| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <5445BCBF.5090002@atmel.com>
Date: Tue, 21 Oct 2014 09:54:07 +0800
From: Bo Shen <voice.shen@...el.com>
To: Peter Rosin <peda@...ntia.se>
CC: Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>,
Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.de>,
"'alsa-devel@...a-project.org'" <alsa-devel@...a-project.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [alsa-devel] [PATCH] ASoC: atmel_ssc_dai: Track playback and
capture CMR dividers separately.
Hi Peter,
On 10/20/2014 09:45 PM, Peter Rosin wrote:
> From 1e5621d7b9887c648d1a66238dc82d715c1e2cad Mon Sep 17 00:00:00 2001
> From: Peter Rosin <peda@...ntia.se>
> Date: Mon, 20 Oct 2014 14:38:04 +0200
> Subject: [PATCH] ASoC: atmel_ssc_dai: Track playback and capture CMR dividers
> separately.
>
> The CMR divider register is shared by playback and capture. The SSC driver
> therefore tries to enforce rules so that the needed register content do
> not conflict during simultaneous playback/capture. However, the
> implementation also prevents changing the register content in a
> half-duplex scenario, which is needed when changing sample rates.
I am not fully get what you mean here, do you mean:
- when playback, first playback 48kHz, and then playback 8Khz, the
8Khz still playback in 48kHz mode?
or other things?
> Thus, keep track of the desired playback and capture clock dividers
> separately, and allow changing rates without closing the stream.
>
> Signed-off-by: Peter Rosin <peda@...ntia.se>
> ---
> sound/soc/atmel/atmel_ssc_dai.c | 31 ++++++++++++++++++++++---------
> sound/soc/atmel/atmel_ssc_dai.h | 10 ++++++----
> 2 files changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
> index f403f39..fec14fb 100644
> --- a/sound/soc/atmel/atmel_ssc_dai.c
> +++ b/sound/soc/atmel/atmel_ssc_dai.c
> @@ -277,7 +277,8 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
> /* Reset the SSC */
> ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
> /* Clear the SSC dividers */
> - ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
> + ssc_p->tcmr_div = ssc_p->rcmr_div = 0;
> + ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
> }
> spin_unlock_irq(&ssc_p->lock);
> }
> @@ -304,17 +305,27 @@ static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
> struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
>
> switch (div_id) {
> - case ATMEL_SSC_CMR_DIV:
> + case ATMEL_SSC_TCMR_DIV:
> /*
> * The same master clock divider is used for both
> * transmit and receive, so if a value has already
> - * been set, it must match this value.
> + * been set for the other direction, it must match
> + * this value.
> */
> - if (ssc_p->cmr_div == 0)
> - ssc_p->cmr_div = div;
> - else
> - if (div != ssc_p->cmr_div)
> - return -EBUSY;
> + if (ssc_p->rcmr_div == 0)
> + ssc_p->tcmr_div = div;
> + else if (div != ssc_p->rcmr_div)
> + return -EBUSY;
> + break;
> +
> + case ATMEL_SSC_RCMR_DIV:
> + /*
> + * See ATMEL_SSC_TCMR_DIV.
> + */
> + if (ssc_p->tcmr_div == 0)
> + ssc_p->rcmr_div = div;
> + else if (div != ssc_p->tcmr_div)
> + return -EBUSY;
> break;
>
> case ATMEL_SSC_TCMR_PERIOD:
> @@ -345,6 +356,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> struct atmel_pcm_dma_params *dma_params;
> int dir, channels, bits;
> u32 tfmr, rfmr, tcmr, rcmr;
> + u16 cmr;
should be u32.
> int start_event;
> int ret;
> int fslen, fslen_ext;
> @@ -626,7 +638,8 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> }
>
> /* set SSC clock mode register */
> - ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->cmr_div);
> + cmr = ssc_p->tcmr_div ? ssc_p->tcmr_div : ssc_p->rcmr_div;
> + ssc_writel(ssc_p->ssc->regs, CMR, cmr);
>
> /* set receive clock mode and format */
> ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
> diff --git a/sound/soc/atmel/atmel_ssc_dai.h b/sound/soc/atmel/atmel_ssc_dai.h
> index b1f08d5..a25df7a 100644
> --- a/sound/soc/atmel/atmel_ssc_dai.h
> +++ b/sound/soc/atmel/atmel_ssc_dai.h
> @@ -39,9 +39,10 @@
> #define ATMEL_SYSCLK_MCK 0 /* SSC uses AT91 MCK as system clock */
>
> /* SSC divider ids */
> -#define ATMEL_SSC_CMR_DIV 0 /* MCK divider for BCLK */
> -#define ATMEL_SSC_TCMR_PERIOD 1 /* BCLK divider for transmit FS */
> -#define ATMEL_SSC_RCMR_PERIOD 2 /* BCLK divider for receive FS */
> +#define ATMEL_SSC_TCMR_DIV 0 /* MCK divider for transmit BCLK */
> +#define ATMEL_SSC_RCMR_DIV 1 /* MCK divider for receive BCLK */
> +#define ATMEL_SSC_TCMR_PERIOD 2 /* BCLK divider for transmit FS */
> +#define ATMEL_SSC_RCMR_PERIOD 3 /* BCLK divider for receive FS */
> /*
> * SSC direction masks
> */
> @@ -110,7 +111,8 @@ struct atmel_ssc_info {
> unsigned short dir_mask; /* 0=unused, 1=playback, 2=capture */
> unsigned short initialized; /* true if SSC has been initialized */
> unsigned short daifmt;
> - unsigned short cmr_div;
> + unsigned short tcmr_div;
> + unsigned short rcmr_div;
> unsigned short tcmr_period;
> unsigned short rcmr_period;
> struct atmel_pcm_dma_params *dma_params[2];
>
Best Regards,
Bo Shen
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists