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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pmi driver
4 *
5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
6 *
7 * PMI (Platform Management Interrupt) is a way to communicate
8 * with the BMC (Baseboard Management Controller) via interrupts.
9 * Unlike IPMI it is bidirectional and has a low latency.
10 *
11 * Author: Christian Krafft <krafft@de.ibm.com>
12 */
13
14#include <linux/interrupt.h>
15#include <linux/slab.h>
16#include <linux/completion.h>
17#include <linux/spinlock.h>
18#include <linux/module.h>
19#include <linux/mod_devicetable.h>
20#include <linux/workqueue.h>
21#include <linux/of_address.h>
22#include <linux/of_irq.h>
23#include <linux/platform_device.h>
24
25#include <asm/io.h>
26#include <asm/pmi.h>
27
28struct pmi_data {
29 struct list_head handler;
30 spinlock_t handler_spinlock;
31 spinlock_t pmi_spinlock;
32 struct mutex msg_mutex;
33 pmi_message_t msg;
34 struct completion *completion;
35 struct platform_device *dev;
36 int irq;
37 u8 __iomem *pmi_reg;
38 struct work_struct work;
39};
40
41static struct pmi_data *data;
42
43static irqreturn_t pmi_irq_handler(int irq, void *dev_id)
44{
45 u8 type;
46 int rc;
47
48 spin_lock(&data->pmi_spinlock);
49
50 type = ioread8(data->pmi_reg + PMI_READ_TYPE);
51 pr_debug("pmi: got message of type %d\n", type);
52
53 if (type & PMI_ACK && !data->completion) {
54 printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
55 rc = -EIO;
56 goto unlock;
57 }
58
59 if (data->completion && !(type & PMI_ACK)) {
60 printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
61 rc = -EIO;
62 goto unlock;
63 }
64
65 data->msg.type = type;
66 data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
67 data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
68 data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
69 rc = 0;
70unlock:
71 spin_unlock(&data->pmi_spinlock);
72
73 if (rc == -EIO) {
74 rc = IRQ_HANDLED;
75 goto out;
76 }
77
78 if (data->msg.type & PMI_ACK) {
79 complete(data->completion);
80 rc = IRQ_HANDLED;
81 goto out;
82 }
83
84 schedule_work(&data->work);
85
86 rc = IRQ_HANDLED;
87out:
88 return rc;
89}
90
91
92static const struct of_device_id pmi_match[] = {
93 { .type = "ibm,pmi", .name = "ibm,pmi" },
94 { .type = "ibm,pmi" },
95 {},
96};
97
98MODULE_DEVICE_TABLE(of, pmi_match);
99
100static void pmi_notify_handlers(struct work_struct *work)
101{
102 struct pmi_handler *handler;
103
104 spin_lock(&data->handler_spinlock);
105 list_for_each_entry(handler, &data->handler, node) {
106 pr_debug("pmi: notifying handler %p\n", handler);
107 if (handler->type == data->msg.type)
108 handler->handle_pmi_message(data->msg);
109 }
110 spin_unlock(&data->handler_spinlock);
111}
112
113static int pmi_of_probe(struct platform_device *dev)
114{
115 struct device_node *np = dev->dev.of_node;
116 int rc;
117
118 if (data) {
119 printk(KERN_ERR "pmi: driver has already been initialized.\n");
120 rc = -EBUSY;
121 goto out;
122 }
123
124 data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
125 if (!data) {
126 printk(KERN_ERR "pmi: could not allocate memory.\n");
127 rc = -ENOMEM;
128 goto out;
129 }
130
131 data->pmi_reg = of_iomap(np, 0);
132 if (!data->pmi_reg) {
133 printk(KERN_ERR "pmi: invalid register address.\n");
134 rc = -EFAULT;
135 goto error_cleanup_data;
136 }
137
138 INIT_LIST_HEAD(&data->handler);
139
140 mutex_init(&data->msg_mutex);
141 spin_lock_init(&data->pmi_spinlock);
142 spin_lock_init(&data->handler_spinlock);
143
144 INIT_WORK(&data->work, pmi_notify_handlers);
145
146 data->dev = dev;
147
148 data->irq = irq_of_parse_and_map(np, 0);
149 if (!data->irq) {
150 printk(KERN_ERR "pmi: invalid interrupt.\n");
151 rc = -EFAULT;
152 goto error_cleanup_iomap;
153 }
154
155 rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL);
156 if (rc) {
157 printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
158 data->irq, rc);
159 goto error_cleanup_iomap;
160 }
161
162 printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
163
164 goto out;
165
166error_cleanup_iomap:
167 iounmap(data->pmi_reg);
168
169error_cleanup_data:
170 kfree(data);
171
172out:
173 return rc;
174}
175
176static int pmi_of_remove(struct platform_device *dev)
177{
178 struct pmi_handler *handler, *tmp;
179
180 free_irq(data->irq, NULL);
181 iounmap(data->pmi_reg);
182
183 spin_lock(&data->handler_spinlock);
184
185 list_for_each_entry_safe(handler, tmp, &data->handler, node)
