xref: /openbmc/linux/drivers/interconnect/imx/imx.c (revision 7a2f6f61)
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_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
29 {
30 	*avg = 0;
31 	*peak = 0;
32 
33 	return 0;
34 }
35 
36 static int imx_icc_node_set(struct icc_node *node)
37 {
38 	struct device *dev = node->provider->dev;
39 	struct imx_icc_node *node_data = node->data;
40 	u64 freq;
41 
42 	if (!node_data->qos_dev)
43 		return 0;
44 
45 	freq = (node->avg_bw + node->peak_bw) * node_data->desc->adj->bw_mul;
46 	do_div(freq, node_data->desc->adj->bw_div);
47 	dev_dbg(dev, "node %s device %s avg_bw %ukBps peak_bw %ukBps min_freq %llukHz\n",
48 		node->name, dev_name(node_data->qos_dev),
49 		node->avg_bw, node->peak_bw, freq);
50 
51 	if (freq > S32_MAX) {
52 		dev_err(dev, "%s can't request more than S32_MAX freq\n",
53 				node->name);
54 		return -ERANGE;
55 	}
56 
57 	dev_pm_qos_update_request(&node_data->qos_req, freq);
58 
59 	return 0;
60 }
61 
62 static int imx_icc_set(struct icc_node *src, struct icc_node *dst)
63 {
64 	return imx_icc_node_set(dst);
65 }
66 
67 /* imx_icc_node_destroy() - Destroy an imx icc_node, including private data */
68 static void imx_icc_node_destroy(struct icc_node *node)
69 {
70 	struct imx_icc_node *node_data = node->data;
71 	int ret;
72 
73 	if (dev_pm_qos_request_active(&node_data->qos_req)) {
74 		ret = dev_pm_qos_remove_request(&node_data->qos_req);
75 		if (ret)
76 			dev_warn(node->provider->dev,
77 				 "failed to remove qos request for %s\n",
78 				 dev_name(node_data->qos_dev));
79 	}
80 
81 	put_device(node_data->qos_dev);
82 	icc_node_del(node);
83 	icc_node_destroy(node->id);
84 }
85 
86 static int imx_icc_node_init_qos(struct icc_provider *provider,
87 				 struct icc_node *node)
88 {
89 	struct imx_icc_node *node_data = node->data;
90 	const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
91 	struct device *dev = provider->dev;
92 	struct device_node *dn = NULL;
93 	struct platform_device *pdev;
94 
95 	if (adj->main_noc) {
96 		node_data->qos_dev = dev;
97 		dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
98 			node->name, node->id);
99 	} else {
100 		dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
101 		if (!dn) {
102 			dev_warn(dev, "Failed to parse %s\n",
103 				 adj->phandle_name);
104 			return -ENODEV;
105 		}
106 		/* Allow scaling to be disabled on a per-node basis */
107 		if (!of_device_is_available(dn)) {
108 			dev_warn(dev, "Missing property %s, skip scaling %s\n",
109 				 adj->phandle_name, node->name);
110 			of_node_put(dn);
111 			return 0;
112 		}
113 
114 		pdev = of_find_device_by_node(dn);
115 		of_node_put(dn);
116 		if (!pdev) {
117 			dev_warn(dev, "node %s[%d] missing device for %pOF\n",
118 				 node->name, node->id, dn);
119 			return -EPROBE_DEFER;
120 		}
121 		node_data->qos_dev = &pdev->dev;
122 		dev_dbg(dev, "node %s[%d] has device node %pOF\n",
123 			node->name, node->id, dn);
124 	}
125 
126 	return dev_pm_qos_add_request(node_data->qos_dev,
127 				      &node_data->qos_req,
128 				      DEV_PM_QOS_MIN_FREQUENCY, 0);
129 }
130 
131 static struct icc_node *imx_icc_node_add(struct icc_provider *provider,
132 					 const struct imx_icc_node_desc *node_desc)
133 {
134 	struct device *dev = provider->dev;
135 	struct imx_icc_node *node_data;
136 	struct icc_node *node;
137 	int ret;
138 
139 	node = icc_node_create(node_desc->id);
140 	if (IS_ERR(node)) {
141 		dev_err(dev, "failed to create node %d\n", node_desc->id);
142 		return node;
143 	}
144 
145 	if (node->data) {
146 		dev_err(dev, "already created node %s id=%d\n",
147 			node_desc->name, node_desc->id);
148 		return ERR_PTR(-EEXIST);
