Shortens the variable name to save space, useful for dev_err outputs.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patches unifies the error message in the "failed to xxxx" format.

It also reduces the length of one line and adds spaces to an operator.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch just simply unifies the coding style.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch renames CCSR_SSI_xxx to REG_SSI_xxx and SSI_xxx_yyy style.
It also slightly reduces the length of them to save some space.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch refines the comments by:
1) Removing all out-of-date comments
2) Removing all not-so-useful comments
3) Unifying the styles of all comments
4) Shortening comments to be more conise
5) Adding comments to improve code readablity
6) Moving all register related comments to fsl_ssi.h
7) Adding comments to all register and field defines
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

There should be no trouble to understand dev = pdev->dev.
This can save some space to have more print info or save
some wrapped lines.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Shorten the private data structure to save some wrapped lines.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Tested-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

When testing AC'97 capture on UDOO board (currently the only user of
fsl_ssi driver in the AC'97 mode) it become obvious that there is a massive
distortion above certain, small input signal.

This problem has been traced to silicon errata ERR003778:
"In AC97, 16-bit mode, received data is shifted by 4-bit locations" that
has "No fix scheduled".
This errata suggests a workaround of doing a 4-bit shift back in SDMA
script for this specific operation mode, however our SDMA scripts are
shared between various SoC peripherals so we can't really modify them.

There is a simple way to avoid this problem, however, that is to disallow
recording in 16-bit mode and only support it in AC'97-native 20-bit mode.
We have to use a 4-byte format for this since SSI FIFOs do not allow 3-byte
accesses (and these aren't supported by imx-sdma driver anyway).
With this change the capture distortion is gone.

We can also add this format as an additional one supported for playback,
using this opportunity to make sure that we use CPU-endian-native formats
in AC'97 mode as we already do in I2S mode.

There is no problem in using different bit widths in playback and capture
in AC'97 mode so allow this, too.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: NMark Brown <broonie@kernel.org>

We need to make sure that only proper channel slots (in SACCST register)
are enabled at playback start time since some AC'97 CODECs (like VT1613 on
UDOO board) were observed requesting via SLOTREQ spurious ones just after
an AC'97 link is started but before the CODEC is configured by its driver.
When a bit for some channel slot is set in a SLOTREQ request then SSI sets
the relevant bit in SACCST automatically, which then 'sticks' until it is
manually unset.
The SACCST register is not writable directly, we have to use SACCDIS and
SACCEN registers to configure it instead (these aren't normal registers:
writing a '1' bit at some position in SACCEN sets the relevant bit in
SACCST; SACCDIS operates in a similar way but allows unsetting bits in
SACCST).

Theoretically, this should be necessary only for the very first playback
but since some CODECs are so untrustworthy and extra channel slots enabled
mean ruined playback let's play safe here and make sure that no extra
slots are enabled in SACCST every time a playback is started.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

In AC'97 mode we configure and start SSI RX / TX on probe path via
a call to _fsl_ssi_set_dai_fmt() function.
We don't need to call this function again later and in fact don't want to
do it since this function temporarily sets STCR, SRCR and SCR to some
intermediate values.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

We don't need to set CCSR_SSI_SIER_RFF0_EN / CCSR_SSI_SIER_TFE0_EN bits
in reg->rx.sier / reg->tx.sier variables in a non-AC'97 mode considering we
had just initialized these variables to these very values unconditionally a
few lines earlier.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

AC'97 register access operations (both read and write) on SSI use a one,
shared set of SSI registers for AC'97 register address and data.
This means that only one such access is possible at a time and so all these
operations need to be serialized.

Since an AC'97 register access operation in this driver takes 100us+ let's
use a mutex for this.

Use this opportunity to also change a default value returned from AC'97
register read function from -1 to 0, since that's what AC'97 specs require
to be returned when unknown / undefined registers are read.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: NMark Brown <broonie@kernel.org>

AC'97 ops (register read / write) need SSI regmap and clock, so they have
to be set after them.

We also need to set these ops back to NULL if we fail the probe.
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

The set_sysclk() now is used to override the output bit clock rate.
But this is not a common way to implement a set_dai_sysclk(). And
this creates a problem when a general machine driver (simple-card
for example) tries to do set_dai_sysclk() by passing an input clock
rate for the baud clock instead of setting the bit clock rate as
fsl_ssi driver expected.

So this patch solves this problem by firstly removing set_sysclk()
since the hw_params() can calculate the bit clock rate. Secondly,
in order not to break those TDM use cases which previously might
have been using set_sysclk() to override the bit clock rate, this
patch changes the driver to calculate the bit clock rate using the
slot number and the slot width from the via set_tdm_slot().

The patch also removes an obsolete comment of the dir parameter.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Omit an extra message for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdfSigned-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NMark Brown <broonie@kernel.org>

Code can be simplified by using the standard tolower() funtion.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The comment for the FSLSSI_I2S_RATES definition states that the
driver currently only supports I2S slave mode, which is no longer
correct.

