GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / firmware / arm_scpi.c
1 /*
2  * System Control and Power Interface (SCPI) Message Protocol driver
3  *
4  * SCPI Message Protocol is used between the System Control Processor(SCP)
5  * and the Application Processors(AP). The Message Handling Unit(MHU)
6  * provides a mechanism for inter-processor communication between SCP's
7  * Cortex M3 and AP.
8  *
9  * SCP offers control and management of the core/cluster power states,
10  * various power domain DVFS including the core/cluster, certain system
11  * clocks configuration, thermal sensors and many others.
12  *
13  * Copyright (C) 2015 ARM Ltd.
14  *
15  * This program is free software; you can redistribute it and/or modify it
16  * under the terms and conditions of the GNU General Public License,
17  * version 2, as published by the Free Software Foundation.
18  *
19  * This program is distributed in the hope it will be useful, but WITHOUT
20  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22  * more details.
23  *
24  * You should have received a copy of the GNU General Public License along
25  * with this program. If not, see <http://www.gnu.org/licenses/>.
26  */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/bitmap.h>
31 #include <linux/device.h>
32 #include <linux/err.h>
33 #include <linux/export.h>
34 #include <linux/io.h>
35 #include <linux/kernel.h>
36 #include <linux/list.h>
37 #include <linux/mailbox_client.h>
38 #include <linux/module.h>
39 #include <linux/of_address.h>
40 #include <linux/of_platform.h>
41 #include <linux/printk.h>
42 #include <linux/scpi_protocol.h>
43 #include <linux/slab.h>
44 #include <linux/sort.h>
45 #include <linux/spinlock.h>
46
47 #define CMD_ID_SHIFT            0
48 #define CMD_ID_MASK             0x7f
49 #define CMD_TOKEN_ID_SHIFT      8
50 #define CMD_TOKEN_ID_MASK       0xff
51 #define CMD_DATA_SIZE_SHIFT     16
52 #define CMD_DATA_SIZE_MASK      0x1ff
53 #define PACK_SCPI_CMD(cmd_id, tx_sz)                    \
54         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |   \
55         (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
56 #define ADD_SCPI_TOKEN(cmd, token)                      \
57         ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
58
59 #define CMD_SIZE(cmd)   (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
60 #define CMD_UNIQ_MASK   (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
61 #define CMD_XTRACT_UNIQ(cmd)    ((cmd) & CMD_UNIQ_MASK)
62
63 #define SCPI_SLOT               0
64
65 #define MAX_DVFS_DOMAINS        8
66 #define MAX_DVFS_OPPS           8
67 #define DVFS_LATENCY(hdr)       (le32_to_cpu(hdr) >> 16)
68 #define DVFS_OPP_COUNT(hdr)     ((le32_to_cpu(hdr) >> 8) & 0xff)
69
70 #define PROTOCOL_REV_MINOR_BITS 16
71 #define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
72 #define PROTOCOL_REV_MAJOR(x)   ((x) >> PROTOCOL_REV_MINOR_BITS)
73 #define PROTOCOL_REV_MINOR(x)   ((x) & PROTOCOL_REV_MINOR_MASK)
74
75 #define FW_REV_MAJOR_BITS       24
76 #define FW_REV_MINOR_BITS       16
77 #define FW_REV_PATCH_MASK       ((1U << FW_REV_MINOR_BITS) - 1)
78 #define FW_REV_MINOR_MASK       ((1U << FW_REV_MAJOR_BITS) - 1)
79 #define FW_REV_MAJOR(x)         ((x) >> FW_REV_MAJOR_BITS)
80 #define FW_REV_MINOR(x)         (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
81 #define FW_REV_PATCH(x)         ((x) & FW_REV_PATCH_MASK)
82
83 #define MAX_RX_TIMEOUT          (msecs_to_jiffies(20))
84
85 enum scpi_error_codes {
86         SCPI_SUCCESS = 0, /* Success */
87         SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
88         SCPI_ERR_ALIGN = 2, /* Invalid alignment */
89         SCPI_ERR_SIZE = 3, /* Invalid size */
90         SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
91         SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
92         SCPI_ERR_RANGE = 6, /* Value out of range */
93         SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
94         SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
95         SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
96         SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
97         SCPI_ERR_DEVICE = 11, /* Device error */
98         SCPI_ERR_BUSY = 12, /* Device busy */
99         SCPI_ERR_MAX
100 };
101
102 enum scpi_std_cmd {
103         SCPI_CMD_INVALID                = 0x00,
104         SCPI_CMD_SCPI_READY             = 0x01,
105         SCPI_CMD_SCPI_CAPABILITIES      = 0x02,
106         SCPI_CMD_SET_CSS_PWR_STATE      = 0x03,
107         SCPI_CMD_GET_CSS_PWR_STATE      = 0x04,
