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 static int hdac_component_master_bind(struct device *dev)
 122 {
 123         struct i915_audio_component *acomp = hdac_acomp;
 124         int ret;
 125
 126         ret = component_bind_all(dev, acomp);
 127         if (ret < 0)
 128                 return ret;
 129
 130         if (WARN_ON(!(acomp->dev && acomp->ops && acomp->ops->get_power &&
 131                       acomp->ops->put_power && acomp->ops->get_cdclk_freq))) {
 132                 ret = -EINVAL;
 133                 goto out_unbind;
 134         }
 135
 136         /*
 137          * Atm, we don't support dynamic unbinding initiated by the child
 138          * component, so pin its containing module until we unbind.
 139          */
 140         if (!try_module_get(acomp->ops->owner)) {
 141                 ret = -ENODEV;
 142                 goto out_unbind;
 143         }
 144
 145         return 0;
 146
 147 out_unbind:
 148         component_unbind_all(dev, acomp);
 149
 150         return ret;
 151 }
 152
 153 static void hdac_component_master_unbind(struct device *dev)
 154 {
 155         struct i915_audio_component *acomp = hdac_acomp;
 156
 157         module_put(acomp->ops->owner);
 158         component_unbind_all(dev, acomp);
 159         WARN_ON(acomp->ops || acomp->dev);
 160 }
 161
 162 static const struct component_master_ops hdac_component_master_ops = {
 163         .bind = hdac_component_master_bind,
 164         .unbind = hdac_component_master_unbind,
 165 };
 166
 167 static int hdac_component_master_match(struct device *dev, void *data)
 168 {
 169         /* i915 is the only supported component */
 170         return !strcmp(dev->driver->name, "i915");
 171 }
 172
 173 /**
 174  * snd_hdac_i915_register_notifier - Register i915 audio component ops
 175  * @aops: i915 audio component ops
 176  *
 177  * This function is supposed to be used only by a HD-audio controller
 178  * driver that needs the interaction with i915 graphics.
 179  *
 180  * This function sets the given ops to be called by the i915 graphics driver.
 181  *
 182  * Returns zero for success or a negative error code.
 183  */
 184 int snd_hdac_i915_register_notifier(const struct i915_audio_component_audio_ops *aops)
 185 {
 186         if (WARN_ON(!hdac_acomp))
 187                 return -ENODEV;
 188
 189         hdac_acomp->audio_ops = aops;
 190         return 0;
 191 }
 192 EXPORT_SYMBOL_GPL(snd_hdac_i915_register_notifier);
 193
 194 /**
 195  * snd_hdac_i915_init - Initialize i915 audio component
 196  * @bus: HDA core bus
 197  *
 198  * This function is supposed to be used only by a HD-audio controller
 199  * driver that needs the interaction with i915 graphics.
 200  *
 201  * This function initializes and sets up the audio component to communicate
 202  * with i915 graphics driver.
 203  *
 204  * Returns zero for success or a negative error code.
 205  */
 206 int snd_hdac_i915_init(struct hdac_bus *bus)
 207 {
 208         struct component_match *match = NULL;
 209         struct device *dev = bus->dev;
 210         struct i915_audio_component *acomp;
 211         int ret;
 212
 213         acomp = kzalloc(sizeof(*acomp), GFP_KERNEL);
 214         if (!acomp)
 215                 return -ENOMEM;
 216         bus->audio_component = acomp;
 217         hdac_acomp = acomp;
 218
 219         component_match_add(dev, &match, hdac_component_master_match, bus);
 220         ret = component_master_add_with_match(dev, &hdac_component_master_ops,
 221                                               match);
 222         if (ret < 0)
 223                 goto out_err;
 224
 225         /*
 226          * Atm, we don't support deferring the component binding, so make sure
 227          * i915 is loaded and that the binding successfully completes.
 228          */
 229         request_module("i915");
 230
 231         if (!acomp->ops) {
 232                 ret = -ENODEV;
 233                 goto out_master_del;
 234         }
 235         dev_dbg(dev, "bound to i915 component master\n");
 236
 237         return 0;
 238 out_master_del:
 239         component_master_del(dev, &hdac_component_master_ops);
 240 out_err:
 241         kfree(acomp);
 242         bus->audio_component = NULL;
 243         dev_err(dev, "failed to add i915 component master (%d)\n", ret);
 244
 245         return ret;
 246 }
 247 EXPORT_SYMBOL_GPL(snd_hdac_i915_init);
 248
 249 /**
 250  * snd_hdac_i915_exit - Finalize i915 audio component
 251  * @bus: HDA core bus
 252  *
 253  * This function is supposed to be used only by a HD-audio controller
 254  * driver that needs the interaction with i915 graphics.
 255  *
 256  * This function releases the i915 audio component that has been used.
 257  *
 258  * Returns zero for success or a negative error code.
 259  */
 260 int snd_hdac_i915_exit(struct hdac_bus *bus)
 261 {
 262         struct device *dev = bus->dev;
 263         struct i915_audio_component *acomp = bus->audio_component;
 264
 265         if (!acomp)
 266                 return 0;
 267
 268         WARN_ON(bus->i915_power_refcount);
 269         if (bus->i915_power_refcount > 0 && acomp->ops)
 270                 acomp->ops->put_power(acomp->dev);
 271
 272         component_master_del(dev, &hdac_component_master_ops);
 273
 274         kfree(acomp);
 275         bus->audio_component = NULL;
 276
 277         return 0;
 278 }
 279 EXPORT_SYMBOL_GPL(snd_hdac_i915_exit);