On 03/26/2014 11:41 PM, Songhee Baek wrote:
On 03/26/2014 01:02 AM, Arun Shamanna Lakshmi wrote:
The way you describe this it seems to me that a value array for this kind of mux would look like.
0x00000000, 0x00000000, 0x00000001 0x00000000, 0x00000000, 0x00000002 0x00000000, 0x00000000, 0x00000003 0x00000000, 0x00000000, 0x00000004 0x00000000, 0x00000000, 0x00000008 ...
That seems to be extremely tedious. If the MUX uses a one hot encoding how about storing the index of the bit in the values array and use (1 << value) when writing the value to the register?
If we store the index of the bit, the value will be duplicated for each
registers inputs since register has 0 to 31bits to shift, then we need to decode the index to interpret value for which registers to set. If we need to interpret the decoded value of index, it is better to have custom put/get function in our driver, isn't it?
I'm not sure I understand. If you use (val / 32) to pick the register and (val % 32) to pick the bit in the register this should work just fine. Maybe I'm missing something. Do you have a real world code example of of the this type of enum is used?
I can use val/32 and val%32 for this multi register mux.
With this logic, put function would be easy however get function becomes tedious due to looping on each bit per register for 3 of them in our case. Rather, it would be easy to identify a unique MUX_OFFSET to distinguish between the 3 registers as shown in the code below.
#define MULTI_MUX_INPUT_OFFSET(n) (5 * n)
int snd_soc_dapm_get_enum_double(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_codec *codec = snd_soc_dapm_kcontrol_codec(kcontrol); struct soc_enum *e = (struct soc_enum *)kcontrol->private_value; unsigned int reg_val, val, reg_idx;
if (e->reg[0] != SND_SOC_NOPM) { for (reg_idx = 0; reg_idx < e->num_regs; reg_idx) { reg_val = snd_soc_read(codec, e->reg[reg_idx]); val = (reg_val >> e->shift_l) & e->mask[reg_idx]; if (val) val += MULTI_MUX_INPUT_OFFSET(reg_idx); } } else { reg_val = dapm_kcontrol_get_value(kcontrol); val = (reg_val >> e->shift_l) & e->mask[0]; }
ucontrol->value.enumerated.item[0] = snd_soc_enum_val_to_item(e, val); if (e->shift_l != e->shift_r) { val = (reg_val >> e->shift_r) & e->mask[0]; val = snd_soc_enum_val_to_item(e, val); ucontrol->value.enumerated.item[1] = val; }
return 0; }
int snd_soc_dapm_put_enum_double(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_codec *codec = snd_soc_dapm_kcontrol_codec(kcontrol); struct snd_soc_card *card = codec->card; struct soc_enum *e = (struct soc_enum *)kcontrol->private_value; unsigned int *item = ucontrol->value.enumerated.item; unsigned int change, i, value, update_idx = 0; unsigned int mask; struct snd_soc_dapm_update update; int ret = 0, reg_val;
if (item[0] >= e->items) return -EINVAL;
value = snd_soc_enum_item_to_val(e, item[0]) << e->shift_l; mask = e->mask[0] << e->shift_l; if (e->shift_l != e->shift_r) { if (item[1] > e->items) return -EINVAL; value |= snd_soc_enum_item_to_val(e, item[1]) << e->shift_l; mask |= e->mask[0] << e->shift_r; }
if (e->num_regs < 2) { goto update_reg; }
for (i = 0; i < e->num_regs; i++) { reg_val = value - MULTI_MUX_INPUT_OFFSET(i);
/* checking reg_val is power of 2 : one-hot code */ /* if reg_val after subtract MULTI_MUX_INPUT_OFFSET is not power of 2, reg[i] should be zero */ if (reg_val & (reg_val - 1)) { /* clear the current input register */ snd_soc_write(codec, e->reg[i], 0); } else { /* reg_val is power of 2, store updated info */ value = reg_val; mask = e->mask[i]; update_idx = i; } }
update_reg: mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
if (e->reg[update_idx] != SND_SOC_NOPM) change = snd_soc_test_bits(codec, e->reg[update_idx], mask, value); else change = dapm_kcontrol_set_value(kcontrol, value);
if (change) { if (e->reg[update_idx] != SND_SOC_NOPM) { update.kcontrol = kcontrol; update.reg = e->reg[update_idx]; update.mask= mask; update.val = value; card->update = &update; } ret = soc_dapm_mux_update_power(card, kcontrol, item[0], e);
card->update = NULL; } mutex_unlock(&card->dapm_mutex);
if (ret > 0) soc_dpcm_runtime_update(card);
return change; }
- int reg;
- int reg[SOC_ENUM_MAX_REGS]; unsigned char shift_l; unsigned char shift_r; unsigned int items;
- unsigned int mask;
- unsigned int mask[SOC_ENUM_MAX_REGS];
If you make mask and reg pointers instead of arrays this should be much more flexible and not be limited to 3 registers.
We will make reg* and mask* instead of arrays and since we use the same structure, the plan is to share the get and put function code.
Thanks. Songhee.