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(30))
 84
 85enum 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
 
102enum 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
135struct 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
147struct 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
160struct 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 */
174struct scpi_shared_mem {
175	__le32 command;
176	__le32 status;
177	u8 payload[0];
178} __packed;
179
 
 
 
 
 
180struct scp_capabilities {
181	__le32 protocol_version;
182	__le32 event_version;
183	__le32 platform_version;
184	__le32 commands[4];
185} __packed;
186
187struct clk_get_info {
188	__le16 id;
189	__le16 flags;
190	__le32 min_rate;
191	__le32 max_rate;
192	u8 name[20];
193} __packed;
194
195struct clk_get_value {
196	__le32 rate;
197} __packed;
198
199struct clk_set_value {
200	__le16 id;
201	__le16 reserved;
202	__le32 rate;
203} __packed;
204
 
 
 
 
 
 
205struct dvfs_info {
206	__le32 header;
207	struct {
208		__le32 freq;
209		__le32 m_volt;
210	} opps[MAX_DVFS_OPPS];
211} __packed;
212
213struct dvfs_get {
214	u8 index;
215} __packed;
216
217struct dvfs_set {
218	u8 domain;
219	u8 index;
220} __packed;
221
222struct sensor_capabilities {
223	__le16 sensors;
224} __packed;
225
226struct _scpi_sensor_info {
227	__le16 sensor_id;
228	u8 class;
229	u8 trigger_type;
230	char name[20];
231};
232
233struct sensor_value {
234	__le32 lo_val;
235	__le32 hi_val;
236} __packed;
237
 
 
 
 
 
238static struct scpi_drvinfo *scpi_info;
239
240static int scpi_linux_errmap[SCPI_ERR_MAX] = {
241	/* better than switch case as long as return value is continuous */
242	0, /* SCPI_SUCCESS */
243	-EINVAL, /* SCPI_ERR_PARAM */
244	-ENOEXEC, /* SCPI_ERR_ALIGN */
245	-EMSGSIZE, /* SCPI_ERR_SIZE */
246	-EINVAL, /* SCPI_ERR_HANDLER */
247	-EACCES, /* SCPI_ERR_ACCESS */
248	-ERANGE, /* SCPI_ERR_RANGE */
249	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
250	-ENOMEM, /* SCPI_ERR_NOMEM */
251	-EINVAL, /* SCPI_ERR_PWRSTATE */
252	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
253	-EIO, /* SCPI_ERR_DEVICE */
254	-EBUSY, /* SCPI_ERR_BUSY */
255};
256
257static inline int scpi_to_linux_errno(int errno)
258{
259	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
260		return scpi_linux_errmap[errno];
261	return -EIO;
262}
263
264static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
265{
266	unsigned long flags;
267	struct scpi_xfer *t, *match = NULL;
268
269	spin_lock_irqsave(&ch->rx_lock, flags);
270	if (list_empty(&ch->rx_pending)) {
271		spin_unlock_irqrestore(&ch->rx_lock, flags);
272		return;
273	}
274
275	list_for_each_entry(t, &ch->rx_pending, node)
276		if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
277			list_del(&t->node);
278			match = t;
279			break;
280		}
 
 
 
 
 
 
 
 
 
 
281	/* check if wait_for_completion is in progress or timed-out */
282	if (match && !completion_done(&match->done)) {
283		struct scpi_shared_mem *mem = ch->rx_payload;
284		unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
285
286		match->status = le32_to_cpu(mem->status);
287		memcpy_fromio(match->rx_buf, mem->payload, len);
288		if (match->rx_len > len)
289			memset(match->rx_buf + len, 0, match->rx_len - len);
290		complete(&match->done);
291	}
292	spin_unlock_irqrestore(&ch->rx_lock, flags);
293}
294
295static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
296{
297	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
298	struct scpi_shared_mem *mem = ch->rx_payload;
299	u32 cmd = le32_to_cpu(mem->command);
 
 
 
300
301	scpi_process_cmd(ch, cmd);
302}
303
304static void scpi_tx_prepare(struct mbox_client *c, void *msg)
305{
306	unsigned long flags;
307	struct scpi_xfer *t = msg;
308	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
309	struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
310
311	if (t->tx_buf)
312		memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
 
 
 
 
 
313	if (t->rx_buf) {
314		if (!(++ch->token))
315			++ch->token;
316		ADD_SCPI_TOKEN(t->cmd, ch->token);
317		spin_lock_irqsave(&ch->rx_lock, flags);
318		list_add_tail(&t->node, &ch->rx_pending);
319		spin_unlock_irqrestore(&ch->rx_lock, flags);
320	}
321	mem->command = cpu_to_le32(t->cmd);
 
