1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Xilinx Zynq MPSoC Power Management
4 *
5 *  Copyright (C) 2014-2019 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/mailbox_client.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/reboot.h>
17#include <linux/suspend.h>
18
19#include <linux/firmware/xlnx-zynqmp.h>
20#include <linux/firmware/xlnx-event-manager.h>
21#include <linux/mailbox/zynqmp-ipi-message.h>
22
23/**
24 * struct zynqmp_pm_work_struct - Wrapper for struct work_struct
25 * @callback_work:	Work structure
26 * @args:		Callback arguments
27 */
28struct zynqmp_pm_work_struct {
29	struct work_struct callback_work;
30	u32 args[CB_ARG_CNT];
31};
32
33static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
34static struct mbox_chan *rx_chan;
35static bool event_registered;
36
37enum pm_suspend_mode {
38	PM_SUSPEND_MODE_FIRST = 0,
39	PM_SUSPEND_MODE_STD = PM_SUSPEND_MODE_FIRST,
40	PM_SUSPEND_MODE_POWER_OFF,
41};
42
43#define PM_SUSPEND_MODE_FIRST	PM_SUSPEND_MODE_STD
44
45static const char *const suspend_modes[] = {
46	[PM_SUSPEND_MODE_STD] = "standard",
47	[PM_SUSPEND_MODE_POWER_OFF] = "power-off",
48};
49
50static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
51
52static void zynqmp_pm_get_callback_data(u32 *buf)
53{
54	zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
55}
56
57static void suspend_event_callback(const u32 *payload, void *data)
58{
59	/* First element is callback API ID, others are callback arguments */
60	if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
61		return;
62
63	/* Copy callback arguments into work's structure */
64	memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
65	       sizeof(zynqmp_pm_init_suspend_work->args));
66
67	queue_work(system_unbound_wq, &zynqmp_pm_init_suspend_work->callback_work);
68}
69
70static irqreturn_t zynqmp_pm_isr(int irq, void *data)
71{
72	u32 payload[CB_PAYLOAD_SIZE];
73
74	zynqmp_pm_get_callback_data(payload);
75
76	/* First element is callback API ID, others are callback arguments */
77	if (payload[0] == PM_INIT_SUSPEND_CB) {
78		switch (payload[1]) {
79		case SUSPEND_SYSTEM_SHUTDOWN:
80			orderly_poweroff(true);
81			break;
82		case SUSPEND_POWER_REQUEST:
83			pm_suspend(PM_SUSPEND_MEM);
84			break;
85		default:
86			pr_err("%s Unsupported InitSuspendCb reason "
87				"code %d\n", __func__, payload[1]);
88		}
89	}
90
91	return IRQ_HANDLED;
92}
93
94static void ipi_receive_callback(struct mbox_client *cl, void *data)
95{
96	struct zynqmp_ipi_message *msg = (struct zynqmp_ipi_message *)data;
97	u32 payload[CB_PAYLOAD_SIZE];
98	int ret;
99
100	memcpy(payload, msg->data, sizeof(msg->len));
101	/* First element is callback API ID, others are callback arguments */
102	if (payload[0] == PM_INIT_SUSPEND_CB) {
103		if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
104			return;
105
106		/* Copy callback arguments into work's structure */
107		memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
108		       sizeof(zynqmp_pm_init_suspend_work->args));
109
110		queue_work(system_unbound_wq,
111			   &zynqmp_pm_init_suspend_work->callback_work);
112
113		/* Send NULL message to mbox controller to ack the message */
114		ret = mbox_send_message(rx_chan, NULL);
115		if (ret)
116			pr_err("IPI ack failed. Error %d\n", ret);
117	}
118}
119
120/**
121 * zynqmp_pm_init_suspend_work_fn - Initialize suspend
122 * @work:	Pointer to work_struct
123 *
124 * Bottom-half of PM callback IRQ handler.
