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