xref: /linux/drivers/interconnect/imx/imx.c (revision cbafa54aa2ae23939846e150ad4ba98c784f6395)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Interconnect framework driver for i.MX SoC
4  *
5  * Copyright (c) 2019, BayLibre
6  * Copyright (c) 2019-2020, NXP
7  * Author: Alexandre Bailon <abailon@baylibre.com>
8  * Author: Leonard Crestez <leonard.crestez@nxp.com>
9  */
10 
11 #include <linux/device.h>
12 #include <linux/interconnect-provider.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_qos.h>
18 
19 #include "imx.h"
20 
21 /* private icc_node data */
22 struct imx_icc_node {
23 	const struct imx_icc_node_desc *desc;
24 	struct device *qos_dev;
25 	struct dev_pm_qos_request qos_req;
26 };
27 
28 static int imx_icc_node_set(struct icc_node *node)
29 {
30 	struct device *dev = node->provider->dev;
31 	struct imx_icc_node *node_data = node->data;
32 	u64 freq;
33 
34 	if (!node_data->qos_dev)
35 		return 0;
36 
37 	freq = (node->avg_bw + node->peak_bw) * node_data->desc->adj->bw_mul;
38 	do_div(freq, node_data->desc->adj->bw_div);
39 	dev_dbg(dev, "node %s device %s avg_bw %ukBps peak_bw %ukBps min_freq %llukHz\n",
40 		node->name, dev_name(node_data->qos_dev),
41 		node->avg_bw, node->peak_bw, freq);
42 
43 	if (freq > S32_MAX) {
44 		dev_err(dev, "%s can't request more than S32_MAX freq\n",
45 				node->name);
46 		return -ERANGE;
47 	}
48 
49 	dev_pm_qos_update_request(&node_data->qos_req, freq);
50 
51 	return 0;
52 }
53 
54 static int imx_icc_set(struct icc_node *src, struct icc_node *dst)
55 {
56 	return imx_icc_node_set(dst);
57 }
58 
59 /* imx_icc_node_destroy() - Destroy an imx icc_node, including private data */
60 static void imx_icc_node_destroy(struct icc_node *node)
61 {
62 	struct imx_icc_node *node_data = node->data;
63 	int ret;
64 
65 	if (dev_pm_qos_request_active(&node_data->qos_req)) {
66 		ret = dev_pm_qos_remove_request(&node_data->qos_req);
67 		if (ret)
68 			dev_warn(node->provider->dev,
69 				 "failed to remove qos request for %s\n",
70 				 dev_name(node_data->qos_dev));
71 	}
72 
73 	put_device(node_data->qos_dev);
74 	icc_node_del(node);
75 	icc_node_destroy(node->id);
76 }
77 
78 static int imx_icc_node_init_qos(struct icc_provider *provider,
79 				 struct icc_node *node)
80 {
81 	struct imx_icc_node *node_data = node->data;
82 	const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
83 	struct device *dev = provider->dev;
84 	struct device_node *dn = NULL;
85 	struct platform_device *pdev;
86 
87 	if (adj->main_noc) {
88 		node_data->qos_dev = dev;
89 		dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
90 			node->name, node->id);
91 	} else {
92 		dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
93 		if (!dn) {
94 			dev_warn(dev, "Failed to parse %s\n",
95 				 adj->phandle_name);
96 			return -ENODEV;
97 		}
98 		/* Allow scaling to be disabled on a per-node basis */
99 		if (!of_device_is_available(dn)) {
100 			dev_warn(dev, "Missing property %s, skip scaling %s\n",
101 				 adj->phandle_name, node->name);
102 			of_node_put(dn);
103 			return 0;
104 		}
105 
106 		pdev = of_find_device_by_node(dn);
107 		of_node_put(dn);
108 		if (!pdev) {
109 			dev_warn(dev, "node %s[%d] missing device for %pOF\n",
110 				 node->name, node->id, dn);
111 			return -EPROBE_DEFER;
112 		}
113 		node_data->qos_dev = &pdev->dev;
114 		dev_dbg(dev, "node %s[%d] has device node %pOF\n",
115 			node->name, node->id, dn);
116 	}
117 
118 	return dev_pm_qos_add_request(node_data->qos_dev,
119 				      &node_data->qos_req,
120 				      DEV_PM_QOS_MIN_FREQUENCY, 0);
121 }
122 
123 static struct icc_node *imx_icc_node_add(struct icc_provider *provider,
124 					 const struct imx_icc_node_desc *node_desc)
125 {
126 	struct device *dev = provider->dev;
127 	struct imx_icc_node *node_data;
128 	struct icc_node *node;
129 	int ret;
130 
131 	node = icc_node_create(node_desc->id);
132 	if (IS_ERR(node)) {
