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 <sound/core.h> 19 #include <sound/hdaudio.h> 20 #include <sound/hda_i915.h> 21 #include <sound/hda_register.h> 22 23 static struct completion bind_complete; 24 25 #define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \ 26 ((pci)->device == 0x0c0c) || \ 27 ((pci)->device == 0x0d0c) || \ 28 ((pci)->device == 0x160c)) 29 30 /** 31 * snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW 32 * @bus: HDA core bus 33 * 34 * Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK 35 * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value) 36 * are used to convert CDClk (Core Display Clock) to 24MHz BCLK: 37 * BCLK = CDCLK * M / N 38 * The values will be lost when the display power well is disabled and need to 39 * be restored to avoid abnormal playback speed. 40 * 41 * Call this function at initializing and changing power well, as well as 42 * at ELD notifier for the hotplug. 43 */ 44 void snd_hdac_i915_set_bclk(struct hdac_bus *bus) 45 { 46 struct drm_audio_component *acomp = bus->audio_component; 47 struct pci_dev *pci = to_pci_dev(bus->dev); 48 int cdclk_freq; 49 unsigned int bclk_m, bclk_n; 50 51 if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq) 52 return; /* only for i915 binding */ 53 if (!CONTROLLER_IN_GPU(pci)) 54 return; /* only HSW/BDW */ 55 56 cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev); 57 switch (cdclk_freq) { 58 case 337500: 59 bclk_m = 16; 60 bclk_n = 225; 61 break; 62 63 case 450000: 64 default: /* default CDCLK 450MHz */ 65 bclk_m = 4; 66 bclk_n = 75; 67 break; 68 69 case 540000: 70 bclk_m = 4; 71 bclk_n = 90; 72 break; 73 74 case 675000: 75 bclk_m = 8; 76 bclk_n = 225; 77 break; 78 } 79 80 snd_hdac_chip_writew(bus, HSW_EM4, bclk_m); 81 snd_hdac_chip_writew(bus, HSW_EM5, bclk_n); 82 } 83 EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk); 84 85 static int i915_component_master_match(struct device *dev, void *data) 86 { 87 return !strcmp(dev->driver->name, "i915"); 88 } 89 90 /* check whether intel graphics is present */ 91 static bool i915_gfx_present(void) 92 { 93 static const struct pci_device_id ids[] = { 94 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_ANY_ID), 95 .class = PCI_BASE_CLASS_DISPLAY << 16, 96 .class_mask = 0xff << 16 }, 97 {} 98 }; 99 return pci_dev_present(ids); 100 } 101 102 static int i915_master_bind(struct device *dev, 103 struct drm_audio_component *acomp) 104 { 105 complete_all(&bind_complete); 106 /* clear audio_ops here as it was needed only for completion call */ 107 acomp->audio_ops = NULL; 108 return 0; 109 } 110 111 static const struct drm_audio_component_audio_ops i915_init_ops = { 112 .master_bind = i915_master_bind 113 }; 114 115 /** 116 * snd_hdac_i915_init - Initialize i915 audio component 117 * @bus: HDA core bus 118 * 119 * This function is supposed to be used only by a HD-audio controller 120 * driver that needs the interaction with i915 graphics. 121 * 122 * This function initializes and sets up the audio component to communicate 123 * with i915 graphics driver. 124 * 125 * Returns zero for success or a negative error code. 126 */ 127 int snd_hdac_i915_init(struct hdac_bus *bus) 128 { 129 struct drm_audio_component *acomp; 130 int err; 131 132 if (!i915_gfx_present()) 133 return -ENODEV; 134 135 init_completion(&bind_complete); 136 137 err = snd_hdac_acomp_init(bus, &i915_init_ops, 138 i915_component_master_match, 139 sizeof(struct i915_audio_component) - sizeof(*acomp)); 140 if (err < 0) 141 return err; 142 acomp = bus->audio_component; 143 if (!acomp) 144 return -ENODEV; 145 if (!acomp->ops) { 146 request_module("i915"); 147 /* 10s timeout */ 148 wait_for_completion_timeout(&bind_complete, 149 msecs_to_jiffies(10 * 1000)); 150 } 151 if (!acomp->ops) { 152 dev_info(bus->dev, "couldn't bind with audio component\n"); 153 snd_hdac_acomp_exit(bus); 154 return -ENODEV; 155 } 156 return 0; 157 } 158 EXPORT_SYMBOL_GPL(snd_hdac_i915_init); 159