* General Public License for more details.
*/
+#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#define BCM2835_I2S_CHWID(v) (v)
#define BCM2835_I2S_CH1(v) ((v) << 16)
#define BCM2835_I2S_CH2(v) (v)
+#define BCM2835_I2S_CH1_POS(v) BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(v))
+#define BCM2835_I2S_CH2_POS(v) BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(v))
#define BCM2835_I2S_TX_PANIC(v) ((v) << 24)
#define BCM2835_I2S_RX_PANIC(v) ((v) << 16)
#define BCM2835_I2S_INT_RXR BIT(1)
#define BCM2835_I2S_INT_TXW BIT(0)
+/* Frame length register is 10 bit, maximum length 1024 */
+#define BCM2835_I2S_MAX_FRAME_LENGTH 1024
+
/* General device struct */
struct bcm2835_i2s_dev {
struct device *dev;
struct snd_dmaengine_dai_dma_data dma_data[2];
unsigned int fmt;
- unsigned int bclk_ratio;
+ unsigned int tdm_slots;
+ unsigned int rx_mask;
+ unsigned int tx_mask;
+ unsigned int slot_width;
+ unsigned int frame_length;
struct regmap *i2s_regmap;
struct clk *clk;
unsigned int ratio)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
- dev->bclk_ratio = ratio;
+
+ if (!ratio) {
+ dev->tdm_slots = 0;
+ return 0;
+ }
+
+ if (ratio > BCM2835_I2S_MAX_FRAME_LENGTH)
+ return -EINVAL;
+
+ dev->tdm_slots = 2;
+ dev->rx_mask = 0x03;
+ dev->tx_mask = 0x03;
+ dev->slot_width = ratio / 2;
+ dev->frame_length = ratio;
+
+ return 0;
+}
+
+static int bcm2835_i2s_set_dai_tdm_slot(struct snd_soc_dai *dai,
+ unsigned int tx_mask, unsigned int rx_mask,
+ int slots, int width)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ if (slots) {
+ if (slots < 0 || width < 0)
+ return -EINVAL;
+
+ /* Limit masks to available slots */
+ rx_mask &= GENMASK(slots - 1, 0);
+ tx_mask &= GENMASK(slots - 1, 0);
+
+ /*
+ * The driver is limited to 2-channel setups.
+ * Check that exactly 2 bits are set in the masks.
+ */
+ if (hweight_long((unsigned long) rx_mask) != 2
+ || hweight_long((unsigned long) tx_mask) != 2)
+ return -EINVAL;
+
+ if (slots * width > BCM2835_I2S_MAX_FRAME_LENGTH)
+ return -EINVAL;
+ }
+
+ dev->tdm_slots = slots;
+
+ dev->rx_mask = rx_mask;
+ dev->tx_mask = tx_mask;
+ dev->slot_width = width;
+ dev->frame_length = slots * width;
+
return 0;
}
+/*
+ * Convert logical slot number into physical slot number.
+ *
+ * If odd_offset is 0 sequential number is identical to logical number.
+ * This is used for DSP modes with slot numbering 0 1 2 3 ...
+ *
+ * Otherwise odd_offset defines the physical offset for odd numbered
+ * slots. This is used for I2S and left/right justified modes to
+ * translate from logical slot numbers 0 1 2 3 ... into physical slot
+ * numbers 0 2 ... 3 4 ...
+ */
+static int bcm2835_i2s_convert_slot(unsigned int slot, unsigned int odd_offset)
+{
+ if (!odd_offset)
+ return slot;
+
+ if (slot & 1)
+ return (slot >> 1) + odd_offset;
+
+ return slot >> 1;
+}
+
+/*
+ * Calculate channel position from mask and slot width.
+ *
+ * Mask must contain exactly 2 set bits.
+ * Lowest set bit is channel 1 position, highest set bit channel 2.
+ * The constant offset is added to both channel positions.
+ *
+ * If odd_offset is > 0 slot positions are translated to
+ * I2S-style TDM slot numbering ( 0 2 ... 3 4 ...) with odd
+ * logical slot numbers starting at physical slot odd_offset.
+ */
+static void bcm2835_i2s_calc_channel_pos(
+ unsigned int *ch1_pos, unsigned int *ch2_pos,
+ unsigned int mask, unsigned int width,
+ unsigned int bit_offset, unsigned int odd_offset)
+{
+ *ch1_pos = bcm2835_i2s_convert_slot((ffs(mask) - 1), odd_offset)
+ * width + bit_offset;
+ *ch2_pos = bcm2835_i2s_convert_slot((fls(mask) - 1), odd_offset)
+ * width + bit_offset;
+}
+
static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
- unsigned int sampling_rate = params_rate(params);
- unsigned int data_length, data_delay, bclk_ratio;
- unsigned int ch1pos, ch2pos, mode, format;
+ unsigned int data_length, data_delay, framesync_length;
+ unsigned int slots, slot_width, odd_slot_offset;
+ int frame_length, bclk_rate;
+ unsigned int rx_mask, tx_mask;
+ unsigned int rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos;
+ unsigned int mode, format;
uint32_t csreg;
+ int ret = 0;
/*
* If a stream is already enabled,
if (csreg & (BCM2835_I2S_TXON | BCM2835_I2S_RXON))
return 0;
- /*
- * Adjust the data length according to the format.
- * We prefill the half frame length with an integer
- * divider of 2400 as explained at the clock settings.
- * Maybe it is overwritten there, if the Integer mode
- * does not apply.
