[PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Nicolin Chen]

[ Maciej, could you please send your Tested-by/Reviewed-by for AC97
  once you confirm this series?
  
  And Caleb, this version does not need a test for non-AC97 cases.

  Thanks both! ]

==Change log==
v5
 * Reworked the series by taking suggestions from Maciej for AC97
  + Fixed SSI lockup issue by changing cleanup sequence in PATCH-13
  + Moved fsl_ssi_hw_clean() after unregistering the CODEC device
    in PATCH-13
  + Set NULL as the parent of CODEC platform device to fix a NULL
    pointer dereference bug in PATCH-16
 * Updated comments of three variables/pointers in struct fsl_ssi
   to describe them more accurately in PATCH-16
v4
 * Reworked the series by taking suggestions from Maciej
  + Added TXBIT0 bit back to play safe in PATCH-14
  + Made bool synchronous exclusive with AC97 mode in PATCH-16
v3
 * Reworked the series by taking suggestions from Maciej
  + Added PATCH-01 to make RX and TX more clearly defined
  + Replaced "bool dir" with "int dir" in PATCH-04
  + Replaced "!dir" with "int adir" in PATCH-05
  + Put CBM_CFS behind the baudclk check to keep the same
    program flow in PATCH-14
  + Removed all cpu_dai_drv changes in PATCH-15
v2
 * Reworked the series by taking suggestions from Maciej
  + Added PATCH-01 to keep all ssi->i2s_net updated
  + Replaced bool tx with bool dir in PATCH-03 and PATCH-06
  + Moved all initial register configurations from dai probe() to
    platform probe() so as to let AC97 CODEC successfully probe.
 * Added Tested-by from Caleb for TDM test cases.

==Background==
The fsl_ssi driver was designed for PPC originally and then it has
been updated to support different modes for i.MX Series, including
SDMA, I2S Master mode, AC97 and older i.MXs with FIQ, by different
contributors for different use cases in different coding styles.

Additionally, in order to fix/work-around hardware bugs and design
flaws, the driver made a lot of compromise so now its program flow
looks very complicated and it's getting hard to maintain or update.

So I am going to clean up the driver on both coding style level and
program flow level.

==Introduction==
This series of patches is the second set to clean up fsl_ssi driver
in the program flow level. Any patch here may impact a fundamental
test case like playback or record.

==Verification==
This series of patches require fully tested. I have done such tests
on i.MX6SoloX with WM8962 using imx_v6_v7_defconfig as:
 - Playback via I2S Master and Slave mode
 - Record via I2S Master and Slave mode
 - Simultaneous playback and record via I2S Master and Slave mode
 - Background playback with foreground record (starting at different
   time) via I2S Master and Slave mode
 - Background record with foreground playback (starting at different
   time) via I2S Master and Slave mode
 * All tests above by hacking offline_config to true in imx51.

Caleb has tested v1-v4 with TDM lookback tests on i.MX6.

Example of uncovered tests: AC97, PowerPC and FIQ.

Nicolin Chen (17):
  ASoC: fsl_ssi: Redefine RX and TX macros
  ASoC: fsl_ssi: Keep ssi->i2s_net updated
  ASoC: fsl_ssi: Clean up set_dai_tdm_slot()
  ASoC: fsl_ssi: Maintain a mask of active streams
  ASoC: fsl_ssi: Rename fsl_ssi_disable_val macro
  ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()
  ASoC: fsl_ssi: Clean up helper functions of trigger()
  ASoC: fsl_ssi: Add DAIFMT define for AC97
  ASoC: fsl_ssi: Clean up fsl_ssi_setup_regvals()
  ASoC: fsl_ssi: Set xFEN0 and xFEN1 together
  ASoC: fsl_ssi: Use snd_soc_init_dma_data instead
  ASoC: fsl_ssi: Move one-time configurations to probe()
  ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()
  ASoC: fsl_ssi: Clean up _fsl_ssi_set_dai_fmt()
  ASoC: fsl_ssi: Add bool synchronous to mark synchronous mode
  ASoC: fsl_ssi: Move DT related code to a separate probe()
  ASoC: fsl_ssi: Use ssi->streams instead of reading register

 sound/soc/fsl/fsl_ssi.c | 756 +++++++++++++++++++++++++-----------------------
 sound/soc/fsl/fsl_ssi.h |   3 -
 2 files changed, 395 insertions(+), 364 deletions(-)

-- 
2.7.4

[PATCH v5 01/17] ASoC: fsl_ssi: Redefine RX and TX macros

[Nicolin Chen]

The RX and TX macros were defined implicitly and there was
a potential risk if someone changes their values.

Since they were defined to index the array ssi->regvals[2],
this patch moves these two macros to fsl_ssi.c, closer to
its owner ssi->regvals. And it also puts some comments here
to limit their value within [0, 1].

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 4 ++++
 sound/soc/fsl/fsl_ssi.h | 3 ---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index aecd00f..001e453 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -56,6 +56,10 @@
 #include "fsl_ssi.h"
 #include "imx-pcm.h"
 
+/* Define RX and TX to index ssi->regvals array; Can be 0 or 1 only */
+#define RX 0
+#define TX 1
+
 /**
  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
  *
diff --git a/sound/soc/fsl/fsl_ssi.h b/sound/soc/fsl/fsl_ssi.h
index de2fdc5..18f8dd5 100644
--- a/sound/soc/fsl/fsl_ssi.h
+++ b/sound/soc/fsl/fsl_ssi.h
@@ -12,9 +12,6 @@
 #ifndef _MPC8610_I2S_H
 #define _MPC8610_I2S_H
 
-#define RX 0
-#define TX 1
-
 /* -- SSI Register Map -- */
 
 /* SSI Transmit Data Register 0 */
-- 
2.7.4

[PATCH v5 01/17] ASoC: fsl_ssi: Redefine RX and TX macros

[Nicolin Chen]

The RX and TX macros were defined implicitly and there was
a potential risk if someone changes their values.

Since they were defined to index the array ssi->regvals[2],
this patch moves these two macros to fsl_ssi.c, closer to
its owner ssi->regvals. And it also puts some comments here
to limit their value within [0, 1].

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 4 ++++
 sound/soc/fsl/fsl_ssi.h | 3 ---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index aecd00f..001e453 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -56,6 +56,10 @@
 #include "fsl_ssi.h"
 #include "imx-pcm.h"
 
+/* Define RX and TX to index ssi->regvals array; Can be 0 or 1 only */
+#define RX 0
+#define TX 1
+
 /**
  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
  *
diff --git a/sound/soc/fsl/fsl_ssi.h b/sound/soc/fsl/fsl_ssi.h
index de2fdc5..18f8dd5 100644
--- a/sound/soc/fsl/fsl_ssi.h
+++ b/sound/soc/fsl/fsl_ssi.h
@@ -12,9 +12,6 @@
 #ifndef _MPC8610_I2S_H
 #define _MPC8610_I2S_H
 
-#define RX 0
-#define TX 1
-
 /* -- SSI Register Map -- */
 
 /* SSI Transmit Data Register 0 */
-- 
2.7.4

[PATCH v5 02/17] ASoC: fsl_ssi: Keep ssi->i2s_net updated

[Nicolin Chen]

The hw_params() overwrites i2s_net settings for special cases like
mono-channel support, however, it doesn't update ssi->i2s_net as
set_dai_fmt() does.

