1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * System Control and Management Interface (SCMI) Clock Protocol
4 *
5 * Copyright (C) 2018-2021 ARM Ltd.
6 */
7
8 #include <linux/module.h>
9 #include <linux/sort.h>
10
11 #include "common.h"
12
13 enum scmi_clock_protocol_cmd {
14 CLOCK_ATTRIBUTES = 0x3,
15 CLOCK_DESCRIBE_RATES = 0x4,
16 CLOCK_RATE_SET = 0x5,
17 CLOCK_RATE_GET = 0x6,
18 CLOCK_CONFIG_SET = 0x7,
19 };
20
21 struct scmi_msg_resp_clock_protocol_attributes {
22 __le16 num_clocks;
23 u8 max_async_req;
24 u8 reserved;
25 };
26
27 struct scmi_msg_resp_clock_attributes {
28 __le32 attributes;
29 #define CLOCK_ENABLE BIT(0)
30 u8 name[SCMI_MAX_STR_SIZE];
31 };
32
33 struct scmi_clock_set_config {
34 __le32 id;
35 __le32 attributes;
36 };
37
38 struct scmi_msg_clock_describe_rates {
39 __le32 id;
40 __le32 rate_index;
41 };
42
43 struct scmi_msg_resp_clock_describe_rates {
44 __le32 num_rates_flags;
45 #define NUM_RETURNED(x) ((x) & 0xfff)
46 #define RATE_DISCRETE(x) !((x) & BIT(12))
47 #define NUM_REMAINING(x) ((x) >> 16)
48 struct {
49 __le32 value_low;
50 __le32 value_high;
51 } rate[0];
52 #define RATE_TO_U64(X) \
53 ({ \
54 typeof(X) x = (X); \
55 le32_to_cpu((x).value_low) | (u64)le32_to_cpu((x).value_high) << 32; \
56 })
57 };
58
59 struct scmi_clock_set_rate {
60 __le32 flags;
61 #define CLOCK_SET_ASYNC BIT(0)
62 #define CLOCK_SET_IGNORE_RESP BIT(1)
63 #define CLOCK_SET_ROUND_UP BIT(2)
64 #define CLOCK_SET_ROUND_AUTO BIT(3)
65 __le32 id;
66 __le32 value_low;
67 __le32 value_high;
68 };
69
70 struct clock_info {
71 u32 version;
72 int num_clocks;
73 int max_async_req;
74 atomic_t cur_async_req;
75 struct scmi_clock_info *clk;
76 };
77
78 static int
scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle * ph,struct clock_info * ci)79 scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
80 struct clock_info *ci)
81 {
82 int ret;
83 struct scmi_xfer *t;
84 struct scmi_msg_resp_clock_protocol_attributes *attr;
85
86 ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
87 0, sizeof(*attr), &t);
88 if (ret)
89 return ret;
90
91 attr = t->rx.buf;
92
93 ret = ph->xops->do_xfer(ph, t);
94 if (!ret) {
95 ci->num_clocks = le16_to_cpu(attr->num_clocks);
96 ci->max_async_req = attr->max_async_req;
97 }
98
99 ph->xops->xfer_put(ph, t);
100 return ret;
101 }
102
scmi_clock_attributes_get(const struct scmi_protocol_handle * ph,u32 clk_id,struct scmi_clock_info * clk)103 static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
104 u32 clk_id, struct scmi_clock_info *clk)
105 {
106 int ret;
107 struct scmi_xfer *t;
108 struct scmi_msg_resp_clock_attributes *attr;
109
110 ret = ph->xops->xfer_get_init(ph, CLOCK_ATTRIBUTES,
111 sizeof(clk_id), sizeof(*attr), &t);
112 if (ret)
113 return ret;
114
115 put_unaligned_le32(clk_id, t->tx.buf);
116 attr = t->rx.buf;
117
118 ret = ph->xops->do_xfer(ph, t);
119 if (!ret)
120 strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
121 else
122 clk->name[0] = '\0';
123
124 ph->xops->xfer_put(ph, t);
125 return ret;
126 }
127
rate_cmp_func(const void * _r1,const void * _r2)128 static int rate_cmp_func(const void *_r1, const void *_r2)
129 {
130 const u64 *r1 = _r1, *r2 = _r2;
131
132 if (*r1 < *r2)
133 return -1;
134 else if (*r1 == *r2)
135 return 0;
136 else
137 return 1;
138 }
139
140 static int
scmi_clock_describe_rates_get(const struct scmi_protocol_handle * ph,u32 clk_id,struct scmi_clock_info * clk)141 scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