186 list_del(&handler->node);
187
188 spin_unlock(&data->handler_spinlock);
189
190 kfree(data);
191 data = NULL;
192
193 return 0;
194}
195
196static struct platform_driver pmi_of_platform_driver = {
197 .probe = pmi_of_probe,
198 .remove = pmi_of_remove,
199 .driver = {
200 .name = "pmi",
201 .of_match_table = pmi_match,
202 },
203};
204module_platform_driver(pmi_of_platform_driver);
205
206int pmi_send_message(pmi_message_t msg)
207{
208 unsigned long flags;
209 DECLARE_COMPLETION_ONSTACK(completion);
210
211 if (!data)
212 return -ENODEV;
213
214 mutex_lock(&data->msg_mutex);
215
216 data->msg = msg;
217 pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg);
218
219 data->completion = &completion;
220
221 spin_lock_irqsave(&data->pmi_spinlock, flags);
222 iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
223 iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
224 iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
225 iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
226 spin_unlock_irqrestore(&data->pmi_spinlock, flags);
227
228 pr_debug("pmi_send_message: wait for completion\n");
229
230 wait_for_completion_interruptible_timeout(data->completion,
231 PMI_TIMEOUT);
232
233 data->completion = NULL;
234
235 mutex_unlock(&data->msg_mutex);
236
237 return 0;
238}
239EXPORT_SYMBOL_GPL(pmi_send_message);
240
241int pmi_register_handler(struct pmi_handler *handler)
242{
243 if (!data)
244 return -ENODEV;
245
246 spin_lock(&data->handler_spinlock);
247 list_add_tail(&handler->node, &data->handler);
248 spin_unlock(&data->handler_spinlock);
249
250 return 0;
251}
252EXPORT_SYMBOL_GPL(pmi_register_handler);
253
254void pmi_unregister_handler(struct pmi_handler *handler)
255{
256 if (!data)
257 return;
258
259 pr_debug("pmi: unregistering handler %p\n", handler);
260
261 spin_lock(&data->handler_spinlock);
262 list_del(&handler->node);
263 spin_unlock(&data->handler_spinlock);
264}
265EXPORT_SYMBOL_GPL(pmi_unregister_handler);
266
267MODULE_LICENSE("GPL");
268MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
269MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");
1/*
2 * pmi driver
3 *
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
5 *
6 * PMI (Platform Management Interrupt) is a way to communicate
7 * with the BMC (Baseboard Management Controller) via interrupts.
8 * Unlike IPMI it is bidirectional and has a low latency.
9 *
10 * Author: Christian Krafft <krafft@de.ibm.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27#include <linux/interrupt.h>
28#include <linux/slab.h>
29#include <linux/completion.h>
30#include <linux/spinlock.h>
31#include <linux/workqueue.h>
32#include <linux/of_device.h>
33#include <linux/of_platform.h>
34
35#include <asm/io.h>
36#include <asm/pmi.h>
37#include <asm/prom.h>
38
39struct pmi_data {
40 struct list_head handler;
41 spinlock_t handler_spinlock;
42 spinlock_t pmi_spinlock;
43 struct mutex msg_mutex;
44 pmi_message_t msg;
45 struct completion *completion;
46 struct platform_device *dev;
47 int irq;
48 u8 __iomem *pmi_reg;
49 struct work_struct work;
50};
51
52static struct pmi_data *data;
53
54static irqreturn_t pmi_irq_handler(int irq, void *dev_id)
55{
56 u8 type;
57 int rc;
58
59 spin_lock(&data->pmi_spinlock);
60
61 type = ioread8(data->pmi_reg + PMI_READ_TYPE);
62 pr_debug("pmi: got message of type %d\n", type);
63
64 if (type & PMI_ACK && !data->completion) {
65 printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
66 rc = -EIO;
67 goto unlock;
68 }
69
70 if (data->completion && !(type & PMI_ACK)) {
71 printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
72 rc = -EIO;
73 goto unlock;
74 }
75
76 data->msg.type = type;
77 data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
78 data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
79 data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
80 rc = 0;
81unlock:
82 spin_unlock(&data->pmi_spinlock);
83
84 if (rc == -EIO) {
85 rc = IRQ_HANDLED;
86 goto out;
87 }
88
89 if (data->msg.type & PMI_ACK) {
90 complete(data->completion);
91 rc = IRQ_HANDLED;
92 goto out;
93 }
94
95 schedule_work(&data->work);
96
97 rc = IRQ_HANDLED;
98out:
99 return rc;
100}
101
102
103static struct of_device_id pmi_match[] = {
104 { .type = "ibm,pmi", .name = "ibm,pmi" },
105 { .type = "ibm,pmi" },
106 {},
107};
108
109MODULE_DEVICE_TABLE(of, pmi_match);
110
111static void pmi_notify_handlers(struct work_struct *work)
112{
