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
zynqmp_pm_get_callback_data(u32 * buf)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
suspend_event_callback(const u32 * payload,void * data)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
zynqmp_pm_isr(int irq,void * data)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
ipi_receive_callback(struct mbox_client * cl,void * data)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 */
zynqmp_pm_init_suspend_work_fn(struct work_struct * work)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
suspend_mode_show(struct device * dev,struct device_attribute * attr,char * buf)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
suspend_mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
zynqmp_pm_probe(struct platform_device * pdev)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 ret = zynqmp_pm_get_api_version(&pm_api_version);
192 if (ret)
193 return ret;
194
195 /* Check PM API version number */
196 if (pm_api_version < ZYNQMP_PM_VERSION)
197 return -ENODEV;
198
199 /*
200 * First try to use Xilinx Event Manager by registering suspend_event_callback
201 * for suspend/shutdown event.
202 * If xlnx_register_event() returns -EACCES (Xilinx Event Manager
203 * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
204 * then use ipi-mailbox or interrupt method.
205 */
206 ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
207 suspend_event_callback, NULL);
208 if (!ret) {
209 zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
210 sizeof(struct zynqmp_pm_work_struct),
211 GFP_KERNEL);
212 if (!zynqmp_pm_init_suspend_work) {
213 xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
214 suspend_event_callback, NULL);
215 return -ENOMEM;
216 }
217 event_registered = true;
218
219 INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
220 zynqmp_pm_init_suspend_work_fn);
221 } else if (ret != -EACCES && ret != -ENODEV) {
222 dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
223 return ret;
224 } else if (of_property_present(pdev->dev.of_node, "mboxes")) {
225 zynqmp_pm_init_suspend_work =
226 devm_kzalloc(&pdev->dev,
227 sizeof(struct zynqmp_pm_work_struct),
228 GFP_KERNEL);
229 if (!zynqmp_pm_init_suspend_work)
230 return -ENOMEM;
231
232 INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
233 zynqmp_pm_init_suspend_work_fn);
234 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
235 if (!client)
236 return -ENOMEM;
237
238 client->dev = &pdev->dev;
239 client->rx_callback = ipi_receive_callback;
240
241 rx_chan = mbox_request_channel_byname(client, "rx");
242 if (IS_ERR(rx_chan)) {
243 dev_err(&pdev->dev, "Failed to request rx channel\n");
244 return PTR_ERR(rx_chan);
245 }
246 } else if (of_property_present(pdev->dev.of_node, "interrupts")) {
247 irq = platform_get_irq(pdev, 0);
248 if (irq < 0)
249 return irq;
250
251 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
252 zynqmp_pm_isr,
253 IRQF_NO_SUSPEND | IRQF_ONESHOT,
254 dev_name(&pdev->dev),
255 &pdev->dev);
256 if (ret) {
257 dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
258 "failed with %d\n", irq, ret);
259 return ret;
260 }
261 } else {
262 dev_err(&pdev->dev, "Required property not found in DT node\n");
263 return -ENOENT;
264 }
265
266 ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
267 if (ret) {
268 if (event_registered) {
269 xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback,
270 NULL);
271 event_registered = false;
272 }
273 dev_err(&pdev->dev, "unable to create sysfs interface\n");
274 return ret;
275 }
276
277 return 0;
278 }
279
zynqmp_pm_remove(struct platform_device * pdev)280 static int zynqmp_pm_remove(struct platform_device *pdev)
281 {
282 sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
283 if (event_registered)
284 xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);
285
286 if (!rx_chan)
287 mbox_free_channel(rx_chan);
288
289 return 0;
290 }
291
292 static const struct of_device_id pm_of_match[] = {
293 { .compatible = "xlnx,zynqmp-power", },
294 { /* end of table */ },
295 };
296 MODULE_DEVICE_TABLE(of, pm_of_match);
297
298 static struct platform_driver zynqmp_pm_platform_driver = {
299 .probe = zynqmp_pm_probe,
300 .remove = zynqmp_pm_remove,
301 .driver = {
302 .name = "zynqmp_power",
303 .of_match_table = pm_of_match,
304 },
305 };
306 module_platform_driver(zynqmp_pm_platform_driver);
307