As FSLSSI_I2S_RATES is the same as the standard SNDRV_PCM_RATE_CONTINUOUS,
just remove its definition and its comments to make the code simpler.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The fsl_ssi fifo watermark is by default set to 2 free spaces (i.e.
activate DMA on FIFO when only 2 spaces are left.)  This means the
DMA must service the fifo within 2 audio samples, which is just not
enough time  for many use cases with high data rate.  In many
configurations the audio channel slips (causing l/r swap in stereo
configurations, or channel slipping in multi-channel configurations).

This patch gives more breathing room and allows the SSI to operate
reliably by changing the fifio refill watermark to 8.

There is no change in behavior for older chips (with an 8-deep fifo).
Only the newer chips with a 15-deep fifo get the new behavior. I
suspect a new fifo depth setting could be optimized on the older
chips too, but I have not tested.
Signed-off-by: NCaleb Crome <caleb@crome.org>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The recent series of changes to the caching in the SSI driver have
caused a number of problems to appear in some test systems.  These are
still not fully understood but we're coming up to the merge window so
for now let's revert commit 7de2763d (ASoC: fsl_ssi: Remove
.num_reg_defaults_raw from regmap_config) as backing that out seems to
resolve the problem on affected systems.
Reported-by: NMaciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: NMark Brown <broonie@kernel.org>
Reviewed-by: NMarek Vasut <marex@denx.de>

This driver provides no .reg_defaults_raw in regmap_config, so
the .num_reg_defaults_raw is useless, and, in fact harmful. It
triggers kernel crash in regmap_init which tries to access the
register defaults.
Signed-off-by: NMarek Vasut <marex@denx.de>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Same as commit ce492b3b
Subject: drm/fsl-dcu: use flat regmap cache

Using flat regmap cache instead of RB-tree to avoid the following
lockdep warning on driver load:
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2871 lockdep_trace_alloc+0x104/0x128
DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))

The RB-tree regmap cache needs to allocate new space on first
writes. However, allocations in an atomic context (e.g. when a
spinlock is held) are not allowed. The function regmap_write
calls map->lock, which acquires a spinlock in the fast_io case.
Since the driver uses MMIO, the regmap bus of type regmap_mmio
is being used which has fast_io set to true.
Signed-off-by: NMarek Vasut <marex@denx.de>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The i.MX51 datasheet says:
Chapter 56.1.2.4 I2S Mode
...
When I2S modes are entered (I2S master (01) or I2S slave (10)),
the following settings are recommended:
...
- TX Frame Rate should be 2 i.e. (STCCR[12:8] = 1)
- RX Frame Rate should be 2 i.e. (SRCCR[12:8] = 1)

Chapter 56.3.3.12 SSI Transmit and Receive Clock Control Registers (STCCR & SRCCR)
...
Bits 12-8 DC4-DC0
Frame Rate Divider Control. These bits are used to control the divide ratio
for the programmable frame rate dividers. The divide ratio works on the word
clock. In Normal mode, this ratio determines the word transfer rate.
In Network mode, this ratio sets the number of words per frame. The divide
ratio ranges from 1 to 32 in Normal mode and from 2 to 32 in Network mode.
In Normal mode, a divide ratio of 1 (DC=00000) provides continuous periodic
data word transfer. A bit-length frame sync must be used in this case.

Function fsl_ssi_hw_params() setup Normal mode for MONO output,
so with DC=0, SSI enters to continuous periodic data word transfer.
To fix this, setup DC for any I2S mode.
Patch has tested on custom board based on Digi CCMX-51 module (i.MX51).
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NMark Brown <broonie@kernel.org>

Happened when the Playback (or Capture) is running continuously
and Capture (or Playback) is restarted (xrun, manual stop/start...)

Since the RX (or TX) FIFO are only reset when the whole SSI is disabled,
pending samples from previous capture (or playback) session may still
be present. They must be erased to not introduce channel slipping.

FIFO Clear register fields are documented in IMX51, IMX35 reference manual.
They are not documented in IMX50 or IMX6 RM, despite they are
working as expected on IMX6SL and IMX6solo.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Previously, SCR.SSIEN and SCR.TE were enabled at once if no capture
stream was also running.
This may not give a chance for the DMA to write the first sample in
TX FIFO before the streaming starts on the PCM bus, inserting void
samples first.
Those void samples are then responsible for slipping the channels.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the capture is already running while playback is started, it is highly
probable (>80% in a 8 channels scenario) that samples are lost between
the DMA and TX fifo.

The reason is that SIER.TDMAE is set before STCR.TFEN0, leaving a time
window where the FIFO doesn't receive the samples written by the DMA.

