diff options
Diffstat (limited to '')
| -rw-r--r-- | sound/ac97/Kconfig | 19 | ||||
| -rw-r--r-- | sound/ac97/Makefile | 9 | ||||
| -rw-r--r-- | sound/ac97/ac97_core.h | 13 | ||||
| -rw-r--r-- | sound/ac97/bus.c | 557 | ||||
| -rw-r--r-- | sound/ac97/codec.c | 12 | ||||
| -rw-r--r-- | sound/ac97/snd_ac97_compat.c | 120 | ||||
| -rw-r--r-- | sound/ac97_bus.c | 109 |
7 files changed, 839 insertions, 0 deletions
diff --git a/sound/ac97/Kconfig b/sound/ac97/Kconfig new file mode 100644 index 000000000..f0e31f2bb --- /dev/null +++ b/sound/ac97/Kconfig @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# AC97 configuration +# + + +config AC97_BUS_NEW + tristate + help + This is the new AC97 bus type, successor of AC97_BUS. The ported + drivers which benefit from the AC97 automatic probing should "select" + this instead of the AC97_BUS. + Say Y here if you want to have AC97 devices, which are sound oriented + devices around an AC-Link. + +config AC97_BUS_COMPAT + bool + depends on AC97_BUS_NEW + depends on !AC97_BUS diff --git a/sound/ac97/Makefile b/sound/ac97/Makefile new file mode 100644 index 000000000..f5efa1ad7 --- /dev/null +++ b/sound/ac97/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# make for AC97 bus drivers +# + +obj-$(CONFIG_AC97_BUS_NEW) += ac97.o + +ac97-y += bus.o codec.o +ac97-$(CONFIG_AC97_BUS_COMPAT) += snd_ac97_compat.o diff --git a/sound/ac97/ac97_core.h b/sound/ac97/ac97_core.h new file mode 100644 index 000000000..5a9677c3d --- /dev/null +++ b/sound/ac97/ac97_core.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr> + */ + +unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv, + unsigned int codec_num); + +static inline bool ac97_ids_match(unsigned int id1, unsigned int id2, + unsigned int mask) +{ + return (id1 & mask) == (id2 & mask); +} diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c new file mode 100644 index 000000000..045330883 --- /dev/null +++ b/sound/ac97/bus.c @@ -0,0 +1,557 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr> + */ + +#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/of.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 struct device_node * +ac97_of_get_child_device(struct ac97_controller *ac97_ctrl, int idx, + unsigned int vendor_id) +{ + struct device_node *node; + u32 reg; + char compat[] = "ac97,0000,0000"; + + snprintf(compat, sizeof(compat), "ac97,%04x,%04x", + vendor_id >> 16, vendor_id & 0xffff); + + for_each_child_of_node(ac97_ctrl->parent->of_node, node) { + if ((idx != of_property_read_u32(node, "reg", ®)) || + !of_device_is_compatible(node, compat)) + continue; + return node; + } + + return NULL; +} + +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; + of_node_put(dev->of_node); + 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); + codec->dev.of_node = ac97_of_get_child_device(ac97_ctrl, idx, + vendor_id); + + ret = device_add(&codec->dev); + if (ret) { + put_device(&codec->dev); + return ret; + } + + return 0; +} + +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 const 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 sysfs_emit(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 void 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_resume_and_get(dev); + if (ret < 0) + return; + + ret = adrv->remove(adev); + pm_runtime_put_noidle(dev); + if (ret == 0) + ac97_put_disable_clk(adev); + + pm_runtime_disable(dev); +} + +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>"); diff --git a/sound/ac97/codec.c b/sound/ac97/codec.c new file mode 100644 index 000000000..1c8357ad6 --- /dev/null +++ b/sound/ac97/codec.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr> + */ + +#include <sound/ac97_codec.h> +#include <sound/ac97/codec.h> +#include <sound/ac97/controller.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <sound/soc.h> /* For compat_ac97_* */ + diff --git a/sound/ac97/snd_ac97_compat.c b/sound/ac97/snd_ac97_compat.c new file mode 100644 index 000000000..d2479bba7 --- /dev/null +++ b/sound/ac97/snd_ac97_compat.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr> + */ + +#include <linux/list.h> +#include <linux/slab.h> +#include <sound/ac97/codec.h> +#include <sound/ac97/compat.h> +#include <sound/ac97/controller.h> +#include <sound/soc.h> + +#include "ac97_core.h" + +static void compat_ac97_release(struct device *dev) +{ + kfree(to_ac97_t(dev)); +} + +static void compat_ac97_reset(struct snd_ac97 *ac97) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + if (actrl->ops->reset) + actrl->ops->reset(actrl); +} + +static void compat_ac97_warm_reset(struct snd_ac97 *ac97) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + if (actrl->ops->warm_reset) + actrl->ops->warm_reset(actrl); +} + +static void compat_ac97_write(struct snd_ac97 *ac97, unsigned short reg, + unsigned short val) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + actrl->ops->write(actrl, ac97->num, reg, val); +} + +static unsigned short compat_ac97_read(struct snd_ac97 *ac97, + unsigned short reg) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + return actrl->ops->read(actrl, ac97->num, reg); +} + +static const struct snd_ac97_bus_ops compat_snd_ac97_bus_ops = { + .reset = compat_ac97_reset, + .warm_reset = compat_ac97_warm_reset, + .write = compat_ac97_write, + .read = compat_ac97_read, +}; + +static struct snd_ac97_bus compat_soc_ac97_bus = { + .ops = &compat_snd_ac97_bus_ops, +}; + +struct snd_ac97 *snd_ac97_compat_alloc(struct ac97_codec_device *adev) +{ + struct snd_ac97 *ac97; + int ret; + + ac97 = kzalloc(sizeof(struct snd_ac97), GFP_KERNEL); + if (ac97 == NULL) + return ERR_PTR(-ENOMEM); + + ac97->private_data = adev; + ac97->bus = &compat_soc_ac97_bus; + + ac97->dev.parent = &adev->dev; + ac97->dev.release = compat_ac97_release; + dev_set_name(&ac97->dev, "%s-compat", dev_name(&adev->dev)); + ret = device_register(&ac97->dev); + if (ret) { + put_device(&ac97->dev); + return ERR_PTR(ret); + } + + return ac97; +} +EXPORT_SYMBOL_GPL(snd_ac97_compat_alloc); + +void snd_ac97_compat_release(struct snd_ac97 *ac97) +{ + device_unregister(&ac97->dev); +} +EXPORT_SYMBOL_GPL(snd_ac97_compat_release); + +int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id, + unsigned int id_mask) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + unsigned int scanned; + + if (try_warm) { + compat_ac97_warm_reset(ac97); + scanned = snd_ac97_bus_scan_one(actrl, adev->num); + if (ac97_ids_match(scanned, adev->vendor_id, id_mask)) + return 1; + } + + compat_ac97_reset(ac97); + compat_ac97_warm_reset(ac97); + scanned = snd_ac97_bus_scan_one(actrl, adev->num); + if (ac97_ids_match(scanned, adev->vendor_id, id_mask)) + return 0; + + return -ENODEV; +} +EXPORT_SYMBOL_GPL(snd_ac97_reset); diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c new file mode 100644 index 000000000..b4685c53f --- /dev/null +++ b/sound/ac97_bus.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux driver model AC97 bus interface + * + * Author: Nicolas Pitre + * Created: Jan 14, 2005 + * Copyright: (C) MontaVista Software Inc. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/string.h> +#include <sound/ac97_codec.h> + +/* + * snd_ac97_check_id() - Reads and checks the vendor ID of the device + * @ac97: The AC97 device to check + * @id: The ID to compare to + * @id_mask: Mask that is applied to the device ID before comparing to @id + * + * If @id is 0 this function returns true if the read device vendor ID is + * a valid ID. If @id is non 0 this functions returns true if @id + * matches the read vendor ID. Otherwise the function returns false. + */ +static bool snd_ac97_check_id(struct snd_ac97 *ac97, unsigned int id, + unsigned int id_mask) +{ + ac97->id = ac97->bus->ops->read(ac97, AC97_VENDOR_ID1) << 16; + ac97->id |= ac97->bus->ops->read(ac97, AC97_VENDOR_ID2); + + if (ac97->id == 0x0 || ac97->id == 0xffffffff) + return false; + + if (id != 0 && id != (ac97->id & id_mask)) + return false; + + return true; +} + +/** + * snd_ac97_reset() - Reset AC'97 device + * @ac97: The AC'97 device to reset + * @try_warm: Try a warm reset first + * @id: Expected device vendor ID + * @id_mask: Mask that is applied to the device ID before comparing to @id + * + * This function resets the AC'97 device. If @try_warm is true the function + * first performs a warm reset. If the warm reset is successful the function + * returns 1. Otherwise or if @try_warm is false the function issues cold reset + * followed by a warm reset. If this is successful the function returns 0, + * otherwise a negative error code. If @id is 0 any valid device ID will be + * accepted, otherwise only the ID that matches @id and @id_mask is accepted. + */ +int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id, + unsigned int id_mask) +{ + const struct snd_ac97_bus_ops *ops = ac97->bus->ops; + + if (try_warm && ops->warm_reset) { + ops->warm_reset(ac97); + if (snd_ac97_check_id(ac97, id, id_mask)) + return 1; + } + + if (ops->reset) + ops->reset(ac97); + if (ops->warm_reset) + ops->warm_reset(ac97); + + if (snd_ac97_check_id(ac97, id, id_mask)) + return 0; + + return -ENODEV; +} +EXPORT_SYMBOL_GPL(snd_ac97_reset); + +/* + * Let drivers decide whether they want to support given codec from their + * probe method. Drivers have direct access to the struct snd_ac97 + * structure and may decide based on the id field amongst other things. + */ +static int ac97_bus_match(struct device *dev, struct device_driver *drv) +{ + return 1; +} + +struct bus_type ac97_bus_type = { + .name = "ac97", + .match = ac97_bus_match, +}; + +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); + +EXPORT_SYMBOL(ac97_bus_type); + +MODULE_LICENSE("GPL"); |