1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ZynqMP Generic PM domain support
4  *
5  *  Copyright (C) 2015-2019 Xilinx, Inc.
6  *
7  *  Davorin Mista <davorin.mista@aggios.com>
8  *  Jolly Shah <jollys@xilinx.com>
9  *  Rajan Vaja <rajan.vaja@xilinx.com>
10  */
11 
12 #include <linux/err.h>
13 #include <linux/list.h>
14 #include <linux/module.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_domain.h>
18 #include <linux/slab.h>
19 
20 #include <linux/firmware/xlnx-zynqmp.h>
21 
22 #define ZYNQMP_NUM_DOMAINS		(100)
23 
24 static int min_capability;
25 
26 /**
27  * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
28  * @gpd:		Generic power domain
29  * @node_id:		PM node ID corresponding to device inside PM domain
30  * @requested:		The PM node mapped to the PM domain has been requested
31  */
32 struct zynqmp_pm_domain {
33 	struct generic_pm_domain gpd;
34 	u32 node_id;
35 	bool requested;
36 };
37 
38 #define to_zynqmp_pm_domain(pm_domain) \
39 	container_of(pm_domain, struct zynqmp_pm_domain, gpd)
40 
41 /**
42  * zynqmp_gpd_is_active_wakeup_path() - Check if device is in wakeup source
43  *					path
44  * @dev:	Device to check for wakeup source path
45  * @not_used:	Data member (not required)
46  *
47  * This function is checks device's child hierarchy and checks if any device is
48  * set as wakeup source.
49  *
50  * Return: 1 if device is in wakeup source path else 0
51  */
52 static int zynqmp_gpd_is_active_wakeup_path(struct device *dev, void *not_used)
53 {
54 	int may_wakeup;
55 
56 	may_wakeup = device_may_wakeup(dev);
57 	if (may_wakeup)
58 		return may_wakeup;
59 
60 	return device_for_each_child(dev, NULL,
61 			zynqmp_gpd_is_active_wakeup_path);
62 }
63 
64 /**
65  * zynqmp_gpd_power_on() - Power on PM domain
66  * @domain:	Generic PM domain
67  *
68  * This function is called before devices inside a PM domain are resumed, to
69  * power on PM domain.
70  *
71  * Return: 0 on success, error code otherwise
72  */
73 static int zynqmp_gpd_power_on(struct generic_pm_domain *domain)
74 {
75 	struct zynqmp_pm_domain *pd = to_zynqmp_pm_domain(domain);
76 	int ret;
77 
78 	ret = zynqmp_pm_set_requirement(pd->node_id,
79 					ZYNQMP_PM_CAPABILITY_ACCESS,
80 					ZYNQMP_PM_MAX_QOS,
81 					ZYNQMP_PM_REQUEST_ACK_BLOCKING);
82 	if (ret) {
83 		dev_err(&domain->dev,
84 			"failed to set requirement to 0x%x for PM node id %d: %d\n",
85 			ZYNQMP_PM_CAPABILITY_ACCESS, pd->node_id, ret);
86 		return ret;
87 	}
88 
89 	dev_dbg(&domain->dev, "set requirement to 0x%x for PM node id %d\n",
90 		ZYNQMP_PM_CAPABILITY_ACCESS, pd->node_id);
91 
92 	return 0;
93 }
94 
95 /**
96  * zynqmp_gpd_power_off() - Power off PM domain
97  * @domain:	Generic PM domain
98  *
99  * This function is called after devices inside a PM domain are suspended, to
100  * power off PM domain.
101  *
102  * Return: 0 on success, error code otherwise
103  */
104 static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
105 {
106 	struct zynqmp_pm_domain *pd = to_zynqmp_pm_domain(domain);
107 	int ret;
108 	struct pm_domain_data *pdd, *tmp;
109 	u32 capabilities = min_capability;
110 	bool may_wakeup;
111 
112 	/* If domain is already released there is nothing to be done */
113 	if (!pd->requested) {
114 		dev_dbg(&domain->dev, "PM node id %d is already released\n",
115 			pd->node_id);
116 		return 0;
117 	}
118 
119 	list_for_each_entry_safe(pdd, tmp, &domain->dev_list, list_node) {
120 		/* If device is in wakeup path, set capability to WAKEUP */
121 		may_wakeup = zynqmp_gpd_is_active_wakeup_path(pdd->dev, NULL);
122 		if (may_wakeup) {
123 			dev_dbg(pdd->dev, "device is in wakeup path in %s\n",
124 				domain->name);
125 			capabilities = ZYNQMP_PM_CAPABILITY_WAKEUP;
126 			break;
127 		}
128 	}
129 
130 	ret = zynqmp_pm_set_requirement(pd->node_id, capabilities, 0,
131 					ZYNQMP_PM_REQUEST_ACK_NO);
132 	if (ret) {
133 		dev_err(&domain->dev,
134 			"failed to set requirement to 0x%x for PM node id %d: %d\n",
135 			capabilities, pd->node_id, ret);
136 		return ret;
137 	}
138 
139 	dev_dbg(&domain->dev, "set requirement to 0x%x for PM node id %d\n",
140 		capabilities, pd->node_id);
141 
142 	return 0;
143 }
144 
145 /**
146  * zynqmp_gpd_attach_dev() - Attach device to the PM domain
147  * @domain:	Generic PM domain
148  * @dev:	Device to attach
149  *
150  * Return: 0 on success, error code otherwise
151  */
152 static int zynqmp_gpd_attach_dev(struct generic_pm_domain *domain,
153 				 struct device *dev)
154 {
155 	struct zynqmp_pm_domain *pd = to_zynqmp_pm_domain(domain);
156 	struct device_link *link;
157 	int ret;
158 
159 	link = device_link_add(dev, &domain->dev, DL_FLAG_SYNC_STATE_ONLY);