108         SCPI_CMD_SET_SYS_PWR_STATE      = 0x05,
109         SCPI_CMD_SET_CPU_TIMER          = 0x06,
110         SCPI_CMD_CANCEL_CPU_TIMER       = 0x07,
111         SCPI_CMD_DVFS_CAPABILITIES      = 0x08,
112         SCPI_CMD_GET_DVFS_INFO          = 0x09,
113         SCPI_CMD_SET_DVFS               = 0x0a,
114         SCPI_CMD_GET_DVFS               = 0x0b,
115         SCPI_CMD_GET_DVFS_STAT          = 0x0c,
116         SCPI_CMD_CLOCK_CAPABILITIES     = 0x0d,
117         SCPI_CMD_GET_CLOCK_INFO         = 0x0e,
118         SCPI_CMD_SET_CLOCK_VALUE        = 0x0f,
119         SCPI_CMD_GET_CLOCK_VALUE        = 0x10,
120         SCPI_CMD_PSU_CAPABILITIES       = 0x11,
121         SCPI_CMD_GET_PSU_INFO           = 0x12,
122         SCPI_CMD_SET_PSU                = 0x13,
123         SCPI_CMD_GET_PSU                = 0x14,
124         SCPI_CMD_SENSOR_CAPABILITIES    = 0x15,
125         SCPI_CMD_SENSOR_INFO            = 0x16,
126         SCPI_CMD_SENSOR_VALUE           = 0x17,
127         SCPI_CMD_SENSOR_CFG_PERIODIC    = 0x18,
128         SCPI_CMD_SENSOR_CFG_BOUNDS      = 0x19,
129         SCPI_CMD_SENSOR_ASYNC_VALUE     = 0x1a,
130         SCPI_CMD_SET_DEVICE_PWR_STATE   = 0x1b,
131         SCPI_CMD_GET_DEVICE_PWR_STATE   = 0x1c,
132         SCPI_CMD_COUNT
133 };
134
135 struct scpi_xfer {
136         u32 slot; /* has to be first element */
137         u32 cmd;
138         u32 status;
139         const void *tx_buf;
140         void *rx_buf;
141         unsigned int tx_len;
142         unsigned int rx_len;
143         struct list_head node;
144         struct completion done;
145 };
146
147 struct scpi_chan {
148         struct mbox_client cl;
149         struct mbox_chan *chan;
150         void __iomem *tx_payload;
151         void __iomem *rx_payload;
152         struct list_head rx_pending;
153         struct list_head xfers_list;
154         struct scpi_xfer *xfers;
155         spinlock_t rx_lock; /* locking for the rx pending list */
156         struct mutex xfers_lock;
157         u8 token;
158 };
159
160 struct scpi_drvinfo {
161         u32 protocol_version;
162         u32 firmware_version;
163         int num_chans;
164         atomic_t next_chan;
165         struct scpi_ops *scpi_ops;
166         struct scpi_chan *channels;
167         struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
168 };
169
170 /*
171  * The SCP firmware only executes in little-endian mode, so any buffers
172  * shared through SCPI should have their contents converted to little-endian
173  */
174 struct scpi_shared_mem {
175         __le32 command;
176         __le32 status;
177         u8 payload[0];
178 } __packed;
179
180 struct scp_capabilities {
181         __le32 protocol_version;
182         __le32 event_version;
183         __le32 platform_version;
184         __le32 commands[4];
185 } __packed;
186
187 struct clk_get_info {
188         __le16 id;
189         __le16 flags;
190         __le32 min_rate;
191         __le32 max_rate;
192         u8 name[20];
193 } __packed;
194
195 struct clk_get_value {
196         __le32 rate;
197 } __packed;
198
199 struct clk_set_value {
200         __le16 id;
201         __le16 reserved;
202         __le32 rate;
203 } __packed;
204
205 struct dvfs_info {
206         __le32 header;
207         struct {
208                 __le32 freq;
209                 __le32 m_volt;
210         } opps[MAX_DVFS_OPPS];
211 } __packed;
212
213 struct dvfs_get {
214         u8 index;
215 } __packed;
216
217 struct dvfs_set {
218         u8 domain;
219         u8 index;
220 } __packed;
221
222 struct sensor_capabilities {
223         __le16 sensors;
224 } __packed;
225
226 struct _scpi_sensor_info {
227         __le16 sensor_id;
228         u8 class;
229         u8 trigger_type;
230         char name[20];
231 };
232
233 struct sensor_value {
234         __le32 val;
235 } __packed;
236
237 static struct scpi_drvinfo *scpi_info;
238
239 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
240         /* better than switch case as long as return value is continuous */
241         0, /* SCPI_SUCCESS */
242         -EINVAL, /* SCPI_ERR_PARAM */
243         -ENOEXEC, /* SCPI_ERR_ALIGN */
244         -EMSGSIZE, /* SCPI_ERR_SIZE */
245         -EINVAL, /* SCPI_ERR_HANDLER */
246         -EACCES, /* SCPI_ERR_ACCESS */
247         -ERANGE, /* SCPI_ERR_RANGE */
248         -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
249         -ENOMEM, /* SCPI_ERR_NOMEM */
250         -EINVAL, /* SCPI_ERR_PWRSTATE */
251         -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
252         -EIO, /* SCPI_ERR_DEVICE */
