diff options
Diffstat (limited to 'sound/ac97_bus.c')
| -rw-r--r-- | sound/ac97_bus.c | 82 |
1 files changed, 59 insertions, 23 deletions
diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c index 2b50cbe6aca9..52e4bc54c9ac 100644 --- a/sound/ac97_bus.c +++ b/sound/ac97_bus.c @@ -18,44 +18,80 @@ #include <sound/ac97_codec.h> /* - * 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. + * 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 int ac97_bus_match(struct device *dev, struct device_driver *drv) +static bool snd_ac97_check_id(struct snd_ac97 *ac97, unsigned int id, + unsigned int id_mask) { - return 1; -} + ac97->id = ac97->bus->ops->read(ac97, AC97_VENDOR_ID1) << 16; + ac97->id |= ac97->bus->ops->read(ac97, AC97_VENDOR_ID2); -#ifdef CONFIG_PM -static int ac97_bus_suspend(struct device *dev, pm_message_t state) -{ - int ret = 0; + if (ac97->id == 0x0 || ac97->id == 0xffffffff) + return false; - if (dev->driver && dev->driver->suspend) - ret = dev->driver->suspend(dev, state); + if (id != 0 && id != (ac97->id & id_mask)) + return false; - return ret; + return true; } -static int ac97_bus_resume(struct device *dev) +/** + * 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) { - int ret = 0; + 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 (dev->driver && dev->driver->resume) - ret = dev->driver->resume(dev); + if (ops->reset) + ops->reset(ac97); + if (ops->warm_reset) + ops->warm_reset(ac97); - return ret; + 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; } -#endif /* CONFIG_PM */ struct bus_type ac97_bus_type = { .name = "ac97", .match = ac97_bus_match, -#ifdef CONFIG_PM - .suspend = ac97_bus_suspend, - .resume = ac97_bus_resume, -#endif /* CONFIG_PM */ }; static int __init ac97_bus_init(void) |