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 */
zynqmp_gpd_is_active_wakeup_path(struct device * dev,void * not_used)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 */
zynqmp_gpd_power_on(struct generic_pm_domain * domain)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 */
zynqmp_gpd_power_off(struct generic_pm_domain * domain)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 */
zynqmp_gpd_attach_dev(struct generic_pm_domain * domain,struct device * dev)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 */
zynqmp_gpd_detach_dev(struct generic_pm_domain * domain,struct device * dev)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
zynqmp_gpd_xlate(struct of_phandle_args * genpdspec,void * data)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
zynqmp_gpd_probe(struct platform_device * pdev)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
zynqmp_gpd_remove(struct platform_device * pdev)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
zynqmp_gpd_sync_state(struct device * dev)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