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
19struct sdw_group_params {
20 unsigned int rate;
21 int full_bw;
22 int payload_bw;
23 int hwidth;
24};
25
26struct sdw_group {
27 unsigned int count;
28 unsigned int max_size;
29 unsigned int *rates;
30};
31
32void 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(params: &p_rt->transport_params,
54 port_num: p_rt->num, grp_ctrl_valid: false,
55 grp_ctrl: SDW_BLK_GRP_CNT_1,
56 sample_int, off1: port_bo, off2: port_bo >> 8,
57 hstart: t_data->hstart,
58 hstop: t_data->hstop,
59 pack_mode: SDW_BLK_PKG_PER_PORT, lane_ctrl: 0x0);
60
61 sdw_fill_port_params(params: &p_rt->port_params,
62 port_num: p_rt->num, bps,
63 SDW_PORT_FLOW_MODE_ISOCH,
64 data_mode: 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}
82EXPORT_SYMBOL(sdw_compute_slave_ports);
83
84static 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(params: &p_rt->transport_params, port_num: p_rt->num,
110 grp_ctrl_valid: false, grp_ctrl: SDW_BLK_GRP_CNT_1, sample_int,
111 off1: port_bo, off2: port_bo >> 8, hstart, hstop,
112 pack_mode: SDW_BLK_PKG_PER_PORT, lane_ctrl: 0x0);
113
114 sdw_fill_port_params(params: &p_rt->port_params,
115 port_num: p_rt->num, bps,
116 SDW_PORT_FLOW_MODE_ISOCH,
117 data_mode: 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
137static 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, params: &params[i], port_bo, hstop);
150
151 port_bo += m_rt->ch_count * m_rt->stream->params.bps;
152 }
153
154 hstop = hstop - params[i].hwidth;
155 }
156}
157
158static int sdw_compute_group_params(struct sdw_bus *bus,
159 struct sdw_group_params *params,
160 int *rates, int count)
161{
162 struct sdw_master_runtime *m_rt;
163 int sel_col = bus->params.col;
164 unsigned int rate, bps, ch;
165 int i, column_needed = 0;
166
167 /* Calculate bandwidth per group */
168 for (i = 0; i < count; i++) {
169 params[i].rate = rates[i];
170 params[i].full_bw = bus->params.curr_dr_freq / params[i].rate;
171 }
172
173 list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
174 rate = m_rt->stream->params.rate;
175 bps = m_rt->stream->params.bps;
176 ch = m_rt->ch_count;
177
178 for (i = 0; i < count; i++) {
179 if (rate == params[i].rate)
180 params[i].payload_bw += bps * ch;
181 }
182 }
183
184 for (i = 0; i < count; i++) {
185 params[i].hwidth = (sel_col *
186 params[i].payload_bw + params[i].full_bw - 1) /
187 params[i].full_bw;
188
189 column_needed += params[i].hwidth;
190 }
191
192 if (column_needed > sel_col - 1)
193 return -EINVAL;
194
195 return 0;
196}
197
198static int sdw_add_element_group_count(struct sdw_group *group,
199 unsigned int rate)
200{
201 int num = group->count;
202 int i;
203
204 for (i = 0; i <= num; i++) {
205 if (rate == group->rates[i])
206 break;
207
208 if (i != num)
209 continue;
210
211 if (group->count >= group->max_size) {
212 unsigned int *rates;
213
214 group->max_size += 1;
215 rates = krealloc(objp: group->rates,
216 new_size: (sizeof(int) * group->max_size),
217 GFP_KERNEL);
218 if (!rates)
219 return -ENOMEM;
220 group->rates = rates;
221 }
222
223 group->rates[group->count++] = rate;
224 }
225
226 return 0;
227}
228
229static int sdw_get_group_count(struct sdw_bus *bus,
230 struct sdw_group *group)
231{
232 struct sdw_master_runtime *m_rt;
233 unsigned int rate;
234 int ret = 0;
235
236 group->count = 0;
237 group->max_size = SDW_STRM_RATE_GROUPING;
238 group->rates = kcalloc(n: group->max_size, size: sizeof(int), GFP_KERNEL);
239 if (!group->rates)
240 return -ENOMEM;
241
242 list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
243 rate = m_rt->stream->params.rate;
244 if (m_rt == list_first_entry(&bus->m_rt_list,
245 struct sdw_master_runtime,
246 bus_node)) {
247 group->rates[group->count++] = rate;
248
249 } else {
250 ret = sdw_add_element_group_count(group, rate);
251 if (ret < 0) {
252 kfree(objp: group->rates);
253 return ret;
254 }
255 }
256 }
257
258 return ret;
259}
260
