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 /* Flag stating if PM nodes mapped to the PM domain has been requested */
24 #define ZYNQMP_PM_DOMAIN_REQUESTED BIT(0)
25
26 static int min_capability;
27
28 /**
29 * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
30 * @gpd: Generic power domain
31 * @node_id: PM node ID corresponding to device inside PM domain
32 * @flags: ZynqMP PM domain flags
33 */
34 struct zynqmp_pm_domain {
35 struct generic_pm_domain gpd;
36 u32 node_id;
37 u8 flags;
38 };
39
40 /**
41 * zynqmp_gpd_is_active_wakeup_path() - Check if device is in wakeup source
42 * path
43 * @dev: Device to check for wakeup source path
44 * @not_used: Data member (not required)
45 *
46 * This function is checks device's child hierarchy and checks if any device is
47 * set as wakeup source.
48 *
49 * Return: 1 if device is in wakeup source path else 0
50 */
zynqmp_gpd_is_active_wakeup_path(struct device * dev,void * not_used)51 static int zynqmp_gpd_is_active_wakeup_path(struct device *dev, void *not_used)
52 {
53 int may_wakeup;
54
55 may_wakeup = device_may_wakeup(dev);
56 if (may_wakeup)
57 return may_wakeup;
58
59 return device_for_each_child(dev, NULL,
60 zynqmp_gpd_is_active_wakeup_path);
61 }
62
63 /**
64 * zynqmp_gpd_power_on() - Power on PM domain
65 * @domain: Generic PM domain
66 *
67 * This function is called before devices inside a PM domain are resumed, to
68 * power on PM domain.
69 *
70 * Return: 0 on success, error code otherwise
71 */
zynqmp_gpd_power_on(struct generic_pm_domain * domain)72 static int zynqmp_gpd_power_on(struct generic_pm_domain *domain)
73 {
74 int ret;
75 struct zynqmp_pm_domain *pd;
76
77 pd = container_of(domain, struct zynqmp_pm_domain, gpd);
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 pr_err("%s() %s set requirement for node %d failed: %d\n",
84 __func__, domain->name, pd->node_id, ret);
85 return ret;
86 }
87
88 pr_debug("%s() Powered on %s domain\n", __func__, domain->name);
89 return 0;
90 }
91
92 /**
93 * zynqmp_gpd_power_off() - Power off PM domain
94 * @domain: Generic PM domain
95 *
96 * This function is called after devices inside a PM domain are suspended, to
97 * power off PM domain.
98 *
99 * Return: 0 on success, error code otherwise
100 */
zynqmp_gpd_power_off(struct generic_pm_domain * domain)101 static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
102 {
103 int ret;
104 struct pm_domain_data *pdd, *tmp;
105 struct zynqmp_pm_domain *pd;
106 u32 capabilities = min_capability;
107 bool may_wakeup;
108
109 pd = container_of(domain, struct zynqmp_pm_domain, gpd);
110
111 /* If domain is already released there is nothing to be done */
112 if (!(pd->flags & ZYNQMP_PM_DOMAIN_REQUESTED)) {
113 pr_debug("%s() %s domain is already released\n",
114 __func__, domain->name);
115 return 0;
116 }
117
118 list_for_each_entry_safe(pdd, tmp, &domain->dev_list, list_node) {
119 /* If device is in wakeup path, set capability to WAKEUP */
120 may_wakeup = zynqmp_gpd_is_active_wakeup_path(pdd->dev, NULL);
121 if (may_wakeup) {
122 dev_dbg(pdd->dev, "device is in wakeup path in %s\n",
123 domain->name);
124 capabilities = ZYNQMP_PM_CAPABILITY_WAKEUP;
125 break;
126 }
127 }
128
129 ret = zynqmp_pm_set_requirement(pd->node_id, capabilities, 0,
130 ZYNQMP_PM_REQUEST_ACK_NO);
131 /**
132 * If powering down of any node inside this domain fails,
133 * report and return the error
134 */
135 if (ret) {
136 pr_err("%s() %s set requirement for node %d failed: %d\n",
137 __func__, domain->name, pd->node_id, ret);
138 return ret;
139 }
140
141 pr_debug("%s() Powered off %s domain\n", __func__, domain->name);
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 int ret;
156 struct zynqmp_pm_domain *pd;
157
158 pd = container_of(domain, struct zynqmp_pm_domain, gpd);
159
160 /* If this is not the first device to attach there is nothing to do */
161 if (domain->device_count)
162 return 0;
163
164 ret = zynqmp_pm_request_node(pd->node_id, 0, 0,
165 ZYNQMP_PM_REQUEST_ACK_BLOCKING);
166 /* If requesting a node fails print and return the error */
167 if (ret) {
168 pr_err("%s() %s request failed for node %d: %d\n",
169 __func__, domain->name, pd->node_id, ret);
