ASRC can be used on memory to memory case, define several
functions for m2m usage.

m2m_prepare: prepare for the start step
m2m_start: the start step
m2m_unprepare: unprepare for stop step, optional
m2m_stop: stop step
m2m_check_format: check format is supported or not
m2m_calc_out_len: calculate output length according to input length
m2m_get_maxburst: burst size for dma
m2m_pair_suspend: suspend function of pair, optional.
m2m_pair_resume: resume function of pair
get_output_fifo_size: get remaining data size in FIFO

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/soc/fsl/fsl_asrc.c        | 142 ++++++++++++++++++++++++++++++++
 sound/soc/fsl/fsl_asrc.h        |   2 +
 sound/soc/fsl/fsl_asrc_common.h |  61 ++++++++++++++
 3 files changed, 205 insertions(+)

diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
index bd5c46d763c0..471753276209 100644
--- a/sound/soc/fsl/fsl_asrc.c
+++ b/sound/soc/fsl/fsl_asrc.c
@@ -1063,6 +1063,139 @@ static int fsl_asrc_get_fifo_addr(u8 dir, enum asrc_pair_index index)
 	return REG_ASRDx(dir, index);
 }
 
+/* Get sample numbers in FIFO */
+static unsigned int fsl_asrc_get_output_fifo_size(struct fsl_asrc_pair *pair)
+{
+	struct fsl_asrc *asrc = pair->asrc;
+	enum asrc_pair_index index = pair->index;
+	u32 val;
+
+	regmap_read(asrc->regmap, REG_ASRFST(index), &val);
+
+	val &= ASRFSTi_OUTPUT_FIFO_MASK;
+
+	return val >> ASRFSTi_OUTPUT_FIFO_SHIFT;
+}
+
+static int fsl_asrc_m2m_prepare(struct fsl_asrc_pair *pair)
+{
+	struct fsl_asrc_pair_priv *pair_priv = pair->private;
+	struct fsl_asrc *asrc = pair->asrc;
+	struct device *dev = &asrc->pdev->dev;
+	struct asrc_config config;
+	int ret;
+
+	/* fill config */
+	config.pair = pair->index;
+	config.channel_num = pair->channels;
+	config.input_sample_rate = pair->rate[IN];
+	config.output_sample_rate = pair->rate[OUT];
+	config.input_format = pair->sample_format[IN];
+	config.output_format = pair->sample_format[OUT];
+	config.inclk = INCLK_NONE;
+	config.outclk = OUTCLK_ASRCK1_CLK;
+
+	pair_priv->config = &config;
+	ret = fsl_asrc_config_pair(pair, true);
+	if (ret) {
+		dev_err(dev, "failed to config pair: %d\n", ret);
+		return ret;
+	}
+
+	pair->first_convert = 1;
+
+	return 0;
+}
+
+static int fsl_asrc_m2m_start(struct fsl_asrc_pair *pair)
+{
+	if (pair->first_convert) {
+		fsl_asrc_start_pair(pair);
+		pair->first_convert = 0;
+	}
+	/*
+	 * Clear DMA request during the stall state of ASRC:
+	 * During STALL state, the remaining in input fifo would never be
+	 * smaller than the input threshold while the output fifo would not
+	 * be bigger than output one. Thus the DMA request would be cleared.
+	 */
+	fsl_asrc_set_watermarks(pair, ASRC_FIFO_THRESHOLD_MIN,
+				ASRC_FIFO_THRESHOLD_MAX);
+
+	/* Update the real input threshold to raise DMA request */
+	fsl_asrc_set_watermarks(pair, ASRC_M2M_INPUTFIFO_WML,
+				ASRC_M2M_OUTPUTFIFO_WML);
+
+	return 0;
+}
+
+static int fsl_asrc_m2m_stop(struct fsl_asrc_pair *pair)
+{
+	if (!pair->first_convert) {
+		fsl_asrc_stop_pair(pair);
+		pair->first_convert = 1;
+	}
+
+	return 0;
+}
+
+/* calculate capture data length according to output data length and sample rate */
+static int fsl_asrc_m2m_calc_out_len(struct fsl_asrc_pair *pair, int input_buffer_length)
+{
+	unsigned int in_width, out_width;
+	unsigned int channels = pair->channels;
+	unsigned int in_samples, out_samples;
+	unsigned int out_length;
+
+	in_width = snd_pcm_format_physical_width(pair->sample_format[IN]) / 8;
+	out_width = snd_pcm_format_physical_width(pair->sample_format[OUT]) / 8;
+
+	in_samples = input_buffer_length / in_width / channels;
+	out_samples = pair->rate[OUT] * in_samples / pair->rate[IN];
+	out_length = (out_samples - ASRC_OUTPUT_LAST_SAMPLE) * out_width * channels;
+
+	return out_length;
+}
+
+static int fsl_asrc_m2m_get_maxburst(u8 dir, struct fsl_asrc_pair *pair)
+{
+	struct fsl_asrc *asrc = pair->asrc;
+	struct fsl_asrc_priv *asrc_priv = asrc->private;
+	int wml = (dir == IN) ? ASRC_M2M_INPUTFIFO_WML : ASRC_M2M_OUTPUTFIFO_WML;
+
+	if (!asrc_priv->soc->use_edma)
+		return wml * pair->channels;
+	else
+		return 1;
+}
+
+static int fsl_asrc_m2m_get_cap(struct fsl_asrc_m2m_cap *cap)
+{
+	cap->fmt_in = FSL_ASRC_FORMATS;
+	cap->fmt_out = FSL_ASRC_FORMATS | SNDRV_PCM_FMTBIT_S8;
+
+	cap->rate_in = supported_asrc_rate;
+	cap->rate_in_count = ARRAY_SIZE(supported_asrc_rate);
+	cap->rate_out = supported_asrc_rate;
+	cap->rate_out_count = ARRAY_SIZE(supported_asrc_rate);
+	cap->chan_min = 1;
+	cap->chan_max = 10;
+
+	return 0;
+}
+
+static int fsl_asrc_m2m_pair_resume(struct fsl_asrc_pair *pair)
+{
+	struct fsl_asrc *asrc = pair->asrc;
+	int i;
+
+	for (i = 0; i < pair->channels * 4; i++)
+		regmap_write(asrc->regmap, REG_ASRDI(pair->index), 0);
+
+	pair->first_convert = 1;
+	return 0;
+}
+
 static int fsl_asrc_runtime_resume(struct device *dev);
 static int fsl_asrc_runtime_suspend(struct device *dev);
 