261/**
262 * sdw_compute_port_params: Compute transport and port parameters
263 *
264 * @bus: SDW Bus instance
265 */
266static int sdw_compute_port_params(struct sdw_bus *bus)
267{
268 struct sdw_group_params *params = NULL;
269 struct sdw_group group;
270 int ret;
271
272 ret = sdw_get_group_count(bus, group: &group);
273 if (ret < 0)
274 return ret;
275
276 if (group.count == 0)
277 goto out;
278
279 params = kcalloc(n: group.count, size: sizeof(*params), GFP_KERNEL);
280 if (!params) {
281 ret = -ENOMEM;
282 goto out;
283 }
284
285 /* Compute transport parameters for grouped streams */
286 ret = sdw_compute_group_params(bus, params,
287 rates: &group.rates[0], count: group.count);
288 if (ret < 0)
289 goto free_params;
290
291 _sdw_compute_port_params(bus, params, count: group.count);
292
293free_params:
294 kfree(objp: params);
295out:
296 kfree(objp: group.rates);
297
298 return ret;
299}
300
301static int sdw_select_row_col(struct sdw_bus *bus, int clk_freq)
302{
303 struct sdw_master_prop *prop = &bus->prop;
304 int frame_int, frame_freq;
305 int r, c;
306
307 for (c = 0; c < SDW_FRAME_COLS; c++) {
308 for (r = 0; r < SDW_FRAME_ROWS; r++) {
309 if (sdw_rows[r] != prop->default_row ||
310 sdw_cols[c] != prop->default_col)
311 continue;
312
313 frame_int = sdw_rows[r] * sdw_cols[c];
314 frame_freq = clk_freq / frame_int;
315
316 if ((clk_freq - (frame_freq * SDW_FRAME_CTRL_BITS)) <
317 bus->params.bandwidth)
318 continue;
319
320 bus->params.row = sdw_rows[r];
321 bus->params.col = sdw_cols[c];
322 return 0;
323 }
324 }
325
326 return -EINVAL;
327}
328
329/**
330 * sdw_compute_bus_params: Compute bus parameters
331 *
332 * @bus: SDW Bus instance
333 */
334static int sdw_compute_bus_params(struct sdw_bus *bus)
335{
336 unsigned int curr_dr_freq = 0;
337 struct sdw_master_prop *mstr_prop = &bus->prop;
338 int i, clk_values, ret;
339 bool is_gear = false;
340 u32 *clk_buf;
341
342 if (mstr_prop->num_clk_gears) {
343 clk_values = mstr_prop->num_clk_gears;
344 clk_buf = mstr_prop->clk_gears;
345 is_gear = true;
346 } else if (mstr_prop->num_clk_freq) {
347 clk_values = mstr_prop->num_clk_freq;
348 clk_buf = mstr_prop->clk_freq;
349 } else {
350 clk_values = 1;
351 clk_buf = NULL;
352 }
353
354 for (i = 0; i < clk_values; i++) {
355 if (!clk_buf)
356 curr_dr_freq = bus->params.max_dr_freq;
357 else
358 curr_dr_freq = (is_gear) ?
359 (bus->params.max_dr_freq >> clk_buf[i]) :
360 clk_buf[i] * SDW_DOUBLE_RATE_FACTOR;
361
362 if (curr_dr_freq <= bus->params.bandwidth)
363 continue;
364
365 break;
366
367 /*
368 * TODO: Check all the Slave(s) port(s) audio modes and find
369 * whether given clock rate is supported with glitchless
370 * transition.
371 */
372 }
373
374 if (i == clk_values) {
375 dev_err(bus->dev, "%s: could not find clock value for bandwidth %d\n",
376 __func__, bus->params.bandwidth);
377 return -EINVAL;
378 }
379
380 ret = sdw_select_row_col(bus, clk_freq: curr_dr_freq);
381 if (ret < 0) {
382 dev_err(bus->dev, "%s: could not find frame configuration for bus dr_freq %d\n",
383 __func__, curr_dr_freq);
384 return -EINVAL;
385 }
386
387 bus->params.curr_dr_freq = curr_dr_freq;
388 return 0;
389}
390
391/**
392 * sdw_compute_params: Compute bus, transport and port parameters
393 *
394 * @bus: SDW Bus instance
395 */
396int sdw_compute_params(struct sdw_bus *bus)
397{
398 int ret;
399
400 /* Computes clock frequency, frame shape and frame frequency */
401 ret = sdw_compute_bus_params(bus);
402 if (ret < 0)
403 return ret;
404
405 /* Compute transport and port params */
406 ret = sdw_compute_port_params(bus);
407 if (ret < 0) {
408 dev_err(bus->dev, "Compute transport params failed: %d\n", ret);
409 return ret;
410 }
411
412 return 0;
413}
414EXPORT_SYMBOL(sdw_compute_params);
415
416MODULE_LICENSE("Dual BSD/GPL");
417MODULE_DESCRIPTION("SoundWire Generic Bandwidth Allocation");
418

source code of linux/drivers/soundwire/generic_bandwidth_allocation.c