sound/soc/codecs: add LAPIS Semiconductor ML26124

sound/soc/lapis/ml7213ioh-machine.c new file +37 -0

+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS0, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS1, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS2, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS3, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS4, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_BCLKFS5, bclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_MCLKFS0, mclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_MCLKFS1, mclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_MCLKFS2, mclkfs);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ML7213IOH_MCLKFS3, mclkfs);

+/*****************************************************************************
+ * I2S HAL (Hardware Abstruction Layer)
+ *****************************************************************************/

+/*****************************************************************************
+ * I2S Middle ware
+ *****************************************************************************/

+static bool filter(struct dma_chan *chan, void *slave)

sound/soc/lapis/ml7213ioh-plat.c new file +3 -0

+		/* Rx configuration */
+		if (atomic_read(&dma->rx_busy)) {
+			dev_err(i2s_data->dev, "rx i2s%dalready opened\n", ch);

sound/soc/lapis/ml7213ioh-plat.c line 40

Quoted 4 lines

sound/soc/lapis/ml7213ioh-plat.c new file +3 -0

+static int ignore_overrun = 1;
+module_param(ignore_overrun, int, 0444);
+MODULE_PARM_DESC(ignore_overrun, "ignore RX overruns (default=0)");

This shouldn't be a driver specific thing, and if we were to have such a feature a module parameter doesn't seem like a great way of doing it.

Quoted 4 lines

+/*****************************************************************************
+ *   I2S HAL (Hardware Abstruction Layer)
+ *****************************************************************************/

Please follow the kernel coding style in terms of comments.

sound/soc/lapis/ml7213ioh-plat.c line 59

Quoted 10 lines

sound/soc/lapis/ml7213ioh-plat.c new file +9 -0

+static void ioh_i2s_enable_interrupts(int ch, enum dma_data_direction dir)
+{
+     unsigned int intr_lines;
+
+     if (dir)
+             intr_lines = 1 << (I2S_IMASK_RX_BIT_START + ch);
+
+     else
+             intr_lines = 1 << (I2S_IMASK_TX_BIT_START + ch);

I'd expect a switch statement corresponding to the enum, not an if statement.

sound/soc/lapis/ml7213ioh-plat.c line 70

Quoted 7 lines

sound/soc/lapis/ml7213ioh-plat.c new file +6 -0

+static void ioh_i2s_disable_interrupts(int ch, enum dma_data_direction dir)
+{
+     unsigned int intr_lines;
+
+     /*intr_lines&=I2S_ALL_INTERRUPT_BITS; */
+     intr_lines = ioread32(i2s_data->iobase + I2SIMASK_OFFSET);

What's this commented out code for?  Also as a coding style thing you should have a space between /* and the text in the comment (this applies throughout the driver).

Quoted 9 lines

+     /*disable interrupts for specified channel */
+     if (dir)
+             intr_lines |= 1 << (I2S_IMASK_RX_BIT_START + ch);
+     else
+             intr_lines |= 1 << (I2S_IMASK_TX_BIT_START + ch); +
+     /*Mask the specific interrupt bits */
+     iowrite32(intr_lines, i2s_data->iobase + I2SIMASK_OFFSET);

What ensures that this read/modify/write cycle can't race with another caller?

sound/soc/lapis/ml7213ioh-plat.c line 113

Quoted 9 lines

sound/soc/lapis/ml7213ioh-plat.c new file +8 -0

+/* Clear interrupt status */
+static void ioh_i2s_clear_tx_sts_ir(int ch)
+{
+     int offset = ch * 0x800;
+
+     iowrite32(I2S_TX_FINT | I2S_TX_AFINT | I2S_TX_EINT | I2S_TX_AEINT,
+             i2s_data->iobase + I2SISTTX_OFFSET + offset);
+}

This appears to unconditionally acknowledge all interrupts, generally you should only acknowledge interrupts that have been handled. Otherwise it's possible that interrupts may be dropped if they're flagged between the status read and acknowledgement write.

Quoted 4 lines

+/*****************************************************************************
+ *   I2S Middle ware
+ *****************************************************************************/

I'm really not convinced of the value of these layers, reading the code it really feels incredibly verbose in comparison with what I'd expect from such a driver and I can't help that think that a lot of this verbosity is down to muddling through these abstraction layers.

Quoted 1 line

+static bool filter(struct dma_chan *chan, void *slave)

This needs a better name.  It's not namespaced and it's not clear what it's filtering.