 
322}
323
324static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
325{
326	struct scpi_xfer *t;
327
328	mutex_lock(&ch->xfers_lock);
329	if (list_empty(&ch->xfers_list)) {
330		mutex_unlock(&ch->xfers_lock);
331		return NULL;
332	}
333	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
334	list_del(&t->node);
335	mutex_unlock(&ch->xfers_lock);
336	return t;
337}
338
339static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
340{
341	mutex_lock(&ch->xfers_lock);
342	list_add_tail(&t->node, &ch->xfers_list);
343	mutex_unlock(&ch->xfers_lock);
344}
345
346static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
347			     void *rx_buf, unsigned int rx_len)
348{
349	int ret;
350	u8 chan;
 
351	struct scpi_xfer *msg;
352	struct scpi_chan *scpi_chan;
353
354	chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
 
 
 
 
 
 
 
 
 
355	scpi_chan = scpi_info->channels + chan;
356
357	msg = get_scpi_xfer(scpi_chan);
358	if (!msg)
359		return -ENOMEM;
360
361	msg->slot = BIT(SCPI_SLOT);
362	msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
 
 
 
 
 
363	msg->tx_buf = tx_buf;
364	msg->tx_len = tx_len;
365	msg->rx_buf = rx_buf;
366	msg->rx_len = rx_len;
367	init_completion(&msg->done);
368
369	ret = mbox_send_message(scpi_chan->chan, msg);
370	if (ret < 0 || !rx_buf)
371		goto out;
372
373	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
374		ret = -ETIMEDOUT;
375	else
376		/* first status word */
377		ret = msg->status;
378out:
379	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
380		scpi_process_cmd(scpi_chan, msg->cmd);
381
382	put_scpi_xfer(msg, scpi_chan);
383	/* SCPI error codes > 0, translate them to Linux scale*/
384	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
385}
386
387static u32 scpi_get_version(void)
388{
389	return scpi_info->protocol_version;
390}
391
392static int
393scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
394{
395	int ret;
396	struct clk_get_info clk;
397	__le16 le_clk_id = cpu_to_le16(clk_id);
398
399	ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
400				sizeof(le_clk_id), &clk, sizeof(clk));
401	if (!ret) {
402		*min = le32_to_cpu(clk.min_rate);
403		*max = le32_to_cpu(clk.max_rate);
404	}
405	return ret;
406}
407
408static unsigned long scpi_clk_get_val(u16 clk_id)
409{
410	int ret;
411	struct clk_get_value clk;
412	__le16 le_clk_id = cpu_to_le16(clk_id);
413
414	ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
415				sizeof(le_clk_id), &clk, sizeof(clk));
 
416	return ret ? ret : le32_to_cpu(clk.rate);
417}
418
419static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
420{
421	int stat;
422	struct clk_set_value clk = {
423		.id = cpu_to_le16(clk_id),
424		.rate = cpu_to_le32(rate)
425	};
426
427	return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 
 
 
 
 
 
 
 
 
 
 
 
428				 &stat, sizeof(stat));
429}
430
431static int scpi_dvfs_get_idx(u8 domain)
432{
433	int ret;
434	struct dvfs_get dvfs;
 
 
 
435
436	ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
437				&dvfs, sizeof(dvfs));
438	return ret ? ret : dvfs.index;
439}
440
441static int scpi_dvfs_set_idx(u8 domain, u8 index)
442{
443	int stat;
444	struct dvfs_set dvfs = {domain, index};
445
446	return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
447				 &stat, sizeof(stat));
448}
449
450static int opp_cmp_func(const void *opp1, const void *opp2)
451{
452	const struct scpi_opp *t1 = opp1, *t2 = opp2;
453
454	return t1->freq - t2->freq;
455}
456
457static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
458{
459	struct scpi_dvfs_info *info;
460	struct scpi_opp *opp;
461	struct dvfs_info buf;
462	int ret, i;
463
464	if (domain >= MAX_DVFS_DOMAINS)
465		return ERR_PTR(-EINVAL);
466
467	if (scpi_info->dvfs[domain])	/* data already populated */
468		return scpi_info->dvfs[domain];
469
470	ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
471				&buf, sizeof(buf));
472
473	if (ret)
474		return ERR_PTR(ret);
475
476	info = kmalloc(sizeof(*info), GFP_KERNEL);
477	if (!info)
478		return ERR_PTR(-ENOMEM);
479
480	info->count = DVFS_OPP_COUNT(buf.header);
481	info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
482
483	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
484	if (!info->opps) {
485		kfree(info);
486		return ERR_PTR(-ENOMEM);
487	}
488
489	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
490		opp->freq = le32_to_cpu(buf.opps[i].freq);
491		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
492	}
493
494	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
495
496	scpi_info->dvfs[domain] = info;
497	return info;
498}
499
500static int scpi_sensor_get_capability(u16 *sensors)
501{
502	struct sensor_capabilities cap_buf;
503	int ret;
504
505	ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
506				sizeof(cap_buf));
507	if (!ret)
508		*sensors = le16_to_cpu(cap_buf.sensors);
509
510	return ret;
511}
512
513static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
514{
515	__le16 id = cpu_to_le16(sensor_id);
516	struct _scpi_sensor_info _info;
517	int ret;
518
519	ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
520				&_info, sizeof(_info));
521	if (!ret) {
522		memcpy(info, &_info, sizeof(*info));
523		info->sensor_id = le16_to_cpu(_info.sensor_id);
524	}
525
526	return ret;
527}
528
529int scpi_sensor_get_value(u16 sensor, u64 *val)
530{
531	__le16 id = cpu_to_le16(sensor);
532	struct sensor_value buf;
533	int ret;
534
535	ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
536				&buf, sizeof(buf));
537	if (!ret)
 
