ASoC: fsl_sai: add sai master mode support

When sai works on master mode, set its bit clock and frame clock.

SAI has 4 MCLK source, bus clock, MCLK1, MCLK2 and MCLK3. fsl_sai_set_bclk
will select proper MCLK source, then calculate and set the bit clock divider.

After fsl_sai_set_bclk, enable the selected mclk in hw_params(), and add
hw_free() to disable the mclk.

Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index ec79c3d5e65e28acb24b6be4190a1fe091252e7a..cca72b8287a984ce585312d1dcf2d428d3779bc4 100644 (file)
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -1,7 +1,7 @@
 /*
  * Freescale ALSA SoC Digital Audio Interface (SAI) driver.
  *
- * Copyright 2012-2013 Freescale Semiconductor, Inc.
+ * Copyright 2012-2015 Freescale Semiconductor, Inc.
  *
  * This program is free software, you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -251,12 +251,14 @@ static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai,
                val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
                break;
        case SND_SOC_DAIFMT_CBM_CFM:
+               sai->is_slave_mode = true;
                break;
        case SND_SOC_DAIFMT_CBS_CFM:
                val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
                break;
        case SND_SOC_DAIFMT_CBM_CFS:
                val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
+               sai->is_slave_mode = true;
                break;
        default:
                return -EINVAL;
@@ -288,6 +290,79 @@ static int fsl_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
        return ret;
 }
 
+static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
+{
+       struct fsl_sai *sai = snd_soc_dai_get_drvdata(dai);
+       unsigned long clk_rate;
+       u32 savediv = 0, ratio, savesub = freq;
+       u32 id;
+       int ret = 0;
+
+       /* Don't apply to slave mode */
+       if (sai->is_slave_mode)
+               return 0;
+
+       for (id = 0; id < FSL_SAI_MCLK_MAX; id++) {
+               clk_rate = clk_get_rate(sai->mclk_clk[id]);
+               if (!clk_rate)
+                       continue;
+
+               ratio = clk_rate / freq;
+
+               ret = clk_rate - ratio * freq;
+
+               /*
+                * Drop the source that can not be
+                * divided into the required rate.
+                */
+               if (ret != 0 && clk_rate / ret < 1000)
+                       continue;
+
+               dev_dbg(dai->dev,
+                       "ratio %d for freq %dHz based on clock %ldHz\n",
+                       ratio, freq, clk_rate);
+
+               if (ratio % 2 == 0 && ratio >= 2 && ratio <= 512)
+                       ratio /= 2;
+               else
+                       continue;
+
+               if (ret < savesub) {
+                       savediv = ratio;
+                       sai->mclk_id[tx] = id;
+                       savesub = ret;
+               }
+
+               if (ret == 0)
+                       break;
+       }
+
+       if (savediv == 0) {
+               dev_err(dai->dev, "failed to derive required %cx rate: %d\n",
+                               tx ? 'T' : 'R', freq);
+               return -EINVAL;
+       }
+
+       if ((tx && sai->synchronous[TX]) || (!tx && !sai->synchronous[RX])) {
+               regmap_update_bits(sai->regmap, FSL_SAI_RCR2,
+                                  FSL_SAI_CR2_MSEL_MASK,
+                                  FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
+               regmap_update_bits(sai->regmap, FSL_SAI_RCR2,
+                                  FSL_SAI_CR2_DIV_MASK, savediv - 1);
+       } else {
+               regmap_update_bits(sai->regmap, FSL_SAI_TCR2,
+                                  FSL_SAI_CR2_MSEL_MASK,
+                                  FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
+               regmap_update_bits(sai->regmap, FSL_SAI_TCR2,
+                                  FSL_SAI_CR2_DIV_MASK, savediv - 1);
+       }
+
+       dev_dbg(dai->dev, "best fit: clock id=%d, div=%d, deviation =%d\n",
+                       sai->mclk_id[tx], savediv, savesub);
+
+       return 0;
+}
+
 static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params,
                struct snd_soc_dai *cpu_dai)
@@ -297,6 +372,24 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
        unsigned int channels = params_channels(params);
        u32 word_width = snd_pcm_format_width(params_format(params));
        u32 val_cr4 = 0, val_cr5 = 0;
+       int ret;
+
+       if (!sai->is_slave_mode) {
+               ret = fsl_sai_set_bclk(cpu_dai, tx,
+                       2 * word_width * params_rate(params));
+               if (ret)
+                       return ret;
+
+               /* Do not enable the clock if it is already enabled */
+               if (!(sai->mclk_streams & BIT(substream->stream))) {
+                       ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[tx]]);
+                       if (ret)
+                               return ret;
+
+                       sai->mclk_streams |= BIT(substream->stream);
+               }
+
+       }
 
        if (!sai->is_dsp_mode)
                val_cr4 |= FSL_SAI_CR4_SYWD(word_width);
@@ -322,6 +415,22 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
        return 0;
 }
 