149 	}
150 
151 	node_data = devm_kzalloc(dev, sizeof(*node_data), GFP_KERNEL);
152 	if (!node_data) {
153 		icc_node_destroy(node->id);
154 		return ERR_PTR(-ENOMEM);
155 	}
156 
157 	node->name = node_desc->name;
158 	node->data = node_data;
159 	node_data->desc = node_desc;
160 	icc_node_add(node, provider);
161 
162 	if (node_desc->adj) {
163 		ret = imx_icc_node_init_qos(provider, node);
164 		if (ret < 0) {
165 			imx_icc_node_destroy(node);
166 			return ERR_PTR(ret);
167 		}
168 	}
169 
170 	return node;
171 }
172 
173 static void imx_icc_unregister_nodes(struct icc_provider *provider)
174 {
175 	struct icc_node *node, *tmp;
176 
177 	list_for_each_entry_safe(node, tmp, &provider->nodes, node_list)
178 		imx_icc_node_destroy(node);
179 }
180 
181 static int imx_icc_register_nodes(struct icc_provider *provider,
182 				  const struct imx_icc_node_desc *descs,
183 				  int count)
184 {
185 	struct icc_onecell_data *provider_data = provider->data;
186 	int ret;
187 	int i;
188 
189 	for (i = 0; i < count; i++) {
190 		struct icc_node *node;
191 		const struct imx_icc_node_desc *node_desc = &descs[i];
192 		size_t j;
193 
194 		node = imx_icc_node_add(provider, node_desc);
195 		if (IS_ERR(node)) {
196 			ret = dev_err_probe(provider->dev, PTR_ERR(node),
197 					    "failed to add %s\n", node_desc->name);
198 			goto err;
199 		}
200 		provider_data->nodes[node->id] = node;
201 
202 		for (j = 0; j < node_desc->num_links; j++) {
203 			ret = icc_link_create(node, node_desc->links[j]);
204 			if (ret) {
205 				dev_err(provider->dev, "failed to link node %d to %d: %d\n",
206 					node->id, node_desc->links[j], ret);
207 				goto err;
208 			}
209 		}
210 	}
211 
212 	return 0;
213 
214 err:
215 	imx_icc_unregister_nodes(provider);
216 
217 	return ret;
218 }
219 
220 static int get_max_node_id(struct imx_icc_node_desc *nodes, int nodes_count)
221 {
222 	int i, ret = 0;
223 
224 	for (i = 0; i < nodes_count; ++i)
225 		if (nodes[i].id > ret)
226 			ret = nodes[i].id;
227 
228 	return ret;
229 }
230 
231 int imx_icc_register(struct platform_device *pdev,
232 		     struct imx_icc_node_desc *nodes, int nodes_count)
233 {
234 	struct device *dev = &pdev->dev;
235 	struct icc_onecell_data *data;
236 	struct icc_provider *provider;
237 	int max_node_id;
238 	int ret;
239 
240 	/* icc_onecell_data is indexed by node_id, unlike nodes param */
241 	max_node_id = get_max_node_id(nodes, nodes_count);
242 	data = devm_kzalloc(dev, struct_size(data, nodes, max_node_id),
243 			    GFP_KERNEL);
244 	if (!data)
245 		return -ENOMEM;
246 	data->num_nodes = max_node_id;
247 
248 	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
249 	if (!provider)
250 		return -ENOMEM;
251 	provider->set = imx_icc_set;
252 	provider->get_bw = imx_icc_get_bw;
253 	provider->aggregate = icc_std_aggregate;
254 	provider->xlate = of_icc_xlate_onecell;
255 	provider->data = data;
256 	provider->dev = dev->parent;
257 	platform_set_drvdata(pdev, provider);
258 
259 	ret = icc_provider_add(provider);
260 	if (ret) {
261 		dev_err(dev, "error adding interconnect provider: %d\n", ret);
262 		return ret;
263 	}
264 
265 	ret = imx_icc_register_nodes(provider, nodes, nodes_count);
266 	if (ret)
267 		goto provider_del;
268 
269 	return 0;
270 
271 provider_del:
272 	icc_provider_del(provider);
273 	return ret;
274 }
275 EXPORT_SYMBOL_GPL(imx_icc_register);
276 
277 int imx_icc_unregister(struct platform_device *pdev)
278 {
279 	struct icc_provider *provider = platform_get_drvdata(pdev);
280 
281 	imx_icc_unregister_nodes(provider);
282 
283 	return icc_provider_del(provider);
284 }
285 EXPORT_SYMBOL_GPL(imx_icc_unregister);
286 
287 MODULE_LICENSE("GPL v2");
288