kernel/sound/hda/hdac_bus.c

   1 /*
   2  * HD-audio core bus driver
   3  */
   4
   5 #include <linux/init.h>
   6 #include <linux/device.h>
   7 #include <linux/module.h>
   8 #include <linux/export.h>
   9 #include <sound/hdaudio.h>
  10 #include "trace.h"
  11
  12 static void process_unsol_events(struct work_struct *work);
  13
  14 /**
  15  * snd_hdac_bus_init - initialize a HD-audio bas bus
  16  * @bus: the pointer to bus object
  17  *
  18  * Returns 0 if successful, or a negative error code.
  19  */
  20 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
  21                       const struct hdac_bus_ops *ops)
  22 {
  23         memset(bus, 0, sizeof(*bus));
  24         bus->dev = dev;
  25         bus->ops = ops;
  26         INIT_LIST_HEAD(&bus->codec_list);
  27         INIT_WORK(&bus->unsol_work, process_unsol_events);
  28         mutex_init(&bus->cmd_mutex);
  29         return 0;
  30 }
  31 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
  32
  33 /**
  34  * snd_hdac_bus_exit - clean up a HD-audio bas bus
  35  * @bus: the pointer to bus object
  36  */
  37 void snd_hdac_bus_exit(struct hdac_bus *bus)
  38 {
  39         WARN_ON(!list_empty(&bus->codec_list));
  40         cancel_work_sync(&bus->unsol_work);
  41 }
  42 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
  43
  44 /**
  45  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
  46  * @bus: bus object
  47  * @cmd: HD-audio encoded verb
  48  * @res: pointer to store the response, NULL if performing asynchronously
  49  *
  50  * Returns 0 if successful, or a negative error code.
  51  */
  52 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
  53                            unsigned int cmd, unsigned int *res)
  54 {
  55         int err;
  56
  57         mutex_lock(&bus->cmd_mutex);
  58         err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
  59         mutex_unlock(&bus->cmd_mutex);
  60         return err;
  61 }
  62 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
  63
  64 /**
  65  * snd_hdac_bus_exec_verb_unlocked - unlocked version
  66  * @bus: bus object
  67  * @cmd: HD-audio encoded verb
  68  * @res: pointer to store the response, NULL if performing asynchronously
  69  *
  70  * Returns 0 if successful, or a negative error code.
  71  */
  72 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
  73                                     unsigned int cmd, unsigned int *res)
  74 {
  75         unsigned int tmp;
  76         int err;
  77
  78         if (cmd == ~0)
  79                 return -EINVAL;
  80
  81         if (res)
  82                 *res = -1;
  83         else if (bus->sync_write)
  84                 res = &tmp;
  85         for (;;) {
  86                 trace_hda_send_cmd(bus, cmd);
  87                 err = bus->ops->command(bus, cmd);
  88                 if (err != -EAGAIN)
  89                         break;
  90                 /* process pending verbs */
  91                 err = bus->ops->get_response(bus, addr, &tmp);
  92                 if (err)
  93                         break;
  94         }
  95         if (!err && res) {
  96                 err = bus->ops->get_response(bus, addr, res);
  97                 trace_hda_get_response(bus, addr, *res);
  98         }
  99         return err;
 100 }
 101 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
 102
 103 /**
 104  * snd_hdac_bus_queue_event - add an unsolicited event to queue
 105  * @bus: the BUS
 106  * @res: unsolicited event (lower 32bit of RIRB entry)
 107  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
 108  *
 109  * Adds the given event to the queue.  The events are processed in
 110  * the workqueue asynchronously.  Call this function in the interrupt
 111  * hanlder when RIRB receives an unsolicited event.
 112  */
 113 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
 114 {
 115         unsigned int wp;
 116
 117         if (!bus)
 118                 return;
 119
 120         trace_hda_unsol_event(bus, res, res_ex);
 121         wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
 122         bus->unsol_wp = wp;
 123
 124         wp <<= 1;
 125         bus->unsol_queue[wp] = res;
 126         bus->unsol_queue[wp + 1] = res_ex;
 127
 128         schedule_work(&bus->unsol_work);
 129 }
 130 EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
 131
 132 /*
 133  * process queued unsolicited events
 134  */
 135 static void process_unsol_events(struct work_struct *work)
 136 {
 137         struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
 138         struct hdac_device *codec;
 139         struct hdac_driver *drv;
 140         unsigned int rp, caddr, res;
 141
 142         while (bus->unsol_rp != bus->unsol_wp) {
 143                 rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
 144                 bus->unsol_rp = rp;
 145                 rp <<= 1;
 146                 res = bus->unsol_queue[rp];
 147                 caddr = bus->unsol_queue[rp + 1];
 148                 if (!(caddr & (1 << 4))) /* no unsolicited event? */
 149                         continue;
 150                 codec = bus->caddr_tbl[caddr & 0x0f];
 151                 if (!codec || !codec->dev.driver)
 152                         continue;
 153                 drv = drv_to_hdac_driver(codec->dev.driver);
 154                 if (drv->unsol_event)
 155                         drv->unsol_event(codec, res);
 156         }
 157 }
 158
 159 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
 160 {
 161         if (bus->caddr_tbl[codec->addr]) {
 162                 dev_err(bus->dev, "address 0x%x is already occupied\n",
 163                         codec->addr);
 164                 return -EBUSY;
 165         }
 166
 167         list_add_tail(&codec->list, &bus->codec_list);
 168         bus->caddr_tbl[codec->addr] = codec;
 169         set_bit(codec->addr, &bus->codec_powered);
 170         bus->num_codecs++;
 171         return 0;
 172 }
 173 EXPORT_SYMBOL_GPL(snd_hdac_bus_add_device);
 174
 175 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
 176                                 struct hdac_device *codec)
 177 {
 178         WARN_ON(bus != codec->bus);
 179         if (list_empty(&codec->list))
 180                 return;
 181         list_del_init(&codec->list);
 182         bus->caddr_tbl[codec->addr] = NULL;
 183         clear_bit(codec->addr, &bus->codec_powered);
 184         bus->num_codecs--;
 185 }
 186 EXPORT_SYMBOL_GPL(snd_hdac_bus_remove_device);