253         -EBUSY, /* SCPI_ERR_BUSY */
254 };
255
256 static inline int scpi_to_linux_errno(int errno)
257 {
258         if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
259                 return scpi_linux_errmap[errno];
260         return -EIO;
261 }
262
263 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
264 {
265         unsigned long flags;
266         struct scpi_xfer *t, *match = NULL;
267
268         spin_lock_irqsave(&ch->rx_lock, flags);
269         if (list_empty(&ch->rx_pending)) {
270                 spin_unlock_irqrestore(&ch->rx_lock, flags);
271                 return;
272         }
273
274         list_for_each_entry(t, &ch->rx_pending, node)
275                 if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
276                         list_del(&t->node);
277                         match = t;
278                         break;
279                 }
280         /* check if wait_for_completion is in progress or timed-out */
281         if (match && !completion_done(&match->done)) {
282                 struct scpi_shared_mem *mem = ch->rx_payload;
283                 unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
284
285                 match->status = le32_to_cpu(mem->status);
286                 memcpy_fromio(match->rx_buf, mem->payload, len);
287                 if (match->rx_len > len)
288                         memset(match->rx_buf + len, 0, match->rx_len - len);
289                 complete(&match->done);
290         }
291         spin_unlock_irqrestore(&ch->rx_lock, flags);
292 }
293
294 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
295 {
296         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
297         struct scpi_shared_mem *mem = ch->rx_payload;
298         u32 cmd = le32_to_cpu(mem->command);
299
300         scpi_process_cmd(ch, cmd);
301 }
302
303 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
304 {
305         unsigned long flags;
306         struct scpi_xfer *t = msg;
307         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
308         struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
309
310         if (t->tx_buf)
311                 memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
312         if (t->rx_buf) {
313                 if (!(++ch->token))
314                         ++ch->token;
315                 ADD_SCPI_TOKEN(t->cmd, ch->token);
316                 spin_lock_irqsave(&ch->rx_lock, flags);
317                 list_add_tail(&t->node, &ch->rx_pending);
318                 spin_unlock_irqrestore(&ch->rx_lock, flags);
319         }
320         mem->command = cpu_to_le32(t->cmd);
321 }
322
323 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
324 {
325         struct scpi_xfer *t;
326
327         mutex_lock(&ch->xfers_lock);
328         if (list_empty(&ch->xfers_list)) {
329                 mutex_unlock(&ch->xfers_lock);
330                 return NULL;
331         }
332         t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
333         list_del(&t->node);
334         mutex_unlock(&ch->xfers_lock);
335         return t;
336 }
337
338 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
339 {
340         mutex_lock(&ch->xfers_lock);
341         list_add_tail(&t->node, &ch->xfers_list);
342         mutex_unlock(&ch->xfers_lock);
343 }
344
345 static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
346                              void *rx_buf, unsigned int rx_len)
347 {
348         int ret;
349         u8 chan;
350         struct scpi_xfer *msg;
351         struct scpi_chan *scpi_chan;
352
353         chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
354         scpi_chan = scpi_info->channels + chan;
355
356         msg = get_scpi_xfer(scpi_chan);
357         if (!msg)
358                 return -ENOMEM;
359
360         msg->slot = BIT(SCPI_SLOT);
361         msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
362         msg->tx_buf = tx_buf;
363         msg->tx_len = tx_len;
364         msg->rx_buf = rx_buf;
365         msg->rx_len = rx_len;
366         init_completion(&msg->done);
367
368         ret = mbox_send_message(scpi_chan->chan, msg);
369         if (ret < 0 || !rx_buf)
370                 goto out;
371
372         if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
373                 ret = -ETIMEDOUT;
374         else
375                 /* first status word */
376                 ret = le32_to_cpu(msg->status);
377 out:
378         if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