This patch removes the local i2s_net variable and directly updates
ssi->i2s_net in the hw_params() so that the driver can simply look
up the ssi->i2s_net instead of reading the register.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 001e453..9847a1d 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -838,16 +838,16 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	if (!fsl_ssi_is_ac97(ssi)) {
-		u8 i2s_net;
 		/* Normal + Network mode to send 16-bit data in 32-bit frames */
 		if (fsl_ssi_is_i2s_cbm_cfs(ssi) && sample_size == 16)
-			i2s_net = SSI_SCR_I2S_MODE_NORMAL | SSI_SCR_NET;
-		else
-			i2s_net = ssi->i2s_net;
+			ssi->i2s_net = SSI_SCR_I2S_MODE_NORMAL | SSI_SCR_NET;
+
+		/* Use Normal mode to send mono data at 1st slot of 2 slots */
+		if (channels == 1)
+			ssi->i2s_net = SSI_SCR_I2S_MODE_NORMAL;
 
 		regmap_update_bits(regs, REG_SSI_SCR,
-				   SSI_SCR_I2S_NET_MASK,
-				   channels == 1 ? 0 : i2s_net);
+				   SSI_SCR_I2S_NET_MASK, ssi->i2s_net);
 	}
 
 	/* In synchronous mode, the SSI uses STCCR for capture */
-- 
2.7.4

[PATCH v5 03/17] ASoC: fsl_ssi: Clean up set_dai_tdm_slot()

[Nicolin Chen]

This patch replaces the register read with ssi->i2s_net for
simplification. It also removes masking SSIEN from scr value
since it's handled later by regmap_update_bits() to set this
scr value back.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 9847a1d..8984ee2 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -1055,9 +1055,7 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	}
 
 	/* The slot number should be >= 2 if using Network mode or I2S mode */
-	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_I2S_MODE_MASK | SSI_SCR_NET;
-	if (val && slots < 2) {
+	if (ssi->i2s_net && slots < 2) {
 		dev_err(dai->dev, "slot number should be >= 2 in I2S or NET\n");
 		return -EINVAL;
 	}
@@ -1067,9 +1065,8 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	regmap_update_bits(regs, REG_SSI_SRCCR,
 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
 
-	/* Save SSIEN bit of the SCR register */
+	/* Save the SCR register value */
 	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_SSIEN;
 	/* Temporarily enable SSI to allow SxMSKs to be configurable */
 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, SSI_SCR_SSIEN);
 
-- 
2.7.4

[PATCH v5 03/17] ASoC: fsl_ssi: Clean up set_dai_tdm_slot()

[Nicolin Chen]

This patch replaces the register read with ssi->i2s_net for
simplification. It also removes masking SSIEN from scr value
since it's handled later by regmap_update_bits() to set this
scr value back.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 9847a1d..8984ee2 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -1055,9 +1055,7 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	}
 
 	/* The slot number should be >= 2 if using Network mode or I2S mode */
-	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_I2S_MODE_MASK | SSI_SCR_NET;
-	if (val && slots < 2) {
+	if (ssi->i2s_net && slots < 2) {
 		dev_err(dai->dev, "slot number should be >= 2 in I2S or NET\n");
 		return -EINVAL;
 	}
@@ -1067,9 +1065,8 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
 	regmap_update_bits(regs, REG_SSI_SRCCR,
 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
 
-	/* Save SSIEN bit of the SCR register */
+	/* Save the SCR register value */
 	regmap_read(regs, REG_SSI_SCR, &val);
-	val &= SSI_SCR_SSIEN;
 	/* Temporarily enable SSI to allow SxMSKs to be configurable */
 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, SSI_SCR_SSIEN);
 
-- 
2.7.4

[PATCH v5 04/17] ASoC: fsl_ssi: Maintain a mask of active streams

[Nicolin Chen]

Checking TE and RE bits in SCR register doesn't work for AC97 mode
which enables SSIEN, TE and RE in the fsl_ssi_setup_ac97() that's
called during probe().

So when running into the trigger(), it will always get the result
of both TE and RE being enabled already, even if actually there is
no active stream.

This patch fixes this issue by adding a variable to log the active
streams manually.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced "bool dir" with "int dir"
v2
 * Replaced bool tx with bool dir

 sound/soc/fsl/fsl_ssi.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 8984ee2..51e7405 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -205,6 +205,7 @@ struct fsl_ssi_soc_data {
  * @cpu_dai_drv: CPU DAI driver for this device
  *
  * @dai_fmt: DAI configuration this device is currently used with
+ * @streams: Mask of current active streams: BIT(TX) and BIT(RX)
  * @i2s_net: I2S and Network mode configurations of SCR register
  * @use_dma: DMA is used or FIQ with stream filter
  * @use_dual_fifo: DMA with support for dual FIFO mode
@@ -249,6 +250,7 @@ struct fsl_ssi {
 	struct snd_soc_dai_driver cpu_dai_drv;
 
 	unsigned int dai_fmt;
+	u8 streams;
 	u8 i2s_net;
 	bool use_dma;
 	bool use_dual_fifo;
@@ -444,15 +446,14 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
+	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
 	int nr_active_streams;
-	u32 scr;
 	int keep_active;
 
-	regmap_read(regs, REG_SSI_SCR, &scr);
-
-	nr_active_streams = !!(scr & SSI_SCR_TE) + !!(scr & SSI_SCR_RE);
+	nr_active_streams = !!(ssi->streams & BIT(TX)) +
+			    !!(ssi->streams & BIT(RX));
 
 	if (nr_active_streams - 1 > 0)
 		keep_active = 1;
@@ -474,6 +475,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 					      keep_active);
 		/* Safely disable SCR register for the stream */
 		regmap_update_bits(regs, REG_SSI_SCR, scr, 0);
+
+		/* Log the disabled stream to the mask */
+		ssi->streams &= ~BIT(dir);
 	}
 
 	/*
@@ -549,6 +553,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		}
 		/* Enable all remaining bits */
 		regmap_update_bits(regs, REG_SSI_SCR, vals->scr, vals->scr);
+
+		/* Log the enabled stream to the mask */
+		ssi->streams |= BIT(dir);
 	}
 }
 
-- 
2.7.4

[PATCH v5 04/17] ASoC: fsl_ssi: Maintain a mask of active streams

[Nicolin Chen]

Checking TE and RE bits in SCR register doesn't work for AC97 mode
which enables SSIEN, TE and RE in the fsl_ssi_setup_ac97() that's
called during probe().

So when running into the trigger(), it will always get the result
of both TE and RE being enabled already, even if actually there is
no active stream.

This patch fixes this issue by adding a variable to log the active
streams manually.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced "bool dir" with "int dir"
v2
 * Replaced bool tx with bool dir

 sound/soc/fsl/fsl_ssi.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 8984ee2..51e7405 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -205,6 +205,7 @@ struct fsl_ssi_soc_data {
  * @cpu_dai_drv: CPU DAI driver for this device
  *
  * @dai_fmt: DAI configuration this device is currently used with
+ * @streams: Mask of current active streams: BIT(TX) and BIT(RX)
  * @i2s_net: I2S and Network mode configurations of SCR register
  * @use_dma: DMA is used or FIQ with stream filter
  * @use_dual_fifo: DMA with support for dual FIFO mode
@@ -249,6 +250,7 @@ struct fsl_ssi {
 	struct snd_soc_dai_driver cpu_dai_drv;
 
 	unsigned int dai_fmt;
+	u8 streams;
 	u8 i2s_net;
 	bool use_dma;
 	bool use_dual_fifo;
@@ -444,15 +446,14 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
+	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
 	int nr_active_streams;
-	u32 scr;
 	int keep_active;
 
-	regmap_read(regs, REG_SSI_SCR, &scr);
-
-	nr_active_streams = !!(scr & SSI_SCR_TE) + !!(scr & SSI_SCR_RE);
+	nr_active_streams = !!(ssi->streams & BIT(TX)) +
+			    !!(ssi->streams & BIT(RX));
 
 	if (nr_active_streams - 1 > 0)
 		keep_active = 1;
@@ -474,6 +475,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 					      keep_active);
 		/* Safely disable SCR register for the stream */
 		regmap_update_bits(regs, REG_SSI_SCR, scr, 0);
+
+		/* Log the disabled stream to the mask */
+		ssi->streams &= ~BIT(dir);
 	}
 
 	/*
@@ -549,6 +553,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		}
 		/* Enable all remaining bits */
 		regmap_update_bits(regs, REG_SSI_SCR, vals->scr, vals->scr);
+
+		/* Log the enabled stream to the mask */
+		ssi->streams |= BIT(dir);
 	}
 }
 
-- 
2.7.4

[PATCH v5 05/17] ASoC: fsl_ssi: Rename fsl_ssi_disable_val macro

[Nicolin Chen]

The define of fsl_ssi_disable_val is not so clear as it mixes two
steps of calculations together. And those parameter names are also
a bit long to read.

Since it just tries to exclude the shared bits from the regvals of
current stream while the opposite stream is active, it's better to
use something like ssi_excl_shared_bits.

This patch also bisects fsl_ssi_disable_val into two macros of two
corresponding steps and then shortens its parameter names. It also
updates callers in the fsl_ssi_config() accordingly.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced !dir with int adir

 sound/soc/fsl/fsl_ssi.c | 55 +++++++++++++++++++++----------------------------
 1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 51e7405..bbeef71 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -421,24 +421,24 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 }
 
 /**
- * Calculate the bits that have to be disabled for the current stream that is
- * getting disabled. This keeps the bits enabled that are necessary for the
- * second stream to work if 'stream_active' is true.
+ * Exclude bits that are used by the opposite stream
  *
- * Detailed calculation:
- * These are the values that need to be active after disabling. For non-active
- * second stream, this is 0:
- *	vals_stream * !!stream_active
+ * When both streams are active, disabling some bits for the current stream
+ * might break the other stream if these bits are used by it.
  *
- * The following computes the overall differences between the setup for the
- * to-disable stream and the active stream, a simple XOR:
- *	vals_disable ^ (vals_stream * !!(stream_active))
+ * @vals : regvals of the current stream
+ * @avals: regvals of the opposite stream
+ * @aactive: active state of the opposite stream
  *
- * The full expression adds a mask on all values we care about
+ *  1) XOR vals and avals to get the differences if the other stream is active;
+ *     Otherwise, return current vals if the other stream is not active
+ *  2) AND the result of 1) with the current vals
  */
-#define fsl_ssi_disable_val(vals_disable, vals_stream, stream_active) \
-	((vals_disable) & \
-	 ((vals_disable) ^ ((vals_stream) * (u32)!!(stream_active))))
+#define _ssi_xor_shared_bits(vals, avals, aactive) \
+	((vals) ^ ((avals) * (aactive)))
+
+#define ssi_excl_shared_bits(vals, avals, aactive) \
+	((vals) & _ssi_xor_shared_bits(vals, avals, aactive))
 
 /**
  * Enable or disable SSI configuration.
@@ -446,19 +446,14 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
+	int adir = (&ssi->regvals[TX] == vals) ? RX : TX;
 	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
-	int nr_active_streams;
-	int keep_active;
-
-	nr_active_streams = !!(ssi->streams & BIT(TX)) +
-			    !!(ssi->streams & BIT(RX));
+	bool aactive;
 
-	if (nr_active_streams - 1 > 0)
-		keep_active = 1;
-	else
-		keep_active = 0;
+	/* Check if the opposite stream is active */
+	aactive = ssi->streams & BIT(adir);
 
 	/* Get the opposite direction to keep its values untouched */
 	if (&ssi->regvals[RX] == vals)
@@ -471,8 +466,7 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		 * To keep the other stream safe, exclude shared bits between
 		 * both streams, and get safe bits to disable current stream
 		 */
-		u32 scr = fsl_ssi_disable_val(vals->scr, avals->scr,
-					      keep_active);
+		u32 scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
 		/* Safely disable SCR register for the stream */
 		regmap_update_bits(regs, REG_SSI_SCR, scr, 0);
 
@@ -487,7 +481,7 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 	 * 2) Disable all remaining bits of both streams when last stream ends
 	 */
 	if (ssi->soc->offline_config) {
-		if ((enable && !nr_active_streams) || (!enable && !keep_active))
+		if ((enable && !ssi->streams) || (!enable && !aactive))
 			fsl_ssi_rxtx_config(ssi, enable);
 
 		goto config_done;
@@ -509,12 +503,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		 * To keep the other stream safe, exclude shared bits between
 		 * both streams, and get safe bits to disable current stream
 		 */
-		sier = fsl_ssi_disable_val(vals->sier, avals->sier,
-					   keep_active);
-		srcr = fsl_ssi_disable_val(vals->srcr, avals->srcr,
-					   keep_active);
-		stcr = fsl_ssi_disable_val(vals->stcr, avals->stcr,
-					   keep_active);
+		sier = ssi_excl_shared_bits(vals->sier, avals->sier, aactive);
+		srcr = ssi_excl_shared_bits(vals->srcr, avals->srcr, aactive);
+		stcr = ssi_excl_shared_bits(vals->stcr, avals->stcr, aactive);
 
 		/* Safely disable other control registers for the stream */
 		regmap_update_bits(regs, REG_SSI_SRCR, srcr, 0);
-- 
2.7.4

[PATCH v5 05/17] ASoC: fsl_ssi: Rename fsl_ssi_disable_val macro

[Nicolin Chen]

The define of fsl_ssi_disable_val is not so clear as it mixes two
steps of calculations together. And those parameter names are also
a bit long to read.

Since it just tries to exclude the shared bits from the regvals of
current stream while the opposite stream is active, it's better to
use something like ssi_excl_shared_bits.

This patch also bisects fsl_ssi_disable_val into two macros of two
corresponding steps and then shortens its parameter names. It also
updates callers in the fsl_ssi_config() accordingly.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced !dir with int adir

 sound/soc/fsl/fsl_ssi.c | 55 +++++++++++++++++++++----------------------------
 1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 51e7405..bbeef71 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -421,24 +421,24 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 }
 
 /**
- * Calculate the bits that have to be disabled for the current stream that is
- * getting disabled. This keeps the bits enabled that are necessary for the
- * second stream to work if 'stream_active' is true.
+ * Exclude bits that are used by the opposite stream
  *
- * Detailed calculation:
- * These are the values that need to be active after disabling. For non-active
- * second stream, this is 0:
- *	vals_stream * !!stream_active
+ * When both streams are active, disabling some bits for the current stream
+ * might break the other stream if these bits are used by it.
  *
- * The following computes the overall differences between the setup for the
- * to-disable stream and the active stream, a simple XOR:
- *	vals_disable ^ (vals_stream * !!(stream_active))
+ * @vals : regvals of the current stream
+ * @avals: regvals of the opposite stream
+ * @aactive: active state of the opposite stream
  *
- * The full expression adds a mask on all values we care about
+ *  1) XOR vals and avals to get the differences if the other stream is active;
+ *     Otherwise, return current vals if the other stream is not active
+ *  2) AND the result of 1) with the current vals
  */
-#define fsl_ssi_disable_val(vals_disable, vals_stream, stream_active) \
-	((vals_disable) & \
-	 ((vals_disable) ^ ((vals_stream) * (u32)!!(stream_active))))
+#define _ssi_xor_shared_bits(vals, avals, aactive) \
+	((vals) ^ ((avals) * (aactive)))
+
+#define ssi_excl_shared_bits(vals, avals, aactive) \
+	((vals) & _ssi_xor_shared_bits(vals, avals, aactive))
 
 /**
  * Enable or disable SSI configuration.
@@ -446,19 +446,14 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
+	int adir = (&ssi->regvals[TX] == vals) ? RX : TX;
 	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
-	int nr_active_streams;
-	int keep_active;
-
-	nr_active_streams = !!(ssi->streams & BIT(TX)) +
-			    !!(ssi->streams & BIT(RX));
+	bool aactive;
 
-	if (nr_active_streams - 1 > 0)
-		keep_active = 1;
-	else
-		keep_active = 0;
+	/* Check if the opposite stream is active */
+	aactive = ssi->streams & BIT(adir);
 
 	/* Get the opposite direction to keep its values untouched */
 	if (&ssi->regvals[RX] == vals)
@@ -471,8 +466,7 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		 * To keep the other stream safe, exclude shared bits between
 		 * both streams, and get safe bits to disable current stream
 		 */
-		u32 scr = fsl_ssi_disable_val(vals->scr, avals->scr,
-					      keep_active);
+		u32 scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
 		/* Safely disable SCR register for the stream */
 		regmap_update_bits(regs, REG_SSI_SCR, scr, 0);
 
@@ -487,7 +481,7 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 	 * 2) Disable all remaining bits of both streams when last stream ends
 	 */
 	if (ssi->soc->offline_config) {
-		if ((enable && !nr_active_streams) || (!enable && !keep_active))
+		if ((enable && !ssi->streams) || (!enable && !aactive))
 			fsl_ssi_rxtx_config(ssi, enable);
 
 		goto config_done;
@@ -509,12 +503,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		 * To keep the other stream safe, exclude shared bits between
 		 * both streams, and get safe bits to disable current stream
 		 */
-		sier = fsl_ssi_disable_val(vals->sier, avals->sier,
-					   keep_active);
-		srcr = fsl_ssi_disable_val(vals->srcr, avals->srcr,
-					   keep_active);
-		stcr = fsl_ssi_disable_val(vals->stcr, avals->stcr,
-					   keep_active);
+		sier = ssi_excl_shared_bits(vals->sier, avals->sier, aactive);
+		srcr = ssi_excl_shared_bits(vals->srcr, avals->srcr, aactive);
+		stcr = ssi_excl_shared_bits(vals->stcr, avals->stcr, aactive);
 
 		/* Safely disable other control registers for the stream */
 		regmap_update_bits(regs, REG_SSI_SRCR, srcr, 0);
-- 
2.7.4

[PATCH v5 06/17] ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()

[Nicolin Chen]

The FIFO clear helper function is just one line of code now.
So it could be cleaned up by removing it and calling regmap
directly.

Meanwhile, FIFO clear could be applied to all use cases, not
confined to AC97. So this patch also moves FIFO clear in the
trigger() to fsl_ssi_config() and removes the AC97 check.

Note that SOR register is safe from offline_config HW limit.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced "bool dir" with "int dir" and "int adir"
v2
 * Replaced bool tx with bool dir

 sound/soc/fsl/fsl_ssi.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index bbeef71..a2ac92f 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -410,17 +410,6 @@ static void fsl_ssi_rxtx_config(struct fsl_ssi *ssi, bool enable)
 }
 
 /**
- * Clear remaining data in the FIFO to avoid dirty data or channel slipping
- */
-static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
-{
-	bool tx = !is_rx;
-
-	regmap_update_bits(ssi->regs, REG_SSI_SOR,
-			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
-}
-
-/**
  * Exclude bits that are used by the opposite stream
  *
  * When both streams are active, disabling some bits for the current stream
@@ -446,10 +435,11 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
-	int adir = (&ssi->regvals[TX] == vals) ? RX : TX;
-	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
+	bool tx = &ssi->regvals[TX] == vals;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
+	int adir = tx ? RX : TX;
+	int dir = tx ? TX : RX;
 	bool aactive;
 
 	/* Check if the opposite stream is active */
@@ -489,7 +479,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 
 	/* Online configure single direction while SSI is running */
 	if (enable) {
-		fsl_ssi_fifo_clear(ssi, vals->scr & SSI_SCR_RE);
+		/* Clear FIFO to prevent dirty data or channel slipping */
+		regmap_update_bits(ssi->regs, REG_SSI_SOR,
+				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 
 		regmap_update_bits(regs, REG_SSI_SRCR, vals->srcr, vals->srcr);
 		regmap_update_bits(regs, REG_SSI_STCR, vals->stcr, vals->stcr);
@@ -511,6 +503,10 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		regmap_update_bits(regs, REG_SSI_SRCR, srcr, 0);
 		regmap_update_bits(regs, REG_SSI_STCR, stcr, 0);
 		regmap_update_bits(regs, REG_SSI_SIER, sier, 0);
+
+		/* Clear FIFO to prevent dirty data or channel slipping */
+		regmap_update_bits(ssi->regs, REG_SSI_SOR,
+				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 	}
 
 config_done:
@@ -1091,7 +1087,6 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(rtd->cpu_dai);
-	struct regmap *regs = ssi->regs;
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
@@ -1116,14 +1111,6 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 		return -EINVAL;
 	}
 
-	/* Clear corresponding FIFO */
-	if (fsl_ssi_is_ac97(ssi)) {
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-			regmap_write(regs, REG_SSI_SOR, SSI_SOR_TX_CLR);
-		else
-			regmap_write(regs, REG_SSI_SOR, SSI_SOR_RX_CLR);
-	}
-
 	return 0;
 }
 
-- 
2.7.4

[PATCH v5 06/17] ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()

[Nicolin Chen]

The FIFO clear helper function is just one line of code now.
So it could be cleaned up by removing it and calling regmap
directly.

Meanwhile, FIFO clear could be applied to all use cases, not
confined to AC97. So this patch also moves FIFO clear in the
trigger() to fsl_ssi_config() and removes the AC97 check.

Note that SOR register is safe from offline_config HW limit.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Replaced "bool dir" with "int dir" and "int adir"
v2
 * Replaced bool tx with bool dir

 sound/soc/fsl/fsl_ssi.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index bbeef71..a2ac92f 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -410,17 +410,6 @@ static void fsl_ssi_rxtx_config(struct fsl_ssi *ssi, bool enable)
 }
 
 /**
- * Clear remaining data in the FIFO to avoid dirty data or channel slipping
- */
-static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
-{
-	bool tx = !is_rx;
-
-	regmap_update_bits(ssi->regs, REG_SSI_SOR,
-			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
-}
-
-/**
  * Exclude bits that are used by the opposite stream
  *
  * When both streams are active, disabling some bits for the current stream
@@ -446,10 +435,11 @@ static void fsl_ssi_fifo_clear(struct fsl_ssi *ssi, bool is_rx)
 static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 			   struct fsl_ssi_regvals *vals)
 {
-	int adir = (&ssi->regvals[TX] == vals) ? RX : TX;
-	int dir = (&ssi->regvals[TX] == vals) ? TX : RX;
+	bool tx = &ssi->regvals[TX] == vals;
 	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *avals;
+	int adir = tx ? RX : TX;
+	int dir = tx ? TX : RX;
 	bool aactive;
 
 	/* Check if the opposite stream is active */
@@ -489,7 +479,9 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 
 	/* Online configure single direction while SSI is running */
 	if (enable) {
-		fsl_ssi_fifo_clear(ssi, vals->scr & SSI_SCR_RE);
+		/* Clear FIFO to prevent dirty data or channel slipping */
+		regmap_update_bits(ssi->regs, REG_SSI_SOR,
+				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 
 		regmap_update_bits(regs, REG_SSI_SRCR, vals->srcr, vals->srcr);
 		regmap_update_bits(regs, REG_SSI_STCR, vals->stcr, vals->stcr);
@@ -511,6 +503,10 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		regmap_update_bits(regs, REG_SSI_SRCR, srcr, 0);
 		regmap_update_bits(regs, REG_SSI_STCR, stcr, 0);
 		regmap_update_bits(regs, REG_SSI_SIER, sier, 0);
+
+		/* Clear FIFO to prevent dirty data or channel slipping */
+		regmap_update_bits(ssi->regs, REG_SSI_SOR,
+				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 	}
 
 config_done:
@@ -1091,7 +1087,6 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(rtd->cpu_dai);
-	struct regmap *regs = ssi->regs;
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
@@ -1116,14 +1111,6 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 		return -EINVAL;
 	}
 
-	/* Clear corresponding FIFO */
-	if (fsl_ssi_is_ac97(ssi)) {
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-			regmap_write(regs, REG_SSI_SOR, SSI_SOR_TX_CLR);
-		else
-			regmap_write(regs, REG_SSI_SOR, SSI_SOR_RX_CLR);
-	}
-
 	return 0;
 }
 
-- 
2.7.4

[PATCH v5 07/17] ASoC: fsl_ssi: Clean up helper functions of trigger()

[Nicolin Chen]

The trigger() calls fsl_ssi_tx_config() and fsl_ssi_rx_config(),
and both of them jump to fsl_ssi_config(). And fsl_ssi_config()
later calls another fsl_ssi_rxtx_config().

However, the whole routine, especially fsl_ssi_config() function,
is too complicated because of the folowing reasons:
1) It has to handle the concern of the opposite stream.
2) It has to handle cases of offline configurations support.
3) It has to handle enable and disable operations while they're
   mostly different.

