ALSA: ac97: add an ac97 bus
AC97 is a bus for sound usage. It enables for a AC97 AC-Link to link one
controller to 0 to 4 AC97 codecs.
The goal of this new implementation is to implement a device/driver
model for AC97, with an automatic scan of the bus and automatic
discovery of AC97 codec devices.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c
new file mode 100644
index 0000000..31f858e
--- /dev/null
+++ b/sound/ac97/bus.c
@@ -0,0 +1,539 @@
+/*
+ * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <sound/ac97/codec.h>
+#include <sound/ac97/controller.h>
+#include <sound/ac97/regs.h>
+
+#include "ac97_core.h"
+
+/*
+ * Protects ac97_controllers and each ac97_controller structure.
+ */
+static DEFINE_MUTEX(ac97_controllers_mutex);
+static DEFINE_IDR(ac97_adapter_idr);
+static LIST_HEAD(ac97_controllers);
+
+static struct bus_type ac97_bus_type;
+
+static inline struct ac97_controller*
+to_ac97_controller(struct device *ac97_adapter)
+{
+ return container_of(ac97_adapter, struct ac97_controller, adap);
+}
+
+static int ac97_unbound_ctrl_write(struct ac97_controller *adrv, int slot,
+ unsigned short reg, unsigned short val)
+{
+ return -ENODEV;
+}
+
+static int ac97_unbound_ctrl_read(struct ac97_controller *adrv, int slot,
+ unsigned short reg)
+{
+ return -ENODEV;
+}
+
+static const struct ac97_controller_ops ac97_unbound_ctrl_ops = {
+ .write = ac97_unbound_ctrl_write,
+ .read = ac97_unbound_ctrl_read,
+};
+
+static struct ac97_controller ac97_unbound_ctrl = {
+ .ops = &ac97_unbound_ctrl_ops,
+};
+
+static struct ac97_codec_device *
+ac97_codec_find(struct ac97_controller *ac97_ctrl, unsigned int codec_num)
+{
+ if (codec_num >= AC97_BUS_MAX_CODECS)
+ return ERR_PTR(-EINVAL);
+
+ return ac97_ctrl->codecs[codec_num];
+}
+
+static void ac97_codec_release(struct device *dev)
+{
+ struct ac97_codec_device *adev;
+ struct ac97_controller *ac97_ctrl;
+
+ adev = to_ac97_device(dev);
+ ac97_ctrl = adev->ac97_ctrl;
+ ac97_ctrl->codecs[adev->num] = NULL;
+ kfree(adev);
+}
+
+static int ac97_codec_add(struct ac97_controller *ac97_ctrl, int idx,
+ unsigned int vendor_id)
+{
+ struct ac97_codec_device *codec;
+ int ret;
+
+ codec = kzalloc(sizeof(*codec), GFP_KERNEL);
+ if (!codec)
+ return -ENOMEM;
+ ac97_ctrl->codecs[idx] = codec;
+ codec->vendor_id = vendor_id;
+ codec->dev.release = ac97_codec_release;
+ codec->dev.bus = &ac97_bus_type;
+ codec->dev.parent = &ac97_ctrl->adap;
+ codec->num = idx;
+ codec->ac97_ctrl = ac97_ctrl;
+
+ device_initialize(&codec->dev);
+ dev_set_name(&codec->dev, "%s:%u", dev_name(ac97_ctrl->parent), idx);
+
+ ret = device_add(&codec->dev);
+ if (ret)
+ goto err_free_codec;
+
+ return 0;
+err_free_codec:
+ put_device(&codec->dev);
+ kfree(codec);
+ ac97_ctrl->codecs[idx] = NULL;
+
+ return ret;
+}
+
+unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv,
+ unsigned int codec_num)
+{
+ unsigned short vid1, vid2;
+ int ret;
+
+ ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID1);
+ vid1 = (ret & 0xffff);
+ if (ret < 0)
+ return 0;
+
+ ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID2);
+ vid2 = (ret & 0xffff);
+ if (ret < 0)
+ return 0;
+
+ dev_dbg(&adrv->adap, "%s(codec_num=%u): vendor_id=0x%08x\n",
+ __func__, codec_num, AC97_ID(vid1, vid2));