142 struct scmi_clock_info *clk)
143 {
144 u64 *rate = NULL;
145 int ret, cnt;
146 bool rate_discrete = false;
147 u32 tot_rate_cnt = 0, rates_flag;
148 u16 num_returned, num_remaining;
149 struct scmi_xfer *t;
150 struct scmi_msg_clock_describe_rates *clk_desc;
151 struct scmi_msg_resp_clock_describe_rates *rlist;
152
153 ret = ph->xops->xfer_get_init(ph, CLOCK_DESCRIBE_RATES,
154 sizeof(*clk_desc), 0, &t);
155 if (ret)
156 return ret;
157
158 clk_desc = t->tx.buf;
159 rlist = t->rx.buf;
160
161 do {
162 clk_desc->id = cpu_to_le32(clk_id);
163 /* Set the number of rates to be skipped/already read */
164 clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
165
166 ret = ph->xops->do_xfer(ph, t);
167 if (ret)
168 goto err;
169
170 rates_flag = le32_to_cpu(rlist->num_rates_flags);
171 num_remaining = NUM_REMAINING(rates_flag);
172 rate_discrete = RATE_DISCRETE(rates_flag);
173 num_returned = NUM_RETURNED(rates_flag);
174
175 if (tot_rate_cnt + num_returned > SCMI_MAX_NUM_RATES) {
176 dev_err(ph->dev, "No. of rates > MAX_NUM_RATES");
177 break;
178 }
179
180 if (!rate_discrete) {
181 clk->range.min_rate = RATE_TO_U64(rlist->rate[0]);
182 clk->range.max_rate = RATE_TO_U64(rlist->rate[1]);
183 clk->range.step_size = RATE_TO_U64(rlist->rate[2]);
184 dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
185 clk->range.min_rate, clk->range.max_rate,
186 clk->range.step_size);
187 break;
188 }
189
190 rate = &clk->list.rates[tot_rate_cnt];
191 for (cnt = 0; cnt < num_returned; cnt++, rate++) {
192 *rate = RATE_TO_U64(rlist->rate[cnt]);
193 dev_dbg(ph->dev, "Rate %llu Hz\n", *rate);
194 }
195
196 tot_rate_cnt += num_returned;
197
198 ph->xops->reset_rx_to_maxsz(ph, t);
199 /*
200 * check for both returned and remaining to avoid infinite
201 * loop due to buggy firmware
202 */
203 } while (num_returned && num_remaining);
204
205 if (rate_discrete && rate) {
206 clk->list.num_rates = tot_rate_cnt;
207 sort(rate, tot_rate_cnt, sizeof(*rate), rate_cmp_func, NULL);
208 }
209
210 clk->rate_discrete = rate_discrete;
211
212 err:
213 ph->xops->xfer_put(ph, t);
214 return ret;
215 }
216
217 static int
scmi_clock_rate_get(const struct scmi_protocol_handle * ph,u32 clk_id,u64 * value)218 scmi_clock_rate_get(const struct scmi_protocol_handle *ph,
219 u32 clk_id, u64 *value)
220 {
221 int ret;
222 struct scmi_xfer *t;
223
224 ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_GET,
225 sizeof(__le32), sizeof(u64), &t);
226 if (ret)
227 return ret;
228
229 put_unaligned_le32(clk_id, t->tx.buf);
230
231 ret = ph->xops->do_xfer(ph, t);
232 if (!ret)
233 *value = get_unaligned_le64(t->rx.buf);
234
235 ph->xops->xfer_put(ph, t);
236 return ret;
237 }
238
scmi_clock_rate_set(const struct scmi_protocol_handle * ph,u32 clk_id,u64 rate)239 static int scmi_clock_rate_set(const struct scmi_protocol_handle *ph,
240 u32 clk_id, u64 rate)
241 {
242 int ret;
243 u32 flags = 0;
244 struct scmi_xfer *t;
245 struct scmi_clock_set_rate *cfg;
246 struct clock_info *ci = ph->get_priv(ph);
247
248 ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_SET, sizeof(*cfg), 0, &t);
249 if (ret)
250 return ret;
251
252 if (ci->max_async_req &&
253 atomic_inc_return(&ci->cur_async_req) < ci->max_async_req)
254 flags |= CLOCK_SET_ASYNC;
255
256 cfg = t->tx.buf;
257 cfg->flags = cpu_to_le32(flags);
258 cfg->id = cpu_to_le32(clk_id);
259 cfg->value_low = cpu_to_le32(rate & 0xffffffff);
260 cfg->value_high = cpu_to_le32(rate >> 32);
261
262 if (flags & CLOCK_SET_ASYNC)
263 ret = ph->xops->do_xfer_with_response(ph, t);
264 else
265 ret = ph->xops->do_xfer(ph, t);
266
267 if (ci->max_async_req)
268 atomic_dec(&ci->cur_async_req);
269
270 ph->xops->xfer_put(ph, t);
271 return ret;
272 }
273
274 static int
scmi_clock_config_set(const struct scmi_protocol_handle * ph,u32 clk_id,u32 config)275 scmi_clock_config_set(const struct scmi_protocol_handle *ph, u32 clk_id,
276 u32 config)
277 {
278 int ret;
279 struct scmi_xfer *t;
280 struct scmi_clock_set_config *cfg;
281
282 ret = ph->xops->xfer_get_init(ph, CLOCK_CONFIG_SET,
283 sizeof(*cfg), 0, &t);
284 if (ret)
285 return ret;
286
287 cfg = t->tx.buf;
288 cfg->id = cpu_to_le32(clk_id);
289 cfg->attributes = cpu_to_le32(config);
290
291 ret = ph->xops->do_xfer(ph, t);
292
293 ph->xops->xfer_put(ph, t);
294 return ret;
295 }
296
scmi_clock_enable(const struct scmi_protocol_handle * ph,u32 clk_id)297 static int scmi_clock_enable(const struct scmi_protocol_handle *ph, u32 clk_id)
298 {
299 return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE);
300 }
301
scmi_clock_disable(const struct scmi_protocol_handle * ph,u32 clk_id)302 static int scmi_clock_disable(const struct scmi_protocol_handle *ph, u32 clk_id)
303 {
304 return scmi_clock_config_set(ph, clk_id, 0);
305 }
306
scmi_clock_count_get(const struct scmi_protocol_handle * ph)307 static int scmi_clock_count_get(const struct scmi_protocol_handle *ph)
308 {
309 struct clock_info *ci = ph->get_priv(ph);
310
311 return ci->num_clocks;
312 }
313
314 static const struct scmi_clock_info *
scmi_clock_info_get(const struct scmi_protocol_handle * ph,u32 clk_id)315 scmi_clock_info_get(const struct scmi_protocol_handle *ph, u32 clk_id)
316 {
317 struct clock_info *ci = ph->get_priv(ph);
318 struct scmi_clock_info *clk = ci->clk + clk_id;
319
320 if (!clk->name[0])
321 return NULL;
322
323 return clk;
324 }
325
326 static const struct scmi_clk_proto_ops clk_proto_ops = {
327 .count_get = scmi_clock_count_get,
328 .info_get = scmi_clock_info_get,
329 .rate_get = scmi_clock_rate_get,
330 .rate_set = scmi_clock_rate_set,
331 .enable = scmi_clock_enable,
332 .disable = scmi_clock_disable,
333 };
334
scmi_clock_protocol_init(const struct scmi_protocol_handle * ph)335 static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
336 {
337 u32 version;
338 int clkid, ret;
339 struct clock_info *cinfo;
340
341 ph->xops->version_get(ph, &version);
342
343 dev_dbg(ph->dev, "Clock Version %d.%d\n",
344 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
345
346 cinfo = devm_kzalloc(ph->dev, sizeof(*cinfo), GFP_KERNEL);
347 if (!cinfo)
348 return -ENOMEM;
349
350 scmi_clock_protocol_attributes_get(ph, cinfo);
351
352 cinfo->clk = devm_kcalloc(ph->dev, cinfo->num_clocks,
353 sizeof(*cinfo->clk), GFP_KERNEL);
354 if (!cinfo->clk)
355 return -ENOMEM;
356
357 for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
358 struct scmi_clock_info *clk = cinfo->clk + clkid;
359
360 ret = scmi_clock_attributes_get(ph, clkid, clk);
361 if (!ret)
362 scmi_clock_describe_rates_get(ph, clkid, clk);
363 }
364
365 cinfo->version = version;
366 return ph->set_priv(ph, cinfo);
367 }
368
369 static const struct scmi_protocol scmi_clock = {
370 .id = SCMI_PROTOCOL_CLOCK,
371 .owner = THIS_MODULE,
372 .instance_init = &scmi_clock_protocol_init,
373 .ops = &clk_proto_ops,
374 };
375
376 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(clock, scmi_clock)
377