@@ -1147,6 +1280,15 @@ static int fsl_asrc_probe(struct platform_device *pdev)
 	asrc->get_fifo_addr = fsl_asrc_get_fifo_addr;
 	asrc->pair_priv_size = sizeof(struct fsl_asrc_pair_priv);
 
+	asrc->m2m_prepare = fsl_asrc_m2m_prepare;
+	asrc->m2m_start = fsl_asrc_m2m_start;
+	asrc->m2m_stop = fsl_asrc_m2m_stop;
+	asrc->get_output_fifo_size = fsl_asrc_get_output_fifo_size;
+	asrc->m2m_calc_out_len = fsl_asrc_m2m_calc_out_len;
+	asrc->m2m_get_maxburst = fsl_asrc_m2m_get_maxburst;
+	asrc->m2m_pair_resume = fsl_asrc_m2m_pair_resume;
+	asrc->m2m_get_cap = fsl_asrc_m2m_get_cap;
+
 	if (of_device_is_compatible(np, "fsl,imx35-asrc")) {
 		asrc_priv->clk_map[IN] = input_clk_map_imx35;
 		asrc_priv->clk_map[OUT] = output_clk_map_imx35;
diff --git a/sound/soc/fsl/fsl_asrc.h b/sound/soc/fsl/fsl_asrc.h
index 86d2422ad606..1c492eb237f5 100644
--- a/sound/soc/fsl/fsl_asrc.h
+++ b/sound/soc/fsl/fsl_asrc.h
@@ -12,6 +12,8 @@
 
 #include  "fsl_asrc_common.h"
 
+#define ASRC_M2M_INPUTFIFO_WML		0x4
+#define ASRC_M2M_OUTPUTFIFO_WML		0x2
 #define ASRC_DMA_BUFFER_NUM		2
 #define ASRC_INPUTFIFO_THRESHOLD	32
 #define ASRC_OUTPUTFIFO_THRESHOLD	32
diff --git a/sound/soc/fsl/fsl_asrc_common.h b/sound/soc/fsl/fsl_asrc_common.h
index 7e1c13ca37f1..3bdd6ea07c09 100644
--- a/sound/soc/fsl/fsl_asrc_common.h
+++ b/sound/soc/fsl/fsl_asrc_common.h
@@ -21,6 +21,26 @@ enum asrc_pair_index {
 