Quoted 4 lines

sound/soc/lapis/ml7213ioh-plat.c new file +3 -0

+static struct dma_chan *ioh_request_dma_channel(
+                int ch, struct ioh_i2s_dma *dma, enum dma_data_direction dir)
+{

sound/soc/lapis/ml7213ioh-plat.c line 247

Quoted 10 lines

sound/soc/lapis/ml7213ioh-plat.c new file +10 -0

+     dma_cap_mask_t mask;
+     struct dma_chan *chan;
+     struct pci_dev *dma_dev;
+     dma_cap_zero(mask);
+     dma_cap_set(DMA_SLAVE, mask);
+
+     dma_dev = pci_get_bus_and_slot(2, PCI_DEVFN(0, 1)); /* Get DMA's dev
+                                                             information */
+
+     if (dir == DMA_FROM_DEVICE) { /* Rx */

switch statement to select between multiple options in the enum.  This applies throughout the code.

sound/soc/lapis/ml7213ioh-plat.c line 293

Quoted 6 lines

sound/soc/lapis/ml7213ioh-plat.c new file +5 -0

+static void
+ioh_i2s_write(struct snd_pcm_substream *substream, const void *data, int len)
+{
+     int rem1;
+     int rem2;

What is this supposed to do?  There's an awful lot of it, and it looks like it's supposed to be rewriting the data format for some reason which isn't something that a driver ought to be doing (apart from anything else it does rather defeat the point of DMA).

sound/soc/lapis/ml7213ioh-plat.c line 429

Quoted 4 lines

sound/soc/lapis/ml7213ioh-plat.c new file +3 -0

+static void ioh_i2s_configure_i2s_regs(int ch, enum ioh_direction dir)
+{
+     int offset = ch * 0x800;

You should have a function to map the channel into a number.

Quoted 9 lines

+
+     if (dir) {
+             /* Rx register */
+             iowrite32(I2S_AFULL_THRESH / 2,
+                       i2s_data->iobase + I2SAFRX_OFFSET + offset);
+             iowrite32(0x1F, i2s_data->iobase + I2SAERX_OFFSET + offset);
+             iowrite32(0x1F, i2s_data->iobase + I2SMSKRX_OFFSET + offset);
+             iowrite32(0xC, i2s_data->iobase + I2SISTRX_OFFSET + offset);

Lots of magic numbers here and given that the function is called just "configure" it's not clear what the intended purpose is.  This needs to be clarified.

Quoted 4 lines

+             /* Rx configuration */
+             if (atomic_read(&dma->rx_busy)) {
+                     dev_err(i2s_data->dev, "rx i2s%dalready opened\n", ch);

...

Quoted 3 lines

+     } else {
+             /* Tx configuration */
+             if (atomic_read(&dma->tx_busy)) {

There's a *lot* of duplicate code in the driver for TX and RX, it should be possible to abstract out much more common code.

Quoted 4 lines

sound/soc/lapis/ml7213ioh-plat.c new file +3 -0

+static void i2s_tx_almost_empty_ir(int ch)
+{
+     struct dma_async_tx_descriptor *desc;

sound/soc/lapis/ml7213ioh-plat.c line 924

Quoted 10 lines

sound/soc/lapis/ml7213ioh-plat.c new file +10 -0

+     int num;
+     int tx_comp_index;
+     struct ioh_i2s_dma *dma = &dmadata[ch];
+     struct scatterlist *sg = dma->sg_tx_p;
+     void *cb_ch;
+
+     dev_dbg(i2s_data->dev, "%s: data_head=%p data_complete=%p\n", __func__,
+             dma->tx_data_head, dma->tx_complete);
+
+     num = ((int)dma->tx_avail) / (I2S_AEMPTY_THRESH * 4);

That case looks *very* suspect.

Quoted 3 lines

+     tx_comp_index = (((int)(dma->tx_complete - dma->tx_head))) /\
+                     (I2S_AEMPTY_THRESH * 4);

There is very rarely any need for line continuations outside of macros.

sound/soc/lapis/ml7213ioh-plat.c line 992

Quoted 10 lines

sound/soc/lapis/ml7213ioh-plat.c new file +10 -0

+static inline void ioh_i2s_interrupt_sub_tx(int ch)
+{
+     unsigned int status;
+     int offset = ch * 0x800;
+
+     status = ioread32(i2s_data->iobase + I2SISTTX_OFFSET + offset);
+     if (status & I2S_TX_EINT)
+             i2s_tx_empty_ir(ch);
+     if (status & I2S_TX_AEINT)
+             i2s_tx_almost_empty_ir(ch);

Given that all you're doing is logging just open code the log message.