+ return AC97_ID(vid1, vid2);
+}
+
+static int ac97_bus_scan(struct ac97_controller *ac97_ctrl)
+{
+ int ret, i;
+ unsigned int vendor_id;
+
+ for (i = 0; i < AC97_BUS_MAX_CODECS; i++) {
+ if (ac97_codec_find(ac97_ctrl, i))
+ continue;
+ if (!(ac97_ctrl->slots_available & BIT(i)))
+ continue;
+ vendor_id = snd_ac97_bus_scan_one(ac97_ctrl, i);
+ if (!vendor_id)
+ continue;
+
+ ret = ac97_codec_add(ac97_ctrl, i, vendor_id);
+ if (ret < 0)
+ return ret;
+ }
+ return 0;
+}
+
+static int ac97_bus_reset(struct ac97_controller *ac97_ctrl)
+{
+ ac97_ctrl->ops->reset(ac97_ctrl);
+
+ return 0;
+}
+
+/**
+ * snd_ac97_codec_driver_register - register an AC97 codec driver
+ * @dev: AC97 driver codec to register
+ *
+ * Register an AC97 codec driver to the ac97 bus driver, aka. the AC97 digital
+ * controller.
+ *
+ * Returns 0 on success or error code
+ */
+int snd_ac97_codec_driver_register(struct ac97_codec_driver *drv)
+{
+ drv->driver.bus = &ac97_bus_type;
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_register);
+
+/**
+ * snd_ac97_codec_driver_unregister - unregister an AC97 codec driver
+ * @dev: AC97 codec driver to unregister
+ *
+ * Unregister a previously registered ac97 codec driver.
+ */
+void snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_unregister);
+
+/**
+ * snd_ac97_codec_get_platdata - get platform_data
+ * @adev: the ac97 codec device
+ *
+ * For legacy platforms, in order to have platform_data in codec drivers
+ * available, while ac97 device are auto-created upon probe, this retrieves the
+ * platdata which was setup on ac97 controller registration.
+ *
+ * Returns the platform data pointer
+ */
+void *snd_ac97_codec_get_platdata(const struct ac97_codec_device *adev)
+{
+ struct ac97_controller *ac97_ctrl = adev->ac97_ctrl;
+
+ return ac97_ctrl->codecs_pdata[adev->num];
+}
+EXPORT_SYMBOL_GPL(snd_ac97_codec_get_platdata);
+
+static void ac97_ctrl_codecs_unregister(struct ac97_controller *ac97_ctrl)
+{
+ int i;
+
+ for (i = 0; i < AC97_BUS_MAX_CODECS; i++)
+ if (ac97_ctrl->codecs[i]) {
+ ac97_ctrl->codecs[i]->ac97_ctrl = &ac97_unbound_ctrl;
+ device_unregister(&ac97_ctrl->codecs[i]->dev);
+ }
+}
+
+static ssize_t cold_reset_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t len)
+{
+ struct ac97_controller *ac97_ctrl;
+
+ mutex_lock(&ac97_controllers_mutex);
+ ac97_ctrl = to_ac97_controller(dev);
+ ac97_ctrl->ops->reset(ac97_ctrl);
+ mutex_unlock(&ac97_controllers_mutex);
+ return len;
+}
+static DEVICE_ATTR_WO(cold_reset);
+
+static ssize_t warm_reset_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t len)
+{
+ struct ac97_controller *ac97_ctrl;
+
+ if (!dev)
+ return -ENODEV;
+
+ mutex_lock(&ac97_controllers_mutex);
+ ac97_ctrl = to_ac97_controller(dev);
+ ac97_ctrl->ops->warm_reset(ac97_ctrl);
+ mutex_unlock(&ac97_controllers_mutex);
+ return len;
+}
+static DEVICE_ATTR_WO(warm_reset);
+
+static struct attribute *ac97_controller_device_attrs[] = {
+ &dev_attr_cold_reset.attr,
+ &dev_attr_warm_reset.attr,
+ NULL
+};
+
+static struct attribute_group ac97_adapter_attr_group = {
+ .name = "ac97_operations",
+ .attrs = ac97_controller_device_attrs,
+};
+
+static const struct attribute_group *ac97_adapter_groups[] = {
+ &ac97_adapter_attr_group,
+ NULL,
+};
+
