1 | // SPDX-License-Identifier: (GPL-2.0 OR MIT) |
2 | // |
3 | // Copyright (c) 2018 BayLibre, SAS. |
4 | // Author: Jerome Brunet <jbrunet@baylibre.com> |
5 | |
6 | #include <linux/clk.h> |
7 | #include <linux/module.h> |
8 | #include <linux/of_platform.h> |
9 | #include <linux/regmap.h> |
10 | #include <linux/reset.h> |
11 | #include <sound/soc.h> |
12 | |
13 | #include "axg-tdm-formatter.h" |
14 | |
15 | struct axg_tdm_formatter { |
16 | struct list_head list; |
17 | struct axg_tdm_stream *stream; |
18 | const struct axg_tdm_formatter_driver *drv; |
19 | struct clk *pclk; |
20 | struct clk *sclk; |
21 | struct clk *lrclk; |
22 | struct clk *sclk_sel; |
23 | struct clk *lrclk_sel; |
24 | struct reset_control *reset; |
25 | bool enabled; |
26 | struct regmap *map; |
27 | }; |
28 | |
29 | int axg_tdm_formatter_set_channel_masks(struct regmap *map, |
30 | struct axg_tdm_stream *ts, |
31 | unsigned int offset) |
32 | { |
33 | unsigned int ch = ts->channels; |
34 | u32 val[AXG_TDM_NUM_LANES]; |
35 | int i, j, k; |
36 | |
37 | /* |
38 | * We need to mimick the slot distribution used by the HW to keep the |
39 | * channel placement consistent regardless of the number of channel |
40 | * in the stream. This is why the odd algorithm below is used. |
41 | */ |
42 | memset(val, 0, sizeof(*val) * AXG_TDM_NUM_LANES); |
43 | |
44 | /* |
45 | * Distribute the channels of the stream over the available slots |
46 | * of each TDM lane. We need to go over the 32 slots ... |
47 | */ |
48 | for (i = 0; (i < 32) && ch; i += 2) { |
49 | /* ... of all the lanes ... */ |
50 | for (j = 0; j < AXG_TDM_NUM_LANES; j++) { |
51 | /* ... then distribute the channels in pairs */ |
52 | for (k = 0; k < 2; k++) { |
53 | if ((BIT(i + k) & ts->mask[j]) && ch) { |
54 | val[j] |= BIT(i + k); |
55 | ch -= 1; |
56 | } |
57 | } |
58 | } |
59 | } |
60 | |
61 | /* |
62 | * If we still have channel left at the end of the process, it means |
63 | * the stream has more channels than we can accommodate and we should |
64 | * have caught this earlier. |
65 | */ |
66 | if (WARN_ON(ch != 0)) { |
67 | pr_err("channel mask error\n" ); |
68 | return -EINVAL; |
69 | } |
70 | |
71 | for (i = 0; i < AXG_TDM_NUM_LANES; i++) { |
72 | regmap_write(map, reg: offset, val: val[i]); |
73 | offset += regmap_get_reg_stride(map); |
74 | } |
75 | |
76 | return 0; |
77 | } |
78 | EXPORT_SYMBOL_GPL(axg_tdm_formatter_set_channel_masks); |
79 | |
80 | static int axg_tdm_formatter_enable(struct axg_tdm_formatter *formatter) |
81 | { |
82 | struct axg_tdm_stream *ts = formatter->stream; |
83 | bool invert; |
84 | int ret; |
85 | |
86 | /* Do nothing if the formatter is already enabled */ |
87 | if (formatter->enabled) |
88 | return 0; |
89 | |
90 | /* |
91 | * On the g12a (and possibly other SoCs), when a stream using |
92 | * multiple lanes is restarted, it will sometimes not start |
93 | * from the first lane, but randomly from another used one. |
94 | * The result is an unexpected and random channel shift. |
95 | * |
96 | * The hypothesis is that an HW counter is not properly reset |
97 | * and the formatter simply starts on the lane it stopped |
98 | * before. Unfortunately, there does not seems to be a way to |
99 | * reset this through the registers of the block. |
100 | * |
101 | * However, the g12a has indenpendent reset lines for each audio |
