| Message ID | 20200209154748.3015-9-adam@serbinski.com |
|---|---|
| State | New |
| Headers | show |
| Series | ASoC: qdsp6: db820c: Add support for external and bluetooth audio | expand |
On 2020-02-10 08:36, Mark Brown wrote: > On Sun, Feb 09, 2020 at 10:47:48AM -0500, Adam Serbinski wrote: >> This makes it possible for the backend sample rate to be >> set to 8000 or 16000 Hz, depending on the needs of the HFP >> call being set up. > > This would seem like an excellent thing to put in the driver for the > baseband or bluetooth. The value that must be set to this control is not available to the bluetooth driver. It originates from the bluetooth stack in userspace, typically either blueZ or fluoride, as a result of a negotiation between the two devices participating in the HFP call.
On 2020-02-10 11:18, Jaroslav Kysela wrote: > Dne 09. 02. 20 v 16:47 Adam Serbinski napsal(a): >> This makes it possible for the backend sample rate to be >> set to 8000 or 16000 Hz, depending on the needs of the HFP >> call being set up. > > Two points: > > Why enum? It adds just more code than the integer value handlers. Because enum allows the potential values to be restricted to a set of distinct values rather than a range. And while yes, I understand that the value can be validated, or the step can in this case be set to correspond to the difference between the current 2 values, this approach would neither make it clear to the user what the permitted values are, nor would it scale well once additional values are required. > Also, this belongs to the PCM interface, so it should be handled with > SNDRV_CTL_ELEM_IFACE_PCM not mixer. > > The name should be probably "Rate" and assigned to the corresponding > PCM device. > > Add this to Documentation/sound/designs/control-names.rst . Above 3 lines are noted, I will make these changed.
On Mon, Feb 10, 2020 at 03:00:55PM -0500, Adam Serbinski wrote: > On 2020-02-10 13:26, Mark Brown wrote: > > To repeat my comment on another patch in the series there should still > > be some representation of the DAI for this device in the kernel. > Respectfully, I'm not sure I understand what it is that you are suggesting. > Is it your intention to suggest that instead of adding controls to the > machine driver, I should instead write a codec driver to contain those > controls? I have already separately said that you should write a CODEC driver for this CODEC. I'm saying that this seems like the sort of thing that might fit in that CODEC driver. > Or is it your intention to suggest that something within the kernel is > already aware of the rate to be set, and it is that which should set the > rate rather than a control? That would be one example of how such a CODEC driver could be configured, and is how other baseband/BT devices have ended up going (see cx20442.c for example).
On 2020-02-10 15:08, Mark Brown wrote: > On Mon, Feb 10, 2020 at 03:00:55PM -0500, Adam Serbinski wrote: >> On 2020-02-10 13:26, Mark Brown wrote: > >> > To repeat my comment on another patch in the series there should still >> > be some representation of the DAI for this device in the kernel. > >> Respectfully, I'm not sure I understand what it is that you are >> suggesting. > >> Is it your intention to suggest that instead of adding controls to the >> machine driver, I should instead write a codec driver to contain those >> controls? > > I have already separately said that you should write a CODEC driver for > this CODEC. I'm saying that this seems like the sort of thing that > might fit in that CODEC driver. I see. My initial thought with respect to the codec driver would be just to use bt-sco.c, which is a dummy codec. I can certainly implement a new codec driver. >> Or is it your intention to suggest that something within the kernel is >> already aware of the rate to be set, and it is that which should set >> the >> rate rather than a control? > > That would be one example of how such a CODEC driver could be > configured, and is how other baseband/BT devices have ended up going > (see cx20442.c for example). I am not aware of how this could be done for bluetooth, since the value still has to originate from userspace. The driver you referred to supports only a single sample rate, whereas for bluetooth, 2 sample rates are required, and nothing in the kernel is aware of the appropriate rate, at least in the case of the qca6174a I'm working with right now, or for that matter, TI Wilink 8, which I've also worked with. My concern with implementing this in a new codec driver, is that this codec driver will be bound to qdsp6, since its purpose is to work around a characteristic of this DSP. Under simple-card, for instance, it would be redundant, since in that case, the parameters userspace uses to open the pcm will be propagated to the port. But under qdsp6, userspace could open the pcm at 44.1 kHz, yet the backend port is still set to 8 or 16 kHz, and the DSP resamples between them, so the sole purpose of this change is to allow userspace to deliver the required sample rate to the back end of qdsp6.
On Mon, Feb 10, 2020 at 04:13:52PM -0500, Adam Serbinski wrote: > I am not aware of how this could be done for bluetooth, since the value > still has to originate from userspace. The driver you referred to supports > only a single sample rate, whereas for bluetooth, 2 sample rates are > required, and nothing in the kernel is aware of the appropriate rate, at > least in the case of the qca6174a I'm working with right now, or for that > matter, TI Wilink 8, which I've also worked with. There's generic support in the CODEC<->CODEC link code for setting the DAI configuration from userspace.