This particular case happened only if capture is already enabled as
SCR.SSIEN is already set at the playback startup instant.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Most of functions only receive the ssi_private reference and don't have
a knowledge of 'dev' pointer, even for debug purpose.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

im6sl reference manual 47.7.4:
"
Bit clock - Used to serially clock the data bits in and out of the SSI port.
This clock is either generated internally (from SSI's sys clock) or taken
from external clock source (through the Tx/Rx clock ports).
[...]
Care should be taken to ensure that the bit clock frequency (either
internally generated by dividing the SSI's sys clock or sourced from
external device through Tx/Rx clock ports) is never greater than 1/5
of the ipg_clk (from CCM) frequency.
"

Since, in master mode, the sysclk is a multiple of bitclk, we can
easily reach a high sysclk value, whereas keeping a reasonable bitclk.

ex: 8ch x 16bit x 48kHz = 6144000, requires a 24576000 sysclk (PM=1)
    yet ipg_clk/5 = 66Mhz/5 = 13.2
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The max number of slots in TDM mode is 32:
- Frame Rate Divider Control is a 5bit value
- Time slot mask registers control 32 slots.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The CCSR_SSI_SOR is a register that clears the TX and/or the RX fifo
on the i.MX SSI port.  The fsl_ssi_trigger writes this register in
order to clear the fifo at trigger time.

However, since the CCSR_SSI_SOR register is not in the volatile list,
the caching mechanism prevented the register write in the trigger
function.  This caused the fifo to not be cleared (because the value
was unchanged from the last time the register was written), and thus
causes the channels in both TDM or simple I2S mode to slip and be in
the wrong time slots on SSI restart.

This has gone unnoticed for so long because with simple stereo mode,
the consequence is that left and right are swapped, which isn't that
noticeable.  However, it's catestrophic in some systems that
require the channels to be in the right slots.
Signed-off-by: NCaleb Crome <caleb@crome.org>
Suggested-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is no guarantee that on fsl_ssi module load
SSI registers will have their power-on-reset values.

In fact, if the driver is reloaded the values in
registers will be whatever they were set to previously.

However, the cache needs to be fully populated at probe
time to avoid non-atomic allocations during register
access.

Special case here is imx21-class SSI, since
according to datasheet it don't have SACC{ST,EN,DIS}
regs.

This fixes hard lockup on fsl_ssi module reload,
at least in AC'97 mode.

Fixes: 05cf2379 ("ASoC: fsl_ssi: Add driver suspend and resume to support MEGA Fast")
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Tested-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Commit 5c408fee ("ASoC: fsl_ssi: remove explicit register defaults")
causes the driver to fail to probe:

fsl-ssi-dai 2028000.ssi: No cache defaults, reading back from HW
fsl-ssi-dai 2028000.ssi: Failed to init register map
fsl-ssi-dai: probe of 2028000.ssi failed with error -22

, so revert this commit.
Reported-by: NMika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is no guarantee that on fsl_ssi module load
SSI registers will have their power-on-reset values.

In fact, if the driver is reloaded the values in
registers will be whatever they were set to previously.

However, the cache needs to be fully populated at probe
time to avoid non-atomic allocations during register
access.

Special case here is imx21-class SSI, since
according to datasheet it don't have SACC{ST,EN,DIS}
regs.

This fixes hard lockup on fsl_ssi module reload,
at least in AC'97 mode.

Fixes: 05cf2379 ("ASoC: fsl_ssi: Add driver suspend and resume to support MEGA Fast")
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Tested-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Mark some registers precious since their
reads have side effects (like clearing flags).
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

SACNT register should be marked volatile since
its WR and RD bits are cleared by SSI after
completing the relevant operation.
This unbreaks AC'97 register access.

Fixes: 05cf2379 ("ASoC: fsl_ssi: Add driver suspend and resume to support MEGA Fast")
Signed-off-by: NMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

using params_width function to simplify code.
Signed-off-by: NZidan Wang <zidan.wang@freescale.com>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

using macro for default register map
Signed-off-by: NZidan Wang <zidan.wang@freescale.com>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

For i.MX6 SoloX, there is a mode of the SoC to shutdown all power
source of modules during system suspend and resume procedure. Thus,
SSI needs to save all the values of registers before the system
suspend and restore them after the system resume.

The register SFCSR is volatile, but some bits in it need to be
recovered after suspend/resume.
Signed-off-by: NZidan Wang <zidan.wang@freescale.com>
Acked-by: NNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current code incorrectly treats dai format for AC97 as bit mask
whereas it's actually an integer value. This causes DAI formats
other than AC97 (e.g. DSP_B) to trigger AC97 related code,
which is incorrect and breaks functionality. This patch fixes
the code to correctly compare values to determine AC97 or not.
Signed-off-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Adjust set DAI format function in fsl_ssi driver
so it doesn't fail and clears RXDIR in AC'97 mode.
Signed-off-by: NMaciej Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: NMark Brown <broonie@kernel.org>

Instantiate AC'97 CODEC in fsl_ssi driver AC'97 mode.
Signed-off-by: NMaciej Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: NMark Brown <broonie@kernel.org>