summaryrefslogtreecommitdiff
path: root/drivers/interconnect/icc-clk.c
blob: d787f2ea36d97b0d8bf2474d75779d0514b4725f (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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2023, Linaro Ltd.
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/interconnect-clk.h>
#include <linux/interconnect-provider.h>

struct icc_clk_node {
	struct clk *clk;
	bool enabled;
};

struct icc_clk_provider {
	struct icc_provider provider;
	int num_clocks;
	struct icc_clk_node clocks[] __counted_by(num_clocks);
};

#define to_icc_clk_provider(_provider) \
	container_of(_provider, struct icc_clk_provider, provider)

static int icc_clk_set(struct icc_node *src, struct icc_node *dst)
{
	struct icc_clk_node *qn = src->data;
	int ret;

	if (!qn || !qn->clk)
		return 0;

	if (!src->peak_bw) {
		if (qn->enabled)
			clk_disable_unprepare(qn->clk);
		qn->enabled = false;

		return 0;
	}

	if (!qn->enabled) {
		ret = clk_prepare_enable(qn->clk);
		if (ret)
			return ret;
		qn->enabled = true;
	}

	return clk_set_rate(qn->clk, icc_units_to_bps(src->peak_bw));
}

static int icc_clk_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
{
	struct icc_clk_node *qn = node->data;

	if (!qn || !qn->clk)
		*peak = INT_MAX;
	else
		*peak = Bps_to_icc(clk_get_rate(qn->clk));

	return 0;
}

/**
 * icc_clk_register() - register a new clk-based interconnect provider
 * @dev: device supporting this provider
 * @first_id: an ID of the first provider's node
 * @num_clocks: number of instances of struct icc_clk_data
 * @data: data for the provider
 *
 * Registers and returns a clk-based interconnect provider. It is a simple
 * wrapper around COMMON_CLK framework, allowing other devices to vote on the
 * clock rate.
 *
 * Return: 0 on success, or an error code otherwise
 */
struct icc_provider *icc_clk_register(struct device *dev,
				      unsigned int first_id,
				      unsigned int num_clocks,
				      const struct icc_clk_data *data)
{
	struct icc_clk_provider *qp;
	struct icc_provider *provider;
	struct icc_onecell_data *onecell;
	struct icc_node *node;
	int ret, i, j;

	onecell = devm_kzalloc(dev, struct_size(onecell, nodes, 2 * num_clocks), GFP_KERNEL);
	if (!onecell)
		return ERR_PTR(-ENOMEM);

	qp = devm_kzalloc(dev, struct_size(qp, clocks, num_clocks), GFP_KERNEL);
	if (!qp)
		return ERR_PTR(-ENOMEM);

	qp->num_clocks = num_clocks;

	provider = &qp->provider;
	provider->dev = dev;
	provider->get_bw = icc_clk_get_bw;
	provider->set = icc_clk_set;
	provider->aggregate = icc_std_aggregate;
	provider->xlate = of_icc_xlate_onecell;
	INIT_LIST_HEAD(&provider->nodes);
	provider->data = onecell;

	icc_provider_init(provider);

	for (i = 0, j = 0; i < num_clocks; i++) {
		qp->clocks[i].clk = data[i].clk;

		node = icc_node_create(first_id + j);
		if (IS_ERR(node)) {
			ret = PTR_ERR(node);
			goto err;
		}

		node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_master", data[i].name);
		node->data = &qp->clocks[i];
		icc_node_add(node, provider);
		/* link to the next node, slave */
		icc_link_create(node, first_id + j + 1);
		onecell->nodes[j++] = node;

		node = icc_node_create(first_id + j);
		if (IS_ERR(node)) {
			ret = PTR_ERR(node);
			goto err;
		}

		node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_slave", data[i].name);
		/* no data for slave node */
		icc_node_add(node, provider);
		onecell->nodes[j++] = node;
	}

	onecell->num_nodes = j;

	ret = icc_provider_register(provider);
	if (ret)
		goto err;

	return provider;

err:
	icc_nodes_remove(provider);

	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(icc_clk_register);

/**
 * icc_clk_unregister() - unregister a previously registered clk interconnect provider
 * @provider: provider returned by icc_clk_register()
 */
void icc_clk_unregister(struct icc_provider *provider)
{
	struct icc_clk_provider *qp = container_of(provider, struct icc_clk_provider, provider);
	int i;

	icc_provider_deregister(&qp->provider);
	icc_nodes_remove(&qp->provider);

	for (i = 0; i < qp->num_clocks; i++) {
		struct icc_clk_node *qn = &qp->clocks[i];

		if (qn->enabled)
			clk_disable_unprepare(qn->clk);
	}
}
EXPORT_SYMBOL_GPL(icc_clk_unregister);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Interconnect wrapper for clocks");
MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");