170 return ret;
171 }
172
173 pd->flags |= ZYNQMP_PM_DOMAIN_REQUESTED;
174
175 pr_debug("%s() %s attached to %s domain\n", __func__,
176 dev_name(dev), domain->name);
177 return 0;
178 }
179
180 /**
181 * zynqmp_gpd_detach_dev() - Detach device from the PM domain
182 * @domain: Generic PM domain
183 * @dev: Device to detach
184 */
zynqmp_gpd_detach_dev(struct generic_pm_domain * domain,struct device * dev)185 static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
186 struct device *dev)
187 {
188 int ret;
189 struct zynqmp_pm_domain *pd;
190
191 pd = container_of(domain, struct zynqmp_pm_domain, gpd);
192
193 /* If this is not the last device to detach there is nothing to do */
194 if (domain->device_count)
195 return;
196
197 ret = zynqmp_pm_release_node(pd->node_id);
198 /* If releasing a node fails print the error and return */
199 if (ret) {
200 pr_err("%s() %s release failed for node %d: %d\n",
201 __func__, domain->name, pd->node_id, ret);
202 return;
203 }
204
205 pd->flags &= ~ZYNQMP_PM_DOMAIN_REQUESTED;
206
207 pr_debug("%s() %s detached from %s domain\n", __func__,
208 dev_name(dev), domain->name);
209 }
210
zynqmp_gpd_xlate(struct of_phandle_args * genpdspec,void * data)211 static struct generic_pm_domain *zynqmp_gpd_xlate
212 (struct of_phandle_args *genpdspec, void *data)
213 {
214 struct genpd_onecell_data *genpd_data = data;
215 unsigned int i, idx = genpdspec->args[0];
216 struct zynqmp_pm_domain *pd;
217
218 pd = container_of(genpd_data->domains[0], struct zynqmp_pm_domain, gpd);
219
220 if (genpdspec->args_count != 1)
221 return ERR_PTR(-EINVAL);
222
223 /* Check for existing pm domains */
224 for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
225 if (pd[i].node_id == idx)
226 goto done;
227 }
228
229 /**
230 * Add index in empty node_id of power domain list as no existing
231 * power domain found for current index.
232 */
233 for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
234 if (pd[i].node_id == 0) {
235 pd[i].node_id = idx;
236 break;
237 }
238 }
239
240 done:
241 if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
242 return ERR_PTR(-ENOENT);
243
244 return genpd_data->domains[i];
245 }
246
zynqmp_gpd_probe(struct platform_device * pdev)247 static int zynqmp_gpd_probe(struct platform_device *pdev)
248 {
249 int i;
250 struct genpd_onecell_data *zynqmp_pd_data;
251 struct generic_pm_domain **domains;
252 struct zynqmp_pm_domain *pd;
253 struct device *dev = &pdev->dev;
254
255 pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
256 if (!pd)
257 return -ENOMEM;
258
259 zynqmp_pd_data = devm_kzalloc(dev, sizeof(*zynqmp_pd_data), GFP_KERNEL);
260 if (!zynqmp_pd_data)
261 return -ENOMEM;
262
263 zynqmp_pd_data->xlate = zynqmp_gpd_xlate;
264
265 domains = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*domains),
266 GFP_KERNEL);
267 if (!domains)
268 return -ENOMEM;
269
270 if (!of_device_is_compatible(dev->parent->of_node,
271 "xlnx,zynqmp-firmware"))
272 min_capability = ZYNQMP_PM_CAPABILITY_UNUSABLE;
273
274 for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
275 pd->node_id = 0;
276 pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
277 pd->gpd.power_off = zynqmp_gpd_power_off;
278 pd->gpd.power_on = zynqmp_gpd_power_on;
279 pd->gpd.attach_dev = zynqmp_gpd_attach_dev;
280 pd->gpd.detach_dev = zynqmp_gpd_detach_dev;
281
282 domains[i] = &pd->gpd;
283
284 /* Mark all PM domains as initially powered off */
285 pm_genpd_init(&pd->gpd, NULL, true);
286 }
287
288 zynqmp_pd_data->domains = domains;
289 zynqmp_pd_data->num_domains = ZYNQMP_NUM_DOMAINS;
290 of_genpd_add_provider_onecell(dev->parent->of_node, zynqmp_pd_data);
291
292 return 0;
293 }
294
zynqmp_gpd_remove(struct platform_device * pdev)295 static int zynqmp_gpd_remove(struct platform_device *pdev)
296 {
297 of_genpd_del_provider(pdev->dev.parent->of_node);
298
299 return 0;
300 }
301
302 static struct platform_driver zynqmp_power_domain_driver = {
303 .driver = {
304 .name = "zynqmp_power_controller",
305 },
306 .probe = zynqmp_gpd_probe,
307 .remove = zynqmp_gpd_remove,
308 };
309 module_platform_driver(zynqmp_power_domain_driver);
310
311 MODULE_ALIAS("platform:zynqmp_power_controller");
312