snd_soc_codec_driver.set_pll is implemented to configure the FLL. The codec internal SYSCLK can be from either the MCLK pin directly, or the FLL. This is configured by snd_soc_codec_driver.set_pll.
Signed-off-by: Ben Zhang benzh@chromium.org --- sound/soc/codecs/nau8825.c | 162 +++++++++++++++++++++++++++++++++++++++++++++ sound/soc/codecs/nau8825.h | 28 ++++++-- 2 files changed, 185 insertions(+), 5 deletions(-)
diff --git a/sound/soc/codecs/nau8825.c b/sound/soc/codecs/nau8825.c index 5c1badf..010f50b 100644 --- a/sound/soc/codecs/nau8825.c +++ b/sound/soc/codecs/nau8825.c @@ -29,6 +29,58 @@
#include "nau8825.h"
+#define NAU_FREF_MAX 13500000 +#define NAU_FVCO_MAX 100000000 +#define NAU_FVCO_MIN 90000000 + +struct nau88xx_fll { + int mclk_src; + int ratio; + int fll_frac; + int fll_int; + int clk_ref_div; +}; + +struct nau88xx_fll_attr { + unsigned int param; + unsigned int val; +}; + +/* scaling for mclk from sysclk_src output */ +static const struct nau88xx_fll_attr mclk_src_scaling[] = { + { 1, 0x0 }, + { 2, 0x2 }, + { 4, 0x3 }, + { 8, 0x4 }, + { 16, 0x5 }, + { 32, 0x6 }, + { 3, 0x7 }, + { 6, 0xa }, + { 12, 0xb }, + { 24, 0xc }, + { 48, 0xd }, + { 96, 0xe }, + { 5, 0xf }, +}; + +/* ratio for input clk freq */ +static const struct nau88xx_fll_attr fll_ratio[] = { + { 512000, 0x01 }, + { 256000, 0x02 }, + { 128000, 0x04 }, + { 64000, 0x08 }, + { 32000, 0x10 }, + { 8000, 0x20 }, + { 4000, 0x40 }, +}; + +static const struct nau88xx_fll_attr fll_pre_scalar[] = { + { 1, 0x0 }, + { 2, 0x1 }, + { 4, 0x2 }, + { 8, 0x3 }, +}; + static const struct reg_default nau8825_reg_defaults[] = { { NAU8825_REG_ENA_CTRL, 0x00ff }, { NAU8825_REG_CLK_DIVIDER, 0x0050 }, @@ -808,6 +860,115 @@ static int nau8825_codec_probe(struct snd_soc_codec *codec) return 0; }
+/** + * nau88xx_calc_fll_param - Calculate FLL parameters. + * @fll_in: external clock provided to codec. + * @fs: sampling rate. + * @fll_param: Pointer to structure of FLL parameters. + * + * Calculate FLL parameters to configure codec. + * + * Returns 0 for success or negative error code. + */ +static int nau88xx_calc_fll_param(unsigned int fll_in, unsigned int fs, + struct nau88xx_fll *fll_param) +{ + u64 fref, fvco, fll_input; + int i; + + /* Ensure the reference clock frequency (FREF) is <= 13.5MHz by dividing + * freq_in by 1, 2, 4, or 8 using FLL pre-scalar. + * FREF = freq_in / NAU8825_FLL_REF_DIV_MASK + */ + for (i = 0; i < ARRAY_SIZE(fll_pre_scalar); i++) { + fref = fll_in / fll_pre_scalar[i].param; + if (fref <= NAU_FREF_MAX) + break; + } + if (i == ARRAY_SIZE(fll_pre_scalar)) + return -EINVAL; + fll_param->clk_ref_div = fll_pre_scalar[i].val; + + /* Choose the FLL ratio based on FREF */ + for (i = 0; i < ARRAY_SIZE(fll_ratio); i++) { + if (fref >= fll_ratio[i].param) + break; + } + if (i == ARRAY_SIZE(fll_ratio)) + return -EINVAL; + fll_param->ratio = fll_ratio[i].val; + + /* Calculate the frequency of DCO (FDCO) given freq_out = 256 * Fs. + * FDCO must be within the 90MHz - 100MHz or the FFL cannot be + * guaranteed across the full range of operation. + * FDCO = freq_out * 2 * mclk_src_scaling + */ + for (i = 0; i < ARRAY_SIZE(mclk_src_scaling); i++) { + fvco = 256 * fs * 2 * mclk_src_scaling[i].param; + if (NAU_FVCO_MIN < fvco && fvco < NAU_FVCO_MAX) + break; + } + if (i == ARRAY_SIZE(mclk_src_scaling)) + return -EINVAL; + fll_param->mclk_src = mclk_src_scaling[i].val; + + /* Calculate the FLL 10-bit integer input and the FLL 16-bit fractional + * input based on FDCO, FREF and FLL ratio. + */ + fll_input = (fvco << 16) / (fref * fll_param->ratio); + fll_param->fll_int = fll_input >> 16; + fll_param->fll_frac = fll_input & 0xFFFF; + return 0; +} + +static void nau88xx_fll_apply(struct nau8825 *nau8825, + struct nau88xx_fll *fll_param) +{ + regmap_update_bits(nau8825->regmap, NAU8825_REG_CLK_DIVIDER, + NAU8825_CLK_MCLK_SRC_MASK, fll_param->mclk_src); + regmap_update_bits(nau8825->regmap, NAU8825_REG_FLL1, + NAU8825_FLL_RATIO_MASK, fll_param->ratio); + /* FLL 16-bit fractional input */ + regmap_write(nau8825->regmap, NAU8825_REG_FLL2, fll_param->fll_frac); + /* FLL 10-bit integer input */ + regmap_update_bits(nau8825->regmap, NAU8825_REG_FLL3, + NAU8825_FLL_INTEGER_MASK, fll_param->fll_int); + /* FLL pre-scaler */ + regmap_update_bits(nau8825->regmap, NAU8825_REG_FLL4, + NAU8825_FLL_REF_DIV_MASK, fll_param->clk_ref_div); + /* select divided VCO input */ + regmap_update_bits(nau8825->regmap, NAU8825_REG_FLL5, + NAU8825_FLL_FILTER_SW_MASK, 0x0000); + /* FLL sigma delta modulator enable */ + regmap_update_bits(nau8825->regmap, NAU8825_REG_FLL6, + NAU8825_SDM_EN_MASK, NAU8825_SDM_EN); +} + +/* freq_out must be 256*Fs in order to achieve the best performance */ +static int nau8825_set_pll(struct snd_soc_codec *codec, int pll_id, int source, + unsigned int freq_in, unsigned int freq_out) +{ + struct nau8825 *nau8825 = snd_soc_codec_get_drvdata(codec); + struct nau88xx_fll fll_param; + int ret, fs; + + fs = freq_out / 256; + ret = nau88xx_calc_fll_param(freq_in, fs, &fll_param); + if (ret < 0) { + dev_err(codec->dev, "Unsupported input clock %d\n", freq_in); + return ret; + } + dev_dbg(codec->dev, "mclk_src=%x ratio=%x fll_frac=%x fll_int=%x clk_ref_div=%x\n", + fll_param.mclk_src, fll_param.ratio, fll_param.fll_frac, + fll_param.fll_int, fll_param.clk_ref_div); + + nau88xx_fll_apply(nau8825, &fll_param); + mdelay(2); + regmap_update_bits(nau8825->regmap, NAU8825_REG_CLK_DIVIDER, + NAU8825_CLK_SRC_MASK, NAU8825_CLK_SRC_VCO); + return 0; +} + static int nau8825_configure_sysclk(struct nau8825 *nau8825, int clk_id, unsigned int freq) { @@ -920,6 +1081,7 @@ static int nau8825_set_bias_level(struct snd_soc_codec *codec, static struct snd_soc_codec_driver nau8825_codec_driver = { .probe = nau8825_codec_probe, .set_sysclk = nau8825_set_sysclk, + .set_pll = nau8825_set_pll, .set_bias_level = nau8825_set_bias_level, .suspend_bias_off = true,
diff --git a/sound/soc/codecs/nau8825.h b/sound/soc/codecs/nau8825.h index 8774923..dff8edb 100644 --- a/sound/soc/codecs/nau8825.h +++ b/sound/soc/codecs/nau8825.h @@ -101,13 +101,31 @@ #define NAU8825_ENABLE_SAR_SFT 1
/* CLK_DIVIDER (0x3) */ -#define NAU8825_CLK_SRC_SFT 15 -#define NAU8825_CLK_SRC_MASK (1 << NAU8825_CLK_SRC_SFT) -#define NAU8825_CLK_SRC_VCO (1 << NAU8825_CLK_SRC_SFT) -#define NAU8825_CLK_SRC_MCLK (0 << NAU8825_CLK_SRC_SFT) +#define NAU8825_CLK_SRC_SFT 15 +#define NAU8825_CLK_SRC_MASK (1 << NAU8825_CLK_SRC_SFT) +#define NAU8825_CLK_SRC_VCO (1 << NAU8825_CLK_SRC_SFT) +#define NAU8825_CLK_SRC_MCLK (0 << NAU8825_CLK_SRC_SFT) +#define NAU8825_CLK_MCLK_SRC_MASK (0xf << 0) + +/* FLL1 (0x04) */ +#define NAU8825_FLL_RATIO_MASK (0x7f << 0) + +/* FLL3 (0x06) */ +#define NAU8825_FLL_INTEGER_MASK (0x3ff << 0) + +/* FLL4 (0x07) */ +#define NAU8825_FLL_REF_DIV_MASK (0x3 << 10) + +/* FLL5 (0x08) */ +#define NAU8825_FLL_FILTER_SW_MASK (0x1 << 14)
/* FLL6 (0x9) */ -#define NAU8825_DCO_EN (1 << 15) +#define NAU8825_DCO_EN_MASK (0x1 << 15) +#define NAU8825_DCO_EN (0x1 << 15) +#define NAU8825_DCO_DIS (0x0 << 15) +#define NAU8825_SDM_EN_MASK (0x1 << 14) +#define NAU8825_SDM_EN (0x1 << 14) +#define NAU8825_SDM_DIS (0x0 << 14)
/* HSD_CTRL (0xc) */ #define NAU8825_HSD_AUTO_MODE (1 << 6)