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
zynqmp_pm_get_callback_data(u32 * buf)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
suspend_event_callback(const u32 * payload,void * data)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
zynqmp_pm_isr(int irq,void * data)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
ipi_receive_callback(struct mbox_client * cl,void * data)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 */
zynqmp_pm_init_suspend_work_fn(struct work_struct * work)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
suspend_mode_show(struct device * dev,struct device_attribute * attr,char * buf)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
suspend_mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
zynqmp_pm_probe(struct platform_device * pdev)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_find_property(pdev->dev.of_node, "mboxes", NULL)) {
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_find_property(pdev->dev.of_node, "interrupts", NULL)) {
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
zynqmp_pm_remove(struct platform_device * pdev)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