Quoted 3 lines

+     default:
+             return -1;

Return error codes, you EPERM almost certainly isn't the error you meant to report.

sound/soc/lapis/ml7213ioh-plat.c line 1937

Quoted 6 lines

sound/soc/lapis/ml7213ioh-plat.c new file +5 -0

+static int ioh_i2s_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+     int ret;
+
+     ioh_i2s_save_reg_conf(pdev);

You should be doing this in ASoC suspend/resume callbacks, not in PCI ones.

2011/12/20 Mark Brown <[email protected]>:

Quoted 9 lines · Tomoya MORINAGA

Quoted 3 lines

+     iowrite32(I2S_TX_FINT | I2S_TX_AFINT | I2S_TX_EINT | I2S_TX_AEINT,
+             i2s_data->iobase + I2SISTTX_OFFSET + offset);

This appears to unconditionally acknowledge all interrupts, generally you should only acknowledge interrupts that have been handled. Otherwise it's possible that interrupts may be dropped if they're flagged between the status read and acknowledgement write.

I can understand your saying.
If following your saying, only called by i2s_dma_tx_complete is enough.

However I think adding clearing interrupt status at both before and after i2s communicating start/finish is better.

Quoted 4 lines

Quoted 1 line

+static bool filter(struct dma_chan *chan, void *slave)

This needs a better name.  It's not namespaced and it's not clear what it's filtering.

In case of using Linux standard DMA API, function "filter" is the most popular name.
Almost drivers which use standard use "filter".

Quoted 9 lines

sound/soc/lapis/ml7213ioh-plat.c line 293

Quoted 4 lines

sound/soc/lapis/ml7213ioh-plat.c new file +4 -0

+ioh_i2s_write(struct snd_pcm_substream *substream, const void *data, int len)
+{
+     int rem1;
+     int rem2;

What is this supposed to do?  There's an awful lot of it, and it looks like it's supposed to be rewriting the data format for some reason which isn't something that a driver ought to be doing (apart from anything else it does rather defeat the point of DMA).

This driver has buffer which is for preventing noisy sound by jitter So, this buffer is variable.

Quoted 3 lines

Quoted 1 line

+     num = ((int)dma->tx_avail) / (I2S_AEMPTY_THRESH * 4);

That case looks *very* suspect.

This is correct.
Why do you think so ?

Quoted 11 lines

2011/12/20 Mark Brown <[email protected]>:

Quoted 9 lines · Tomoya MORINAGA

Quoted 3 lines

+     iowrite32(I2S_TX_FINT | I2S_TX_AFINT | I2S_TX_EINT | I2S_TX_AEINT,
+             i2s_data->iobase + I2SISTTX_OFFSET + offset);

This appears to unconditionally acknowledge all interrupts, generally you should only acknowledge interrupts that have been handled. Otherwise it's possible that interrupts may be dropped if they're flagged between the status read and acknowledgement write.

Quoted 5 lines

I can understand your saying.
If following your saying, only called by i2s_dma_tx_complete is enough.

However I think adding clearing interrupt status at both before and after i2s communicating start/finish is better.

No, the issue is that you're acknowleding a hard coded set of interrupts, not the interrupts that were actually handled.  The ordering isn't really the issue, the issue is that you could acknowledge things that weren't handled.  For example:

  1. ISR runs, reads status A
  2. Condition B happens
  3. ISR handles condition A.
  4. ISR acknowledges both A and B.

would mean that B would just get ignored.

Quoted 5 lines

Quoted 5 lines

Quoted 2 lines

+static bool filter(struct dma_chan *chan, void *slave)

This needs a better name.  It's not namespaced and it's not clear what it's filtering.

Quoted 3 lines

In case of using Linux standard DMA API, function "filter" is the most popular name.
Almost drivers which use standard use "filter".

I suspect they may have the filter immediately next to the code that uses it, which certainly isn't the case here.

Quoted 10 lines

Quoted 10 lines

sound/soc/lapis/ml7213ioh-plat.c line 293

Quoted 5 lines

sound/soc/lapis/ml7213ioh-plat.c new file +4 -0

+ioh_i2s_write(struct snd_pcm_substream *substream, const void *data, int len)
+{
+     int rem1;
+     int rem2;

What is this supposed to do?  There's an awful lot of it, and it looks like it's supposed to be rewriting the data format for some reason which isn't something that a driver ought to be doing (apart from anything else it does rather defeat the point of DMA).

