xref: /openbmc/linux/drivers/interconnect/imx/imx.c (revision 82df5b73)
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 (!dn || !of_device_is_available(dn)) {
100 			dev_warn(dev, "Missing property %s, skip scaling %s\n",
101 				 adj->phandle_name, node->name);
102 			return 0;
103 		}
104 
105 		pdev = of_find_device_by_node(dn);
106 		of_node_put(dn);
107 		if (!pdev) {
108 			dev_warn(dev, "node %s[%d] missing device for %pOF\n",
109 				 node->name, node->id, dn);
110 			return -EPROBE_DEFER;
111 		}
112 		node_data->qos_dev = &pdev->dev;
113 		dev_dbg(dev, "node %s[%d] has device node %pOF\n",
114 			node->name, node->id, dn);
115 	}
116 
117 	return dev_pm_qos_add_request(node_data->qos_dev,
118 				      &node_data->qos_req,
119 				      DEV_PM_QOS_MIN_FREQUENCY, 0);
120 }
121 
122 static struct icc_node *imx_icc_node_add(struct icc_provider *provider,
123 					 const struct imx_icc_node_desc *node_desc)
124 {
125 	struct device *dev = provider->dev;
126 	struct imx_icc_node *node_data;
127 	struct icc_node *node;
128 	int ret;
129 
130 	node = icc_node_create(node_desc->id);
131 	if (IS_ERR(node)) {
132 		dev_err(dev, "failed to create node %d\n", node_desc->id);
133 		return node;
134 	}
135 
136 	if (node->data) {
137 		dev_err(dev, "already created node %s id=%d\n",
138 			node_desc->name, node_desc->id);
139 		return ERR_PTR(-EEXIST);
140 	}
141 
142 	node_data = devm_kzalloc(dev, sizeof(*node_data), GFP_KERNEL);
143 	if (!node_data) {
144 		icc_node_destroy(node->id);
145 		return ERR_PTR(-ENOMEM);
146 	}
147 
148 	node->name = node_desc->name;
149 	node->data = node_data;
150 	node_data->desc = node_desc;
151 	icc_node_add(node, provider);
152 
153 	if (node_desc->adj) {
154 		ret = imx_icc_node_init_qos(provider, node);
155 		if (ret < 0) {
156 			imx_icc_node_destroy(node);
157 			return ERR_PTR(ret);
158 		}
159 	}
160 
161 	return node;
162 }
163 
164 static void imx_icc_unregister_nodes(struct icc_provider *provider)
165 {
166 	struct icc_node *node, *tmp;
167 
168 	list_for_each_entry_safe(node, tmp, &provider->nodes, node_list)
169 		imx_icc_node_destroy(node);
170 }
171 
172 static int imx_icc_register_nodes(struct icc_provider *provider,
173 				  const struct imx_icc_node_desc *descs,
174 				  int count)
175 {
176 	struct icc_onecell_data *provider_data = provider->data;
177 	int ret;
178 	int i;
179 
180 	for (i = 0; i < count; i++) {
181 		struct icc_node *node;
182 		const struct imx_icc_node_desc *node_desc = &descs[i];
183 		size_t j;
184 
185 		node = imx_icc_node_add(provider, node_desc);
186 		if (IS_ERR(node)) {
187 			ret = PTR_ERR(node);
188 			if (ret != -EPROBE_DEFER)
189 				dev_err(provider->dev, "failed to add %s: %d\n",
190 					node_desc->name, ret);
191 			goto err;
192 		}
193 		provider_data->nodes[node->id] = node;
194 
195 		for (j = 0; j < node_desc->num_links; j++) {
196 			ret = icc_link_create(node, node_desc->links[j]);
197 			if (ret) {
198 				dev_err(provider->dev, "failed to link node %d to %d: %d\n",
199 					node->id, node_desc->links[j], ret);
200 				goto err;
201 			}
202 		}
203 	}
204 
205 	return 0;
206 
207 err:
208 	imx_icc_unregister_nodes(provider);
209 
210 	return ret;
211 }
212 
213 static int get_max_node_id(struct imx_icc_node_desc *nodes, int nodes_count)
214 {
215 	int i, ret = 0;
216 
217 	for (i = 0; i < nodes_count; ++i)
218 		if (nodes[i].id > ret)
219 			ret = nodes[i].id;
220 
221 	return ret;
222 }
223 
224 int imx_icc_register(struct platform_device *pdev,
225 		     struct imx_icc_node_desc *nodes, int nodes_count)
226 {
227 	struct device *dev = &pdev->dev;
228 	struct icc_onecell_data *data;
229 	struct icc_provider *provider;
230 	int max_node_id;
231 	int ret;
232 
233 	/* icc_onecell_data is indexed by node_id, unlike nodes param */
234 	max_node_id = get_max_node_id(nodes, nodes_count);
235 	data = devm_kzalloc(dev, struct_size(data, nodes, max_node_id),
236 			    GFP_KERNEL);
237 	if (!data)
238 		return -ENOMEM;
239 	data->num_nodes = max_node_id;
240 
241 	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
242 	if (!provider)
243 		return -ENOMEM;
244 	provider->set = imx_icc_set;
245 	provider->aggregate = icc_std_aggregate;
246 	provider->xlate = of_icc_xlate_onecell;
247 	provider->data = data;
248 	provider->dev = dev->parent;
249 	platform_set_drvdata(pdev, provider);
250 
251 	ret = icc_provider_add(provider);
252 	if (ret) {
253 		dev_err(dev, "error adding interconnect provider: %d\n", ret);
254 		return ret;
255 	}
256 
257 	ret = imx_icc_register_nodes(provider, nodes, nodes_count);
258 	if (ret)
259 		goto provider_del;
260 
261 	return 0;
262 
263 provider_del:
264 	icc_provider_del(provider);
265 	return ret;
266 }
267 EXPORT_SYMBOL_GPL(imx_icc_register);
268 
269 int imx_icc_unregister(struct platform_device *pdev)
270 {
271 	struct icc_provider *provider = platform_get_drvdata(pdev);
272 	int ret;
273 
274 	imx_icc_unregister_nodes(provider);
275 
276 	ret = icc_provider_del(provider);
277 	if (ret)
278 		return ret;
279 
280 	return 0;
281 }
282 EXPORT_SYMBOL_GPL(imx_icc_unregister);
283 
284 MODULE_LICENSE("GPL v2");
285