ALSA: hda - Move some codes up to hdac_bus struct

A few basic codes for communicating over HD-audio bus are moved to
struct hdac_bus now.  It has only command and get_response ops in
addition to the unsolicited event handling.

Note that the codec-side tracing support is disabled temporarily
during this transition due to the code shuffling.  It will be
re-enabled later once when all pieces are settled down.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 182 insertions, 1 deletions

diff --git a/sound/hda/Makefile b/sound/hda/Makefile
index 59c8d1feb5aa..828680b282fa 100644
--- a/sound/hda/Makefile
+++ b/sound/hda/Makefile
@@ -1,3 +1,3 @@
-snd-hda-core-objs := hda_bus_type.o
+snd-hda-core-objs := hda_bus_type.o hdac_bus.o
 
 obj-$(CONFIG_SND_HDA_CORE) += snd-hda-core.o
diff --git a/sound/hda/hdac_bus.c b/sound/hda/hdac_bus.c
new file mode 100644
index 000000000000..364f64c0e4a3
--- /dev/null
+++ b/sound/hda/hdac_bus.c
@@ -0,0 +1,181 @@
+/*
+ * HD-audio core bus driver
+ */
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/export.h>
+#include <sound/hdaudio.h>
+
+static void process_unsol_events(struct work_struct *work);
+
+/**
+ * snd_hdac_bus_init - initialize a HD-audio bas bus
+ * @bus: the pointer to bus object
+ *
+ * Returns 0 if successful, or a negative error code.
+ */
+int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
+                      const struct hdac_bus_ops *ops)
+{
+        memset(bus, 0, sizeof(*bus));
+        bus->dev = dev;
+        bus->ops = ops;
+        INIT_LIST_HEAD(&bus->codec_list);
+        INIT_WORK(&bus->unsol_work, process_unsol_events);
+        mutex_init(&bus->cmd_mutex);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
+
+/**
+ * snd_hdac_bus_exit - clean up a HD-audio bas bus
+ * @bus: the pointer to bus object
+ */
+void snd_hdac_bus_exit(struct hdac_bus *bus)
+{
+        WARN_ON(!list_empty(&bus->codec_list));
+        cancel_work_sync(&bus->unsol_work);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
+
+/**
+ * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
+ * @bus: bus object
+ * @cmd: HD-audio encoded verb
+ * @res: pointer to store the response, NULL if performing asynchronously
+ *
+ * Returns 0 if successful, or a negative error code.
+ */
+int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
+                           unsigned int cmd, unsigned int *res)
+{
+        int err;
+
+        mutex_lock(&bus->cmd_mutex);
+        err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
+        mutex_unlock(&bus->cmd_mutex);
+        return err;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
+
+/**
+ * snd_hdac_bus_exec_verb_unlocked - unlocked version
+ * @bus: bus object
+ * @cmd: HD-audio encoded verb
+ * @res: pointer to store the response, NULL if performing asynchronously
+ *
+ * Returns 0 if successful, or a negative error code.
+ */
+int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
+                                    unsigned int cmd, unsigned int *res)
+{
+        unsigned int tmp;
+        int err;
+
+        if (cmd == ~0)
+                return -EINVAL;
+
+        if (res)
+                *res = -1;
+        else if (bus->sync_write)
+                res = &tmp;
+        for (;;) {
+                err = bus->ops->command(bus, cmd);
+                if (err != -EAGAIN)
+                        break;
+                /* process pending verbs */
+                err = bus->ops->get_response(bus, addr, &tmp);
+                if (err)
+                        break;
+        }
+        if (!err && res)
+                err = bus->ops->get_response(bus, addr, res);
+        return err;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
+
+/**
+ * snd_hdac_bus_queue_event - add an unsolicited event to queue
+ * @bus: the BUS
+ * @res: unsolicited event (lower 32bit of RIRB entry)
+ * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
+ *
+ * Adds the given event to the queue.  The events are processed in
+ * the workqueue asynchronously.  Call this function in the interrupt
+ * hanlder when RIRB receives an unsolicited event.
+ */
+void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
+{
+        unsigned int wp;
+
+        if (!bus)
+                return;
+
+        wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
+        bus->unsol_wp = wp;
+
+        wp <<= 1;
+        bus->unsol_queue[wp] = res;
+        bus->unsol_queue[wp + 1] = res_ex;
+
+        schedule_work(&bus->unsol_work);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
+
+/*
+ * process queued unsolicited events
+ */
+static void process_unsol_events(struct work_struct *work)
+{
+        struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
+        struct hdac_device *codec;
+        struct hdac_driver *drv;
+        unsigned int rp, caddr, res;
+
+        while (bus->unsol_rp != bus->unsol_wp) {
+                rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
+                bus->unsol_rp = rp;
+                rp <<= 1;
+                res = bus->unsol_queue[rp];
+                caddr = bus->unsol_queue[rp + 1];
+                if (!(caddr & (1 << 4))) /* no unsolicited event? */
+                        continue;
+                codec = bus->caddr_tbl[caddr & 0x0f];
+                if (!codec || !codec->dev.driver)
+                        continue;
+                drv = drv_to_hdac_driver(codec->dev.driver);
+                if (drv->unsol_event)
+                        drv->unsol_event(codec, res);
+        }
+}
+
+int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
+{
+        if (bus->caddr_tbl[codec->addr]) {
+                dev_err(bus->dev, "address 0x%x is already occupied\n",
+                        codec->addr);
+                return -EBUSY;
+        }
+
+        list_add_tail(&codec->list, &bus->codec_list);
+        bus->caddr_tbl[codec->addr] = codec;
+        set_bit(codec->addr, &bus->codec_powered);
+        bus->num_codecs++;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_add_device);
+
+void snd_hdac_bus_remove_device(struct hdac_bus *bus,
+                                struct hdac_device *codec)
+{
+        WARN_ON(bus != codec->bus);
+        if (list_empty(&codec->list))
+                return;
+        list_del_init(&codec->list);
+        bus->caddr_tbl[codec->addr] = NULL;
+        clear_bit(codec->addr, &bus->codec_powered);
+        bus->num_codecs--;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_remove_device);