ASoC: fsi: modify variable name to easy to understand

Current FSI driver is using
data-length / width / number / offset for variables.
But it was a very confusing name.

This patch rename them to easy to understand,
and add new functions for it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/sh/fsi.c

@@ -101,6 +101,15 @@
 
 #define FSI_FMTS (SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S16_LE)
 
+/*
+ * FSI driver use below type name for variable
+ *
+ * xxx_len	: data length
+ * xxx_width	: data width
+ * xxx_offset	: data offset
+ * xxx_num	: number of data
+ */
+
 /*
  *		struct
  */
@@ -110,13 +119,13 @@ struct fsi_priv {
 	struct snd_pcm_substream *substream;
 	struct fsi_master *master;
 
-	int fifo_max;
-	int chan;
+	int fifo_max_num;
+	int chan_num;
 
-	int byte_offset;
+	int buff_offset;
+	int buff_len;
 	int period_len;
-	int buffer_len;
-	int periods;
+	int period_num;
 
 	u32 mst_ctrl;
 };
@@ -320,32 +329,43 @@ static void fsi_stream_push(struct fsi_priv *fsi,
 			    u32 period_len)
 {
 	fsi->substream		= substream;
-	fsi->buffer_len		= buffer_len;
+	fsi->buff_len		= buffer_len;
+	fsi->buff_offset	= 0;
 	fsi->period_len		= period_len;
-	fsi->byte_offset	= 0;
-	fsi->periods		= 0;
+	fsi->period_num		= 0;
 }
 
 static void fsi_stream_pop(struct fsi_priv *fsi)
 {
 	fsi->substream		= NULL;
-	fsi->buffer_len		= 0;
+	fsi->buff_len		= 0;
+	fsi->buff_offset	= 0;
 	fsi->period_len		= 0;
-	fsi->byte_offset	= 0;
-	fsi->periods		= 0;
+	fsi->period_num		= 0;
 }
 
-static int fsi_get_fifo_residue(struct fsi_priv *fsi, int is_play)
+static int fsi_get_fifo_data_num(struct fsi_priv *fsi, int is_play)
 {
 	u32 status;
 	u32 reg = is_play ? DOFF_ST : DIFF_ST;
-	int residue;
+	int data_num;
 
 	status = fsi_reg_read(fsi, reg);
-	residue = 0x1ff & (status >> 8);
-	residue *= fsi->chan;
+	data_num = 0x1ff & (status >> 8);
+	data_num *= fsi->chan_num;
+
+	return data_num;
+}
 
-	return residue;
+static int fsi_len2num(int len, int width)
+{
+	return len / width;
+}
+
+#define fsi_num2offset(a, b) fsi_num2len(a, b)
+static int fsi_num2len(int num, int width)
+{
+	return num * width;
 }
 
 /*
@@ -354,50 +374,50 @@ static int fsi_get_fifo_residue(struct fsi_priv *fsi, int is_play)
 
 static u8 *fsi_dma_get_area(struct fsi_priv *fsi)
 {
-	return fsi->substream->runtime->dma_area + fsi->byte_offset;
+	return fsi->substream->runtime->dma_area + fsi->buff_offset;
 }
 
-static void fsi_dma_soft_push16(struct fsi_priv *fsi, int size)
+static void fsi_dma_soft_push16(struct fsi_priv *fsi, int num)
 {
 	u16 *start;
 	int i;
 
 	start  = (u16 *)fsi_dma_get_area(fsi);
 
-	for (i = 0; i < size; i++)
+	for (i = 0; i < num; i++)
 		fsi_reg_write(fsi, DODT, ((u32)*(start + i) << 8));
 }
 
-static void fsi_dma_soft_pop16(struct fsi_priv *fsi, int size)
+static void fsi_dma_soft_pop16(struct fsi_priv *fsi, int num)
 {
 	u16 *start;
 	int i;
 
 	start  = (u16 *)fsi_dma_get_area(fsi);
 
-	for (i = 0; i < size; i++)
+	for (i = 0; i < num; i++)
 		*(start + i) = (u16)(fsi_reg_read(fsi, DIDT) >> 8);
 }
 
-static void fsi_dma_soft_push32(struct fsi_priv *fsi, int size)
+static void fsi_dma_soft_push32(struct fsi_priv *fsi, int num)
 {
 	u32 *start;
 	int i;
 
 	start  = (u32 *)fsi_dma_get_area(fsi);
 
-	for (i = 0; i < size; i++)
+	for (i = 0; i < num; i++)
 		fsi_reg_write(fsi, DODT, *(start + i));
 }
 
-static void fsi_dma_soft_pop32(struct fsi_priv *fsi, int size)
+static void fsi_dma_soft_pop32(struct fsi_priv *fsi, int num)
 {
 	u32 *start;
 	int i;
 
 	start  = (u32 *)fsi_dma_get_area(fsi);
 
-	for (i = 0; i < size; i++)
+	for (i = 0; i < num; i++)
 		*(start + i) = fsi_reg_read(fsi, DIDT);
 }
 
@@ -492,8 +512,8 @@ static void fsi_fifo_init(struct fsi_priv *fsi,
 	shift = fsi_master_read(master, FIFO_SZ);
 	shift >>= fsi_is_port_a(fsi) ? AO_SZ_SHIFT : BO_SZ_SHIFT;
 	shift &= OUT_SZ_MASK;
-	fsi->fifo_max = 256 << shift;
-	dev_dbg(dai->dev, "fifo = %d words\n", fsi->fifo_max);
+	fsi->fifo_max_num = 256 << shift;
+	dev_dbg(dai->dev, "fifo = %d words\n", fsi->fifo_max_num);
 
 	/*
 	 * The maximum number of sample data varies depending
@@ -514,9 +534,10 @@ static void fsi_fifo_init(struct fsi_priv *fsi,
 	 * 7 channels:  32 ( 32 x 7 = 224)
 	 * 8 channels:  32 ( 32 x 8 = 256)
 	 */
-	for (i = 1; i < fsi->chan; i <<= 1)
-		fsi->fifo_max >>= 1;
-	dev_dbg(dai->dev, "%d channel %d store\n", fsi->chan, fsi->fifo_max);
+	for (i = 1; i < fsi->chan_num; i <<= 1)
+		fsi->fifo_max_num >>= 1;
+	dev_dbg(dai->dev, "%d channel %d store\n",
+		fsi->chan_num, fsi->fifo_max_num);
 
 	ctrl = is_play ? DOFF_CTL : DIFF_CTL;
 
@@ -545,9 +566,9 @@ static int fsi_data_push(struct fsi_priv *fsi, int startup)
 	struct snd_pcm_runtime *runtime;
 	struct snd_pcm_substream *substream = NULL;
 	u32 status;
-	int send;
-	int fifo_free;
-	int width;
+	int push_num;
+	int push_num_max;
+	int ch_width;
 	int over_period;
 
 	if (!fsi			||
@@ -562,41 +583,40 @@ static int fsi_data_push(struct fsi_priv *fsi, int startup)
 	/* FSI FIFO has limit.
 	 * So, this driver can not send periods data at a time
 	 */
-	if (fsi->byte_offset >=
-	    fsi->period_len * (fsi->periods + 1)) {
+	if (fsi->buff_offset >=
+	    fsi_num2offset(fsi->period_num + 1, fsi->period_len)) {
 
 		over_period = 1;
-		fsi->periods = (fsi->periods + 1) % runtime->periods;
+		fsi->period_num = (fsi->period_num + 1) % runtime->periods;
 
-		if (0 == fsi->periods)
-			fsi->byte_offset = 0;
+		if (0 == fsi->period_num)
+			fsi->buff_offset = 0;
 	}
 
 	/* get 1 channel data width */
-	width = frames_to_bytes(runtime, 1) / fsi->chan;
+	ch_width = frames_to_bytes(runtime, 1) / fsi->chan_num;
 
-	/* get send size for alsa */
-	send = (fsi->buffer_len - fsi->byte_offset) / width;
+	/* number of push data */
+	push_num = fsi_len2num(fsi->buff_len - fsi->buff_offset, ch_width);
 
-	/*  get FIFO free size */
-	fifo_free = (fsi->fifo_max * fsi->chan) - fsi_get_fifo_residue(fsi, 1);
+	/* max number of push data */
+	push_num_max = (fsi->fifo_max_num * fsi->chan_num) -
+			fsi_get_fifo_data_num(fsi, 1);
 
-	/* size check */
-	if (fifo_free < send)
-		send = fifo_free;
+	push_num = min(push_num, push_num_max);
 
-	switch (width) {
+	switch (ch_width) {
 	case 2:
-		fsi_dma_soft_push16(fsi, send);
+		fsi_dma_soft_push16(fsi, push_num);
 		break;
 	case 4:
-		fsi_dma_soft_push32(fsi, send);
+		fsi_dma_soft_push32(fsi, push_num);
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	fsi->byte_offset += send * width;
+	fsi->buff_offset += fsi_num2offset(push_num, ch_width);
 
 	status = fsi_reg_read(fsi, DOFF_ST);
 	if (!startup) {
@@ -622,9 +642,9 @@ static int fsi_data_pop(struct fsi_priv *fsi, int startup)
 	struct snd_pcm_runtime *runtime;
 	struct snd_pcm_substream *substream = NULL;
 	u32 status;
-	int free;
-	int fifo_fill;
-	int width;
+	int pop_num;
+	int pop_num_max;
+	int ch_width;
 	int over_period;
 
 	if (!fsi			||
@@ -639,40 +659,39 @@ static int fsi_data_pop(struct fsi_priv *fsi, int startup)
 	/* FSI FIFO has limit.
 	 * So, this driver can not send periods data at a time
 	 */
-	if (fsi->byte_offset >=
-	    fsi->period_len * (fsi->periods + 1)) {
+	if (fsi->buff_offset >=
+	    fsi_num2offset(fsi->period_num + 1, fsi->period_len)) {
 
 		over_period = 1;
-		fsi->periods = (fsi->periods + 1) % runtime->periods;
+		fsi->period_num = (fsi->period_num + 1) % runtime->periods;
 
-		if (0 == fsi->periods)
-			fsi->byte_offset = 0;
+		if (0 == fsi->period_num)
+			fsi->buff_offset = 0;
 	}
 
 	/* get 1 channel data width */
-	width = frames_to_bytes(runtime, 1) / fsi->chan;
+	ch_width = frames_to_bytes(runtime, 1) / fsi->chan_num;
 
 	/* get free space for alsa */
-	free = (fsi->buffer_len - fsi->byte_offset) / width;
+	pop_num_max = fsi_len2num(fsi->buff_len - fsi->buff_offset, ch_width);
 
 	/* get recv size */
-	fifo_fill = fsi_get_fifo_residue(fsi, 0);
+	pop_num = fsi_get_fifo_data_num(fsi, 0);
 
-	if (free < fifo_fill)
-		fifo_fill = free;
+	pop_num = min(pop_num_max, pop_num);
 
-	switch (width) {
+	switch (ch_width) {
 	case 2:
-		fsi_dma_soft_pop16(fsi, fifo_fill);
+		fsi_dma_soft_pop16(fsi, pop_num);
 		break;
 	case 4:
-		fsi_dma_soft_pop32(fsi, fifo_fill);
+		fsi_dma_soft_pop32(fsi, pop_num);
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	fsi->byte_offset += fifo_fill * width;
+	fsi->buff_offset += fsi_num2offset(pop_num, ch_width);
 
 	status = fsi_reg_read(fsi, DIFF_ST);
 	if (!startup) {
@@ -763,29 +782,29 @@ static int fsi_dai_startup(struct snd_pcm_substream *substream,
 	switch (fmt) {
 	case SH_FSI_FMT_MONO:
 		data = CR_MONO;
-		fsi->chan = 1;
+		fsi->chan_num = 1;
 		break;
 	case SH_FSI_FMT_MONO_DELAY:
 		data = CR_MONO_D;
-		fsi->chan = 1;
+		fsi->chan_num = 1;
 		break;
 	case SH_FSI_FMT_PCM:
 		data = CR_PCM;
-		fsi->chan = 2;
+		fsi->chan_num = 2;
 		break;
 	case SH_FSI_FMT_I2S:
 		data = CR_I2S;
-		fsi->chan = 2;
+		fsi->chan_num = 2;
 		break;
 	case SH_FSI_FMT_TDM:
-		fsi->chan = is_play ?
+		fsi->chan_num = is_play ?
 			SH_FSI_GET_CH_O(flags) : SH_FSI_GET_CH_I(flags);
-		data = CR_TDM | (fsi->chan - 1);
+		data = CR_TDM | (fsi->chan_num - 1);
 		break;
 	case SH_FSI_FMT_TDM_DELAY:
-		fsi->chan = is_play ?
+		fsi->chan_num = is_play ?
 			SH_FSI_GET_CH_O(flags) : SH_FSI_GET_CH_I(flags);
-		data = CR_TDM_D | (fsi->chan - 1);
+		data = CR_TDM_D | (fsi->chan_num - 1);
 		break;
 	case SH_FSI_FMT_SPDIF:
 		if (master->core->ver < 2) {
@@ -793,7 +812,7 @@ static int fsi_dai_startup(struct snd_pcm_substream *substream,
 			return -EINVAL;
 		}
 		data = CR_SPDIF;
-		fsi->chan = 2;
+		fsi->chan_num = 2;
 		fsi_spdif_clk_ctrl(fsi, 1);
 		fsi_reg_mask_set(fsi, OUT_SEL, 0x0010, 0x0010);
 		break;
@@ -992,7 +1011,7 @@ static snd_pcm_uframes_t fsi_pointer(struct snd_pcm_substream *substream)
 	struct fsi_priv *fsi = fsi_get_priv(substream);
 	long location;
 
-	location = (fsi->byte_offset - 1);
+	location = (fsi->buff_offset - 1);
 	if (location < 0)
 		location = 0;