 
 
 
 
 
538		*val = (u64)le32_to_cpu(buf.hi_val) << 32 |
539			le32_to_cpu(buf.lo_val);
540
541	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
542}
543
544static struct scpi_ops scpi_ops = {
545	.get_version = scpi_get_version,
546	.clk_get_range = scpi_clk_get_range,
547	.clk_get_val = scpi_clk_get_val,
548	.clk_set_val = scpi_clk_set_val,
549	.dvfs_get_idx = scpi_dvfs_get_idx,
550	.dvfs_set_idx = scpi_dvfs_set_idx,
551	.dvfs_get_info = scpi_dvfs_get_info,
552	.sensor_get_capability = scpi_sensor_get_capability,
553	.sensor_get_info = scpi_sensor_get_info,
554	.sensor_get_value = scpi_sensor_get_value,
 
 
555};
556
557struct scpi_ops *get_scpi_ops(void)
558{
559	return scpi_info ? scpi_info->scpi_ops : NULL;
560}
561EXPORT_SYMBOL_GPL(get_scpi_ops);
562
563static int scpi_init_versions(struct scpi_drvinfo *info)
564{
565	int ret;
566	struct scp_capabilities caps;
567
568	ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
569				&caps, sizeof(caps));
570	if (!ret) {
571		info->protocol_version = le32_to_cpu(caps.protocol_version);
572		info->firmware_version = le32_to_cpu(caps.platform_version);
573	}
 
 
 
 
574	return ret;
575}
576
577static ssize_t protocol_version_show(struct device *dev,
578				     struct device_attribute *attr, char *buf)
579{
580	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
581
582	return sprintf(buf, "%d.%d\n",
583		       PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
584		       PROTOCOL_REV_MINOR(scpi_info->protocol_version));
585}
586static DEVICE_ATTR_RO(protocol_version);
587
588static ssize_t firmware_version_show(struct device *dev,
589				     struct device_attribute *attr, char *buf)
590{
591	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
592
593	return sprintf(buf, "%d.%d.%d\n",
594		       FW_REV_MAJOR(scpi_info->firmware_version),
595		       FW_REV_MINOR(scpi_info->firmware_version),
596		       FW_REV_PATCH(scpi_info->firmware_version));
597}
598static DEVICE_ATTR_RO(firmware_version);
599
600static struct attribute *versions_attrs[] = {
601	&dev_attr_firmware_version.attr,
602	&dev_attr_protocol_version.attr,
603	NULL,
604};
605ATTRIBUTE_GROUPS(versions);
606
607static void
608scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
609{
610	int i;
611
612	for (i = 0; i < count && pchan->chan; i++, pchan++) {
613		mbox_free_channel(pchan->chan);
614		devm_kfree(dev, pchan->xfers);
615		devm_iounmap(dev, pchan->rx_payload);
616	}
617}
618
619static int scpi_remove(struct platform_device *pdev)
620{
621	int i;
622	struct device *dev = &pdev->dev;
623	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
624
625	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
626
627	of_platform_depopulate(dev);
628	sysfs_remove_groups(&dev->kobj, versions_groups);
629	scpi_free_channels(dev, info->channels, info->num_chans);
630	platform_set_drvdata(pdev, NULL);
631
632	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
633		kfree(info->dvfs[i]->opps);
634		kfree(info->dvfs[i]);
635	}
636	devm_kfree(dev, info->channels);
637	devm_kfree(dev, info);
638
639	return 0;
640}
641
642#define MAX_SCPI_XFERS		10
643static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
644{
645	int i;
646	struct scpi_xfer *xfers;
647
648	xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
649	if (!xfers)
650		return -ENOMEM;
651
652	ch->xfers = xfers;
653	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
654		list_add_tail(&xfers->node, &ch->xfers_list);
655	return 0;
656}
657
 