160 	if (!link)
161 		dev_dbg(&domain->dev, "failed to create device link for %s\n",
162 			dev_name(dev));
163 
164 	/* If this is not the first device to attach there is nothing to do */
165 	if (domain->device_count)
166 		return 0;
167 
168 	ret = zynqmp_pm_request_node(pd->node_id, 0, 0,
169 				     ZYNQMP_PM_REQUEST_ACK_BLOCKING);
170 	if (ret) {
171 		dev_err(&domain->dev, "%s request failed for node %d: %d\n",
172 			domain->name, pd->node_id, ret);
173 		return ret;
174 	}
175 
176 	pd->requested = true;
177 
178 	dev_dbg(&domain->dev, "%s requested PM node id %d\n",
179 		dev_name(dev), pd->node_id);
180 
181 	return 0;
182 }
183 
184 /**
185  * zynqmp_gpd_detach_dev() - Detach device from the PM domain
186  * @domain:	Generic PM domain
187  * @dev:	Device to detach
188  */
189 static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
190 				  struct device *dev)
191 {
192 	struct zynqmp_pm_domain *pd = to_zynqmp_pm_domain(domain);
193 	int ret;
194 
195 	/* If this is not the last device to detach there is nothing to do */
196 	if (domain->device_count)
197 		return;
198 
199 	ret = zynqmp_pm_release_node(pd->node_id);
200 	if (ret) {
201 		dev_err(&domain->dev, "failed to release PM node id %d: %d\n",
202 			pd->node_id, ret);
203 		return;
204 	}
205 
206 	pd->requested = false;
207 
208 	dev_dbg(&domain->dev, "%s released PM node id %d\n",
209 		dev_name(dev), pd->node_id);
210 }
211 
212 static struct generic_pm_domain *zynqmp_gpd_xlate
213 				(struct of_phandle_args *genpdspec, void *data)
214 {
215 	struct genpd_onecell_data *genpd_data = data;
216 	unsigned int i, idx = genpdspec->args[0];
217 	struct zynqmp_pm_domain *pd;
218 
219 	pd = to_zynqmp_pm_domain(genpd_data->domains[0]);
220 
221 	if (genpdspec->args_count != 1)
222 		return ERR_PTR(-EINVAL);
223 
224 	/* Check for existing pm domains */
225 	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
226 		if (pd[i].node_id == idx)
227 			goto done;
228 	}
229 
230 	/*
231 	 * Add index in empty node_id of power domain list as no existing
232 	 * power domain found for current index.
233 	 */
234 	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
235 		if (pd[i].node_id == 0) {
236 			pd[i].node_id = idx;
237 			break;
238 		}
239 	}
240 
241 done:
242 	if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
243 		return ERR_PTR(-ENOENT);
244 
245 	return genpd_data->domains[i];
246 }
247 
248 static int zynqmp_gpd_probe(struct platform_device *pdev)
249 {
250 	int i;
251 	struct genpd_onecell_data *zynqmp_pd_data;
252 	struct generic_pm_domain **domains;
253 	struct zynqmp_pm_domain *pd;
254 	struct device *dev = &pdev->dev;
255 
256 	pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
257 	if (!pd)
258 		return -ENOMEM;
259 
260 	zynqmp_pd_data = devm_kzalloc(dev, sizeof(*zynqmp_pd_data), GFP_KERNEL);
261 	if (!zynqmp_pd_data)
262 		return -ENOMEM;
263 
264 	zynqmp_pd_data->xlate = zynqmp_gpd_xlate;
265 
266 	domains = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*domains),
267 			       GFP_KERNEL);
268 	if (!domains)
269 		return -ENOMEM;
270 
271 	if (!of_device_is_compatible(dev->parent->of_node,
272 				     "xlnx,zynqmp-firmware"))
273 		min_capability = ZYNQMP_PM_CAPABILITY_UNUSABLE;
274 
275 	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
276 		pd->node_id = 0;
277 		pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
278 		pd->gpd.power_off = zynqmp_gpd_power_off;
279 		pd->gpd.power_on = zynqmp_gpd_power_on;
280 		pd->gpd.attach_dev = zynqmp_gpd_attach_dev;
281 		pd->gpd.detach_dev = zynqmp_gpd_detach_dev;
282 
283 		domains[i] = &pd->gpd;
284 
285 		/* Mark all PM domains as initially powered off */
286 		pm_genpd_init(&pd->gpd, NULL, true);
287 	}
288 
289 	zynqmp_pd_data->domains = domains;
290 	zynqmp_pd_data->num_domains = ZYNQMP_NUM_DOMAINS;
291 	of_genpd_add_provider_onecell(dev->parent->of_node, zynqmp_pd_data);
292 
293 	return 0;
294 }
295 
296 static int zynqmp_gpd_remove(struct platform_device *pdev)
297 {
298 	of_genpd_del_provider(pdev->dev.parent->of_node);
299 
300 	return 0;
301 }
302 
303 static void zynqmp_gpd_sync_state(struct device *dev)
304 {
305 	int ret;
306 
307 	ret = zynqmp_pm_init_finalize();
308 	if (ret)
309 		dev_warn(dev, "failed to release power management to firmware\n");
310 }
311 
312 static struct platform_driver zynqmp_power_domain_driver = {
313 	.driver	= {
314 		.name = "zynqmp_power_controller",
315 		.sync_state = zynqmp_gpd_sync_state,
316 	},
317 	.probe = zynqmp_gpd_probe,
318 	.remove = zynqmp_gpd_remove,
319 };
320 module_platform_driver(zynqmp_power_domain_driver);
321 
322 MODULE_ALIAS("platform:zynqmp_power_controller");
323