+static int fsl_sai_hw_free(struct snd_pcm_substream *substream,
+               struct snd_soc_dai *cpu_dai)
+{
+       struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
+       bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+
+       if (!sai->is_slave_mode &&
+                       sai->mclk_streams & BIT(substream->stream)) {
+               clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[tx]]);
+               sai->mclk_streams &= ~BIT(substream->stream);
+       }
+
+       return 0;
+}
+
+
 static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
                struct snd_soc_dai *cpu_dai)
 {
@@ -428,6 +537,7 @@ static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
        .set_sysclk     = fsl_sai_set_dai_sysclk,
        .set_fmt        = fsl_sai_set_dai_fmt,
        .hw_params      = fsl_sai_hw_params,
+       .hw_free        = fsl_sai_hw_free,
        .trigger        = fsl_sai_trigger,
        .startup        = fsl_sai_startup,
        .shutdown       = fsl_sai_shutdown,
@@ -600,8 +710,9 @@ static int fsl_sai_probe(struct platform_device *pdev)
                sai->bus_clk = NULL;
        }
 
-       for (i = 0; i < FSL_SAI_MCLK_MAX; i++) {
-               sprintf(tmp, "mclk%d", i + 1);
+       sai->mclk_clk[0] = sai->bus_clk;
+       for (i = 1; i < FSL_SAI_MCLK_MAX; i++) {
+               sprintf(tmp, "mclk%d", i);
                sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);
                if (IS_ERR(sai->mclk_clk[i])) {
                        dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",

diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 34667209b607d435d3abd9ac10bbfe6e8cf9a64c..066280953c8503bd03d2dc1a2469004978215e1a 100644 (file)
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -72,13 +72,15 @@
 
 /* SAI Transmit and Recieve Configuration 2 Register */
 #define FSL_SAI_CR2_SYNC       BIT(30)
-#define FSL_SAI_CR2_MSEL_MASK  (0xff << 26)
+#define FSL_SAI_CR2_MSEL_MASK  (0x3 << 26)
 #define FSL_SAI_CR2_MSEL_BUS   0
 #define FSL_SAI_CR2_MSEL_MCLK1 BIT(26)
 #define FSL_SAI_CR2_MSEL_MCLK2 BIT(27)
 #define FSL_SAI_CR2_MSEL_MCLK3 (BIT(26) | BIT(27))
+#define FSL_SAI_CR2_MSEL(ID)   ((ID) << 26)
 #define FSL_SAI_CR2_BCP                BIT(25)
 #define FSL_SAI_CR2_BCD_MSTR   BIT(24)
+#define FSL_SAI_CR2_DIV_MASK   0xff
 
 /* SAI Transmit and Recieve Configuration 3 Register */
 #define FSL_SAI_CR3_TRCE       BIT(16)
@@ -120,7 +122,7 @@
 #define FSL_SAI_CLK_MAST2      2
 #define FSL_SAI_CLK_MAST3      3
 
-#define FSL_SAI_MCLK_MAX       3
+#define FSL_SAI_MCLK_MAX       4
 
 /* SAI data transfer numbers per DMA request */
 #define FSL_SAI_MAXBURST_TX 6
@@ -132,11 +134,14 @@ struct fsl_sai {
        struct clk *bus_clk;
        struct clk *mclk_clk[FSL_SAI_MCLK_MAX];
 
+       bool is_slave_mode;
        bool is_lsb_first;
        bool is_dsp_mode;
        bool sai_on_imx;
        bool synchronous[2];
 
+       unsigned int mclk_id[2];
+       unsigned int mclk_streams;
        struct snd_dmaengine_dai_dma_data dma_params_rx;
        struct snd_dmaengine_dai_dma_data dma_params_tx;
 };