sound/hda/hdac_i915.c

   1 /*
   2  *  hdac_i915.c - routines for sync between HD-A core and i915 display driver
   3  *
   4  *  This program is free software; you can redistribute it and/or modify it
   5  *  under the terms of the GNU General Public License as published by the Free
   6  *  Software Foundation; either version 2 of the License, or (at your option)
   7  *  any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful, but
  10  *  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/pci.h>
  18 #include <linux/component.h>
  19 #include <drm/i915_component.h>
  20 #include <sound/core.h>
  21 #include <sound/hdaudio.h>
  22 #include <sound/hda_i915.h>
  23
  24 static struct i915_audio_component *hdac_acomp;
  25
  26 /**
  27  * snd_hdac_set_codec_wakeup - Enable / disable HDMI/DP codec wakeup
  28  * @bus: HDA core bus
  29  * @enable: enable or disable the wakeup
  30  *
  31  * This function is supposed to be used only by a HD-audio controller
  32  * driver that needs the interaction with i915 graphics.
  33  *
  34  * This function should be called during the chip reset, also called at
  35  * resume for updating STATESTS register read.
  36  *
  37  * Returns zero for success or a negative error code.
  38  */
  39 int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
  40 {
  41         struct i915_audio_component *acomp = bus->audio_component;
  42
  43         if (!acomp || !acomp->ops)
  44                 return -ENODEV;
  45
  46         if (!acomp->ops->codec_wake_override) {
  47                 dev_warn(bus->dev,
  48                         "Invalid codec wake callback\n");
  49                 return 0;
  50         }
  51
  52         dev_dbg(bus->dev, "%s codec wakeup\n",
  53                 enable ? "enable" : "disable");
  54
  55         acomp->ops->codec_wake_override(acomp->dev, enable);
  56
  57         return 0;
  58 }
  59 EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);
  60
  61 /**
  62  * snd_hdac_display_power - Power up / down the power refcount
  63  * @bus: HDA core bus
  64  * @enable: power up or down
  65  *
  66  * This function is supposed to be used only by a HD-audio controller
  67  * driver that needs the interaction with i915 graphics.
  68  *
  69  * This function manages a refcount and calls the i915 get_power() and
  70  * put_power() ops accordingly, toggling the codec wakeup, too.
  71  *
  72  * Returns zero for success or a negative error code.
  73  */
  74 int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
  75 {
  76         struct i915_audio_component *acomp = bus->audio_component;
  77
  78         if (!acomp || !acomp->ops)
  79                 return -ENODEV;
  80
  81         dev_dbg(bus->dev, "display power %s\n",
  82                 enable ? "enable" : "disable");
  83
  84         if (enable) {
  85                 if (!bus->i915_power_refcount++) {
  86                         acomp->ops->get_power(acomp->dev);
  87                         snd_hdac_set_codec_wakeup(bus, true);
  88                         snd_hdac_set_codec_wakeup(bus, false);
  89                 }
  90         } else {
  91                 WARN_ON(!bus->i915_power_refcount);
  92                 if (!--bus->i915_power_refcount)
  93                         acomp->ops->put_power(acomp->dev);
  94         }
  95
  96         return 0;
  97 }
  98 EXPORT_SYMBOL_GPL(snd_hdac_display_power);
  99
 100 /**
 101  * snd_hdac_get_display_clk - Get CDCLK in kHz
 102  * @bus: HDA core bus
 103  *
 104  * This function is supposed to be used only by a HD-audio controller
 105  * driver that needs the interaction with i915 graphics.
 106  *
 107  * This function queries CDCLK value in kHz from the graphics driver and
 108  * returns the value.  A negative code is returned in error.