133 		dev_err(dev, "failed to create node %d\n", node_desc->id);
134 		return node;
135 	}
136 
137 	if (node->data) {
138 		dev_err(dev, "already created node %s id=%d\n",
139 			node_desc->name, node_desc->id);
140 		return ERR_PTR(-EEXIST);
141 	}
142 
143 	node_data = devm_kzalloc(dev, sizeof(*node_data), GFP_KERNEL);
144 	if (!node_data) {
145 		icc_node_destroy(node->id);
146 		return ERR_PTR(-ENOMEM);
147 	}
148 
149 	node->name = node_desc->name;
150 	node->data = node_data;
151 	node_data->desc = node_desc;
152 	icc_node_add(node, provider);
153 
154 	if (node_desc->adj) {
155 		ret = imx_icc_node_init_qos(provider, node);
156 		if (ret < 0) {
157 			imx_icc_node_destroy(node);
158 			return ERR_PTR(ret);
159 		}
160 	}
161 
162 	return node;
163 }
164 
165 static void imx_icc_unregister_nodes(struct icc_provider *provider)
166 {
167 	struct icc_node *node, *tmp;
168 
169 	list_for_each_entry_safe(node, tmp, &provider->nodes, node_list)
170 		imx_icc_node_destroy(node);
171 }
172 
173 static int imx_icc_register_nodes(struct icc_provider *provider,
174 				  const struct imx_icc_node_desc *descs,
175 				  int count)
176 {
177 	struct icc_onecell_data *provider_data = provider->data;
178 	int ret;
179 	int i;
180 
181 	for (i = 0; i < count; i++) {
182 		struct icc_node *node;
183 		const struct imx_icc_node_desc *node_desc = &descs[i];
184 		size_t j;
185 
186 		node = imx_icc_node_add(provider, node_desc);
187 		if (IS_ERR(node)) {
188 			ret = dev_err_probe(provider->dev, PTR_ERR(node),
189 					    "failed to add %s\n", node_desc->name);
190 			goto err;
191 		}
192 		provider_data->nodes[node->id] = node;
193 
194 		for (j = 0; j < node_desc->num_links; j++) {
195 			ret = icc_link_create(node, node_desc->links[j]);
196 			if (ret) {
197 				dev_err(provider->dev, "failed to link node %d to %d: %d\n",
198 					node->id, node_desc->links[j], ret);
199 				goto err;
200 			}
201 		}
202 	}
203 
204 	return 0;
205 
206 err:
207 	imx_icc_unregister_nodes(provider);
208 
209 	return ret;
210 }
211 
212 static int get_max_node_id(struct imx_icc_node_desc *nodes, int nodes_count)
213 {
214 	int i, ret = 0;
215 
216 	for (i = 0; i < nodes_count; ++i)
217 		if (nodes[i].id > ret)
218 			ret = nodes[i].id;
219 
220 	return ret;
221 }
222 
223 int imx_icc_register(struct platform_device *pdev,
224 		     struct imx_icc_node_desc *nodes, int nodes_count)
225 {
226 	struct device *dev = &pdev->dev;
227 	struct icc_onecell_data *data;
228 	struct icc_provider *provider;
229 	int max_node_id;
230 	int ret;
231 
232 	/* icc_onecell_data is indexed by node_id, unlike nodes param */
233 	max_node_id = get_max_node_id(nodes, nodes_count);
234 	data = devm_kzalloc(dev, struct_size(data, nodes, max_node_id),
235 			    GFP_KERNEL);
236 	if (!data)
237 		return -ENOMEM;
238 	data->num_nodes = max_node_id;
239 
240 	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
241 	if (!provider)
242 		return -ENOMEM;
243 	provider->set = imx_icc_set;
244 	provider->aggregate = icc_std_aggregate;
245 	provider->xlate = of_icc_xlate_onecell;
246 	provider->data = data;
247 	provider->dev = dev->parent;
248 	platform_set_drvdata(pdev, provider);
249 
250 	ret = icc_provider_add(provider);
251 	if (ret) {
252 		dev_err(dev, "error adding interconnect provider: %d\n", ret);
253 		return ret;
254 	}
255 
256 	ret = imx_icc_register_nodes(provider, nodes, nodes_count);
257 	if (ret)
258 		goto provider_del;
259 
260 	return 0;
261 
262 provider_del:
263 	icc_provider_del(provider);
264 	return ret;
265 }
266 EXPORT_SYMBOL_GPL(imx_icc_register);
267 
268 int imx_icc_unregister(struct platform_device *pdev)
269 {
270 	struct icc_provider *provider = platform_get_drvdata(pdev);
271 
272 	imx_icc_unregister_nodes(provider);
273 
274 	return icc_provider_del(provider);
275 }
276 EXPORT_SYMBOL_GPL(imx_icc_unregister);
277 
278 MODULE_LICENSE("GPL v2");
279