1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
2 // Copyright(c) 2015-2020 Intel Corporation.
3
4 /*
5 * Bandwidth management algorithm based on 2^n gears
6 *
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/slab.h>
14 #include <linux/soundwire/sdw.h>
15 #include "bus.h"
16
17 #define SDW_STRM_RATE_GROUPING 1
18
19 struct sdw_group_params {
20 unsigned int rate;
21 int full_bw;
22 int payload_bw;
23 int hwidth;
24 };
25
26 struct sdw_group {
27 unsigned int count;
28 unsigned int max_size;
29 unsigned int *rates;
30 };
31
sdw_compute_slave_ports(struct sdw_master_runtime * m_rt,struct sdw_transport_data * t_data)32 void sdw_compute_slave_ports(struct sdw_master_runtime *m_rt,
33 struct sdw_transport_data *t_data)
34 {
35 struct sdw_slave_runtime *s_rt = NULL;
36 struct sdw_port_runtime *p_rt;
37 int port_bo, sample_int;
38 unsigned int rate, bps, ch = 0;
39 unsigned int slave_total_ch;
40 struct sdw_bus_params *b_params = &m_rt->bus->params;
41
42 port_bo = t_data->block_offset;
43
44 list_for_each_entry(s_rt, &m_rt->slave_rt_list, m_rt_node) {
45 rate = m_rt->stream->params.rate;
46 bps = m_rt->stream->params.bps;
47 sample_int = (m_rt->bus->params.curr_dr_freq / rate);
48 slave_total_ch = 0;
49
50 list_for_each_entry(p_rt, &s_rt->port_list, port_node) {
51 ch = hweight32(p_rt->ch_mask);
52
53 sdw_fill_xport_params(&p_rt->transport_params,
54 p_rt->num, false,
55 SDW_BLK_GRP_CNT_1,
56 sample_int, port_bo, port_bo >> 8,
57 t_data->hstart,
58 t_data->hstop,
59 SDW_BLK_PKG_PER_PORT, 0x0);
60
61 sdw_fill_port_params(&p_rt->port_params,
62 p_rt->num, bps,
63 SDW_PORT_FLOW_MODE_ISOCH,
64 b_params->s_data_mode);
65
66 port_bo += bps * ch;
67 slave_total_ch += ch;
68 }
69
70 if (m_rt->direction == SDW_DATA_DIR_TX &&
71 m_rt->ch_count == slave_total_ch) {
72 /*
73 * Slave devices were configured to access all channels
74 * of the stream, which indicates that they operate in
75 * 'mirror mode'. Make sure we reset the port offset for
76 * the next device in the list
77 */
78 port_bo = t_data->block_offset;
79 }
80 }
81 }
82 EXPORT_SYMBOL(sdw_compute_slave_ports);
83
sdw_compute_master_ports(struct sdw_master_runtime * m_rt,struct sdw_group_params * params,int * port_bo,int hstop)84 static void sdw_compute_master_ports(struct sdw_master_runtime *m_rt,
85 struct sdw_group_params *params,
86 int *port_bo, int hstop)
87 {
88 struct sdw_transport_data t_data = {0};
89 struct sdw_port_runtime *p_rt;
90 struct sdw_bus *bus = m_rt->bus;
91 struct sdw_bus_params *b_params = &bus->params;
92 int sample_int, hstart = 0;
93 unsigned int rate, bps, ch;
94
95 rate = m_rt->stream->params.rate;
96 bps = m_rt->stream->params.bps;
97 ch = m_rt->ch_count;
98 sample_int = (bus->params.curr_dr_freq / rate);
99
100 if (rate != params->rate)
101 return;
102
103 t_data.hstop = hstop;
104 hstart = hstop - params->hwidth + 1;
105 t_data.hstart = hstart;
106
107 list_for_each_entry(p_rt, &m_rt->port_list, port_node) {
108
109 sdw_fill_xport_params(&p_rt->transport_params, p_rt->num,
110 false, SDW_BLK_GRP_CNT_1, sample_int,
111 *port_bo, (*port_bo) >> 8, hstart, hstop,
112 SDW_BLK_PKG_PER_PORT, 0x0);
113
114 sdw_fill_port_params(&p_rt->port_params,
115 p_rt->num, bps,
116 SDW_PORT_FLOW_MODE_ISOCH,
117 b_params->m_data_mode);
118
119 /* Check for first entry */
120 if (!(p_rt == list_first_entry(&m_rt->port_list,
121 struct sdw_port_runtime,
122 port_node))) {
123 (*port_bo) += bps * ch;
124 continue;
125 }
126
127 t_data.hstart = hstart;
128 t_data.hstop = hstop;
129 t_data.block_offset = *port_bo;
130 t_data.sub_block_offset = 0;
131 (*port_bo) += bps * ch;
132 }
133
