diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.14/950-0115-ASoC-bcm2835-Add-support-for-TDM-modes.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.14/950-0115-ASoC-bcm2835-Add-support-for-TDM-modes.patch | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.14/950-0115-ASoC-bcm2835-Add-support-for-TDM-modes.patch b/target/linux/brcm2708/patches-4.14/950-0115-ASoC-bcm2835-Add-support-for-TDM-modes.patch new file mode 100644 index 0000000000..ce3800cb22 --- /dev/null +++ b/target/linux/brcm2708/patches-4.14/950-0115-ASoC-bcm2835-Add-support-for-TDM-modes.patch @@ -0,0 +1,402 @@ +From c2b82810c0272bb29a9b426b017b196436957c76 Mon Sep 17 00:00:00 2001 +From: Matthias Reichl <hias@horus.com> +Date: Sun, 7 May 2017 11:34:26 +0200 +Subject: [PATCH 115/454] ASoC: bcm2835: Add support for TDM modes + +bcm2835 supports arbitrary positioning of channel data within +a frame and thus is capable of supporting TDM modes. Since +the driver is limited to 2-channel operations only TDM setups +with exactly 2 active slots are supported. + +Logical TDM slot numbering follows the usual convention: + +For I2S-like modes, with a 50% duty-cycle frame clock, +slots 0, 2, ... are transmitted in the first half of a frame, +slots 1, 3, ... are transmitted in the second half. + +For DSP modes slot numbering is ascending: 0, 1, 2, 3, ... + +Channel position calculation has been refactored to use +TDM info and moved out of hw_params. + +set_tdm_slot, set_bclk_ratio and hw_params now check more +strictly if the configuration is valid. Illegal configurations +like odd number of slots in I2S mode, data lengths exceeding +slot width or frame sizes larger than the hardware limit of +1024 are rejected. Also hw_params now properly checks for +errors from clk_set_rate. + +Allowed PCM formats are already guarded by stream constraints, +thus the formats check in hw_params has been removed and +data_length is now retrieved via params_width(). + +Also standard functions like snd_soc_params_to_bclk are now +being used instead of manual calculations to make the code +more readable. + +Special care has been taken to ensure that set_bclk_ratio works +as before. The bclk ratio is mapped to a 2-channel TDM config +with a slot width of half the ratio. In order to support odd ratios, +which can't be expressed via a TDM config, the ratio (frame length) +is stored and used by hw_params. + +Signed-off-by: Matthias Reichl <hias@horus.com> +--- + sound/soc/bcm/bcm2835-i2s.c | 243 ++++++++++++++++++++++++++++-------- + 1 file changed, 190 insertions(+), 53 deletions(-) + +--- 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_rati + 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 + 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 + + 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: + /* +@@ -307,19 +437,10 @@ static int bcm2835_i2s_hw_params(struct + return -EINVAL; + } + +- ch1pos = data_delay; +- ch2pos = bclk_ratio / 2 + data_delay; +- +- switch (params_channels(params)) { +- case 2: +- case 8: +- 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. +@@ -327,11 +448,16 @@ static int bcm2835_i2s_hw_params(struct + * (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) { + /* +@@ -343,8 +469,8 @@ static int bcm2835_i2s_hw_params(struct + 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) { +@@ -424,7 +550,20 @@ static int bcm2835_i2s_hw_params(struct + /* 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, +@@ -560,6 +699,7 @@ static const struct snd_soc_dai_ops bcm2 + .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) +@@ -700,9 +840,6 @@ static int bcm2835_i2s_probe(struct plat + 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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