On 22.07.2019 21:27, Michał Mirosław wrote:
> SSC driver allows only synchronous TX and RX. In slave mode for BCLK
> it uses only one of TK or RK pin, but for LRCLK it configured separate
> inputs from TF and RF pins. Allow configuration with common FS signal.
>
> Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/misc/atmel-ssc.txt | 4 ++
> drivers/misc/atmel-ssc.c | 2 +
> include/linux/atmel-ssc.h | 1 +
> sound/soc/atmel/atmel_ssc_dai.c | 48 ++++++++++++-------
> 4 files changed, 38 insertions(+), 17 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/misc/atmel-ssc.txt b/Documentation/devicetree/bindings/misc/atmel-ssc.txt
> index f9fb412642fe..89133c5b82cb 100644
> --- a/Documentation/devicetree/bindings/misc/atmel-ssc.txt
> +++ b/Documentation/devicetree/bindings/misc/atmel-ssc.txt
> @@ -24,6 +24,10 @@ Optional properties:
> this parameter to choose where the clock from.
> - By default the clock is from TK pin, if the clock from RK pin, this
> property is needed.
> + - atmel,shared-fs-pin: bool property.
> + - When SSC works in slave mode, by default it gets separate LRCLK signals
> + from RF and TF. This property makes SSC use a single pin for both
> + RX and TX. TF is used unless atmel,clk-from-rk-pin is also present.
> - #sound-dai-cells: Should contain <0>.
> - This property makes the SSC into an automatically registered DAI.
the binding changes should be sent in a separate patch, please see
Documentation/devicetree/bindings/submitting-patches.txt for details.
>
> diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
> index ab4144ea1f11..da63eee1cdf5 100644
> --- a/drivers/misc/atmel-ssc.c
> +++ b/drivers/misc/atmel-ssc.c
> @@ -210,6 +210,8 @@ static int ssc_probe(struct platform_device *pdev)
> struct device_node *np = pdev->dev.of_node;
> ssc->clk_from_rk_pin =
> of_property_read_bool(np, "atmel,clk-from-rk-pin");
> + ssc->shared_fs_pin =
> + of_property_read_bool(np, "atmel,shared-fs-pin");
> }
>
> regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> diff --git a/include/linux/atmel-ssc.h b/include/linux/atmel-ssc.h
> index 6091d2abc1eb..46fdff2dfbb0 100644
> --- a/include/linux/atmel-ssc.h
> +++ b/include/linux/atmel-ssc.h
> @@ -21,6 +21,7 @@ struct ssc_device {
> int user;
> int irq;
> bool clk_from_rk_pin;
> + bool shared_fs_pin;
> bool sound_dai;
> };
These changes should also be in a separate patch, since drivers/misc/*
files are in a different subsystem, with different maintainers.
>
> diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
> index cf2cfc345676..6f595a748618 100644
> --- a/sound/soc/atmel/atmel_ssc_dai.c
> +++ b/sound/soc/atmel/atmel_ssc_dai.c
> @@ -471,7 +471,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> int dir, channels, bits;
> u32 tfmr, rfmr, tcmr, rcmr;
> int ret;
> - int fslen, fslen_ext, fs_osync;
> + int fslen, fslen_ext, fs_osync, fs_edge;
> u32 cmr_div;
> u32 tcmr_period;
> u32 rcmr_period;
> @@ -567,24 +567,20 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> case SND_SOC_DAIFMT_LEFT_J:
> /* left-justified format */
> fs_osync = SSC_FSOS_POSITIVE;
> + fs_edge = SSC_START_RISING_TF;
>
> - rcmr = SSC_BF(RCMR_STTDLY, 0)
> - | SSC_BF(RCMR_START, SSC_START_RISING_RF);
> -
> - tcmr = SSC_BF(TCMR_STTDLY, 0)
> - | SSC_BF(TCMR_START, SSC_START_RISING_TF);
> + rcmr = SSC_BF(RCMR_STTDLY, 0);
> + tcmr = SSC_BF(TCMR_STTDLY, 0);
>
> break;
>
> case SND_SOC_DAIFMT_I2S:
> /* I2S format = left-justified with start bit and inverted LRCLK */
> fs_osync = SSC_FSOS_NEGATIVE;
> + fs_edge = SSC_START_FALLING_TF;
>
> - rcmr = SSC_BF(RCMR_STTDLY, 1)
> - | SSC_BF(RCMR_START, SSC_START_FALLING_RF);
> -
> - tcmr = SSC_BF(TCMR_STTDLY, 1)
> - | SSC_BF(TCMR_START, SSC_START_FALLING_TF);
> + rcmr = SSC_BF(RCMR_STTDLY, 1);
> + tcmr = SSC_BF(TCMR_STTDLY, 1);
>
> break;
>
> @@ -597,13 +593,11 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> * the left channel data.
> */
> fs_osync = SSC_FSOS_POSITIVE;
> + fs_edge = SSC_START_RISING_TF;
> fslen = fslen_ext = 0;
>
> - rcmr = SSC_BF(RCMR_STTDLY, 1)
> - | SSC_BF(RCMR_START, SSC_START_RISING_RF);
> -
> - tcmr = SSC_BF(TCMR_STTDLY, 1)
> - | SSC_BF(TCMR_START, SSC_START_RISING_TF);
> + rcmr = SSC_BF(RCMR_STTDLY, 1);
> + tcmr = SSC_BF(TCMR_STTDLY, 1);
>
> break;
>
> @@ -613,10 +607,30 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
> return -EINVAL;
> }
>
> - if (!atmel_ssc_cfs(ssc_p)) {
> + if (atmel_ssc_cfs(ssc_p)) {
> + /*
> + * SSC provides LRCLK
> + *
> + * Both TF and RF are generated, so use them directly.
> + */
> + rcmr |= SSC_BF(RCMR_START, fs_edge);
> + tcmr |= SSC_BF(TCMR_START, fs_edge);
> + } else {
> fslen = fslen_ext = 0;
> rcmr_period = tcmr_period = 0;
> fs_osync = SSC_FSOS_NONE;
> + if (!ssc->shared_fs_pin) {
> + rcmr |= SSC_BF(RCMR_START, fs_edge);
> + tcmr |= SSC_BF(TCMR_START, fs_edge);
> + } else if (ssc->clk_from_rk_pin) {
> + /* assume RF is to be used when RK is used as BCLK input */
> + /* Note: won't work correctly on SAMA5D2 due to errata */
> + rcmr |= SSC_BF(RCMR_START, fs_edge);
> + tcmr |= SSC_BF(TCMR_START, SSC_START_RECEIVE);
Did you find a platform in which this mode works?
> + } else {
> + rcmr |= SSC_BF(RCMR_START, SSC_START_TRANSMIT);
> + tcmr |= SSC_BF(TCMR_START, fs_edge);
> + }
> }
>
> if (atmel_ssc_cbs(ssc_p)) {
>
I like this feature, just separate the changes in different patches.
Thanks and best regards,
Codrin
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