+static void ac97_del_adapter(struct ac97_controller *ac97_ctrl)
+{
+ mutex_lock(&ac97_controllers_mutex);
+ ac97_ctrl_codecs_unregister(ac97_ctrl);
+ list_del(&ac97_ctrl->controllers);
+ mutex_unlock(&ac97_controllers_mutex);
+
+ device_unregister(&ac97_ctrl->adap);
+}
+
+static void ac97_adapter_release(struct device *dev)
+{
+ struct ac97_controller *ac97_ctrl;
+
+ ac97_ctrl = to_ac97_controller(dev);
+ idr_remove(&ac97_adapter_idr, ac97_ctrl->nr);
+ dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n",
+ dev_name(ac97_ctrl->parent));
+}
+
+static const struct device_type ac97_adapter_type = {
+ .groups = ac97_adapter_groups,
+ .release = ac97_adapter_release,
+};
+
+static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
+{
+ int ret;
+
+ mutex_lock(&ac97_controllers_mutex);
+ ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL);
+ ac97_ctrl->nr = ret;
+ if (ret >= 0) {
+ dev_set_name(&ac97_ctrl->adap, "ac97-%d", ret);
+ ac97_ctrl->adap.type = &ac97_adapter_type;
+ ac97_ctrl->adap.parent = ac97_ctrl->parent;
+ ret = device_register(&ac97_ctrl->adap);
+ if (ret)
+ put_device(&ac97_ctrl->adap);
+ }
+ if (!ret)
+ list_add(&ac97_ctrl->controllers, &ac97_controllers);
+ mutex_unlock(&ac97_controllers_mutex);
+
+ if (!ret)
+ dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n",
+ dev_name(ac97_ctrl->parent));
+ return ret;
+}
+
+/**
+ * snd_ac97_controller_register - register an ac97 controller
+ * @ops: the ac97 bus operations
+ * @dev: the device providing the ac97 DC function
+ * @slots_available: mask of the ac97 codecs that can be scanned and probed
+ * bit0 => codec 0, bit1 => codec 1 ... bit 3 => codec 3
+ *
+ * Register a digital controller which can control up to 4 ac97 codecs. This is
+ * the controller side of the AC97 AC-link, while the slave side are the codecs.
+ *
+ * Returns a valid controller upon success, negative pointer value upon error
+ */
+struct ac97_controller *snd_ac97_controller_register(
+ const struct ac97_controller_ops *ops, struct device *dev,
+ unsigned short slots_available, void **codecs_pdata)
+{
+ struct ac97_controller *ac97_ctrl;
+ int ret, i;
+
+ ac97_ctrl = kzalloc(sizeof(*ac97_ctrl), GFP_KERNEL);
+ if (!ac97_ctrl)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < AC97_BUS_MAX_CODECS && codecs_pdata; i++)
+ ac97_ctrl->codecs_pdata[i] = codecs_pdata[i];
+
+ ac97_ctrl->ops = ops;
+ ac97_ctrl->slots_available = slots_available;
+ ac97_ctrl->parent = dev;
+ ret = ac97_add_adapter(ac97_ctrl);
+
+ if (ret)
+ goto err;
+ ac97_bus_reset(ac97_ctrl);
+ ac97_bus_scan(ac97_ctrl);
+
+ return ac97_ctrl;
+err:
+ kfree(ac97_ctrl);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(snd_ac97_controller_register);
+
+/**
+ * snd_ac97_controller_unregister - unregister an ac97 controller
+ * @ac97_ctrl: the device previously provided to ac97_controller_register()
+ *
+ */
+void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
+{
+ ac97_del_adapter(ac97_ctrl);
+}
+EXPORT_SYMBOL_GPL(snd_ac97_controller_unregister);
+
+#ifdef CONFIG_PM
+static int ac97_pm_runtime_suspend(struct device *dev)
+{
+ struct ac97_codec_device *codec = to_ac97_device(dev);
+ int ret = pm_generic_runtime_suspend(dev);
+
+ if (ret == 0 && dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ clk_disable(codec->clk);
