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
zynqmp_pm_get_callback_data(u32 * buf)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
zynqmp_pm_isr(int irq,void * data)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
ipi_receive_callback(struct mbox_client * cl,void * data)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 */
zynqmp_pm_init_suspend_work_fn(struct work_struct * work)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
suspend_mode_show(struct device * dev,struct device_attribute * attr,char * buf)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
suspend_mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
zynqmp_pm_probe(struct platform_device * pdev)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
zynqmp_pm_remove(struct platform_device * pdev)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