	int err;

	err = mmux_change_sel(ch, true);
	if (err)
		return err;

	err = parent_ops->write(parent_mdio, addr, devad, reg, val);
	mmux_change_sel(ch, false);

	return err;
}

/* Reset wrapper, sets up the mux before issuing a reset on parent MDIO bus */
static int mmux_reset(struct udevice *ch)
{
	struct udevice *mux = ch->parent;
	struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
	struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
	int err;

	/* reset is optional, if it's not implemented just exit */
	if (!parent_ops->reset)
		return 0;

	err = mmux_change_sel(ch, true);
	if (err)
		return err;

	err = parent_ops->reset(parent_mdio);
	mmux_change_sel(ch, false);

	return err;
}

/* Picks up the mux selection value for each child */
static int dm_mdio_mux_child_post_bind(struct udevice *ch)
{
	struct mdio_mux_ch_data *ch_data = dev_get_parent_platdata(ch);

	ch_data->sel = dev_read_u32_default(ch, "reg", MDIO_MUX_SELECT_NONE);

	if (ch_data->sel == MDIO_MUX_SELECT_NONE)
		return -EINVAL;

	return 0;
}

/* Explicitly bind child MDIOs after binding the mux */
static int dm_mdio_mux_post_bind(struct udevice *mux)
{
	ofnode ch_node;
	int err, first_err = 0;

	if (!ofnode_valid(mux->node)) {
		debug("%s: no mux node found, no child MDIO busses set up\n",
		      __func__);
		return 0;
	}

	/*
	 * we're going by Linux bindings so the child nodes do not have
	 * compatible strings.  We're going through them here and binding to
	 * them.
	 */
	dev_for_each_subnode(ch_node, mux) {
		struct udevice *ch_dev;
		const char *ch_name;

		ch_name = ofnode_get_name(ch_node);

		err = device_bind_driver_to_node(mux, MDIO_MUX_CHILD_DRV_NAME,
						 ch_name, ch_node, &ch_dev);
		/* try to bind all, but keep 1st error */
		if (err && !first_err)
			first_err = err;
	}

	return first_err;
}

/* Get a reference to the parent MDIO bus, it should be bound by now */
static int dm_mdio_mux_post_probe(struct udevice *mux)
{
	struct mdio_mux_perdev_priv *priv = dev_get_uclass_priv(mux);
	int err;

	priv->selected = MDIO_MUX_SELECT_NONE;

	/* pick up mdio parent from device tree */
	err = uclass_get_device_by_phandle(UCLASS_MDIO, mux, "mdio-parent-bus",
					   &priv->mdio_parent);
	if (err) {
		debug("%s: didn't find mdio-parent-bus\n", __func__);
		return err;
	}

	return 0;
}

const struct mdio_ops mmux_child_mdio_ops = {
	.read = mmux_read,
	.write = mmux_write,
	.reset = mmux_reset,
};

/* MDIO class driver used for MUX child MDIO buses */
U_BOOT_DRIVER(mdio_mux_child) = {
	.name		= MDIO_MUX_CHILD_DRV_NAME,
	.id		= UCLASS_MDIO,
	.ops		= &mmux_child_mdio_ops,
};

UCLASS_DRIVER(mdio_mux) = {
	.id = UCLASS_MDIO_MUX,
	.name = "mdio-mux",
	.child_post_bind = dm_mdio_mux_child_post_bind,
	.post_bind  = dm_mdio_mux_post_bind,
	.post_probe = dm_mdio_mux_post_probe,
	.per_device_auto_alloc_size = sizeof(struct mdio_mux_perdev_priv),
	.per_child_platdata_auto_alloc_size = sizeof(struct mdio_mux_ch_data),
};