 
 
 
 
658static int scpi_probe(struct platform_device *pdev)
659{
660	int count, idx, ret;
661	struct resource res;
662	struct scpi_chan *scpi_chan;
663	struct device *dev = &pdev->dev;
664	struct device_node *np = dev->of_node;
665
666	scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
667	if (!scpi_info)
668		return -ENOMEM;
669
 
 
 
670	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
671	if (count < 0) {
672		dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
673		return -ENODEV;
674	}
675
676	scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
677	if (!scpi_chan)
678		return -ENOMEM;
679
680	for (idx = 0; idx < count; idx++) {
681		resource_size_t size;
682		struct scpi_chan *pchan = scpi_chan + idx;
683		struct mbox_client *cl = &pchan->cl;
684		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
685
686		if (of_address_to_resource(shmem, 0, &res)) {
 
 
687			dev_err(dev, "failed to get SCPI payload mem resource\n");
688			ret = -EINVAL;
689			goto err;
690		}
691
692		size = resource_size(&res);
693		pchan->rx_payload = devm_ioremap(dev, res.start, size);
694		if (!pchan->rx_payload) {
695			dev_err(dev, "failed to ioremap SCPI payload\n");
696			ret = -EADDRNOTAVAIL;
697			goto err;
698		}
699		pchan->tx_payload = pchan->rx_payload + (size >> 1);
700
701		cl->dev = dev;
702		cl->rx_callback = scpi_handle_remote_msg;
703		cl->tx_prepare = scpi_tx_prepare;
704		cl->tx_block = true;
705		cl->tx_tout = 20;
706		cl->knows_txdone = false; /* controller can't ack */
707
708		INIT_LIST_HEAD(&pchan->rx_pending);
709		INIT_LIST_HEAD(&pchan->xfers_list);
710		spin_lock_init(&pchan->rx_lock);
711		mutex_init(&pchan->xfers_lock);
712
713		ret = scpi_alloc_xfer_list(dev, pchan);
714		if (!ret) {
715			pchan->chan = mbox_request_channel(cl, idx);
716			if (!IS_ERR(pchan->chan))
717				continue;
718			ret = PTR_ERR(pchan->chan);
719			if (ret != -EPROBE_DEFER)
720				dev_err(dev, "failed to get channel%d err %d\n",
721					idx, ret);
722		}
723err:
724		scpi_free_channels(dev, scpi_chan, idx);
725		scpi_info = NULL;
726		return ret;
727	}
728
729	scpi_info->channels = scpi_chan;
730	scpi_info->num_chans = count;
 
 
731	platform_set_drvdata(pdev, scpi_info);
732
 
 
 
 
 
 
 
 
 
 
 
733	ret = scpi_init_versions(scpi_info);
734	if (ret) {
735		dev_err(dev, "incorrect or no SCP firmware found\n");
736		scpi_remove(pdev);
737		return ret;
738	}
739
740	_dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
741		  PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
742		  PROTOCOL_REV_MINOR(scpi_info->protocol_version),
743		  FW_REV_MAJOR(scpi_info->firmware_version),
744		  FW_REV_MINOR(scpi_info->firmware_version),
745		  FW_REV_PATCH(scpi_info->firmware_version));
746	scpi_info->scpi_ops = &scpi_ops;
747
748	ret = sysfs_create_groups(&dev->kobj, versions_groups);
749	if (ret)
750		dev_err(dev, "unable to create sysfs version group\n");
751
752	return of_platform_populate(dev->of_node, NULL, NULL, dev);
753}
754
755static const struct of_device_id scpi_of_match[] = {
756	{.compatible = "arm,scpi"},
 
757	{},
758};
759
760MODULE_DEVICE_TABLE(of, scpi_of_match);
761
762static struct platform_driver scpi_driver = {
763	.driver = {
764		.name = "scpi_protocol",
765		.of_match_table = scpi_of_match,
766	},
767	.probe = scpi_probe,
768	.remove = scpi_remove,
769};
770module_platform_driver(scpi_driver);
771
772MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
773MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
774MODULE_LICENSE("GPL v2");