134 sdw_compute_slave_ports(m_rt, &t_data);
135 }
136
_sdw_compute_port_params(struct sdw_bus * bus,struct sdw_group_params * params,int count)137 static void _sdw_compute_port_params(struct sdw_bus *bus,
138 struct sdw_group_params *params, int count)
139 {
140 struct sdw_master_runtime *m_rt;
141 int hstop = bus->params.col - 1;
142 int port_bo, i;
143
144 /* Run loop for all groups to compute transport parameters */
145 for (i = 0; i < count; i++) {
146 port_bo = 1;
147
148 list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
149 sdw_compute_master_ports(m_rt, ¶ms[i], &port_bo, hstop);
150 }
151
152 hstop = hstop - params[i].hwidth;
153 }
154 }
155
sdw_compute_group_params(struct sdw_bus * bus,struct sdw_group_params * params,int * rates,int count)156 static int sdw_compute_group_params(struct sdw_bus *bus,
157 struct sdw_group_params *params,
158 int *rates, int count)
159 {
160 struct sdw_master_runtime *m_rt;
161 int sel_col = bus->params.col;
162 unsigned int rate, bps, ch;
163 int i, column_needed = 0;
164
165 /* Calculate bandwidth per group */
166 for (i = 0; i < count; i++) {
167 params[i].rate = rates[i];
168 params[i].full_bw = bus->params.curr_dr_freq / params[i].rate;
169 }
170
171 list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
172 rate = m_rt->stream->params.rate;
173 bps = m_rt->stream->params.bps;
174 ch = m_rt->ch_count;
175
176 for (i = 0; i < count; i++) {
177 if (rate == params[i].rate)
178 params[i].payload_bw += bps * ch;
179 }
180 }
181
182 for (i = 0; i < count; i++) {
183 params[i].hwidth = (sel_col *
184 params[i].payload_bw + params[i].full_bw - 1) /
185 params[i].full_bw;
186
187 column_needed += params[i].hwidth;
188 }
189
190 if (column_needed > sel_col - 1)
191 return -EINVAL;
192
193 return 0;
194 }
195
sdw_add_element_group_count(struct sdw_group * group,unsigned int rate)196 static int sdw_add_element_group_count(struct sdw_group *group,
197 unsigned int rate)
198 {
199 int num = group->count;
200 int i;
201
202 for (i = 0; i <= num; i++) {
203 if (rate == group->rates[i])
204 break;
205
206 if (i != num)
207 continue;
208
209 if (group->count >= group->max_size) {
210 unsigned int *rates;
211
212 group->max_size += 1;
213 rates = krealloc(group->rates,
214 (sizeof(int) * group->max_size),
215 GFP_KERNEL);
216 if (!rates)
217 return -ENOMEM;
218 group->rates = rates;
219 }
220
221 group->rates[group->count++] = rate;
222 }
223
224 return 0;
225 }
226
sdw_get_group_count(struct sdw_bus * bus,struct sdw_group * group)227 static int sdw_get_group_count(struct sdw_bus *bus,
228 struct sdw_group *group)
229 {
230 struct sdw_master_runtime *m_rt;
231 unsigned int rate;
232 int ret = 0;
233
234 group->count = 0;
235 group->max_size = SDW_STRM_RATE_GROUPING;
236 group->rates = kcalloc(group->max_size, sizeof(int), GFP_KERNEL);
237 if (!group->rates)
238 return -ENOMEM;
239
240 list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
241 rate = m_rt->stream->params.rate;
242 if (m_rt == list_first_entry(&bus->m_rt_list,
243 struct sdw_master_runtime,
244 bus_node)) {
245 group->rates[group->count++] = rate;
246
247 } else {
248 ret = sdw_add_element_group_count(group, rate);
249 if (ret < 0) {
250 kfree(group->rates);
251 return ret;
252 }
253 }
254 }
255
256 return ret;
257 }
258
259 /**
260 * sdw_compute_port_params: Compute transport and port parameters
261 *
262 * @bus: SDW Bus instance
263 */
sdw_compute_port_params(struct sdw_bus * bus)264 static int sdw_compute_port_params(struct sdw_bus *bus)
265 {
266 struct sdw_group_params *params = NULL;
267 struct sdw_group group;
268 int ret;
269
270 ret = sdw_get_group_count(bus, &group);