Since the enable and disable routines have more differences than
TX and RX rountines, this patch simplifies these helper functions
with the following changes:
- Changing to two helper functions of enable and disable instead
  of TX and RX.
- Removing fsl_ssi_rxtx_config() by separately integrating it to
  two newly introduced enable & disable functions.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 256 +++++++++++++++++++++++-------------------------
 1 file changed, 122 insertions(+), 134 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index a2ac92f..7a6a32b 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -382,31 +382,83 @@ static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
 }
 
 /**
- * Enable or disable all rx/tx config flags at once
+ * Set SCR, SIER, STCR and SRCR registers with cached values in regvals
+ *
+ * Notes:
+ * 1) For offline_config SoCs, enable all necessary bits of both streams
+ *    when 1st stream starts, even if the opposite stream will not start
+ * 2) It also clears FIFO before setting regvals; SOR is safe to set online
  */
-static void fsl_ssi_rxtx_config(struct fsl_ssi *ssi, bool enable)
+static void fsl_ssi_config_enable(struct fsl_ssi *ssi, bool tx)
 {
-	struct regmap *regs = ssi->regs;
 	struct fsl_ssi_regvals *vals = ssi->regvals;
+	int dir = tx ? TX : RX;
+	u32 sier, srcr, stcr;
 
-	if (enable) {
-		regmap_update_bits(regs, REG_SSI_SIER,
-				   vals[RX].sier | vals[TX].sier,
-				   vals[RX].sier | vals[TX].sier);
-		regmap_update_bits(regs, REG_SSI_SRCR,
-				   vals[RX].srcr | vals[TX].srcr,
-				   vals[RX].srcr | vals[TX].srcr);
-		regmap_update_bits(regs, REG_SSI_STCR,
-				   vals[RX].stcr | vals[TX].stcr,
-				   vals[RX].stcr | vals[TX].stcr);
+	/* Clear dirty data in the FIFO; It also prevents channel slipping */
+	regmap_update_bits(ssi->regs, REG_SSI_SOR,
+			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
+
+	/*
+	 * On offline_config SoCs, SxCR and SIER are already configured when
+	 * the previous stream started. So skip all SxCR and SIER settings
+	 * to prevent online reconfigurations, then jump to set SCR directly
+	 */
+	if (ssi->soc->offline_config && ssi->streams)
+		goto enable_scr;
+
+	if (ssi->soc->offline_config) {
+		/*
+		 * Online reconfiguration not supported, so enable all bits for
+		 * both streams at once to avoid necessity of reconfigurations
+		 */
+		srcr = vals[RX].srcr | vals[TX].srcr;
+		stcr = vals[RX].stcr | vals[TX].stcr;
+		sier = vals[RX].sier | vals[TX].sier;
 	} else {
-		regmap_update_bits(regs, REG_SSI_SRCR,
-				   vals[RX].srcr | vals[TX].srcr, 0);
-		regmap_update_bits(regs, REG_SSI_STCR,
-				   vals[RX].stcr | vals[TX].stcr, 0);
-		regmap_update_bits(regs, REG_SSI_SIER,
-				   vals[RX].sier | vals[TX].sier, 0);
+		/* Otherwise, only set bits for the current stream */
+		srcr = vals[dir].srcr;
+		stcr = vals[dir].stcr;
+		sier = vals[dir].sier;
 	}
+
+	/* Configure SRCR, STCR and SIER at once */
+	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, srcr);
+	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, stcr);
+	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, sier);
+
+enable_scr:
+	/*
+	 * Start DMA before setting TE to avoid FIFO underrun
+	 * which may cause a channel slip or a channel swap
+	 *
+	 * TODO: FIQ cases might also need this upon testing
+	 */
+	if (ssi->use_dma && tx) {
+		int try = 100;
+		u32 sfcsr;
+
+		/* Enable SSI first to send TX DMA request */
+		regmap_update_bits(ssi->regs, REG_SSI_SCR,
+				   SSI_SCR_SSIEN, SSI_SCR_SSIEN);
+
+		/* Busy wait until TX FIFO not empty -- DMA working */
+		do {
+			regmap_read(ssi->regs, REG_SSI_SFCSR, &sfcsr);
+			if (SSI_SFCSR_TFCNT0(sfcsr))
+				break;
+		} while (--try);
+
+		/* FIFO still empty -- something might be wrong */
+		if (!SSI_SFCSR_TFCNT0(sfcsr))
+			dev_warn(ssi->dev, "Timeout waiting TX FIFO filling\n");
+	}
+	/* Enable all remaining bits in SCR */
+	regmap_update_bits(ssi->regs, REG_SSI_SCR,
+			   vals[dir].scr, vals[dir].scr);
+
+	/* Log the enabled stream to the mask */
+	ssi->streams |= BIT(dir);
 }
 
 /**
@@ -430,14 +482,17 @@ static void fsl_ssi_rxtx_config(struct fsl_ssi *ssi, bool enable)
 	((vals) & _ssi_xor_shared_bits(vals, avals, aactive))
 
 /**
- * Enable or disable SSI configuration.
+ * Unset SCR, SIER, STCR and SRCR registers with cached values in regvals
+ *
+ * Notes:
+ * 1) For offline_config SoCs, to avoid online reconfigurations, disable all
+ *    bits of both streams at once when the last stream is abort to end
+ * 2) It also clears FIFO after unsetting regvals; SOR is safe to set online
  */
-static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
-			   struct fsl_ssi_regvals *vals)
+static void fsl_ssi_config_disable(struct fsl_ssi *ssi, bool tx)
 {
-	bool tx = &ssi->regvals[TX] == vals;
-	struct regmap *regs = ssi->regs;
-	struct fsl_ssi_regvals *avals;
+	struct fsl_ssi_regvals *vals, *avals;
+	u32 sier, srcr, stcr, scr;
 	int adir = tx ? RX : TX;
 	int dir = tx ? TX : RX;
 	bool aactive;
@@ -445,52 +500,36 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 	/* Check if the opposite stream is active */
 	aactive = ssi->streams & BIT(adir);
 
-	/* Get the opposite direction to keep its values untouched */
-	if (&ssi->regvals[RX] == vals)
-		avals = &ssi->regvals[TX];
-	else
-		avals = &ssi->regvals[RX];
+	vals = &ssi->regvals[dir];
 
-	if (!enable) {
-		/*
-		 * To keep the other stream safe, exclude shared bits between
-		 * both streams, and get safe bits to disable current stream
-		 */
-		u32 scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
-		/* Safely disable SCR register for the stream */
-		regmap_update_bits(regs, REG_SSI_SCR, scr, 0);
-
-		/* Log the disabled stream to the mask */
-		ssi->streams &= ~BIT(dir);
-	}
+	/* Get regvals of the opposite stream to keep opposite stream safe */
+	avals = &ssi->regvals[adir];
 
 	/*
-	 * For cases where online configuration is not supported,
-	 * 1) Enable all necessary bits of both streams when 1st stream starts
-	 *    even if the opposite stream will not start
-	 * 2) Disable all remaining bits of both streams when last stream ends
+	 * To keep the other stream safe, exclude shared bits between
+	 * both streams, and get safe bits to disable current stream
 	 */
-	if (ssi->soc->offline_config) {
-		if ((enable && !ssi->streams) || (!enable && !aactive))
-			fsl_ssi_rxtx_config(ssi, enable);
+	scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
 
-		goto config_done;
-	}
+	/* Disable safe bits of SCR register for the current stream */
+	regmap_update_bits(ssi->regs, REG_SSI_SCR, scr, 0);
 
-	/* Online configure single direction while SSI is running */
-	if (enable) {
-		/* Clear FIFO to prevent dirty data or channel slipping */
-		regmap_update_bits(ssi->regs, REG_SSI_SOR,
-				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
+	/* Log the disabled stream to the mask */
+	ssi->streams &= ~BIT(dir);
 
-		regmap_update_bits(regs, REG_SSI_SRCR, vals->srcr, vals->srcr);
-		regmap_update_bits(regs, REG_SSI_STCR, vals->stcr, vals->stcr);
-		regmap_update_bits(regs, REG_SSI_SIER, vals->sier, vals->sier);
-	} else {
-		u32 sier;
-		u32 srcr;
-		u32 stcr;
+	/*
+	 * On offline_config SoCs, if the other stream is active, skip
+	 * SxCR and SIER settings to prevent online reconfigurations
+	 */
+	if (ssi->soc->offline_config && aactive)
+		goto fifo_clear;
 
+	if (ssi->soc->offline_config) {
+		/* Now there is only current stream active, disable all bits */
+		srcr = vals->srcr | avals->srcr;
+		stcr = vals->stcr | avals->stcr;
+		sier = vals->sier | avals->sier;
+	} else {
 		/*
 		 * To keep the other stream safe, exclude shared bits between
 		 * both streams, and get safe bits to disable current stream
@@ -498,57 +537,17 @@ static void fsl_ssi_config(struct fsl_ssi *ssi, bool enable,
 		sier = ssi_excl_shared_bits(vals->sier, avals->sier, aactive);
 		srcr = ssi_excl_shared_bits(vals->srcr, avals->srcr, aactive);
 		stcr = ssi_excl_shared_bits(vals->stcr, avals->stcr, aactive);
-
-		/* Safely disable other control registers for the stream */
-		regmap_update_bits(regs, REG_SSI_SRCR, srcr, 0);
-		regmap_update_bits(regs, REG_SSI_STCR, stcr, 0);
-		regmap_update_bits(regs, REG_SSI_SIER, sier, 0);
-
-		/* Clear FIFO to prevent dirty data or channel slipping */
-		regmap_update_bits(ssi->regs, REG_SSI_SOR,
-				   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 	}
 
