Hi Sugar Zhang,
Sorry to dig out this old thread, but I have two questions. Please see
below:
On 9/3/21 15:23, Sugar Zhang wrote:
> This patch adds support for rv1126 pdm controller which
> redesign cic filiter for better performance.
>
> Signed-off-by: Sugar Zhang <sugar.zhang@xxxxxxxxxxxxxx>
> ---
>
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
> sound/soc/rockchip/rockchip_pdm.c | 76 +++++++++++++++++++++++++++++++++++----
> sound/soc/rockchip/rockchip_pdm.h | 3 ++
> 2 files changed, 73 insertions(+), 6 deletions(-)
>
> diff --git a/sound/soc/rockchip/rockchip_pdm.c b/sound/soc/rockchip/rockchip_pdm.c
> index 38bd603..67634d1 100644
> --- a/sound/soc/rockchip/rockchip_pdm.c
> +++ b/sound/soc/rockchip/rockchip_pdm.c
> @@ -24,6 +24,7 @@
> enum rk_pdm_version {
> RK_PDM_RK3229,
> RK_PDM_RK3308,
> + RK_PDM_RV1126,
> };
>
> struct rk_pdm_dev {
> @@ -121,6 +122,55 @@ static unsigned int get_pdm_ds_ratio(unsigned int sr)
> return ratio;
> }
>
> +static unsigned int get_pdm_cic_ratio(unsigned int clk)
> +{
> + switch (clk) {
> + case 4096000:
> + case 5644800:
> + case 6144000:
> + return 0;
> + case 2048000:
> + case 2822400:
> + case 3072000:
> + return 1;
> + case 1024000:
> + case 1411200:
> + case 1536000:
> + return 2;
> + default:
> + return 1;
> + }
> +}
> +
> +static unsigned int samplerate_to_bit(unsigned int samplerate)
> +{
> + switch (samplerate) {
> + case 8000:
> + case 11025:
> + case 12000:
> + return 0;
> + case 16000:
> + case 22050:
> + case 24000:
> + return 1;
> + case 32000:
> + return 2;
> + case 44100:
> + case 48000:
> + return 3;
> + case 64000:
> + case 88200:
> + case 96000:
> + return 4;
> + case 128000:
> + case 176400:
> + case 192000:
> + return 5;
> + default:
> + return 1;
> + }
> +}
> +
> static inline struct rk_pdm_dev *to_info(struct snd_soc_dai *dai)
> {
> return snd_soc_dai_get_drvdata(dai);
> @@ -166,7 +216,8 @@ static int rockchip_pdm_hw_params(struct snd_pcm_substream *substream,
> if (ret)
> return -EINVAL;
>
> - if (pdm->version == RK_PDM_RK3308) {
> + if (pdm->version == RK_PDM_RK3308 ||
> + pdm->version == RK_PDM_RV1126) {
> rational_best_approximation(clk_out, clk_src,
> GENMASK(16 - 1, 0),
> GENMASK(16 - 1, 0),
> @@ -194,8 +245,18 @@ static int rockchip_pdm_hw_params(struct snd_pcm_substream *substream,
> PDM_CLK_FD_RATIO_MSK,
> val);
> }
> - val = get_pdm_ds_ratio(samplerate);
> - regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, PDM_DS_RATIO_MSK, val);
> +
> + if (pdm->version == RK_PDM_RV1126) {
> + val = get_pdm_cic_ratio(clk_out);
> + regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, PDM_CIC_RATIO_MSK, val);
> + val = samplerate_to_bit(samplerate);
> + regmap_update_bits(pdm->regmap, PDM_CTRL0,
> + PDM_SAMPLERATE_MSK, PDM_SAMPLERATE(val));
> + } else {
> + val = get_pdm_ds_ratio(samplerate);
> + regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, PDM_DS_RATIO_MSK, val);
> + }
> +
> regmap_update_bits(pdm->regmap, PDM_HPF_CTRL,
> PDM_HPF_CF_MSK, PDM_HPF_60HZ);
> regmap_update_bits(pdm->regmap, PDM_HPF_CTRL,
> @@ -441,9 +502,10 @@ static bool rockchip_pdm_precious_reg(struct device *dev, unsigned int reg)
> }
>
> static const struct reg_default rockchip_pdm_reg_defaults[] = {
> - {0x04, 0x78000017},
> - {0x08, 0x0bb8ea60},
> - {0x18, 0x0000001f},
> + { PDM_CTRL0, 0x78000017 },
> + { PDM_CTRL1, 0x0bb8ea60 },
> + { PDM_CLK_CTRL, 0x0000e401 },
> + { PDM_DMA_CTRL, 0x0000001f },
> };
>
> static const struct regmap_config rockchip_pdm_regmap_config = {
> @@ -469,6 +531,8 @@ static const struct of_device_id rockchip_pdm_match[] __maybe_unused = {
> .data = (void *)RK_PDM_RK3308 },
> { .compatible = "rockchip,rk3308-pdm",
> .data = (void *)RK_PDM_RK3308 },
> + { .compatible = "rockchip,rv1126-pdm",
> + .data = (void *)RK_PDM_RV1126 },
> {},
> };
> MODULE_DEVICE_TABLE(of, rockchip_pdm_match);
> diff --git a/sound/soc/rockchip/rockchip_pdm.h b/sound/soc/rockchip/rockchip_pdm.h
> index 8e5bbaf..13bfbc2 100644
> --- a/sound/soc/rockchip/rockchip_pdm.h
> +++ b/sound/soc/rockchip/rockchip_pdm.h
> @@ -41,6 +41,8 @@
> #define PDM_PATH1_EN BIT(28)
> #define PDM_PATH0_EN BIT(27)
> #define PDM_HWT_EN BIT(26)
> +#define PDM_SAMPLERATE_MSK GENMASK(7, 5)
> +#define PDM_SAMPLERATE(x) ((x) << 5)
> #define PDM_VDW_MSK (0x1f << 0)
> #define PDM_VDW(X) ((X - 1) << 0)
The TRM of RV1126 and RK3568 both state that sample resolutions from 16
up to 24 bits are supported. However, I don't see anything in this patch
that restricts the capture formats accordingly. In fact, the driver
offers SNDRV_PCM_FMTBIT_S32_LE in my setup and via this PDM_VDW macro 31
is written to PDM_CTRL0, which is undefined behavior according to the TRM.
Are 32 bit samples supported by the RK3568/RV1126 PDM block?
> @@ -66,6 +68,7 @@
> #define PDM_CLK_1280FS (0x2 << 0)
> #define PDM_CLK_2560FS (0x3 << 0)
> #define PDM_CLK_5120FS (0x4 << 0)
> +#define PDM_CIC_RATIO_MSK (0x3 << 0)
>
> /* PDM HPF CTRL */
> #define PDM_HPF_LE BIT(3)
Also, I noticed that the number of channels must be an even number.
Shouldn't it be possible to use a single mono PDM microphone with this
PDM block (i.e., having one channel)?
Thanks a lot and best regards,
Michael
