sound/hda/hdac_bus.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HD-audio core bus driver
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/device.h>
   8 #include <linux/module.h>
   9 #include <linux/export.h>
  10 #include <sound/hdaudio.h>
  11 #include "trace.h"
  12
  13 static const struct hdac_bus_ops default_ops = {
  14         .command = snd_hdac_bus_send_cmd,
  15         .get_response = snd_hdac_bus_get_response,
  16 };
  17
  18 /**
  19  * snd_hdac_bus_init - initialize a HD-audio bas bus
  20  * @bus: the pointer to bus object
  21  * @ops: bus verb operators
  22  * @io_ops: lowlevel I/O operators
  23  *
  24  * Returns 0 if successful, or a negative error code.
  25  */
  26 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
  27                       const struct hdac_bus_ops *ops,
  28                       const struct hdac_io_ops *io_ops)
  29 {
  30         memset(bus, 0, sizeof(*bus));
  31         bus->dev = dev;
  32         if (ops)
  33                 bus->ops = ops;
  34         else
  35                 bus->ops = &default_ops;
  36         bus->io_ops = io_ops;
  37         INIT_LIST_HEAD(&bus->stream_list);
  38         INIT_LIST_HEAD(&bus->codec_list);
  39         INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
  40         spin_lock_init(&bus->reg_lock);
  41         mutex_init(&bus->cmd_mutex);
  42         mutex_init(&bus->lock);
  43         INIT_LIST_HEAD(&bus->hlink_list);
  44         bus->irq = -1;
  45         return 0;
  46 }
  47 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
  48
  49 /**
  50  * snd_hdac_bus_exit - clean up a HD-audio bas bus
  51  * @bus: the pointer to bus object
  52  */
  53 void snd_hdac_bus_exit(struct hdac_bus *bus)
  54 {
  55         WARN_ON(!list_empty(&bus->stream_list));
  56         WARN_ON(!list_empty(&bus->codec_list));
  57         cancel_work_sync(&bus->unsol_work);
  58 }
  59 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
  60
  61 /**
  62  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
  63  * @bus: bus object
  64  * @cmd: HD-audio encoded verb
  65  * @res: pointer to store the response, NULL if performing asynchronously
  66  *
  67  * Returns 0 if successful, or a negative error code.
  68  */
  69 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
  70                            unsigned int cmd, unsigned int *res)
  71 {
  72         int err;
  73
  74         mutex_lock(&bus->cmd_mutex);
  75         err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
  76         mutex_unlock(&bus->cmd_mutex);
  77         return err;
  78 }
  79 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
  80
  81 /**
  82  * snd_hdac_bus_exec_verb_unlocked - unlocked version
  83  * @bus: bus object
  84  * @cmd: HD-audio encoded verb
  85  * @res: pointer to store the response, NULL if performing asynchronously
  86  *
  87  * Returns 0 if successful, or a negative error code.
  88  */
  89 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
  90                                     unsigned int cmd, unsigned int *res)
  91 {
  92         unsigned int tmp;
  93         int err;
  94
  95         if (cmd == ~0)
  96                 return -EINVAL;
  97
  98         if (res)
  99                 *res = -1;
 100         else if (bus->sync_write)
 101                 res = &tmp;
 102         for (;;) {
 103                 trace_hda_send_cmd(bus, cmd);
 104                 err = bus->ops->command(bus, cmd);
 105                 if (err != -EAGAIN)
 106                         break;
 107                 /* process pending verbs */
 108                 err = bus->ops->get_response(bus, addr, &tmp);
 109                 if (err)
 110                         break;
 111         }
 112         if (!err && res) {
 113                 err = bus->ops->get_response(bus, addr, res);
 114                 trace_hda_get_response(bus, addr, *res);
 115         }
 116         return err;
 117 }
 118 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
 119
 120 /**
 121  * snd_hdac_bus_queue_event - add an unsolicited event to queue
 122  * @bus: the BUS
 123  * @res: unsolicited event (lower 32bit of RIRB entry)
 124  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
 125  *
 126  * Adds the given event to the queue.  The events are processed in
 127  * the workqueue asynchronously.  Call this function in the interrupt
 128  * hanlder when RIRB receives an unsolicited event.
 129  */
 130 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
 131 {
 132         unsigned int wp;
 133
 134         if (!bus)
 135                 return;
 136
 137         trace_hda_unsol_event(bus, res, res_ex);
 138         wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
 139         bus->unsol_wp = wp;
 140
 141         wp <<= 1;
 142         bus->unsol_queue[wp] = res;
 143         bus->unsol_queue[wp + 1] = res_ex;
 144
 145         schedule_work(&bus->unsol_work);
 146 }
 147 EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
 148
 149 /*
 150  * process queued unsolicited events
 151  */
 152 void snd_hdac_bus_process_unsol_events(struct work_struct *work)
 153 {
 154         struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
 155         struct hdac_device *codec;
 156         struct hdac_driver *drv;
 157         unsigned int rp, caddr, res;
 158
 159         while (bus->unsol_rp != bus->unsol_wp) {
 160                 rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
 161                 bus->unsol_rp = rp;
 162                 rp <<= 1;
 163                 res = bus->unsol_queue[rp];
 164                 caddr = bus->unsol_queue[rp + 1];
 165                 if (!(caddr & (1 << 4))) /* no unsolicited event? */
 166                         continue;
 167                 codec = bus->caddr_tbl[caddr & 0x0f];
 168                 if (!codec || !codec->dev.driver)
 169                         continue;
 170                 drv = drv_to_hdac_driver(codec->dev.driver);
 171                 if (drv->unsol_event)
 172                         drv->unsol_event(codec, res);
 173         }
 174 }
 175 EXPORT_SYMBOL_GPL(snd_hdac_bus_process_unsol_events);
 176
 177 /**
 178  * snd_hdac_bus_add_device - Add a codec to bus
 179  * @bus: HDA core bus
 180  * @codec: HDA core device to add
 181  *
 182  * Adds the given codec to the list in the bus.  The caddr_tbl array
 183  * and codec_powered bits are updated, as well.
 184  * Returns zero if success, or a negative error code.
 185  */
 186 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
 187 {
 188         if (bus->caddr_tbl[codec->addr]) {
 189                 dev_err(bus->dev, "address 0x%x is already occupied\n",
 190                         codec->addr);
 191                 return -EBUSY;
 192         }
 193
 194         list_add_tail(&codec->list, &bus->codec_list);
 195         bus->caddr_tbl[codec->addr] = codec;
 196         set_bit(codec->addr, &bus->codec_powered);
 197         bus->num_codecs++;
 198         return 0;
 199 }
 200 EXPORT_SYMBOL_GPL(snd_hdac_bus_add_device);
 201
 202 /**
 203  * snd_hdac_bus_remove_device - Remove a codec from bus
 204  * @bus: HDA core bus
 205  * @codec: HDA core device to remove
 206  */
 207 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
 208                                 struct hdac_device *codec)
 209 {
 210         WARN_ON(bus != codec->bus);
 211         if (list_empty(&codec->list))
 212                 return;
 213         list_del_init(&codec->list);
 214         bus->caddr_tbl[codec->addr] = NULL;
 215         clear_bit(codec->addr, &bus->codec_powered);
 216         bus->num_codecs--;
 217         flush_work(&bus->unsol_work);
 218 }
 219 EXPORT_SYMBOL_GPL(snd_hdac_bus_remove_device);