1 files changed, 83 insertions, 20 deletions

diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
index 95f6a9617b0b..02c81d2e34ad 100644
--- a/sound/soc/fsl/fsl_asrc.c
+++ b/sound/soc/fsl/fsl_asrc.c
@@ -37,7 +37,7 @@ static struct snd_pcm_hw_constraint_list fsl_asrc_rate_constraints = {
 	.list = supported_asrc_rate,
 };
 
-/**
+/*
  * The following tables map the relationship between asrc_inclk/asrc_outclk in
  * fsl_asrc.h and the registers of ASRCSR
  */
@@ -68,7 +68,7 @@ static unsigned char output_clk_map_imx53[ASRC_CLK_MAP_LEN] = {
 	0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7, 0x7,
 };
 
-/**
+/*
  * i.MX8QM/i.MX8QXP uses the same map for input and output.
  * clk_map_imx8qm[0] is for i.MX8QM asrc0
  * clk_map_imx8qm[1] is for i.MX8QM asrc1
@@ -102,16 +102,17 @@ static unsigned char clk_map_imx8qxp[2][ASRC_CLK_MAP_LEN] = {
 };
 
 /**
- * Select the pre-processing and post-processing options
+ * fsl_asrc_sel_proc - Select the pre-processing and post-processing options
+ * @inrate: input sample rate
+ * @outrate: output sample rate
+ * @pre_proc: return value for pre-processing option
+ * @post_proc: return value for post-processing option
+ *
  * Make sure to exclude following unsupported cases before
  * calling this function:
  * 1) inrate > 8.125 * outrate
  * 2) inrate > 16.125 * outrate
  *
- * inrate: input sample rate
- * outrate: output sample rate
- * pre_proc: return value for pre-processing option
- * post_proc: return value for post-processing option
  */
 static void fsl_asrc_sel_proc(int inrate, int outrate,
 			     int *pre_proc, int *post_proc)
@@ -148,7 +149,9 @@ static void fsl_asrc_sel_proc(int inrate, int outrate,
 }
 
 /**
- * Request ASRC pair
+ * fsl_asrc_request_pair - Request ASRC pair
+ * @channels: number of channels
+ * @pair: pointer to pair
  *
  * It assigns pair by the order of A->C->B because allocation of pair B,
  * within range [ANCA, ANCA+ANCB-1], depends on the channels of pair A
@@ -193,7 +196,8 @@ static int fsl_asrc_request_pair(int channels, struct fsl_asrc_pair *pair)
 }
 
 /**
- * Release ASRC pair
+ * fsl_asrc_release_pair - Release ASRC pair
+ * @pair: pair to release
  *
  * It clears the resource from asrc and releases the occupied channels.
  */
@@ -217,7 +221,10 @@ static void fsl_asrc_release_pair(struct fsl_asrc_pair *pair)
 }
 
 /**
- * Configure input and output thresholds
+ * fsl_asrc_set_watermarks- configure input and output thresholds
+ * @pair: pointer to pair
+ * @in: input threshold
+ * @out: output threshold
  */
 static void fsl_asrc_set_watermarks(struct fsl_asrc_pair *pair, u32 in, u32 out)
 {
@@ -234,7 +241,9 @@ static void fsl_asrc_set_watermarks(struct fsl_asrc_pair *pair, u32 in, u32 out)
 }
 
 /**
- * Calculate the total divisor between asrck clock rate and sample rate
+ * fsl_asrc_cal_asrck_divisor - Calculate the total divisor between asrck clock rate and sample rate
+ * @pair: pointer to pair
+ * @div: divider
  *
  * It follows the formula clk_rate = samplerate * (2 ^ prescaler) * divider
  */
@@ -250,7 +259,10 @@ static u32 fsl_asrc_cal_asrck_divisor(struct fsl_asrc_pair *pair, u32 div)
 }
 
 /**
- * Calculate and set the ratio for Ideal Ratio mode only
+ * fsl_asrc_set_ideal_ratio - Calculate and set the ratio for Ideal Ratio mode only
+ * @pair: pointer to pair
+ * @inrate: input rate
+ * @outrate: output rate
  *
  * The ratio is a 32-bit fixed point value with 26 fractional bits.
  */
@@ -293,7 +305,9 @@ static int fsl_asrc_set_ideal_ratio(struct fsl_asrc_pair *pair,
 }
 
 /**
- * Configure the assigned ASRC pair
+ * fsl_asrc_config_pair - Configure the assigned ASRC pair
+ * @pair: pointer to pair
+ * @use_ideal_rate: boolean configuration
  *
  * It configures those ASRC registers according to a configuration instance
  * of struct asrc_config which includes in/output sample rate, width, channel
@@ -508,7 +522,8 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair, bool use_ideal_rate)
 }
 
