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  */
28 struct zynqmp_pm_work_struct {
29 	struct work_struct callback_work;
30 	u32 args[CB_ARG_CNT];
31 };
32 
33 static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
34 static struct mbox_chan *rx_chan;
35 static bool event_registered;
36 
37 enum 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 
45 static const char *const suspend_modes[] = {
46 	[PM_SUSPEND_MODE_STD] = "standard",
47 	[PM_SUSPEND_MODE_POWER_OFF] = "power-off",
48 };
49 
50 static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
51 
52 static void zynqmp_pm_get_callback_data(u32 *buf)
53 {
54 	zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
55 }
56 
57 static 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 
70 static 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 
94 static 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  */
126 static 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 
141 static 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 
161 static 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 
183 static DEVICE_ATTR_RW(suspend_mode);
184 
185 static 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 
278 static 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 
290 static const struct of_device_id pm_of_match[] = {
291 	{ .compatible = "xlnx,zynqmp-power", },
292 	{ /* end of table */ },
293 };
294 MODULE_DEVICE_TABLE(of, pm_of_match);
295 
296 static 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 };
304 module_platform_driver(zynqmp_pm_platform_driver);
305