diff options
| -rw-r--r-- | include/sound/ac97_codec.h | 2 | ||||
| -rw-r--r-- | sound/ac97_bus.c | 62 |
2 files changed, 64 insertions, 0 deletions
diff --git a/include/sound/ac97_codec.h b/include/sound/ac97_codec.h index 0e9d75b49bed..74bc85473b58 100644 --- a/include/sound/ac97_codec.h +++ b/include/sound/ac97_codec.h @@ -584,6 +584,8 @@ static inline int snd_ac97_update_power(struct snd_ac97 *ac97, int reg, void snd_ac97_suspend(struct snd_ac97 *ac97); void snd_ac97_resume(struct snd_ac97 *ac97); #endif +int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id, + unsigned int id_mask); /* quirk types */ enum { diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c index 2b50cbe6aca9..55791a0b3943 100644 --- a/sound/ac97_bus.c +++ b/sound/ac97_bus.c @@ -18,6 +18,68 @@ #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) +{ + 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. |