271 if (ret < 0)
272 return ret;
273
274 if (group.count == 0)
275 goto out;
276
277 params = kcalloc(group.count, sizeof(*params), GFP_KERNEL);
278 if (!params) {
279 ret = -ENOMEM;
280 goto out;
281 }
282
283 /* Compute transport parameters for grouped streams */
284 ret = sdw_compute_group_params(bus, params,
285 &group.rates[0], group.count);
286 if (ret < 0)
287 goto free_params;
288
289 _sdw_compute_port_params(bus, params, group.count);
290
291 free_params:
292 kfree(params);
293 out:
294 kfree(group.rates);
295
296 return ret;
297 }
298
sdw_select_row_col(struct sdw_bus * bus,int clk_freq)299 static int sdw_select_row_col(struct sdw_bus *bus, int clk_freq)
300 {
301 struct sdw_master_prop *prop = &bus->prop;
302 int frame_int, frame_freq;
303 int r, c;
304
305 for (c = 0; c < SDW_FRAME_COLS; c++) {
306 for (r = 0; r < SDW_FRAME_ROWS; r++) {
307 if (sdw_rows[r] != prop->default_row ||
308 sdw_cols[c] != prop->default_col)
309 continue;
310
311 frame_int = sdw_rows[r] * sdw_cols[c];
312 frame_freq = clk_freq / frame_int;
313
314 if ((clk_freq - (frame_freq * SDW_FRAME_CTRL_BITS)) <
315 bus->params.bandwidth)
316 continue;
317
318 bus->params.row = sdw_rows[r];
319 bus->params.col = sdw_cols[c];
320 return 0;
321 }
322 }
323
324 return -EINVAL;
325 }
326
327 /**
328 * sdw_compute_bus_params: Compute bus parameters
329 *
330 * @bus: SDW Bus instance
331 */
sdw_compute_bus_params(struct sdw_bus * bus)332 static int sdw_compute_bus_params(struct sdw_bus *bus)
333 {
334 unsigned int curr_dr_freq = 0;
335 struct sdw_master_prop *mstr_prop = &bus->prop;
336 int i, clk_values, ret;
337 bool is_gear = false;
338 u32 *clk_buf;
339
340 if (mstr_prop->num_clk_gears) {
341 clk_values = mstr_prop->num_clk_gears;
342 clk_buf = mstr_prop->clk_gears;
343 is_gear = true;
344 } else if (mstr_prop->num_clk_freq) {
345 clk_values = mstr_prop->num_clk_freq;
346 clk_buf = mstr_prop->clk_freq;
347 } else {
348 clk_values = 1;
349 clk_buf = NULL;
350 }
351
352 for (i = 0; i < clk_values; i++) {
353 if (!clk_buf)
354 curr_dr_freq = bus->params.max_dr_freq;
355 else
356 curr_dr_freq = (is_gear) ?
357 (bus->params.max_dr_freq >> clk_buf[i]) :
358 clk_buf[i] * SDW_DOUBLE_RATE_FACTOR;
359
360 if (curr_dr_freq <= bus->params.bandwidth)
361 continue;
362
363 break;
364
365 /*
366 * TODO: Check all the Slave(s) port(s) audio modes and find
367 * whether given clock rate is supported with glitchless
368 * transition.
369 */
370 }
371
372 if (i == clk_values) {
373 dev_err(bus->dev, "%s: could not find clock value for bandwidth %d\n",
374 __func__, bus->params.bandwidth);
375 return -EINVAL;
376 }
377
378 ret = sdw_select_row_col(bus, curr_dr_freq);
379 if (ret < 0) {
380 dev_err(bus->dev, "%s: could not find frame configuration for bus dr_freq %d\n",
381 __func__, curr_dr_freq);
382 return -EINVAL;
383 }
384
385 bus->params.curr_dr_freq = curr_dr_freq;
386 return 0;
387 }
388
389 /**
390 * sdw_compute_params: Compute bus, transport and port parameters
391 *
392 * @bus: SDW Bus instance
393 */
sdw_compute_params(struct sdw_bus * bus)394 int sdw_compute_params(struct sdw_bus *bus)
395 {
396 int ret;
397
398 /* Computes clock frequency, frame shape and frame frequency */
399 ret = sdw_compute_bus_params(bus);
400 if (ret < 0)
401 return ret;
402
403 /* Compute transport and port params */
404 ret = sdw_compute_port_params(bus);
405 if (ret < 0) {
406 dev_err(bus->dev, "Compute transport params failed: %d\n", ret);
407 return ret;
408 }
409
410 return 0;
411 }
412 EXPORT_SYMBOL(sdw_compute_params);
413
414 MODULE_LICENSE("Dual BSD/GPL");
415 MODULE_DESCRIPTION("SoundWire Generic Bandwidth Allocation");
416