 #define PAIR_CTX_NUM  0x4
 
+/**
+ * struct fsl_asrc_m2m_cap - capability data
+ * @fmt_in: input sample format
+ * @fmt_out: output sample format
+ * @chan_min: minimum channel number
+ * @chan_max: maximum channel number
+ * @rate_in: minimum rate
+ * @rate_out: maximum rete
+ */
+struct fsl_asrc_m2m_cap {
+	u64 fmt_in;
+	u64 fmt_out;
+	int chan_min;
+	int chan_max;
+	const unsigned int *rate_in;
+	int rate_in_count;
+	const unsigned int *rate_out;
+	int rate_out_count;
+};
+
 /**
  * fsl_asrc_pair: ASRC Pair common data
  *
@@ -34,6 +54,13 @@ enum asrc_pair_index {
  * @pos: hardware pointer position
  * @req_dma_chan: flag to release dev_to_dev chan
  * @private: pair private area
+ * @complete: dma task complete
+ * @sample_format: format of m2m
+ * @rate: rate of m2m
+ * @buf_len: buffer length of m2m
+ * @dma_buffer: buffer pointers
+ * @first_convert: start of conversion
+ * @ratio_mod: ratio modification
  */
 struct fsl_asrc_pair {
 	struct fsl_asrc *asrc;
@@ -49,6 +76,15 @@ struct fsl_asrc_pair {
 	bool req_dma_chan;
 
 	void *private;
+
+	/* used for m2m */
+	struct completion complete[2];
+	snd_pcm_format_t sample_format[2];
+	unsigned int rate[2];
+	unsigned int buf_len[2];
+	struct snd_dma_buffer dma_buffer[2];
+	unsigned int first_convert;
+	unsigned int ratio_mod;
 };
 
 /**
@@ -72,6 +108,17 @@ struct fsl_asrc_pair {
  * @request_pair: function pointer
  * @release_pair: function pointer
  * @get_fifo_addr: function pointer
+ * @m2m_get_cap: function pointer
+ * @m2m_prepare: function pointer
+ * @m2m_start: function pointer
+ * @m2m_unprepare: function pointer
+ * @m2m_stop: function pointer
+ * @m2m_calc_out_len: function pointer
+ * @m2m_get_maxburst: function pointer
+ * @m2m_pair_suspend: function pointer
+ * @m2m_pair_resume: function pointer
+ * @m2m_set_ratio_mod: function pointer
+ * @get_output_fifo_size: function pointer
  * @pair_priv_size: size of pair private struct.
  * @private: private data structure
  */
@@ -97,6 +144,20 @@ struct fsl_asrc {
 	int (*request_pair)(int channels, struct fsl_asrc_pair *pair);
 	void (*release_pair)(struct fsl_asrc_pair *pair);
 	int (*get_fifo_addr)(u8 dir, enum asrc_pair_index index);
+	int (*m2m_get_cap)(struct fsl_asrc_m2m_cap *cap);
+
+	int (*m2m_prepare)(struct fsl_asrc_pair *pair);
+	int (*m2m_start)(struct fsl_asrc_pair *pair);
+	int (*m2m_unprepare)(struct fsl_asrc_pair *pair);
+	int (*m2m_stop)(struct fsl_asrc_pair *pair);
+
+	int (*m2m_calc_out_len)(struct fsl_asrc_pair *pair, int input_buffer_length);
+	int (*m2m_get_maxburst)(u8 dir, struct fsl_asrc_pair *pair);
+	int (*m2m_pair_suspend)(struct fsl_asrc_pair *pair);
+	int (*m2m_pair_resume)(struct fsl_asrc_pair *pair);
+	int (*m2m_set_ratio_mod)(struct fsl_asrc_pair *pair, int val);
+
+	unsigned int (*get_output_fifo_size)(struct fsl_asrc_pair *pair);
 	size_t pair_priv_size;
 
 	void *private;
-- 
2.34.1