102 | * devices. Using this reset before each start solves the issue. |
103 | */ |
104 | ret = reset_control_reset(rstc: formatter->reset); |
105 | if (ret) |
106 | return ret; |
107 | |
108 | /* |
109 | * If sclk is inverted, it means the bit should latched on the |
110 | * rising edge which is what our HW expects. If not, we need to |
111 | * invert it before the formatter. |
112 | */ |
113 | invert = axg_tdm_sclk_invert(fmt: ts->iface->fmt); |
114 | ret = clk_set_phase(clk: formatter->sclk, degrees: invert ? 0 : 180); |
115 | if (ret) |
116 | return ret; |
117 | |
118 | /* Setup the stream parameter in the formatter */ |
119 | ret = formatter->drv->ops->prepare(formatter->map, |
120 | formatter->drv->quirks, |
121 | formatter->stream); |
122 | if (ret) |
123 | return ret; |
124 | |
125 | /* Enable the signal clocks feeding the formatter */ |
126 | ret = clk_prepare_enable(clk: formatter->sclk); |
127 | if (ret) |
128 | return ret; |
129 | |
130 | ret = clk_prepare_enable(clk: formatter->lrclk); |
131 | if (ret) { |
132 | clk_disable_unprepare(clk: formatter->sclk); |
133 | return ret; |
134 | } |
135 | |
136 | /* Finally, actually enable the formatter */ |
137 | formatter->drv->ops->enable(formatter->map); |
138 | formatter->enabled = true; |
139 | |
140 | return 0; |
141 | } |
142 | |
143 | static void axg_tdm_formatter_disable(struct axg_tdm_formatter *formatter) |
144 | { |
145 | /* Do nothing if the formatter is already disabled */ |
146 | if (!formatter->enabled) |
147 | return; |
148 | |
149 | formatter->drv->ops->disable(formatter->map); |
150 | clk_disable_unprepare(clk: formatter->lrclk); |
151 | clk_disable_unprepare(clk: formatter->sclk); |
152 | formatter->enabled = false; |
153 | } |
154 | |
155 | static int axg_tdm_formatter_attach(struct axg_tdm_formatter *formatter) |
156 | { |
157 | struct axg_tdm_stream *ts = formatter->stream; |
158 | int ret = 0; |
159 | |
160 | mutex_lock(&ts->lock); |
161 | |
162 | /* Catch up if the stream is already running when we attach */ |
163 | if (ts->ready) { |
164 | ret = axg_tdm_formatter_enable(formatter); |
165 | if (ret) { |
166 | pr_err("failed to enable formatter\n" ); |
167 | goto out; |
168 | } |
169 | } |
170 | |
171 | list_add_tail(new: &formatter->list, head: &ts->formatter_list); |
172 | out: |
173 | mutex_unlock(lock: &ts->lock); |
174 | return ret; |
175 | } |
176 | |
177 | static void axg_tdm_formatter_dettach(struct axg_tdm_formatter *formatter) |
178 | { |
179 | struct axg_tdm_stream *ts = formatter->stream; |
180 | |
181 | mutex_lock(&ts->lock); |
182 | list_del(entry: &formatter->list); |
183 | mutex_unlock(lock: &ts->lock); |
184 | |
185 | axg_tdm_formatter_disable(formatter); |
186 | } |
187 | |
188 | static int axg_tdm_formatter_power_up(struct axg_tdm_formatter *formatter, |
189 | struct snd_soc_dapm_widget *w) |
190 | { |
191 | struct axg_tdm_stream *ts = formatter->drv->ops->get_stream(w); |
192 | int ret; |
193 | |
194 | /* |
195 | * If we don't get a stream at this stage, it would mean that the |
196 | * widget is powering up but is not attached to any backend DAI. |
197 | * It should not happen, ever ! |
198 | */ |
199 | if (WARN_ON(!ts)) |
200 | return -ENODEV; |
201 | |
202 | /* Clock our device */ |
203 | ret = clk_prepare_enable(clk: formatter->pclk); |
204 | if (ret) |
205 | return ret; |
206 | |