379                 scpi_process_cmd(scpi_chan, msg->cmd);
380
381         put_scpi_xfer(msg, scpi_chan);
382         /* SCPI error codes > 0, translate them to Linux scale*/
383         return ret > 0 ? scpi_to_linux_errno(ret) : ret;
384 }
385
386 static u32 scpi_get_version(void)
387 {
388         return scpi_info->protocol_version;
389 }
390
391 static int
392 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
393 {
394         int ret;
395         struct clk_get_info clk;
396         __le16 le_clk_id = cpu_to_le16(clk_id);
397
398         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
399                                 sizeof(le_clk_id), &clk, sizeof(clk));
400         if (!ret) {
401                 *min = le32_to_cpu(clk.min_rate);
402                 *max = le32_to_cpu(clk.max_rate);
403         }
404         return ret;
405 }
406
407 static unsigned long scpi_clk_get_val(u16 clk_id)
408 {
409         int ret;
410         struct clk_get_value clk;
411         __le16 le_clk_id = cpu_to_le16(clk_id);
412
413         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
414                                 sizeof(le_clk_id), &clk, sizeof(clk));
415         return ret ? ret : le32_to_cpu(clk.rate);
416 }
417
418 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
419 {
420         int stat;
421         struct clk_set_value clk = {
422                 .id = cpu_to_le16(clk_id),
423                 .rate = cpu_to_le32(rate)
424         };
425
426         return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
427                                  &stat, sizeof(stat));
428 }
429
430 static int scpi_dvfs_get_idx(u8 domain)
431 {
432         int ret;
433         struct dvfs_get dvfs;
434
435         ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
436                                 &dvfs, sizeof(dvfs));
437         return ret ? ret : dvfs.index;
438 }
439
440 static int scpi_dvfs_set_idx(u8 domain, u8 index)
441 {
442         int stat;
443         struct dvfs_set dvfs = {domain, index};
444
445         return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
446                                  &stat, sizeof(stat));
447 }
448
449 static int opp_cmp_func(const void *opp1, const void *opp2)
450 {
451         const struct scpi_opp *t1 = opp1, *t2 = opp2;
452
453         return t1->freq - t2->freq;
454 }
455
456 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
457 {
458         struct scpi_dvfs_info *info;
459         struct scpi_opp *opp;
460         struct dvfs_info buf;
461         int ret, i;
462
463         if (domain >= MAX_DVFS_DOMAINS)
464                 return ERR_PTR(-EINVAL);
465
466         if (scpi_info->dvfs[domain])    /* data already populated */
467                 return scpi_info->dvfs[domain];
468
469         ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
470                                 &buf, sizeof(buf));
471
472         if (ret)
473                 return ERR_PTR(ret);
474
475         info = kmalloc(sizeof(*info), GFP_KERNEL);
476         if (!info)
477                 return ERR_PTR(-ENOMEM);
478
479         info->count = DVFS_OPP_COUNT(buf.header);
480         info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
481
482         info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
483         if (!info->opps) {
484                 kfree(info);
485                 return ERR_PTR(-ENOMEM);
486         }
487
488         for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
489                 opp->freq = le32_to_cpu(buf.opps[i].freq);
490                 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
491         }
492
493         sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
494
495         scpi_info->dvfs[domain] = info;
496         return info;
497 }
498
499 static int scpi_sensor_get_capability(u16 *sensors)
500 {
501         struct sensor_capabilities cap_buf;
502         int ret;
503
504         ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
505                                 sizeof(cap_buf));
506         if (!ret)
507                 *sensors = le16_to_cpu(cap_buf.sensors);
508
509         return ret;
510 }
511
512 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
513 {
514         __le16 id = cpu_to_le16(sensor_id);
515         struct _scpi_sensor_info _info;
516         int ret;
517
518         ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
519                                 &_info, sizeof(_info));
520         if (!ret) {
521                 memcpy(info, &_info, sizeof(*info));
522                 info->sensor_id = le16_to_cpu(_info.sensor_id);
