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
24static 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 */
32struct 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 */
52static 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 */
73static 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 */
104static 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 */
152static 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 */
189static 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
212static 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
241done:
242	if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
243		return ERR_PTR(-ENOENT);
244
245	return genpd_data->domains[i];
246}
247
248static 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
296static 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
303static 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
312static 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};
320module_platform_driver(zynqmp_power_domain_driver);
321
322MODULE_ALIAS("platform:zynqmp_power_controller");
323