On 2020-02-11 06:42, Mark Brown wrote: > On Mon, Feb 10, 2020 at 04:13:52PM -0500, Adam Serbinski wrote: > >> I am not aware of how this could be done for bluetooth, since the >> value >> still has to originate from userspace. The driver you referred to >> supports >> only a single sample rate, whereas for bluetooth, 2 sample rates are >> required, and nothing in the kernel is aware of the appropriate rate, >> at >> least in the case of the qca6174a I'm working with right now, or for >> that >> matter, TI Wilink 8, which I've also worked with. > > There's generic support in the CODEC<->CODEC link code for setting the > DAI configuration from userspace. Ok. Its going to take some time to get my head around that, so for the time being I'm going to drop this feature and get the rest fixed for inclusion. Thanks.
diff --git a/sound/soc/qcom/apq8096.c b/sound/soc/qcom/apq8096.c index 1edcaa15234f..882f2c456321 100644 --- a/sound/soc/qcom/apq8096.c +++ b/sound/soc/qcom/apq8096.c @@ -16,6 +16,9 @@ #define MI2S_BCLK_RATE 1536000 #define PCM_BCLK_RATE 1024000 +static int pri_pcm_sample_rate = 16000; +static int quat_pcm_sample_rate = 16000; + static int msm_snd_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { @@ -33,10 +36,15 @@ static int msm_snd_hw_params(struct snd_pcm_substream *substream, switch (cpu_dai->id) { case PRIMARY_PCM_RX: case PRIMARY_PCM_TX: + rate->min = pri_pcm_sample_rate; + rate->max = pri_pcm_sample_rate; + channels->min = 1; + channels->max = 1; + break; case QUATERNARY_PCM_RX: case QUATERNARY_PCM_TX: - rate->min = 16000; - rate->max = 16000; + rate->min = quat_pcm_sample_rate; + rate->max = quat_pcm_sample_rate; channels->min = 1; channels->max = 1; break; @@ -121,6 +129,83 @@ static struct snd_soc_ops apq8096_ops = { .startup = msm_snd_startup, }; +static char const *pcm_sample_rate_text[] = {"8 kHz", "16 kHz"}; +static const struct soc_enum pcm_snd_enum = + SOC_ENUM_SINGLE_EXT(2, pcm_sample_rate_text); + +static int get_sample_rate_idx(int sample_rate) +{ + int sample_rate_idx = 0; + + switch (sample_rate) { + case 8000: + sample_rate_idx = 0; + break; + case 16000: + default: + sample_rate_idx = 1; + break; + } + + return sample_rate_idx; +} + +static int pri_pcm_sample_rate_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + ucontrol->value.integer.value[0] = + get_sample_rate_idx(pri_pcm_sample_rate); + return 0; +} + +static int quat_pcm_sample_rate_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + ucontrol->value.integer.value[0] = + get_sample_rate_idx(quat_pcm_sample_rate); + return 0; +} + +static int get_sample_rate(int idx) +{ + int sample_rate_val = 0; + + switch (idx) { + case 0: + sample_rate_val = 8000; + break; + case 1: + default: + sample_rate_val = 16000; + break; + } + + return sample_rate_val; +} + +static int pri_pcm_sample_rate_put(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + pri_pcm_sample_rate = + get_sample_rate(ucontrol->value.integer.value[0]); + return 0; +} + +static int quat_pcm_sample_rate_put(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + quat_pcm_sample_rate = + get_sample_rate(ucontrol->value.integer.value[0]); + return 0; +} + +static const struct snd_kcontrol_new card_controls[] = { + SOC_ENUM_EXT("PRI_PCM SampleRate", pcm_snd_enum, + pri_pcm_sample_rate_get, pri_pcm_sample_rate_put), + SOC_ENUM_EXT("QUAT_PCM SampleRate", pcm_snd_enum, + quat_pcm_sample_rate_get, quat_pcm_sample_rate_put), +}; + static int apq8096_init(struct snd_soc_pcm_runtime *rtd) { struct snd_soc_dai *codec_dai = rtd->codec_dai; @@ -182,6 +267,9 @@ static int apq8096_platform_probe(struct platform_device *pdev) if (ret) goto err_card_register; + snd_soc_add_card_controls(card, card_controls, + ARRAY_SIZE(card_controls)); + return 0; err_card_register:
This makes it possible for the backend sample rate to be set to 8000 or 16000 Hz, depending on the needs of the HFP call being set up. Signed-off-by: Adam Serbinski <adam@serbinski.com> CC: Andy Gross <agross@kernel.org> CC: Mark Rutland <mark.rutland@arm.com> CC: Liam Girdwood <lgirdwood@gmail.com> CC: Patrick Lai <plai@codeaurora.org> CC: Banajit Goswami <bgoswami@codeaurora.org> CC: Jaroslav Kysela <perex@perex.cz> CC: Takashi Iwai <tiwai@suse.com> CC: alsa-devel@alsa-project.org CC: linux-arm-msm@vger.kernel.org CC: devicetree@vger.kernel.org CC: linux-kernel@vger.kernel.org --- sound/soc/qcom/apq8096.c | 92 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 2 deletions(-)