diff options
| -rw-r--r-- | sound/soc/bcm/bcm2835-i2s.c | 242 |
1 files changed, 190 insertions, 52 deletions
diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c index 6ba20498202e..dcacf7f83c93 100644 --- a/sound/soc/bcm/bcm2835-i2s.c +++ b/sound/soc/bcm/bcm2835-i2s.c @@ -31,6 +31,7 @@ * General Public License for more details. */ +#include <linux/bitops.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/device.h> @@ -99,6 +100,8 @@ #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) @@ -110,12 +113,19 @@ #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; @@ -225,19 +235,117 @@ static int bcm2835_i2s_set_dai_bclk_ratio(struct snd_soc_dai *dai, 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, @@ -248,39 +356,44 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, 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; @@ -294,9 +407,26 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, 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: /* @@ -307,18 +437,10 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, 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. @@ -326,11 +448,16 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, * (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) { /* @@ -342,8 +469,8 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, 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) { @@ -423,7 +550,20 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, /* 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, @@ -559,6 +699,7 @@ static const struct snd_soc_dai_ops bcm2835_i2s_dai_ops = { .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) @@ -699,9 +840,6 @@ static int bcm2835_i2s_probe(struct platform_device *pdev) 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); 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