[PATCH 5/5] ASoC: wm_adsp: Support acknowledged controls

From: Richard Fitzgerald
Date: Wed Nov 09 2016 - 12:15:13 EST


This patch handles publishing acknowledged controls through ALSA.
These controls allow user-side to send events to the firmware and
wait for the firmware to acknowledge it.

Note that although acked controls only operate in the direction
host->firmware, and therefore they are write-only as seen from user-
side code, we have to make them readable to account for all the code
out there that assumes that ALSA controls are always readable (amixer
for example.)

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
sound/soc/codecs/wm_adsp.c | 89 +++++++++++++++++++++++++++++++++++++++++-----
sound/soc/codecs/wmfw.h | 1 +
2 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index bdbcc44..4fb6e2f 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -164,6 +164,8 @@

#define WM_ADSP_ACKED_CTL_TIMEOUT_MS 100
#define WM_ADSP_ACKED_CTL_N_QUICKPOLLS 10
+#define WM_ADSP_ACKED_CTL_MIN_VALUE 0
+#define WM_ADSP_ACKED_CTL_MAX_VALUE 0xFFFFFF

/*
* Event control messages
@@ -779,8 +781,20 @@ static int wm_coeff_info(struct snd_kcontrol *kctl,
(struct soc_bytes_ext *)kctl->private_value;
struct wm_coeff_ctl *ctl = bytes_ext_to_ctl(bytes_ext);

- uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
- uinfo->count = ctl->len;
+ switch (ctl->type) {
+ case WMFW_CTL_TYPE_ACKED:
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->value.integer.min = WM_ADSP_ACKED_CTL_MIN_VALUE;
+ uinfo->value.integer.max = WM_ADSP_ACKED_CTL_MAX_VALUE;
+ uinfo->value.integer.step = 1;
+ uinfo->count = 1;
+ break;
+ default:
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
+ uinfo->count = ctl->len;
+ break;
+ }
+
return 0;
}

@@ -920,6 +934,30 @@ static int wm_coeff_tlv_put(struct snd_kcontrol *kctl,
return ret;
}

+static int wm_coeff_put_acked(struct snd_kcontrol *kctl,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct soc_bytes_ext *bytes_ext =
+ (struct soc_bytes_ext *)kctl->private_value;
+ struct wm_coeff_ctl *ctl = bytes_ext_to_ctl(bytes_ext);
+ unsigned int val = ucontrol->value.integer.value[0];
+ int ret;
+
+ if (val == 0)
+ return 0; /* 0 means no event */
+
+ mutex_lock(&ctl->dsp->pwr_lock);
+
+ if (ctl->enabled)
+ ret = wm_coeff_write_acked_control(ctl, val);
+ else
+ ret = -EPERM;
+
+ mutex_unlock(&ctl->dsp->pwr_lock);
+
+ return ret;
+}
+
static int wm_coeff_read_control(struct wm_coeff_ctl *ctl,
void *buf, size_t len)
{
@@ -1007,6 +1045,21 @@ static int wm_coeff_tlv_get(struct snd_kcontrol *kctl,
return ret;
}

+static int wm_coeff_get_acked(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ /*
+ * Although it's not useful to read an acked control, we must satisfy
+ * user-side assumptions that all controls are readable and that a
+ * write of the same value should be filtered out (it's valid to send
+ * the same event number again to the firmware). We therefore return 0,
+ * meaning "no event" so valid event numbers will always be a change
+ */
+ ucontrol->value.integer.value[0] = 0;
+
+ return 0;
+}
+
struct wmfw_ctl_work {
struct wm_adsp *dsp;
struct wm_coeff_ctl *ctl;
@@ -1059,17 +1112,25 @@ static int wmfw_add_ctl(struct wm_adsp *dsp, struct wm_coeff_ctl *ctl)

kcontrol->name = ctl->name;
kcontrol->info = wm_coeff_info;
- kcontrol->get = wm_coeff_get;
- kcontrol->put = wm_coeff_put;
kcontrol->iface = SNDRV_CTL_ELEM_IFACE_MIXER;
kcontrol->tlv.c = snd_soc_bytes_tlv_callback;
kcontrol->private_value = (unsigned long)&ctl->bytes_ext;
+ kcontrol->access = wmfw_convert_flags(ctl->flags, ctl->len);

- ctl->bytes_ext.max = ctl->len;
- ctl->bytes_ext.get = wm_coeff_tlv_get;
- ctl->bytes_ext.put = wm_coeff_tlv_put;
+ switch (ctl->type) {
+ case WMFW_CTL_TYPE_ACKED:
+ kcontrol->get = wm_coeff_get_acked;
+ kcontrol->put = wm_coeff_put_acked;
+ break;
+ default:
+ kcontrol->get = wm_coeff_get;
+ kcontrol->put = wm_coeff_put;

- kcontrol->access = wmfw_convert_flags(ctl->flags, ctl->len);
+ ctl->bytes_ext.max = ctl->len;
+ ctl->bytes_ext.get = wm_coeff_tlv_get;
+ ctl->bytes_ext.put = wm_coeff_tlv_put;
+ break;
+ }

ret = snd_soc_add_card_controls(dsp->card, kcontrol, 1);
if (ret < 0)
@@ -1431,6 +1492,18 @@ static int wm_adsp_parse_coeff(struct wm_adsp *dsp,
switch (coeff_blk.ctl_type) {
case SNDRV_CTL_ELEM_TYPE_BYTES:
break;
+ case WMFW_CTL_TYPE_ACKED:
+ if (coeff_blk.flags & WMFW_CTL_FLAG_SYS)
+ continue; /* ignore */
+
+ ret = wm_adsp_check_coeff_flags(dsp, &coeff_blk,
+ WMFW_CTL_FLAG_VOLATILE |
+ WMFW_CTL_FLAG_WRITEABLE |
+ WMFW_CTL_FLAG_READABLE,
+ 0);
+ if (ret)
+ return -EINVAL;
+ break;
case WMFW_CTL_TYPE_HOSTEVENT:
ret = wm_adsp_check_coeff_flags(dsp, &coeff_blk,
WMFW_CTL_FLAG_SYS |
diff --git a/sound/soc/codecs/wmfw.h b/sound/soc/codecs/wmfw.h
index 892fc74..ec78b9d 100644
--- a/sound/soc/codecs/wmfw.h
+++ b/sound/soc/codecs/wmfw.h
@@ -27,6 +27,7 @@
#define WMFW_CTL_FLAG_READABLE 0x0001

/* Non-ALSA coefficient types start at 0x1000 */
+#define WMFW_CTL_TYPE_ACKED 0x1000 /* acked control */
#define WMFW_CTL_TYPE_HOSTEVENT 0x1001 /* event control */

struct wmfw_header {
--
1.9.1