- */
- switch (params_format(params)) {
- case SNDRV_PCM_FORMAT_S16_LE:
- data_length = 16;
- break;
- case SNDRV_PCM_FORMAT_S24_LE:
- data_length = 24;
- break;
- case SNDRV_PCM_FORMAT_S32_LE:
- data_length = 32;
- break;
- default:
- return -EINVAL;
+ data_length = params_width(params);
+ data_delay = 0;
+ odd_slot_offset = 0;
+ mode = 0;
+
+ if (dev->tdm_slots) {
+ slots = dev->tdm_slots;
+ slot_width = dev->slot_width;
+ frame_length = dev->frame_length;
+ rx_mask = dev->rx_mask;
+ tx_mask = dev->tx_mask;
+ bclk_rate = dev->frame_length * params_rate(params);
+ } else {
+ slots = 2;
+ slot_width = params_width(params);
+ rx_mask = 0x03;
+ tx_mask = 0x03;
+
+ frame_length = snd_soc_params_to_frame_size(params);
+ if (frame_length < 0)
+ return frame_length;
+
+ bclk_rate = snd_soc_params_to_bclk(params);
+ if (bclk_rate < 0)
+ return bclk_rate;
}
- /* If bclk_ratio already set, use that one. */
- if (dev->bclk_ratio)
- bclk_ratio = dev->bclk_ratio;
- else
- /* otherwise calculate a fitting block ratio */
- bclk_ratio = 2 * data_length;
+ /* Check if data fits into slots */
+ if (data_length > slot_width)
+ return -EINVAL;
/* Clock should only be set up here if CPU is clock master */
switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBS_CFM:
- clk_set_rate(dev->clk, sampling_rate * bclk_ratio);
+ ret = clk_set_rate(dev->clk, bclk_rate);
+ if (ret)
+ return ret;
break;
default:
break;
format |= BCM2835_I2S_CHWID((data_length-8)&0xf);
+ /* CH2 format is the same as for CH1 */
+ format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
+
switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
+ /* I2S mode needs an even number of slots */
+ if (slots & 1)
+ return -EINVAL;
+
+ /*
+ * Use I2S-style logical slot numbering: even slots
+ * are in first half of frame, odd slots in second half.
+ */
+ odd_slot_offset = slots >> 1;
+
+ /* MSB starts one cycle after frame start */
data_delay = 1;
+
+ /* Setup frame sync signal for 50% duty cycle */
+ framesync_length = frame_length / 2;
break;
default:
/*
return -EINVAL;
}
- ch1pos = data_delay;
- ch2pos = bclk_ratio / 2 + data_delay;
-
- switch (params_channels(params)) {
- case 2:
- format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
- format |= BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(ch1pos));
- format |= BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(ch2pos));
- break;
- default:
- return -EINVAL;
- }
+ bcm2835_i2s_calc_channel_pos(&rx_ch1_pos, &rx_ch2_pos,
+ rx_mask, slot_width, data_delay, odd_slot_offset);
+ bcm2835_i2s_calc_channel_pos(&tx_ch1_pos, &tx_ch2_pos,
+ tx_mask, slot_width, data_delay, odd_slot_offset);
/*
* Set format for both streams.
* (and therefore word length) anyway,
* so the format will be the same.
*/
- regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
- regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG,
+ format
+ | BCM2835_I2S_CH1_POS(rx_ch1_pos)
+ | BCM2835_I2S_CH2_POS(rx_ch2_pos));
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG,
+ format
+ | BCM2835_I2S_CH1_POS(tx_ch1_pos)
+ | BCM2835_I2S_CH2_POS(tx_ch2_pos));
/* Setup the I2S mode */
- mode = 0;
if (data_length <= 16) {
/*
mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP;
}
- mode |= BCM2835_I2S_FLEN(bclk_ratio - 1);
- mode |= BCM2835_I2S_FSLEN(bclk_ratio / 2);
+ mode |= BCM2835_I2S_FLEN(frame_length - 1);
+ mode |= BCM2835_I2S_FSLEN(framesync_length);
/* Master or slave? */
switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
/* Clear FIFOs */
bcm2835_i2s_clear_fifos(dev, true, true);
- return 0;
+ dev_dbg(dev->dev,
+ "slots: %d width: %d rx mask: 0x%02x tx_mask: 0x%02x\n",
+ slots, slot_width, rx_mask, tx_mask);
+
+ dev_dbg(dev->dev, "frame len: %d sync len: %d data len: %d\n",
+ frame_length, framesync_length, data_length);
+
+ dev_dbg(dev->dev, "rx pos: %d,%d tx pos: %d,%d\n",
+ rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos);
+
+ dev_dbg(dev->dev, "sampling rate: %d bclk rate: %d\n",
+ params_rate(params), bclk_rate);
+
+ return ret;
}
static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream,
.hw_params = bcm2835_i2s_hw_params,
.set_fmt = bcm2835_i2s_set_dai_fmt,
.set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio,
+ .set_tdm_slot = bcm2835_i2s_set_dai_tdm_slot,
};
static int bcm2835_i2s_dai_probe(struct snd_soc_dai *dai)
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].flags =
SND_DMAENGINE_PCM_DAI_FLAG_PACK;
- /* BCLK ratio - use default */
- dev->bclk_ratio = 0;
-
/* Store the pdev */
dev->dev = &pdev->dev;
dev_set_drvdata(&pdev->dev, dev);
projects / openwrt / staging / blogic.git / commitdiff