-config_done:
-	/* Enabling of subunits is done after configuration */
-	if (enable) {
-		/*
-		 * Start DMA before setting TE to avoid FIFO underrun
-		 * which may cause a channel slip or a channel swap
-		 *
-		 * TODO: FIQ cases might also need this upon testing
-		 */
-		if (ssi->use_dma && (vals->scr & SSI_SCR_TE)) {
-			int i;
-			int max_loop = 100;
-
-			/* Enable SSI first to send TX DMA request */
-			regmap_update_bits(regs, REG_SSI_SCR,
-					   SSI_SCR_SSIEN, SSI_SCR_SSIEN);
-
-			/* Busy wait until TX FIFO not empty -- DMA working */
-			for (i = 0; i < max_loop; i++) {
-				u32 sfcsr;
-				regmap_read(regs, REG_SSI_SFCSR, &sfcsr);
-				if (SSI_SFCSR_TFCNT0(sfcsr))
-					break;
-			}
-			if (i == max_loop) {
-				dev_err(ssi->dev,
-					"Timeout waiting TX FIFO filling\n");
-			}
-		}
-		/* Enable all remaining bits */
-		regmap_update_bits(regs, REG_SSI_SCR, vals->scr, vals->scr);
-
-		/* Log the enabled stream to the mask */
-		ssi->streams |= BIT(dir);
-	}
-}
+	/* Clear configurations of SRCR, STCR and SIER at once */
+	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, 0);
+	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, 0);
+	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, 0);
 
-static void fsl_ssi_rx_config(struct fsl_ssi *ssi, bool enable)
-{
-	fsl_ssi_config(ssi, enable, &ssi->regvals[RX]);
+fifo_clear:
+	/* Clear remaining data in the FIFO */
+	regmap_update_bits(ssi->regs, REG_SSI_SOR,
+			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
 }
 
 static void fsl_ssi_tx_ac97_saccst_setup(struct fsl_ssi *ssi)
@@ -564,21 +563,6 @@ static void fsl_ssi_tx_ac97_saccst_setup(struct fsl_ssi *ssi)
 	}
 }
 
-static void fsl_ssi_tx_config(struct fsl_ssi *ssi, bool enable)
-{
-	/*
-	 * SACCST might be modified via AC Link by a CODEC if it sends
-	 * extra bits in their SLOTREQ requests, which'll accidentally
-	 * send valid data to slots other than normal playback slots.
-	 *
-	 * To be safe, configure SACCST right before TX starts.
-	 */
-	if (enable && fsl_ssi_is_ac97(ssi))
-		fsl_ssi_tx_ac97_saccst_setup(ssi);
-
-	fsl_ssi_config(ssi, enable, &ssi->regvals[TX]);
-}
-
 /**
  * Cache critical bits of SIER, SRCR, STCR and SCR to later set them safely
  */
@@ -1087,24 +1071,28 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-			fsl_ssi_tx_config(ssi, true);
-		else
-			fsl_ssi_rx_config(ssi, true);
+		/*
+		 * SACCST might be modified via AC Link by a CODEC if it sends
+		 * extra bits in their SLOTREQ requests, which'll accidentally
+		 * send valid data to slots other than normal playback slots.
+		 *
+		 * To be safe, configure SACCST right before TX starts.
+		 */
+		if (tx && fsl_ssi_is_ac97(ssi))
+			fsl_ssi_tx_ac97_saccst_setup(ssi);
+		fsl_ssi_config_enable(ssi, tx);
 		break;
 
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-			fsl_ssi_tx_config(ssi, false);
-		else
-			fsl_ssi_rx_config(ssi, false);
+		fsl_ssi_config_disable(ssi, tx);
 		break;
 
 	default:
-- 
2.7.4

[PATCH v5 08/17] ASoC: fsl_ssi: Add DAIFMT define for AC97

[Nicolin Chen]

The _fsl_ssi_set_dai_fmt() bypasses an undefined format for AC97
mode. However, it's not really necessary if AC97 has its complete
format defined.

So this patch adds a DAIFMT macro of complete format including a
clock direction and polarity.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 7a6a32b..b76a517 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -90,6 +90,16 @@
 	 SNDRV_PCM_FMTBIT_S24_LE)
 #endif
 
+/*
+ * In AC97 mode, TXDIR bit is forced to 0 and TFDIR bit is forced to 1:
+ *  - SSI inputs external bit clock and outputs frame sync clock -- CBM_CFS
+ *  - Also have NB_NF to mark these two clocks will not be inverted
+ */
+#define FSLSSI_AC97_DAIFMT \
+	(SND_SOC_DAIFMT_AC97 | \
+	 SND_SOC_DAIFMT_CBM_CFS | \
+	 SND_SOC_DAIFMT_NB_NF)
+
 #define FSLSSI_SIER_DBG_RX_FLAGS \
 	(SSI_SIER_RFF0_EN | \
 	 SSI_SIER_RLS_EN | \
@@ -964,8 +974,7 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 		scr &= ~SSI_SCR_SYS_CLK_EN;
 		break;
 	default:
-		if (!fsl_ssi_is_ac97(ssi))
-			return -EINVAL;
+		return -EINVAL;
 	}
 
 	stcr |= strcr;
@@ -1372,7 +1381,7 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	sprop = of_get_property(np, "fsl,mode", NULL);
 	if (sprop) {
 		if (!strcmp(sprop, "ac97-slave"))
-			ssi->dai_fmt = SND_SOC_DAIFMT_AC97;
+			ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
 	}
 
 	/* Select DMA or FIQ */
-- 
2.7.4

[PATCH v5 09/17] ASoC: fsl_ssi: Clean up fsl_ssi_setup_regvals()

[Nicolin Chen]

This patch cleans fsl_ssi_setup_regvals() by following changes:
1) Moving DBG bits to the first lines.
2) Setting SSIE, RE/TE as default and cleaning it for AC97

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index b76a517..e5efee2 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -580,18 +580,16 @@ static void fsl_ssi_setup_regvals(struct fsl_ssi *ssi)
 {
 	struct fsl_ssi_regvals *vals = ssi->regvals;
 
-	vals[RX].sier = SSI_SIER_RFF0_EN;
+	vals[RX].sier = SSI_SIER_RFF0_EN | FSLSSI_SIER_DBG_RX_FLAGS;
 	vals[RX].srcr = SSI_SRCR_RFEN0;
-	vals[RX].scr = 0;
-	vals[TX].sier = SSI_SIER_TFE0_EN;
+	vals[RX].scr = SSI_SCR_SSIEN | SSI_SCR_RE;
+	vals[TX].sier = SSI_SIER_TFE0_EN | FSLSSI_SIER_DBG_TX_FLAGS;
 	vals[TX].stcr = SSI_STCR_TFEN0;
-	vals[TX].scr = 0;
+	vals[TX].scr = SSI_SCR_SSIEN | SSI_SCR_TE;
 
 	/* AC97 has already enabled SSIEN, RE and TE, so ignore them */
-	if (!fsl_ssi_is_ac97(ssi)) {
-		vals[RX].scr = SSI_SCR_SSIEN | SSI_SCR_RE;
-		vals[TX].scr = SSI_SCR_SSIEN | SSI_SCR_TE;
-	}
+	if (fsl_ssi_is_ac97(ssi))
+		vals[RX].scr = vals[TX].scr = 0;
 
 	if (ssi->use_dma) {
 		vals[RX].sier |= SSI_SIER_RDMAE;
@@ -600,9 +598,6 @@ static void fsl_ssi_setup_regvals(struct fsl_ssi *ssi)
 		vals[RX].sier |= SSI_SIER_RIE;
 		vals[TX].sier |= SSI_SIER_TIE;
 	}
-
-	vals[RX].sier |= FSLSSI_SIER_DBG_RX_FLAGS;
-	vals[TX].sier |= FSLSSI_SIER_DBG_TX_FLAGS;
 }
 
 static void fsl_ssi_setup_ac97(struct fsl_ssi *ssi)
-- 
2.7.4

[PATCH v5 10/17] ASoC: fsl_ssi: Set xFEN0 and xFEN1 together

[Nicolin Chen]

