snd_efw_command_get_sampling_rate
int snd_efw_command_get_sampling_rate(struct snd_efw *efw, unsigned int *rate);
err = snd_efw_command_get_sampling_rate(efw, &sampling_rate);
if (snd_efw_command_get_sampling_rate(efw, &sampling_rate) < 0)
err = snd_efw_command_get_sampling_rate(efw, &curr_rate);
err = snd_efw_command_get_sampling_rate(efw, &rate);