523         }
524
525         return ret;
526 }
527
528 int scpi_sensor_get_value(u16 sensor, u32 *val)
529 {
530         struct sensor_value buf;
531         int ret;
532
533         ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &sensor, sizeof(sensor),
534                                 &buf, sizeof(buf));
535         if (!ret)
536                 *val = le32_to_cpu(buf.val);
537
538         return ret;
539 }
540
541 static struct scpi_ops scpi_ops = {
542         .get_version = scpi_get_version,
543         .clk_get_range = scpi_clk_get_range,
544         .clk_get_val = scpi_clk_get_val,
545         .clk_set_val = scpi_clk_set_val,
546         .dvfs_get_idx = scpi_dvfs_get_idx,
547         .dvfs_set_idx = scpi_dvfs_set_idx,
548         .dvfs_get_info = scpi_dvfs_get_info,
549         .sensor_get_capability = scpi_sensor_get_capability,
550         .sensor_get_info = scpi_sensor_get_info,
551         .sensor_get_value = scpi_sensor_get_value,
552 };
553
554 struct scpi_ops *get_scpi_ops(void)
555 {
556         return scpi_info ? scpi_info->scpi_ops : NULL;
557 }
558 EXPORT_SYMBOL_GPL(get_scpi_ops);
559
560 static int scpi_init_versions(struct scpi_drvinfo *info)
561 {
562         int ret;
563         struct scp_capabilities caps;
564
565         ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
566                                 &caps, sizeof(caps));
567         if (!ret) {
568                 info->protocol_version = le32_to_cpu(caps.protocol_version);
569                 info->firmware_version = le32_to_cpu(caps.platform_version);
570         }
571         return ret;
572 }
573
574 static ssize_t protocol_version_show(struct device *dev,
575                                      struct device_attribute *attr, char *buf)
576 {
577         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
578
579         return sprintf(buf, "%d.%d\n",
580                        PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
581                        PROTOCOL_REV_MINOR(scpi_info->protocol_version));
582 }
583 static DEVICE_ATTR_RO(protocol_version);
584
585 static ssize_t firmware_version_show(struct device *dev,
586                                      struct device_attribute *attr, char *buf)
587 {
588         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
589
590         return sprintf(buf, "%d.%d.%d\n",
591                        FW_REV_MAJOR(scpi_info->firmware_version),
592                        FW_REV_MINOR(scpi_info->firmware_version),
593                        FW_REV_PATCH(scpi_info->firmware_version));
594 }
595 static DEVICE_ATTR_RO(firmware_version);
596
597 static struct attribute *versions_attrs[] = {
598         &dev_attr_firmware_version.attr,
599         &dev_attr_protocol_version.attr,
600         NULL,
601 };
602 ATTRIBUTE_GROUPS(versions);
603
604 static void
605 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
606 {
607         int i;
608
609         for (i = 0; i < count && pchan->chan; i++, pchan++) {
610                 mbox_free_channel(pchan->chan);
611                 devm_kfree(dev, pchan->xfers);
612                 devm_iounmap(dev, pchan->rx_payload);
613         }
614 }
615
616 static int scpi_remove(struct platform_device *pdev)
617 {
618         int i;
619         struct device *dev = &pdev->dev;
620         struct scpi_drvinfo *info = platform_get_drvdata(pdev);
621
622         scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
623
624         of_platform_depopulate(dev);
625         sysfs_remove_groups(&dev->kobj, versions_groups);
626         scpi_free_channels(dev, info->channels, info->num_chans);
627         platform_set_drvdata(pdev, NULL);
628
629         for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
630                 kfree(info->dvfs[i]->opps);
631                 kfree(info->dvfs[i]);
632         }
633         devm_kfree(dev, info->channels);
634         devm_kfree(dev, info);
635
636         return 0;
637 }
638
639 #define MAX_SCPI_XFERS          10
640 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
641 {
642         int i;
643         struct scpi_xfer *xfers;
644
645         xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
646         if (!xfers)
647                 return -ENOMEM;
648
649         ch->xfers = xfers;
650         for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
651                 list_add_tail(&xfers->node, &ch->xfers_list);
652         return 0;
653 }
654
655 static int scpi_probe(struct platform_device *pdev)
656 {
657         int count, idx, ret;