It'd be safer to enable both FIFOs for TX or RX at the same time.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index e5efee2..ba06e94 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -591,6 +591,11 @@ static void fsl_ssi_setup_regvals(struct fsl_ssi *ssi)
 	if (fsl_ssi_is_ac97(ssi))
 		vals[RX].scr = vals[TX].scr = 0;
 
+	if (ssi->use_dual_fifo) {
+		vals[RX].srcr |= SSI_SRCR_RFEN1;
+		vals[TX].stcr |= SSI_STCR_TFEN1;
+	}
+
 	if (ssi->use_dma) {
 		vals[RX].sier |= SSI_SIER_RDMAE;
 		vals[TX].sier |= SSI_SIER_TDMAE;
@@ -991,14 +996,9 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 		     SSI_SFCSR_TFWM0(wm) | SSI_SFCSR_RFWM0(wm) |
 		     SSI_SFCSR_TFWM1(wm) | SSI_SFCSR_RFWM1(wm));
 
-	if (ssi->use_dual_fifo) {
-		regmap_update_bits(regs, REG_SSI_SRCR,
-				   SSI_SRCR_RFEN1, SSI_SRCR_RFEN1);
-		regmap_update_bits(regs, REG_SSI_STCR,
-				   SSI_STCR_TFEN1, SSI_STCR_TFEN1);
+	if (ssi->use_dual_fifo)
 		regmap_update_bits(regs, REG_SSI_SCR,
 				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
-	}
 
 	if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_AC97)
 		fsl_ssi_setup_ac97(ssi);
-- 
2.7.4

[PATCH v5 11/17] ASoC: fsl_ssi: Use snd_soc_init_dma_data instead

[Nicolin Chen]

Since there is a helper function, use it to help readability.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index ba06e94..e1fe511 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -1110,10 +1110,9 @@ static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
 {
 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
 
-	if (ssi->soc->imx && ssi->use_dma) {
-		dai->playback_dma_data = &ssi->dma_params_tx;
-		dai->capture_dma_data = &ssi->dma_params_rx;
-	}
+	if (ssi->soc->imx && ssi->use_dma)
+		snd_soc_dai_init_dma_data(dai, &ssi->dma_params_tx,
+					  &ssi->dma_params_rx);
 
 	return 0;
 }
-- 
2.7.4

[PATCH v5 12/17] ASoC: fsl_ssi: Move one-time configurations to probe()

[Nicolin Chen]

The probe() could handle some one-time configurations since
they will not be changed once being configured.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v2
 * Moved all to fsl_ssi_hw_init() in platform probe()

 sound/soc/fsl/fsl_ssi.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index e1fe511..50648f5 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -865,7 +865,6 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 {
 	struct regmap *regs = ssi->regs;
 	u32 strcr = 0, stcr, srcr, scr, mask;
-	u8 wm;
 
 	ssi->dai_fmt = fmt;
 
@@ -874,8 +873,6 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 		return -EINVAL;
 	}
 
-	fsl_ssi_setup_regvals(ssi);
-
 	regmap_read(regs, REG_SSI_SCR, &scr);
 	scr &= ~(SSI_SCR_SYN | SSI_SCR_I2S_MODE_MASK);
 	/* Synchronize frame sync clock for TE to avoid data slipping */
@@ -990,16 +987,6 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 	regmap_write(regs, REG_SSI_SRCR, srcr);
 	regmap_write(regs, REG_SSI_SCR, scr);
 
-	wm = ssi->fifo_watermark;
-
-	regmap_write(regs, REG_SSI_SFCSR,
-		     SSI_SFCSR_TFWM0(wm) | SSI_SFCSR_RFWM0(wm) |
-		     SSI_SFCSR_TFWM1(wm) | SSI_SFCSR_RFWM1(wm));
-
-	if (ssi->use_dual_fifo)
-		regmap_update_bits(regs, REG_SSI_SCR,
-				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
-
 	if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_AC97)
 		fsl_ssi_setup_ac97(ssi);
 
@@ -1249,6 +1236,29 @@ static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
 };
 
 /**
+ * Initialize SSI registers
+ */
+static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
+{
+	u32 wm = ssi->fifo_watermark;
+
+	/* Initialize regvals */
+	fsl_ssi_setup_regvals(ssi);
+
+	/* Set watermarks */
+	regmap_write(ssi->regs, REG_SSI_SFCSR,
+		     SSI_SFCSR_TFWM0(wm) | SSI_SFCSR_RFWM0(wm) |
+		     SSI_SFCSR_TFWM1(wm) | SSI_SFCSR_RFWM1(wm));
+
+	/* Enable Dual FIFO mode */
+	if (ssi->use_dual_fifo)
+		regmap_update_bits(ssi->regs, REG_SSI_SCR,
+				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
+
+	return 0;
+}
+
+/**
  * Make every character in a string lower-case
  */
 static void make_lowercase(char *s)
@@ -1533,6 +1543,9 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	if (ssi->dai_fmt)
 		_fsl_ssi_set_dai_fmt(dev, ssi, ssi->dai_fmt);
 
+	/* Initially configures SSI registers */
+	fsl_ssi_hw_init(ssi);
+
 	if (fsl_ssi_is_ac97(ssi)) {
 		u32 ssi_idx;
 
-- 
2.7.4

[PATCH v5 13/17] ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()

[Nicolin Chen]

AC97 configures most of registers earlier to start a communication
with CODECs in order to successfully initialize CODEC. Currently,
_fsl_ssi_set_dai_fmt() and fsl_ssi_setup_ac97() are called to get
all SSI registers properly set.

Since now the driver has a fsl_ssi_hw_init() to handle all register
initial settings, this patch moves those register settings of AC97
to the fsl_ssi_hw_init() as well.

Meanwhile it applies _fsl_ssi_set_dai_fmt() call to AC97 only since
other formats would be configured via normal set_dai_fmt() directly.

This patch also adds fsl_ssi_hw_clean() to cleanup control bits for
AC97 in the platform remote() function.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v5
 * Moved fsl_ssi_hw_clean() after unregister CODEC platform dev
 * For cleanup sequence, disabled TE and RE first while SSIEN at last
v2
 * Moved all to fsl_ssi_hw_init() in platform probe()
 * Added fsl_ssi_hw_clean() instead of dai remove()

 sound/soc/fsl/fsl_ssi.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 50648f5..d577f3d 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -987,9 +987,6 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 	regmap_write(regs, REG_SSI_SRCR, srcr);
 	regmap_write(regs, REG_SSI_SCR, scr);
 
-	if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_AC97)
-		fsl_ssi_setup_ac97(ssi);
-
 	return 0;
 }
 
@@ -1255,10 +1252,34 @@ static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
 				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
 
+	/* AC97 should start earlier to communicate with CODECs */
+	if (fsl_ssi_is_ac97(ssi)) {
+		_fsl_ssi_set_dai_fmt(ssi->dev, ssi, ssi->dai_fmt);
+		fsl_ssi_setup_ac97(ssi);
+	}
+
 	return 0;
 }
 
 /**
+ * Clear SSI registers
+ */
+static void fsl_ssi_hw_clean(struct fsl_ssi *ssi)
+{
+	/* Disable registers for AC97 */
+	if (fsl_ssi_is_ac97(ssi)) {
+		/* Disable TE and RE bits first */
+		regmap_update_bits(ssi->regs, REG_SSI_SCR,
+				   SSI_SCR_TE | SSI_SCR_RE, 0);
+		/* Disable AC97 mode */
+		regmap_write(ssi->regs, REG_SSI_SACNT, 0);
+		/* Unset WAIT bits */
+		regmap_write(ssi->regs, REG_SSI_SOR, 0);
+		/* Disable SSI -- software reset */
+		regmap_update_bits(ssi->regs, REG_SSI_SCR, SSI_SCR_SSIEN, 0);
+	}
+}
+/**
  * Make every character in a string lower-case
  */
 static void make_lowercase(char *s)
@@ -1540,9 +1561,6 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	}
 
 done:
-	if (ssi->dai_fmt)
-		_fsl_ssi_set_dai_fmt(dev, ssi, ssi->dai_fmt);
-
 	/* Initially configures SSI registers */
 	fsl_ssi_hw_init(ssi);
 
@@ -1592,6 +1610,9 @@ static int fsl_ssi_remove(struct platform_device *pdev)
 	if (ssi->pdev)
 		platform_device_unregister(ssi->pdev);
 
+	/* Clean up SSI registers */
+	fsl_ssi_hw_clean(ssi);
+
 	if (ssi->soc->imx)
 		fsl_ssi_imx_clean(pdev, ssi);
 
-- 
2.7.4

[PATCH v5 14/17] ASoC: fsl_ssi: Clean up _fsl_ssi_set_dai_fmt()

[Nicolin Chen]

The _fsl_ssi_set_dai_fmt() is a helper function being called from
fsl_ssi_set_dai_fmt() as an ASoC operation and fsl_ssi_hw_init()
mainly for AC97 format initialization.

