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