+ else
+ clk_disable_unprepare(codec->clk);
+ }
+
+ return ret;
+}
+
+static int ac97_pm_runtime_resume(struct device *dev)
+{
+ struct ac97_codec_device *codec = to_ac97_device(dev);
+ int ret;
+
+ if (dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ ret = clk_enable(codec->clk);
+ else
+ ret = clk_prepare_enable(codec->clk);
+ if (ret)
+ return ret;
+ }
+
+ return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops ac97_pm = {
+ .suspend = pm_generic_suspend,
+ .resume = pm_generic_resume,
+ .freeze = pm_generic_freeze,
+ .thaw = pm_generic_thaw,
+ .poweroff = pm_generic_poweroff,
+ .restore = pm_generic_restore,
+ SET_RUNTIME_PM_OPS(
+ ac97_pm_runtime_suspend,
+ ac97_pm_runtime_resume,
+ NULL)
+};
+
+static int ac97_get_enable_clk(struct ac97_codec_device *adev)
+{
+ int ret;
+
+ adev->clk = clk_get(&adev->dev, "ac97_clk");
+ if (IS_ERR(adev->clk))
+ return PTR_ERR(adev->clk);
+
+ ret = clk_prepare_enable(adev->clk);
+ if (ret)
+ clk_put(adev->clk);
+
+ return ret;
+}
+
+static void ac97_put_disable_clk(struct ac97_codec_device *adev)
+{
+ clk_disable_unprepare(adev->clk);
+ clk_put(adev->clk);
+}
+
+static ssize_t vendor_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ac97_codec_device *codec = to_ac97_device(dev);
+
+ return sprintf(buf, "%08x", codec->vendor_id);
+}
+DEVICE_ATTR_RO(vendor_id);
+
+static struct attribute *ac97_dev_attrs[] = {
+ &dev_attr_vendor_id.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(ac97_dev);
+
+static int ac97_bus_match(struct device *dev, struct device_driver *drv)
+{
+ struct ac97_codec_device *adev = to_ac97_device(dev);
+ struct ac97_codec_driver *adrv = to_ac97_driver(drv);
+ const struct ac97_id *id = adrv->id_table;
+ int i = 0;
+
+ if (adev->vendor_id == 0x0 || adev->vendor_id == 0xffffffff)
+ return false;
+
+ do {
+ if (ac97_ids_match(id[i].id, adev->vendor_id, id[i].mask))
+ return true;
+ } while (id[i++].id);
+
+ return false;
+}
+
+static int ac97_bus_probe(struct device *dev)
+{
+ struct ac97_codec_device *adev = to_ac97_device(dev);
+ struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
+ int ret;
+
+ ret = ac97_get_enable_clk(adev);
+ if (ret)
+ return ret;
+
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ ret = adrv->probe(adev);
+ if (ret == 0)
+ return 0;
+
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+ ac97_put_disable_clk(adev);
+
+ return ret;
+}
+
+static int ac97_bus_remove(struct device *dev)
+{
+ struct ac97_codec_device *adev = to_ac97_device(dev);
+ struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
+ int ret;
+
+ ret = pm_runtime_get_sync(dev);
+ if (ret)
+ return ret;
+
+ ret = adrv->remove(adev);
+ pm_runtime_put_noidle(dev);
+ if (ret == 0)
+ ac97_put_disable_clk(adev);
+
+ return ret;
+}
+
+static struct bus_type ac97_bus_type = {
+ .name = "ac97bus",
+ .dev_groups = ac97_dev_groups,
+ .match = ac97_bus_match,
+ .pm = &ac97_pm,
+ .probe = ac97_bus_probe,
+ .remove = ac97_bus_remove,
+};
+
+static int __init ac97_bus_init(void)
+{
+ return bus_register(&ac97_bus_type);
+}
+subsys_initcall(ac97_bus_init);
+
+static void __exit ac97_bus_exit(void)
+{
+ bus_unregister(&ac97_bus_type);
+}
+module_exit(ac97_bus_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");