1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2023, Linaro Ltd.
4 */
5
6 #include <linux/clk.h>
7 #include <linux/device.h>
8 #include <linux/interconnect-clk.h>
9 #include <linux/interconnect-provider.h>
10
11 struct icc_clk_node {
12 struct clk *clk;
13 bool enabled;
14 };
15
16 struct icc_clk_provider {
17 struct icc_provider provider;
18 int num_clocks;
19 struct icc_clk_node clocks[] __counted_by(num_clocks);
20 };
21
22 #define to_icc_clk_provider(_provider) \
23 container_of(_provider, struct icc_clk_provider, provider)
24
icc_clk_set(struct icc_node * src,struct icc_node * dst)25 static int icc_clk_set(struct icc_node *src, struct icc_node *dst)
26 {
27 struct icc_clk_node *qn = src->data;
28 int ret;
29
30 if (!qn || !qn->clk)
31 return 0;
32
33 if (!src->peak_bw) {
34 if (qn->enabled)
35 clk_disable_unprepare(qn->clk);
36 qn->enabled = false;
37
38 return 0;
39 }
40
41 if (!qn->enabled) {
42 ret = clk_prepare_enable(qn->clk);
43 if (ret)
44 return ret;
45 qn->enabled = true;
46 }
47
48 return clk_set_rate(qn->clk, icc_units_to_bps(src->peak_bw));
49 }
50
icc_clk_get_bw(struct icc_node * node,u32 * avg,u32 * peak)51 static int icc_clk_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
52 {
53 struct icc_clk_node *qn = node->data;
54
55 if (!qn || !qn->clk)
56 *peak = INT_MAX;
57 else
58 *peak = Bps_to_icc(clk_get_rate(qn->clk));
59
60 return 0;
61 }
62
63 /**
64 * icc_clk_register() - register a new clk-based interconnect provider
65 * @dev: device supporting this provider
66 * @first_id: an ID of the first provider's node
67 * @num_clocks: number of instances of struct icc_clk_data
68 * @data: data for the provider
69 *
70 * Registers and returns a clk-based interconnect provider. It is a simple
71 * wrapper around COMMON_CLK framework, allowing other devices to vote on the
72 * clock rate.
73 *
74 * Return: 0 on success, or an error code otherwise
75 */
icc_clk_register(struct device * dev,unsigned int first_id,unsigned int num_clocks,const struct icc_clk_data * data)76 struct icc_provider *icc_clk_register(struct device *dev,
77 unsigned int first_id,
78 unsigned int num_clocks,
79 const struct icc_clk_data *data)
80 {
81 struct icc_clk_provider *qp;
82 struct icc_provider *provider;
83 struct icc_onecell_data *onecell;
84 struct icc_node *node;
85 int ret, i, j;
86
87 onecell = devm_kzalloc(dev, struct_size(onecell, nodes, 2 * num_clocks), GFP_KERNEL);
88 if (!onecell)
89 return ERR_PTR(-ENOMEM);
90
91 qp = devm_kzalloc(dev, struct_size(qp, clocks, num_clocks), GFP_KERNEL);
92 if (!qp)
93 return ERR_PTR(-ENOMEM);
94
95 qp->num_clocks = num_clocks;
96
97 provider = &qp->provider;
98 provider->dev = dev;
99 provider->get_bw = icc_clk_get_bw;
100 provider->set = icc_clk_set;
101 provider->aggregate = icc_std_aggregate;
102 provider->xlate = of_icc_xlate_onecell;
103 INIT_LIST_HEAD(&provider->nodes);
104 provider->data = onecell;
105
106 icc_provider_init(provider);
107
108 for (i = 0, j = 0; i < num_clocks; i++) {
109 qp->clocks[i].clk = data[i].clk;
110
111 node = icc_node_create(first_id + j);
112 if (IS_ERR(node)) {
113 ret = PTR_ERR(node);
114 goto err;
115 }
116
117 node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_master", data[i].name);
118 node->data = &qp->clocks[i];
119 icc_node_add(node, provider);
120 /* link to the next node, slave */
121 icc_link_create(node, first_id + j + 1);
122 onecell->nodes[j++] = node;
123
124 node = icc_node_create(first_id + j);
125 if (IS_ERR(node)) {
126 ret = PTR_ERR(node);
127 goto err;
128 }
129
130 node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_slave", data[i].name);
131 /* no data for slave node */
132 icc_node_add(node, provider);
133 onecell->nodes[j++] = node;
134 }
135
136 onecell->num_nodes = j;
137
138 ret = icc_provider_register(provider);
139 if (ret)
140 goto err;
141
142 return provider;
143
144 err:
145 icc_nodes_remove(provider);
146
147 return ERR_PTR(ret);
148 }
149 EXPORT_SYMBOL_GPL(icc_clk_register);
150
151 /**
152 * icc_clk_unregister() - unregister a previously registered clk interconnect provider
153 * @provider: provider returned by icc_clk_register()
154 */
icc_clk_unregister(struct icc_provider * provider)155 void icc_clk_unregister(struct icc_provider *provider)
156 {
157 struct icc_clk_provider *qp = container_of(provider, struct icc_clk_provider, provider);
158 int i;
159
160 icc_provider_deregister(&qp->provider);
161 icc_nodes_remove(&qp->provider);
162
163 for (i = 0; i < qp->num_clocks; i++) {
164 struct icc_clk_node *qn = &qp->clocks[i];
165
166 if (qn->enabled)
167 clk_disable_unprepare(qn->clk);
168 }
169 }
170 EXPORT_SYMBOL_GPL(icc_clk_unregister);
171
172 MODULE_LICENSE("GPL");
173 MODULE_DESCRIPTION("Interconnect wrapper for clocks");
174 MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
175