 109  */
 110 int snd_hdac_get_display_clk(struct hdac_bus *bus)
 111 {
 112         struct i915_audio_component *acomp = bus->audio_component;
 113
 114         if (!acomp || !acomp->ops)
 115                 return -ENODEV;
 116
 117         return acomp->ops->get_cdclk_freq(acomp->dev);
 118 }
 119 EXPORT_SYMBOL_GPL(snd_hdac_get_display_clk);
 120
 121 /* There is a fixed mapping between audio pin node and display port
 122  * on current Intel platforms:
 123  * Pin Widget 5 - PORT B (port = 1 in i915 driver)
 124  * Pin Widget 6 - PORT C (port = 2 in i915 driver)
 125  * Pin Widget 7 - PORT D (port = 3 in i915 driver)
 126  */
 127 static int pin2port(hda_nid_t pin_nid)
 128 {
 129         return pin_nid - 4;
 130 }
 131
 132 /**
 133  * snd_hdac_sync_audio_rate - Set N/CTS based on the sample rate
 134  * @bus: HDA core bus
 135  * @nid: the pin widget NID
 136  * @rate: the sample rate to set
 137  *
 138  * This function is supposed to be used only by a HD-audio controller
 139  * driver that needs the interaction with i915 graphics.
 140  *
 141  * This function sets N/CTS value based on the given sample rate.
 142  * Returns zero for success, or a negative error code.
 143  */
 144 int snd_hdac_sync_audio_rate(struct hdac_bus *bus, hda_nid_t nid, int rate)
 145 {
 146         struct i915_audio_component *acomp = bus->audio_component;
 147
 148         if (!acomp || !acomp->ops || !acomp->ops->sync_audio_rate)
 149                 return -ENODEV;
 150         return acomp->ops->sync_audio_rate(acomp->dev, pin2port(nid), rate);
 151 }
 152 EXPORT_SYMBOL_GPL(snd_hdac_sync_audio_rate);
 153
 154 /**
 155  * snd_hdac_acomp_get_eld - Get the audio state and ELD via component
 156  * @bus: HDA core bus
 157  * @nid: the pin widget NID
 158  * @audio_enabled: the pointer to store the current audio state
 159  * @buffer: the buffer pointer to store ELD bytes
 160  * @max_bytes: the max bytes to be stored on @buffer
 161  *
 162  * This function is supposed to be used only by a HD-audio controller
 163  * driver that needs the interaction with i915 graphics.
 164  *
 165  * This function queries the current state of the audio on the given
 166  * digital port and fetches the ELD bytes onto the given buffer.
 167  * It returns the number of bytes for the total ELD data, zero for
 168  * invalid ELD, or a negative error code.
 169  *
 170  * The return size is the total bytes required for the whole ELD bytes,
 171  * thus it may be over @max_bytes.  If it's over @max_bytes, it implies
 172  * that only a part of ELD bytes have been fetched.
 173  */
 174 int snd_hdac_acomp_get_eld(struct hdac_bus *bus, hda_nid_t nid,
 175                            bool *audio_enabled, char *buffer, int max_bytes)
 176 {
 177         struct i915_audio_component *acomp = bus->audio_component;
 178
 179         if (!acomp || !acomp->ops || !acomp->ops->get_eld)
 180                 return -ENODEV;
 181
 182         return acomp->ops->get_eld(acomp->dev, pin2port(nid), audio_enabled,
 183                                    buffer, max_bytes);
 184 }
 185 EXPORT_SYMBOL_GPL(snd_hdac_acomp_get_eld);
 186
 187 static int hdac_component_master_bind(struct device *dev)
 188 {
 189         struct i915_audio_component *acomp = hdac_acomp;
 190         int ret;
 191
 192         ret = component_bind_all(dev, acomp);
 193         if (ret < 0)
 194                 return ret;
 195
 196         if (WARN_ON(!(acomp->dev && acomp->ops && acomp->ops->get_power &&
 197                       acomp->ops->put_power && acomp->ops->get_cdclk_freq))) {
 198                 ret = -EINVAL;
 199                 goto out_unbind;
 200         }
 201
 202         /*
 203          * Atm, we don't support dynamic unbinding initiated by the child
 204          * component, so pin its containing module until we unbind.