125 */
126static void zynqmp_pm_init_suspend_work_fn(struct work_struct *work)
127{
128	struct zynqmp_pm_work_struct *pm_work =
129		container_of(work, struct zynqmp_pm_work_struct, callback_work);
130
131	if (pm_work->args[0] == SUSPEND_SYSTEM_SHUTDOWN) {
132		orderly_poweroff(true);
133	} else if (pm_work->args[0] == SUSPEND_POWER_REQUEST) {
134		pm_suspend(PM_SUSPEND_MEM);
135	} else {
136		pr_err("%s Unsupported InitSuspendCb reason code %d.\n",
137		       __func__, pm_work->args[0]);
138	}
139}
140
141static ssize_t suspend_mode_show(struct device *dev,
142				 struct device_attribute *attr, char *buf)
143{
144	char *s = buf;
145	int md;
146
147	for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
148		if (suspend_modes[md]) {
149			if (md == suspend_mode)
150				s += sprintf(s, "[%s] ", suspend_modes[md]);
151			else
152				s += sprintf(s, "%s ", suspend_modes[md]);
153		}
154
155	/* Convert last space to newline */
156	if (s != buf)
157		*(s - 1) = '\n';
158	return (s - buf);
159}
160
161static ssize_t suspend_mode_store(struct device *dev,
162				  struct device_attribute *attr,
163				  const char *buf, size_t count)
164{
165	int md, ret = -EINVAL;
166
167	for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
168		if (suspend_modes[md] &&
169		    sysfs_streq(suspend_modes[md], buf)) {
170			ret = 0;
171			break;
172		}
173
174	if (!ret && md != suspend_mode) {
175		ret = zynqmp_pm_set_suspend_mode(md);
176		if (likely(!ret))
177			suspend_mode = md;
178	}
179
180	return ret ? ret : count;
181}
182
183static DEVICE_ATTR_RW(suspend_mode);
184
185static int zynqmp_pm_probe(struct platform_device *pdev)
186{
187	int ret, irq;
188	u32 pm_api_version;
189	struct mbox_client *client;
190
191	zynqmp_pm_get_api_version(&pm_api_version);
192
193	/* Check PM API version number */
194	if (pm_api_version < ZYNQMP_PM_VERSION)
195		return -ENODEV;
196
197	/*
198	 * First try to use Xilinx Event Manager by registering suspend_event_callback
199	 * for suspend/shutdown event.
200	 * If xlnx_register_event() returns -EACCES (Xilinx Event Manager
201	 * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
202	 * then use ipi-mailbox or interrupt method.
203	 */
204	ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
205				  suspend_event_callback, NULL);
206	if (!ret) {
207		zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
208							   sizeof(struct zynqmp_pm_work_struct),
209							   GFP_KERNEL);
210		if (!zynqmp_pm_init_suspend_work) {
211			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
212					      suspend_event_callback, NULL);
213			return -ENOMEM;
214		}
215		event_registered = true;
216
217		INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
218			  zynqmp_pm_init_suspend_work_fn);
219	} else if (ret != -EACCES && ret != -ENODEV) {
220		dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
221		return ret;
222	} else if (of_property_present(pdev->dev.of_node, "mboxes")) {
223		zynqmp_pm_init_suspend_work =
224			devm_kzalloc(&pdev->dev,
225				     sizeof(struct zynqmp_pm_work_struct),
226				     GFP_KERNEL);
227		if (!zynqmp_pm_init_suspend_work)
228			return -ENOMEM;
229
230		INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
231			  zynqmp_pm_init_suspend_work_fn);
232		client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
233		if (!client)
234			return -ENOMEM;
235
236		client->dev = &pdev->dev;
237		client->rx_callback = ipi_receive_callback;
238
239		rx_chan = mbox_request_channel_byname(client, "rx");
240		if (IS_ERR(rx_chan)) {
241			dev_err(&pdev->dev, "Failed to request rx channel\n");
242			return PTR_ERR(rx_chan);
243		}
244	} else if (of_property_present(pdev->dev.of_node, "interrupts")) {
245		irq = platform_get_irq(pdev, 0);
246		if (irq < 0)
247			return irq;
248
249		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
250						zynqmp_pm_isr,
251						IRQF_NO_SUSPEND | IRQF_ONESHOT,
252						dev_name(&pdev->dev),
253						&pdev->dev);
254		if (ret) {
255			dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
256					    "failed with %d\n", irq, ret);
257			return ret;
258		}
259	} else {
260		dev_err(&pdev->dev, "Required property not found in DT node\n");
261		return -ENOENT;
262	}
263
264	ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
265	if (ret) {
266		if (event_registered) {
267			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback,
268					      NULL);
269			event_registered = false;
270		}
271		dev_err(&pdev->dev, "unable to create sysfs interface\n");
272		return ret;
273	}
274
275	return 0;
276}
277
278static int zynqmp_pm_remove(struct platform_device *pdev)
279{
280	sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
281	if (event_registered)
282		xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);
283
284	if (!rx_chan)
285		mbox_free_channel(rx_chan);
286
287	return 0;
288}
289
290static const struct of_device_id pm_of_match[] = {
291	{ .compatible = "xlnx,zynqmp-power", },
292	{ /* end of table */ },
293};
294MODULE_DEVICE_TABLE(of, pm_of_match);
295
296static struct platform_driver zynqmp_pm_platform_driver = {
297	.probe = zynqmp_pm_probe,
298	.remove = zynqmp_pm_remove,
299	.driver = {
300		.name = "zynqmp_power",
301		.of_match_table = pm_of_match,
302	},
303};
304module_platform_driver(zynqmp_pm_platform_driver);
305