277a278,282
> /* RME says n = 104857600000000, but in the windows MADI driver, I see:
> 	return 104857600000000 / rate; // 100 MHz
> 	return 110100480000000 / rate; // 105 MHz
> */	   
> #define DDS_NUMERATOR 104857600000000ULL;  /*  =  2^20 * 10^8 */
1004,1008c1009
< 	/* RME says n = 104857600000000, but in the windows MADI driver, I see:
< //	return 104857600000000 / rate; // 100 MHz
< 	return 110100480000000 / rate; // 105 MHz
<         */	   
< 	n = 104857600000000ULL;  /*  =  2^20 * 10^8 */
---
> 	n = DDS_NUMERATOR;
3087a3089,3159
> #define HDSP_DDS_OFFSET(xname, xindex) \
> { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
>   .name = xname, \
>   .index = xindex, \
>   .info = snd_hdsp_info_dds_offset, \
>   .get = snd_hdsp_get_dds_offset, \
>   .put = snd_hdsp_put_dds_offset \
> }
> 
> static int hdsp_dds_offset(struct hdsp *hdsp)
> {
> 	u64 n;
> 	u32 r;
> 	unsigned int dds_value = hdsp->dds_value;
> 	int system_sample_rate = hdsp->system_sample_rate;
> 
> 	n = DDS_NUMERATOR;
> 	/*
> 	 * dds_value = n / rate
> 	 * rate = n / dds_value
> 	 */
> 	div64_32(&n, dds_value, &r);
> 	if (system_sample_rate >= 112000)
> 		n *= 4;
> 	else if (system_sample_rate >= 56000)
> 		n *= 2;
> 	return ((int)n) - system_sample_rate;
> }
> 
> static int hdsp_set_dds_offset(struct hdsp *hdsp, int offset_hz)
> {
> 	int rate = hdsp->system_sample_rate + offset_hz;
> 	hdsp_set_dds_value(hdsp, rate);
> 	return 0;
> }
> 
> static int snd_hdsp_info_dds_offset(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
> {
> 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
> 	uinfo->count = 1;
> 	uinfo->value.integer.min = -5000;
> 	uinfo->value.integer.max = 5000;
> 	return 0;
> }
> 
> static int snd_hdsp_get_dds_offset(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
> {
> 	struct hdsp *hdsp = snd_kcontrol_chip(kcontrol);
> 	
> 	ucontrol->value.enumerated.item[0] = hdsp_dds_offset(hdsp);
> 	return 0;
> }
> 
> static int snd_hdsp_put_dds_offset(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
> {
> 	struct hdsp *hdsp = snd_kcontrol_chip(kcontrol);
> 	int change;
> 	int val;
> 	
> 	if (!snd_hdsp_use_is_exclusive(hdsp))
> 		return -EBUSY;
> 	val = ucontrol->value.enumerated.item[0];
> 	spin_lock_irq(&hdsp->lock);
> 	if (val != hdsp_dds_offset(hdsp))
> 		change = (hdsp_set_dds_offset(hdsp, val) == 0) ? 1 : 0;
> 	else
> 		change = 0;
> 	spin_unlock_irq(&hdsp->lock);
> 	return change;
> }
> 
3092c3164,3165
< HDSP_XLR_BREAKOUT_CABLE("XLR Breakout Cable", 0)
---
> HDSP_XLR_BREAKOUT_CABLE("XLR Breakout Cable", 0),
> HDSP_DDS_OFFSET("DDS Sample Rate Offset (Hz)", 0)