Quoted 2 lines

This driver has buffer which is for preventing noisy sound  by jitter So, this buffer is variable.

You're implementing some sort of custom buffering in your driver?  That sounds terribly unidiomatic - pretty much all DMA drivers are very thin and manage to work well, I'd expect this is masking some problems in the code rather than anything else.  Can you provide more detail on what this is working around?

Quoted 7 lines

Quoted 4 lines

Quoted 2 lines

+     num = ((int)dma->tx_avail) / (I2S_AEMPTY_THRESH * 4);

That case looks *very* suspect.

This is correct.
Why do you think so ?

I can't tell what it's supposed to do, and casting that isn't super clear especially casting to integer types tends to be a big red flag.

I can understand your saying.
However, in case of Tx interrupt, only ALMOST-EMPTY occurs. in case of Rx, only Rx ALMOST-FULL occurs.
So as long as a user uses ML7213 I2S, your mentioned behavior is never happened.

They have the "filter" function immediately next to the code uses "dma_request_channel".

Anyway, if you want me to change the name, I can change the name. Please decide it.

Quoted 5 lines

You're implementing some sort of custom buffering in your driver?  That sounds terribly unidiomatic - pretty much all DMA drivers are very thin and manage to work well, I'd expect this is masking some problems in the code rather than anything else.  Can you provide more detail on what this is working around?

Not sorted but queuing only.
In sound/voice control system, queuing is not rare, I think. If necessary, though this method is very common, I can send the method of the queue.

Quoted 5 lines

I can understand your saying.
However, in case of Tx interrupt, only ALMOST-EMPTY occurs. in case of Rx, only Rx ALMOST-FULL occurs.
So as long as a user uses ML7213 I2S, your mentioned behavior is never happened.

That's not what your code says...  it may be that the other interrupts are very rare but that's not the same thing.

Quoted 3 lines

They have the "filter" function immediately next to the code uses "dma_request_channel".

That's a rather large function...

Quoted 2 lines

Anyway, if you want me to change the name, I can change the name. Please decide it.

Rename.

Quoted 6 lines

Quoted 6 lines

You're implementing some sort of custom buffering in your driver?  That sounds terribly unidiomatic - pretty much all DMA drivers are very thin and manage to work well, I'd expect this is masking some problems in the code rather than anything else.  Can you provide more detail on what this is working around?

Quoted 4 lines

Not sorted but queuing only.
In sound/voice control system, queuing is not rare, I think. If necessary, though this method is very common, I can send the method of the queue.

No, please describe the problem you're trying to fix.

2011/12/22 Mark Brown <[email protected]>:

Quoted 4 lines

Quoted 4 lines

Not sorted but queuing only.
In sound/voice control system, queuing is not rare, I think. If necessary, though this method is very common, I can send the method of the queue.

Quoted 1 line

No, please describe the problem you're trying to fix.

When CPU is heavy load, this buffer is useful. The heavy load causes delaying receiving processing. If there is no buffer, stream sound/voice can be broken. If there is the buffer, it can prevent the broken sound.

Quoted 8 lines

2011/12/22 Mark Brown <[email protected]>:

Quoted 6 lines

Quoted 4 lines

Not sorted but queuing only.
In sound/voice control system, queuing is not rare, I think. If necessary, though this method is very common, I can send the method of the queue.

No, please describe the problem you're trying to fix.

Quoted 4 lines

When CPU is heavy load, this buffer is useful. The heavy load causes delaying receiving processing. If there is no buffer, stream sound/voice can be broken. If there is the buffer, it can prevent the broken sound.

So you're just talking about standard underflows if the application can't keep up?

There's *no* reason for your driver to do anything about this, it's a really basic thing that affects all audio hardware.  Just write a driver for the hardware.

2011/12/26 Mark Brown <[email protected]>:

Quoted 2 lines

So you're just talking about standard underflows if the application can't keep up?

No. not only underflow but overflow.

Quoted 3 lines

There's *no* reason for your driver to do anything about this, it's a really basic thing that affects all audio hardware.  Just write a driver for the hardware.

In case driver layer doesn't have the function,
which part works for the under/overflow ? Application ? or nothing ?

How have you tested this code?

2011/12/20 Mark Brown <[email protected]>:

Quoted 1 line

How have you tested this code?

No, I haven't tested at all. (Of course, I tested before ASoC.) I'll test the new these drivers after you say "Roughly, how to use ASoC framework is OK"