113 struct pmi_handler *handler;
114
115 spin_lock(&data->handler_spinlock);
116 list_for_each_entry(handler, &data->handler, node) {
117 pr_debug("pmi: notifying handler %p\n", handler);
118 if (handler->type == data->msg.type)
119 handler->handle_pmi_message(data->msg);
120 }
121 spin_unlock(&data->handler_spinlock);
122}
123
124static int pmi_of_probe(struct platform_device *dev)
125{
126 struct device_node *np = dev->dev.of_node;
127 int rc;
128
129 if (data) {
130 printk(KERN_ERR "pmi: driver has already been initialized.\n");
131 rc = -EBUSY;
132 goto out;
133 }
134
135 data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
136 if (!data) {
137 printk(KERN_ERR "pmi: could not allocate memory.\n");
138 rc = -ENOMEM;
139 goto out;
140 }
141
142 data->pmi_reg = of_iomap(np, 0);
143 if (!data->pmi_reg) {
144 printk(KERN_ERR "pmi: invalid register address.\n");
145 rc = -EFAULT;
146 goto error_cleanup_data;
147 }
148
149 INIT_LIST_HEAD(&data->handler);
150
151 mutex_init(&data->msg_mutex);
152 spin_lock_init(&data->pmi_spinlock);
153 spin_lock_init(&data->handler_spinlock);
154
155 INIT_WORK(&data->work, pmi_notify_handlers);
156
157 data->dev = dev;
158
159 data->irq = irq_of_parse_and_map(np, 0);
160 if (data->irq == NO_IRQ) {
161 printk(KERN_ERR "pmi: invalid interrupt.\n");
162 rc = -EFAULT;
163 goto error_cleanup_iomap;
164 }
165
166 rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL);
167 if (rc) {
168 printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
169 data->irq, rc);
170 goto error_cleanup_iomap;
171 }
172
173 printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
174
175 goto out;
176
177error_cleanup_iomap:
178 iounmap(data->pmi_reg);
179
180error_cleanup_data:
181 kfree(data);
182
183out:
184 return rc;
185}
186
187static int pmi_of_remove(struct platform_device *dev)
188{
189 struct pmi_handler *handler, *tmp;
190
191 free_irq(data->irq, NULL);
192 iounmap(data->pmi_reg);
193
194 spin_lock(&data->handler_spinlock);
195
196 list_for_each_entry_safe(handler, tmp, &data->handler, node)
197 list_del(&handler->node);
198
199 spin_unlock(&data->handler_spinlock);
200
201 kfree(data);
202 data = NULL;
203
204 return 0;
205}
206
207static struct platform_driver pmi_of_platform_driver = {
208 .probe = pmi_of_probe,
209 .remove = pmi_of_remove,
210 .driver = {
211 .name = "pmi",
212 .owner = THIS_MODULE,
213 .of_match_table = pmi_match,
214 },
215};
216
217static int __init pmi_module_init(void)
218{
219 return platform_driver_register(&pmi_of_platform_driver);
220}
221module_init(pmi_module_init);
222
223static void __exit pmi_module_exit(void)
224{
225 platform_driver_unregister(&pmi_of_platform_driver);
226}
227module_exit(pmi_module_exit);
228
229int pmi_send_message(pmi_message_t msg)
230{
231 unsigned long flags;
232 DECLARE_COMPLETION_ONSTACK(completion);
233
234 if (!data)
235 return -ENODEV;
236
237 mutex_lock(&data->msg_mutex);
238
239 data->msg = msg;
240 pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg);
241
242 data->completion = &completion;
243
244 spin_lock_irqsave(&data->pmi_spinlock, flags);
245 iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
246 iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
247 iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
248 iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
249 spin_unlock_irqrestore(&data->pmi_spinlock, flags);
250
251 pr_debug("pmi_send_message: wait for completion\n");
252
253 wait_for_completion_interruptible_timeout(data->completion,
254 PMI_TIMEOUT);
255
256 data->completion = NULL;
257
258 mutex_unlock(&data->msg_mutex);
259
260 return 0;
261}
262EXPORT_SYMBOL_GPL(pmi_send_message);
263
264int pmi_register_handler(struct pmi_handler *handler)
265{
266 if (!data)
267 return -ENODEV;
268
269 spin_lock(&data->handler_spinlock);
270 list_add_tail(&handler->node, &data->handler);
271 spin_unlock(&data->handler_spinlock);
272
273 return 0;
274}
275EXPORT_SYMBOL_GPL(pmi_register_handler);
276
277void pmi_unregister_handler(struct pmi_handler *handler)
278{
279 if (!data)
280 return;
281
282 pr_debug("pmi: unregistering handler %p\n", handler);
283
284 spin_lock(&data->handler_spinlock);
285 list_del(&handler->node);
286 spin_unlock(&data->handler_spinlock);
287}
288EXPORT_SYMBOL_GPL(pmi_unregister_handler);
289
290MODULE_LICENSE("GPL");
291MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
292MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");