zynqmp-pm-domains.c

  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	int ret;
157
158	/* If this is not the first device to attach there is nothing to do */
159	if (domain->device_count)
160		return 0;
161
162	ret = zynqmp_pm_request_node(pd->node_id, 0, 0,
163				     ZYNQMP_PM_REQUEST_ACK_BLOCKING);
164	if (ret) {
165		dev_err(&domain->dev, "%s request failed for node %d: %d\n",
166			domain->name, pd->node_id, ret);
167		return ret;
168	}
169
170	pd->requested = true;
171
172	dev_dbg(&domain->dev, "%s requested PM node id %d\n",
173		dev_name(dev), pd->node_id);
174
175	return 0;
176}
177
178/**
179 * zynqmp_gpd_detach_dev() - Detach device from the PM domain
180 * @domain:	Generic PM domain
181 * @dev:	Device to detach
182 */
183static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
184				  struct device *dev)
185{
186	struct zynqmp_pm_domain *pd = to_zynqmp_pm_domain(domain);
187	int ret;
188
189	/* If this is not the last device to detach there is nothing to do */
190	if (domain->device_count)
191		return;
192
193	ret = zynqmp_pm_release_node(pd->node_id);
194	if (ret) {
195		dev_err(&domain->dev, "failed to release PM node id %d: %d\n",
196			pd->node_id, ret);
197		return;
198	}
199
200	pd->requested = false;
201
202	dev_dbg(&domain->dev, "%s released PM node id %d\n",
203		dev_name(dev), pd->node_id);
204}
205
206static struct generic_pm_domain *zynqmp_gpd_xlate
207				(const struct of_phandle_args *genpdspec, void *data)
208{
209	struct genpd_onecell_data *genpd_data = data;
210	unsigned int i, idx = genpdspec->args[0];
211	struct zynqmp_pm_domain *pd;
212
213	pd = to_zynqmp_pm_domain(genpd_data->domains[0]);
214
215	if (genpdspec->args_count != 1)
216		return ERR_PTR(-EINVAL);
217
218	/* Check for existing pm domains */
219	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
220		if (pd[i].node_id == idx)
221			goto done;
222	}
223
224	/*
225	 * Add index in empty node_id of power domain list as no existing
226	 * power domain found for current index.
227	 */
228	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++) {
229		if (pd[i].node_id == 0) {
230			pd[i].node_id = idx;
231			break;
232		}
233	}
234
235done:
236	if (!genpd_data->domains[i] || i == ZYNQMP_NUM_DOMAINS)
237		return ERR_PTR(-ENOENT);
238
239	return genpd_data->domains[i];
240}
241
242static int zynqmp_gpd_probe(struct platform_device *pdev)
243{
244	int i;
245	struct genpd_onecell_data *zynqmp_pd_data;
246	struct generic_pm_domain **domains;
247	struct zynqmp_pm_domain *pd;
248	struct device *dev = &pdev->dev;
249
250	pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
251	if (!pd)
252		return -ENOMEM;
253
254	zynqmp_pd_data = devm_kzalloc(dev, sizeof(*zynqmp_pd_data), GFP_KERNEL);
255	if (!zynqmp_pd_data)
256		return -ENOMEM;
257
258	zynqmp_pd_data->xlate = zynqmp_gpd_xlate;
259
260	domains = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*domains),
261			       GFP_KERNEL);
262	if (!domains)
263		return -ENOMEM;
264
265	if (!of_device_is_compatible(dev->parent->of_node,
266				     "xlnx,zynqmp-firmware"))
267		min_capability = ZYNQMP_PM_CAPABILITY_UNUSABLE;
268
269	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
270		pd->node_id = 0;
271		pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
272		pd->gpd.power_off = zynqmp_gpd_power_off;
273		pd->gpd.power_on = zynqmp_gpd_power_on;
274		pd->gpd.attach_dev = zynqmp_gpd_attach_dev;
275		pd->gpd.detach_dev = zynqmp_gpd_detach_dev;
276
277		domains[i] = &pd->gpd;
278
279		/* Mark all PM domains as initially powered off */
280		pm_genpd_init(&pd->gpd, NULL, true);
281	}
282
283	zynqmp_pd_data->domains = domains;
284	zynqmp_pd_data->num_domains = ZYNQMP_NUM_DOMAINS;
285	of_genpd_add_provider_onecell(dev->parent->of_node, zynqmp_pd_data);
286
287	return 0;
288}
289
290static void zynqmp_gpd_remove(struct platform_device *pdev)
291{
292	of_genpd_del_provider(pdev->dev.parent->of_node);
293}
294
295static struct platform_driver zynqmp_power_domain_driver = {
296	.driver	= {
297		.name = "zynqmp_power_controller",
298	},
299	.probe = zynqmp_gpd_probe,
300	.remove = zynqmp_gpd_remove,
301};
302module_platform_driver(zynqmp_power_domain_driver);
303
304MODULE_ALIAS("platform:zynqmp_power_controller");