207 | /* Reparent the bit clock to the TDM interface */ |
208 | ret = clk_set_parent(clk: formatter->sclk_sel, parent: ts->iface->sclk); |
209 | if (ret) |
210 | goto disable_pclk; |
211 | |
212 | /* Reparent the sample clock to the TDM interface */ |
213 | ret = clk_set_parent(clk: formatter->lrclk_sel, parent: ts->iface->lrclk); |
214 | if (ret) |
215 | goto disable_pclk; |
216 | |
217 | formatter->stream = ts; |
218 | ret = axg_tdm_formatter_attach(formatter); |
219 | if (ret) |
220 | goto disable_pclk; |
221 | |
222 | return 0; |
223 | |
224 | disable_pclk: |
225 | clk_disable_unprepare(clk: formatter->pclk); |
226 | return ret; |
227 | } |
228 | |
229 | static void axg_tdm_formatter_power_down(struct axg_tdm_formatter *formatter) |
230 | { |
231 | axg_tdm_formatter_dettach(formatter); |
232 | clk_disable_unprepare(clk: formatter->pclk); |
233 | formatter->stream = NULL; |
234 | } |
235 | |
236 | int axg_tdm_formatter_event(struct snd_soc_dapm_widget *w, |
237 | struct snd_kcontrol *control, |
238 | int event) |
239 | { |
240 | struct snd_soc_component *c = snd_soc_dapm_to_component(dapm: w->dapm); |
241 | struct axg_tdm_formatter *formatter = snd_soc_component_get_drvdata(c); |
242 | int ret = 0; |
243 | |
244 | switch (event) { |
245 | case SND_SOC_DAPM_PRE_PMU: |
246 | ret = axg_tdm_formatter_power_up(formatter, w); |
247 | break; |
248 | |
249 | case SND_SOC_DAPM_PRE_PMD: |
250 | axg_tdm_formatter_power_down(formatter); |
251 | break; |
252 | |
253 | default: |
254 | dev_err(c->dev, "Unexpected event %d\n" , event); |
255 | return -EINVAL; |
256 | } |
257 | |
258 | return ret; |
259 | } |
260 | EXPORT_SYMBOL_GPL(axg_tdm_formatter_event); |
261 | |
262 | int axg_tdm_formatter_probe(struct platform_device *pdev) |
263 | { |
264 | struct device *dev = &pdev->dev; |
265 | const struct axg_tdm_formatter_driver *drv; |
266 | struct axg_tdm_formatter *formatter; |
267 | void __iomem *regs; |
268 | |
269 | drv = of_device_get_match_data(dev); |
270 | if (!drv) { |
271 | dev_err(dev, "failed to match device\n" ); |
272 | return -ENODEV; |
273 | } |
274 | |
275 | formatter = devm_kzalloc(dev, size: sizeof(*formatter), GFP_KERNEL); |
276 | if (!formatter) |
277 | return -ENOMEM; |
278 | platform_set_drvdata(pdev, data: formatter); |
279 | formatter->drv = drv; |
280 | |
281 | regs = devm_platform_ioremap_resource(pdev, index: 0); |
282 | if (IS_ERR(ptr: regs)) |
283 | return PTR_ERR(ptr: regs); |
284 | |
285 | formatter->map = devm_regmap_init_mmio(dev, regs, drv->regmap_cfg); |
286 | if (IS_ERR(ptr: formatter->map)) { |
287 | dev_err(dev, "failed to init regmap: %ld\n" , |
288 | PTR_ERR(formatter->map)); |
289 | return PTR_ERR(ptr: formatter->map); |
290 | } |
291 | |
292 | /* Peripharal clock */ |
293 | formatter->pclk = devm_clk_get(dev, id: "pclk" ); |
294 | if (IS_ERR(ptr: formatter->pclk)) |
295 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->pclk), fmt: "failed to get pclk\n" ); |
296 | |
297 | /* Formatter bit clock */ |
298 | formatter->sclk = devm_clk_get(dev, id: "sclk" ); |
299 | if (IS_ERR(ptr: formatter->sclk)) |
300 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->sclk), fmt: "failed to get sclk\n" ); |
301 | |
302 | /* Formatter sample clock */ |
303 | formatter->lrclk = devm_clk_get(dev, id: "lrclk" ); |
304 | if (IS_ERR(ptr: formatter->lrclk)) |