 /**
- * Start the assigned ASRC pair
+ * fsl_asrc_start_pair - Start the assigned ASRC pair
+ * @pair: pointer to pair
  *
  * It enables the assigned pair and makes it stopped at the stall level.
  */
@@ -539,7 +554,8 @@ static void fsl_asrc_start_pair(struct fsl_asrc_pair *pair)
 }
 
 /**
- * Stop the assigned ASRC pair
+ * fsl_asrc_stop_pair - Stop the assigned ASRC pair
+ * @pair: pointer to pair
  */
 static void fsl_asrc_stop_pair(struct fsl_asrc_pair *pair)
 {
@@ -552,7 +568,9 @@ static void fsl_asrc_stop_pair(struct fsl_asrc_pair *pair)
 }
 
 /**
- * Get DMA channel according to the pair and direction.
+ * fsl_asrc_get_dma_channel- Get DMA channel according to the pair and direction.
+ * @pair: pointer to pair
+ * @dir: DMA direction
  */
 static struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair,
 						 bool dir)
@@ -582,11 +600,51 @@ static int fsl_asrc_dai_startup(struct snd_pcm_substream *substream,
 			SNDRV_PCM_HW_PARAM_RATE, &fsl_asrc_rate_constraints);
 }
 
+/* Select proper clock source for internal ratio mode */
+static void fsl_asrc_select_clk(struct fsl_asrc_priv *asrc_priv,
+				struct fsl_asrc_pair *pair,
+				int in_rate,
+				int out_rate)
+{
+	struct fsl_asrc_pair_priv *pair_priv = pair->private;
+	struct asrc_config *config = pair_priv->config;
+	int rate[2], select_clk[2]; /* Array size 2 means IN and OUT */
+	int clk_rate, clk_index;
+	int i = 0, j = 0;
+
+	rate[IN] = in_rate;
+	rate[OUT] = out_rate;
+
+	/* Select proper clock source for internal ratio mode */
+	for (j = 0; j < 2; j++) {
+		for (i = 0; i < ASRC_CLK_MAP_LEN; i++) {
+			clk_index = asrc_priv->clk_map[j][i];
+			clk_rate = clk_get_rate(asrc_priv->asrck_clk[clk_index]);
+			/* Only match a perfect clock source with no remainder */
+			if (clk_rate != 0 && (clk_rate / rate[j]) <= 1024 &&
+			    (clk_rate % rate[j]) == 0)
+				break;
+		}
+
+		select_clk[j] = i;
+	}
+
+	/* Switch to ideal ratio mode if there is no proper clock source */
+	if (select_clk[IN] == ASRC_CLK_MAP_LEN || select_clk[OUT] == ASRC_CLK_MAP_LEN) {
+		select_clk[IN] = INCLK_NONE;
+		select_clk[OUT] = OUTCLK_ASRCK1_CLK;
+	}
+
+	config->inclk = select_clk[IN];
+	config->outclk = select_clk[OUT];
+}
+
 static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
 				  struct snd_pcm_hw_params *params,
 				  struct snd_soc_dai *dai)
 {
 	struct fsl_asrc *asrc = snd_soc_dai_get_drvdata(dai);
+	struct fsl_asrc_priv *asrc_priv = asrc->private;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	struct fsl_asrc_pair_priv *pair_priv = pair->private;
@@ -605,8 +663,6 @@ static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
 
 	config.pair = pair->index;
 	config.channel_num = channels;
-	config.inclk = INCLK_NONE;
-	config.outclk = OUTCLK_ASRCK1_CLK;
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		config.input_format   = params_format(params);
@@ -620,6 +676,10 @@ static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
 		config.output_sample_rate = rate;
 	}
 
+	fsl_asrc_select_clk(asrc_priv, pair,
+			    config.input_sample_rate,
+			    config.output_sample_rate);
+
 	ret = fsl_asrc_config_pair(pair, false);
 	if (ret) {
 		dev_err(dai->dev, "fail to config asrc pair\n");
@@ -854,7 +914,8 @@ static const struct regmap_config fsl_asrc_regmap_config = {
 };
 
 /**
- * Initialize ASRC registers with a default configurations
+ * fsl_asrc_init - Initialize ASRC registers with a default configuration
+ * @asrc: ASRC context
  */
 static int fsl_asrc_init(struct fsl_asrc *asrc)
 {
@@ -888,7 +949,9 @@ static int fsl_asrc_init(struct fsl_asrc *asrc)
 }
 
 /**
- * Interrupt handler for ASRC
+ * fsl_asrc_isr- Interrupt handler for ASRC
+ * @irq: irq number
+ * @dev_id: ASRC context
  */
 static irqreturn_t fsl_asrc_isr(int irq, void *dev_id)
 {