658         struct resource res;
659         struct scpi_chan *scpi_chan;
660         struct device *dev = &pdev->dev;
661         struct device_node *np = dev->of_node;
662
663         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
664         if (!scpi_info)
665                 return -ENOMEM;
666
667         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
668         if (count < 0) {
669                 dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
670                 return -ENODEV;
671         }
672
673         scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
674         if (!scpi_chan)
675                 return -ENOMEM;
676
677         for (idx = 0; idx < count; idx++) {
678                 resource_size_t size;
679                 struct scpi_chan *pchan = scpi_chan + idx;
680                 struct mbox_client *cl = &pchan->cl;
681                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
682
683                 if (of_address_to_resource(shmem, 0, &res)) {
684                         dev_err(dev, "failed to get SCPI payload mem resource\n");
685                         ret = -EINVAL;
686                         goto err;
687                 }
688
689                 size = resource_size(&res);
690                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
691                 if (!pchan->rx_payload) {
692                         dev_err(dev, "failed to ioremap SCPI payload\n");
693                         ret = -EADDRNOTAVAIL;
694                         goto err;
695                 }
696                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
697
698                 cl->dev = dev;
699                 cl->rx_callback = scpi_handle_remote_msg;
700                 cl->tx_prepare = scpi_tx_prepare;
701                 cl->tx_block = true;
702                 cl->tx_tout = 50;
703                 cl->knows_txdone = false; /* controller can't ack */
704
705                 INIT_LIST_HEAD(&pchan->rx_pending);
706                 INIT_LIST_HEAD(&pchan->xfers_list);
707                 spin_lock_init(&pchan->rx_lock);
708                 mutex_init(&pchan->xfers_lock);
709
710                 ret = scpi_alloc_xfer_list(dev, pchan);
711                 if (!ret) {
712                         pchan->chan = mbox_request_channel(cl, idx);
713                         if (!IS_ERR(pchan->chan))
714                                 continue;
715                         ret = PTR_ERR(pchan->chan);
716                         if (ret != -EPROBE_DEFER)
717                                 dev_err(dev, "failed to get channel%d err %d\n",
718                                         idx, ret);
719                 }
720 err:
721                 scpi_free_channels(dev, scpi_chan, idx);
722                 scpi_info = NULL;
723                 return ret;
724         }
725
726         scpi_info->channels = scpi_chan;
727         scpi_info->num_chans = count;
728         platform_set_drvdata(pdev, scpi_info);
729
730         ret = scpi_init_versions(scpi_info);
731         if (ret) {
732                 dev_err(dev, "incorrect or no SCP firmware found\n");
733                 scpi_remove(pdev);
734                 return ret;
735         }
736
737         _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
738                   PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
739                   PROTOCOL_REV_MINOR(scpi_info->protocol_version),
740                   FW_REV_MAJOR(scpi_info->firmware_version),
741                   FW_REV_MINOR(scpi_info->firmware_version),
742                   FW_REV_PATCH(scpi_info->firmware_version));
743         scpi_info->scpi_ops = &scpi_ops;
744
745         ret = sysfs_create_groups(&dev->kobj, versions_groups);
746         if (ret)
747                 dev_err(dev, "unable to create sysfs version group\n");
748
749         return of_platform_populate(dev->of_node, NULL, NULL, dev);
750 }
751
752 static const struct of_device_id scpi_of_match[] = {
753         {.compatible = "arm,scpi"},
754         {},
755 };
756
757 MODULE_DEVICE_TABLE(of, scpi_of_match);
758
759 static struct platform_driver scpi_driver = {
760         .driver = {
761                 .name = "scpi_protocol",
762                 .of_match_table = scpi_of_match,
763         },
764         .probe = scpi_probe,
765         .remove = scpi_remove,
766 };
767 module_platform_driver(scpi_driver);
768
769 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
770 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
771 MODULE_LICENSE("GPL v2");