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); 280