 205          */
 206         if (!try_module_get(acomp->ops->owner)) {
 207                 ret = -ENODEV;
 208                 goto out_unbind;
 209         }
 210
 211         return 0;
 212
 213 out_unbind:
 214         component_unbind_all(dev, acomp);
 215
 216         return ret;
 217 }
 218
 219 static void hdac_component_master_unbind(struct device *dev)
 220 {
 221         struct i915_audio_component *acomp = hdac_acomp;
 222
 223         module_put(acomp->ops->owner);
 224         component_unbind_all(dev, acomp);
 225         WARN_ON(acomp->ops || acomp->dev);
 226 }
 227
 228 static const struct component_master_ops hdac_component_master_ops = {
 229         .bind = hdac_component_master_bind,
 230         .unbind = hdac_component_master_unbind,
 231 };
 232
 233 static int hdac_component_master_match(struct device *dev, void *data)
 234 {
 235         /* i915 is the only supported component */
 236         return !strcmp(dev->driver->name, "i915");
 237 }
 238
 239 /**
 240  * snd_hdac_i915_register_notifier - Register i915 audio component ops
 241  * @aops: i915 audio component ops
 242  *
 243  * This function is supposed to be used only by a HD-audio controller
 244  * driver that needs the interaction with i915 graphics.
 245  *
 246  * This function sets the given ops to be called by the i915 graphics driver.
 247  *
 248  * Returns zero for success or a negative error code.
 249  */
 250 int snd_hdac_i915_register_notifier(const struct i915_audio_component_audio_ops *aops)
 251 {
 252         if (WARN_ON(!hdac_acomp))
 253                 return -ENODEV;
 254
 255         hdac_acomp->audio_ops = aops;
 256         return 0;
 257 }
 258 EXPORT_SYMBOL_GPL(snd_hdac_i915_register_notifier);
 259
 260 /**
 261  * snd_hdac_i915_init - Initialize i915 audio component
 262  * @bus: HDA core bus
 263  *
 264  * This function is supposed to be used only by a HD-audio controller
 265  * driver that needs the interaction with i915 graphics.
 266  *
 267  * This function initializes and sets up the audio component to communicate
 268  * with i915 graphics driver.
 269  *
 270  * Returns zero for success or a negative error code.
 271  */
 272 int snd_hdac_i915_init(struct hdac_bus *bus)
 273 {
 274         struct component_match *match = NULL;
 275         struct device *dev = bus->dev;
 276         struct i915_audio_component *acomp;
 277         int ret;
 278
 279         acomp = kzalloc(sizeof(*acomp), GFP_KERNEL);
 280         if (!acomp)
 281                 return -ENOMEM;
 282         bus->audio_component = acomp;
 283         hdac_acomp = acomp;
 284
 285         component_match_add(dev, &match, hdac_component_master_match, bus);
 286         ret = component_master_add_with_match(dev, &hdac_component_master_ops,
 287                                               match);
 288         if (ret < 0)
 289                 goto out_err;
 290
 291         /*
 292          * Atm, we don't support deferring the component binding, so make sure
 293          * i915 is loaded and that the binding successfully completes.
 294          */
 295         request_module("i915");
 296
 297         if (!acomp->ops) {
 298                 ret = -ENODEV;
 299                 goto out_master_del;
 300         }
 301         dev_dbg(dev, "bound to i915 component master\n");
 302
 303         return 0;
 304 out_master_del:
 305         component_master_del(dev, &hdac_component_master_ops);
 306 out_err:
 307         kfree(acomp);
 308         bus->audio_component = NULL;
 309         dev_info(dev, "failed to add i915 component master (%d)\n", ret);
 310
 311         return ret;
 312 }
 313 EXPORT_SYMBOL_GPL(snd_hdac_i915_init);
 314
 315 /**
 316  * snd_hdac_i915_exit - Finalize i915 audio component
 317  * @bus: HDA core bus
 318  *
 319  * This function is supposed to be used only by a HD-audio controller
 320  * driver that needs the interaction with i915 graphics.
 321  *
 322  * This function releases the i915 audio component that has been used.
 323  *
 324  * Returns zero for success or a negative error code.
 325  */
 326 int snd_hdac_i915_exit(struct hdac_bus *bus)
 327 {
 328         struct device *dev = bus->dev;
 329         struct i915_audio_component *acomp = bus->audio_component;
 330
 331         if (!acomp)
 332                 return 0;
 333
 334         WARN_ON(bus->i915_power_refcount);
 335         if (bus->i915_power_refcount > 0 && acomp->ops)
 336                 acomp->ops->put_power(acomp->dev);
 337
 338         component_master_del(dev, &hdac_component_master_ops);
 339
 340         kfree(acomp);
 341         bus->audio_component = NULL;
 342
 343         return 0;
 344 }
 345 EXPORT_SYMBOL_GPL(snd_hdac_i915_exit);