305 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->lrclk), fmt: "failed to get lrclk\n" ); |
306 | |
307 | /* Formatter bit clock input multiplexer */ |
308 | formatter->sclk_sel = devm_clk_get(dev, id: "sclk_sel" ); |
309 | if (IS_ERR(ptr: formatter->sclk_sel)) |
310 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->sclk_sel), fmt: "failed to get sclk_sel\n" ); |
311 | |
312 | /* Formatter sample clock input multiplexer */ |
313 | formatter->lrclk_sel = devm_clk_get(dev, id: "lrclk_sel" ); |
314 | if (IS_ERR(ptr: formatter->lrclk_sel)) |
315 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->lrclk_sel), |
316 | fmt: "failed to get lrclk_sel\n" ); |
317 | |
318 | /* Formatter dedicated reset line */ |
319 | formatter->reset = devm_reset_control_get_optional_exclusive(dev, NULL); |
320 | if (IS_ERR(ptr: formatter->reset)) |
321 | return dev_err_probe(dev, err: PTR_ERR(ptr: formatter->reset), fmt: "failed to get reset\n" ); |
322 | |
323 | return devm_snd_soc_register_component(dev, component_driver: drv->component_drv, |
324 | NULL, num_dai: 0); |
325 | } |
326 | EXPORT_SYMBOL_GPL(axg_tdm_formatter_probe); |
327 | |
328 | int axg_tdm_stream_start(struct axg_tdm_stream *ts) |
329 | { |
330 | struct axg_tdm_formatter *formatter; |
331 | int ret = 0; |
332 | |
333 | mutex_lock(&ts->lock); |
334 | ts->ready = true; |
335 | |
336 | /* Start all the formatters attached to the stream */ |
337 | list_for_each_entry(formatter, &ts->formatter_list, list) { |
338 | ret = axg_tdm_formatter_enable(formatter); |
339 | if (ret) { |
340 | pr_err("failed to start tdm stream\n" ); |
341 | goto out; |
342 | } |
343 | } |
344 | |
345 | out: |
346 | mutex_unlock(lock: &ts->lock); |
347 | return ret; |
348 | } |
349 | EXPORT_SYMBOL_GPL(axg_tdm_stream_start); |
350 | |
351 | void axg_tdm_stream_stop(struct axg_tdm_stream *ts) |
352 | { |
353 | struct axg_tdm_formatter *formatter; |
354 | |
355 | mutex_lock(&ts->lock); |
356 | ts->ready = false; |
357 | |
358 | /* Stop all the formatters attached to the stream */ |
359 | list_for_each_entry(formatter, &ts->formatter_list, list) { |
360 | axg_tdm_formatter_disable(formatter); |
361 | } |
362 | |
363 | mutex_unlock(lock: &ts->lock); |
364 | } |
365 | EXPORT_SYMBOL_GPL(axg_tdm_stream_stop); |
366 | |
367 | struct axg_tdm_stream *axg_tdm_stream_alloc(struct axg_tdm_iface *iface) |
368 | { |
369 | struct axg_tdm_stream *ts; |
370 | |
371 | ts = kzalloc(size: sizeof(*ts), GFP_KERNEL); |
372 | if (ts) { |
373 | INIT_LIST_HEAD(list: &ts->formatter_list); |
374 | mutex_init(&ts->lock); |
375 | ts->iface = iface; |
376 | } |
377 | |
378 | return ts; |
379 | } |
380 | EXPORT_SYMBOL_GPL(axg_tdm_stream_alloc); |
381 | |
382 | void axg_tdm_stream_free(struct axg_tdm_stream *ts) |
383 | { |
384 | /* |
385 | * If the list is not empty, it would mean that one of the formatter |
386 | * widget is still powered and attached to the interface while we |
387 | * are removing the TDM DAI. It should not be possible |
388 | */ |
389 | WARN_ON(!list_empty(&ts->formatter_list)); |
390 | mutex_destroy(lock: &ts->lock); |
391 | kfree(objp: ts); |
392 | } |
393 | EXPORT_SYMBOL_GPL(axg_tdm_stream_free); |
394 | |
395 | MODULE_DESCRIPTION("Amlogic AXG TDM formatter driver" ); |
396 | MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>" ); |
397 | MODULE_LICENSE("GPL v2" ); |
398 | |