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27#include <linux/interrupt.h>
28#include <linux/slab.h>
29#include <linux/completion.h>
30#include <linux/spinlock.h>
31#include <linux/module.h>
32#include <linux/workqueue.h>
33#include <linux/of_device.h>
34#include <linux/of_platform.h>
35
36#include <asm/io.h>
37#include <asm/pmi.h>
38#include <asm/prom.h>
39
40struct pmi_data {
41 struct list_head handler;
42 spinlock_t handler_spinlock;
43 spinlock_t pmi_spinlock;
44 struct mutex msg_mutex;
45 pmi_message_t msg;
46 struct completion *completion;
47 struct platform_device *dev;
48 int irq;
49 u8 __iomem *pmi_reg;
50 struct work_struct work;
51};
52
53static struct pmi_data *data;
54
55static irqreturn_t pmi_irq_handler(int irq, void *dev_id)
56{
57 u8 type;
58 int rc;
59
60 spin_lock(&data->pmi_spinlock);
61
62 type = ioread8(data->pmi_reg + PMI_READ_TYPE);
63 pr_debug("pmi: got message of type %d\n", type);
64
65 if (type & PMI_ACK && !data->completion) {
66 printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
67 rc = -EIO;
68 goto unlock;
69 }
70
71 if (data->completion && !(type & PMI_ACK)) {
72 printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
73 rc = -EIO;
74 goto unlock;
75 }
76
77 data->msg.type = type;
78 data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
79 data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
80 data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
81 rc = 0;
82unlock:
83 spin_unlock(&data->pmi_spinlock);
84
85 if (rc == -EIO) {
86 rc = IRQ_HANDLED;
87 goto out;
88 }
89
90 if (data->msg.type & PMI_ACK) {
91 complete(data->completion);
92 rc = IRQ_HANDLED;
93 goto out;
94 }
95
96 schedule_work(&data->work);
97
98 rc = IRQ_HANDLED;
99out:
100 return rc;
101}
102
103
104static const struct of_device_id pmi_match[] = {
105 { .type = "ibm,pmi", .name = "ibm,pmi" },
106 { .type = "ibm,pmi" },
107 {},
108};
109
110MODULE_DEVICE_TABLE(of, pmi_match);
111
112static void pmi_notify_handlers(struct work_struct *work)
113{
114 struct pmi_handler *handler;
115
116 spin_lock(&data->handler_spinlock);
117 list_for_each_entry(handler, &data->handler, node) {
118 pr_debug("pmi: notifying handler %p\n", handler);
119 if (handler->type == data->msg.type)
120 handler->handle_pmi_message(data->msg);
121 }
122 spin_unlock(&data->handler_spinlock);
123}
124
125static int pmi_of_probe(struct platform_device *dev)
126{
127 struct device_node *np = dev->dev.of_node;
128 int rc;
129
130 if (data) {
131 printk(KERN_ERR "pmi: driver has already been initialized.\n");
132 rc = -EBUSY;
133 goto out;
134 }
135
136 data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
137 if (!data) {
138 printk(KERN_ERR "pmi: could not allocate memory.\n");
139 rc = -ENOMEM;
140 goto out;
141 }
142
143 data->pmi_reg = of_iomap(np, 0);
144 if (!data->pmi_reg) {
145 printk(KERN_ERR "pmi: invalid register address.\n");
146 rc = -EFAULT;
147 goto error_cleanup_data;
148 }
149
150 INIT_LIST_HEAD(&data->handler);
151
152 mutex_init(&data->msg_mutex);
153 spin_lock_init(&data->pmi_spinlock);
154 spin_lock_init(&data->handler_spinlock);
155
156 INIT_WORK(&data->work, pmi_notify_handlers);
157
158 data->dev = dev;
159
160 data->irq = irq_of_parse_and_map(np, 0);
161 if (data->irq == NO_IRQ) {
162 printk(KERN_ERR "pmi: invalid interrupt.\n");
163 rc = -EFAULT;
164 goto error_cleanup_iomap;
165 }
166
167 rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL);
168 if (rc) {
169 printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
170 data->irq, rc);
171 goto error_cleanup_iomap;
172 }
173
174 printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
175
176 goto out;
177
178error_cleanup_iomap:
179 iounmap(data->pmi_reg);
180
181error_cleanup_data:
182 kfree(data);
183
184out:
185 return rc;
186}
187
188static int pmi_of_remove(struct platform_device *dev)
189{
190 struct pmi_handler *handler, *tmp;
191
192 free_irq(data->irq, NULL);
193 iounmap(data->pmi_reg);
194
195 spin_lock(&data->handler_spinlock);
196
197 list_for_each_entry_safe(handler, tmp, &data->handler, node)
198 list_del(&handler->node);
199
200 spin_unlock(&data->handler_spinlock);
201
202 kfree(data);
203 data = NULL;
204
205 return 0;
206}
207
208static struct platform_driver pmi_of_platform_driver = {
209 .probe = pmi_of_probe,
210 .remove = pmi_of_remove,
211 .driver = {
212 .name = "pmi",
213 .of_match_table = pmi_match,
214 },
215};
216module_platform_driver(pmi_of_platform_driver);
217
218int pmi_send_message(pmi_message_t msg)
219{
220 unsigned long flags;
221 DECLARE_COMPLETION_ONSTACK(completion);
222
223 if (!data)
224 return -ENODEV;
225
226 mutex_lock(&data->msg_mutex);
227
228 data->msg = msg;
229 pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg);
230
231 data->completion = &completion;
232
233 spin_lock_irqsave(&data->pmi_spinlock, flags);
234 iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
235 iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
236 iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
237 iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
238 spin_unlock_irqrestore(&data->pmi_spinlock, flags);
239
240 pr_debug("pmi_send_message: wait for completion\n");
241
242 wait_for_completion_interruptible_timeout(data->completion,
243 PMI_TIMEOUT);
244
245 data->completion = NULL;
246
247 mutex_unlock(&data->msg_mutex);
248
249 return 0;
250}
251EXPORT_SYMBOL_GPL(pmi_send_message);
252
253int pmi_register_handler(struct pmi_handler *handler)
254{
255 if (!data)
256 return -ENODEV;
257
258 spin_lock(&data->handler_spinlock);
259 list_add_tail(&handler->node, &data->handler);
260 spin_unlock(&data->handler_spinlock);
261
262 return 0;
263}
264EXPORT_SYMBOL_GPL(pmi_register_handler);
265
266void pmi_unregister_handler(struct pmi_handler *handler)
267{
268 if (!data)
269 return;
270
271 pr_debug("pmi: unregistering handler %p\n", handler);
272
273 spin_lock(&data->handler_spinlock);
274 list_del(&handler->node);
275 spin_unlock(&data->handler_spinlock);
276}
277EXPORT_SYMBOL_GPL(pmi_unregister_handler);
278
279MODULE_LICENSE("GPL");
280MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
281MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");
282
