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
 11struct icc_clk_node {
 12	struct clk *clk;
 13	bool enabled;
 14};
 15
 16struct 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
 25static 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
 51static 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 */
 76struct 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
144err:
145	icc_nodes_remove(provider);
146
147	return ERR_PTR(ret);
148}
149EXPORT_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 */
155void 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}
170EXPORT_SYMBOL_GPL(icc_clk_unregister);
171
172MODULE_LICENSE("GPL");
173MODULE_DESCRIPTION("Interconnect wrapper for clocks");
174MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");