This patch cleans the _fsl_ssi_set_dai_fmt() in following ways:
* Removing *dev pointer in the parameters as it's included in the
  *ssi pointer of struct fsl_ssi.
* Using regmap_update_bits() instead of regmap_read() with masking
  the value manually.
* Moving baudclk check to the switch-case routine to skip the I2S
  master check. And moving SxCCR.DC settings after baudclk check.
* Adding format settings for SND_SOC_DAIFMT_AC97 like others.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v4
 * Added TXBIT0 bit back to play safe
v3
 * Put CBM_CFS behind the baudclk check to keep the same program
   flow as before

 sound/soc/fsl/fsl_ssi.c | 74 +++++++++++++++++++++++--------------------------
 1 file changed, 35 insertions(+), 39 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index d577f3d..f29f3b0 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -860,42 +860,31 @@ static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-static int _fsl_ssi_set_dai_fmt(struct device *dev,
-				struct fsl_ssi *ssi, unsigned int fmt)
+static int _fsl_ssi_set_dai_fmt(struct fsl_ssi *ssi, unsigned int fmt)
 {
-	struct regmap *regs = ssi->regs;
-	u32 strcr = 0, stcr, srcr, scr, mask;
+	u32 strcr = 0, scr = 0, stcr, srcr, mask;
 
 	ssi->dai_fmt = fmt;
 
-	if (fsl_ssi_is_i2s_master(ssi) && IS_ERR(ssi->baudclk)) {
-		dev_err(dev, "missing baudclk for master mode\n");
-		return -EINVAL;
-	}
-
-	regmap_read(regs, REG_SSI_SCR, &scr);
-	scr &= ~(SSI_SCR_SYN | SSI_SCR_I2S_MODE_MASK);
 	/* Synchronize frame sync clock for TE to avoid data slipping */
 	scr |= SSI_SCR_SYNC_TX_FS;
 
-	mask = SSI_STCR_TXBIT0 | SSI_STCR_TFDIR | SSI_STCR_TXDIR |
-	       SSI_STCR_TSCKP | SSI_STCR_TFSI | SSI_STCR_TFSL | SSI_STCR_TEFS;
-	regmap_read(regs, REG_SSI_STCR, &stcr);
-	regmap_read(regs, REG_SSI_SRCR, &srcr);
-	stcr &= ~mask;
-	srcr &= ~mask;
+	/* Set to default shifting settings: LSB_ALIGNED */
+	strcr |= SSI_STCR_TXBIT0;
 
 	/* Use Network mode as default */
 	ssi->i2s_net = SSI_SCR_NET;
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
-		regmap_update_bits(regs, REG_SSI_STCCR,
-				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
-		regmap_update_bits(regs, REG_SSI_SRCCR,
-				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
-		case SND_SOC_DAIFMT_CBM_CFS:
 		case SND_SOC_DAIFMT_CBS_CFS:
+			if (IS_ERR(ssi->baudclk)) {
+				dev_err(ssi->dev,
+					"missing baudclk for master mode\n");
+				return -EINVAL;
+			}
+			/* fall through */
+		case SND_SOC_DAIFMT_CBM_CFS:
 			ssi->i2s_net |= SSI_SCR_I2S_MODE_MASTER;
 			break;
 		case SND_SOC_DAIFMT_CBM_CFM:
@@ -905,30 +894,34 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 			return -EINVAL;
 		}
 
+		regmap_update_bits(ssi->regs, REG_SSI_STCCR,
+				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
+		regmap_update_bits(ssi->regs, REG_SSI_SRCCR,
+				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
+
 		/* Data on rising edge of bclk, frame low, 1clk before data */
-		strcr |= SSI_STCR_TFSI | SSI_STCR_TSCKP |
-			 SSI_STCR_TXBIT0 | SSI_STCR_TEFS;
+		strcr |= SSI_STCR_TFSI | SSI_STCR_TSCKP | SSI_STCR_TEFS;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		/* Data on rising edge of bclk, frame high */
-		strcr |= SSI_STCR_TXBIT0 | SSI_STCR_TSCKP;
+		strcr |= SSI_STCR_TSCKP;
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
 		/* Data on rising edge of bclk, frame high, 1clk before data */
-		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP |
-			 SSI_STCR_TXBIT0 | SSI_STCR_TEFS;
+		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP | SSI_STCR_TEFS;
 		break;
 	case SND_SOC_DAIFMT_DSP_B:
 		/* Data on rising edge of bclk, frame high */
-		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP | SSI_STCR_TXBIT0;
+		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP;
 		break;
 	case SND_SOC_DAIFMT_AC97:
 		/* Data on falling edge of bclk, frame high, 1clk before data */
-		ssi->i2s_net |= SSI_SCR_I2S_MODE_NORMAL;
+		strcr |= SSI_STCR_TEFS;
 		break;
 	default:
 		return -EINVAL;
 	}
+
 	scr |= ssi->i2s_net;
 
 	/* DAI clock inversion */
@@ -962,20 +955,17 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 		break;
 	case SND_SOC_DAIFMT_CBM_CFM:
 		/* Input bit or frame sync clocks */
-		scr &= ~SSI_SCR_SYS_CLK_EN;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFS:
 		/* Input bit clock but output frame sync clock */
-		strcr &= ~SSI_STCR_TXDIR;
 		strcr |= SSI_STCR_TFDIR;
-		scr &= ~SSI_SCR_SYS_CLK_EN;
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	stcr |= strcr;
-	srcr |= strcr;
+	stcr = strcr;
+	srcr = strcr;
 
 	/* Set SYN mode and clear RXDIR bit when using SYN or AC97 mode */
 	if (ssi->cpu_dai_drv.symmetric_rates || fsl_ssi_is_ac97(ssi)) {
@@ -983,9 +973,15 @@ static int _fsl_ssi_set_dai_fmt(struct device *dev,
 		scr |= SSI_SCR_SYN;
 	}
 
-	regmap_write(regs, REG_SSI_STCR, stcr);
-	regmap_write(regs, REG_SSI_SRCR, srcr);
-	regmap_write(regs, REG_SSI_SCR, scr);
+	mask = SSI_STCR_TFDIR | SSI_STCR_TXDIR | SSI_STCR_TSCKP |
+	       SSI_STCR_TFSL | SSI_STCR_TFSI | SSI_STCR_TEFS | SSI_STCR_TXBIT0;
+
+	regmap_update_bits(ssi->regs, REG_SSI_STCR, mask, stcr);
+	regmap_update_bits(ssi->regs, REG_SSI_SRCR, mask, srcr);
+
+	mask = SSI_SCR_SYNC_TX_FS | SSI_SCR_I2S_MODE_MASK |
+	       SSI_SCR_SYS_CLK_EN | SSI_SCR_SYN;
+	regmap_update_bits(ssi->regs, REG_SSI_SCR, mask, scr);
 
 	return 0;
 }
@@ -1001,7 +997,7 @@ static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 	if (fsl_ssi_is_ac97(ssi))
 		return 0;
 
-	return _fsl_ssi_set_dai_fmt(dai->dev, ssi, fmt);
+	return _fsl_ssi_set_dai_fmt(ssi, fmt);
 }
 
 /**
@@ -1254,7 +1250,7 @@ static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
 
 	/* AC97 should start earlier to communicate with CODECs */
 	if (fsl_ssi_is_ac97(ssi)) {
-		_fsl_ssi_set_dai_fmt(ssi->dev, ssi, ssi->dai_fmt);
+		_fsl_ssi_set_dai_fmt(ssi, ssi->dai_fmt);
 		fsl_ssi_setup_ac97(ssi);
 	}
 
-- 
2.7.4

[PATCH v5 15/17] ASoC: fsl_ssi: Add bool synchronous to mark synchronous mode

[Nicolin Chen]

Using symmetric_rates in the cpu_dai_drv is a bit implicit,
so this patch adds a bool synchronous instead.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v3
 * Removed all cpu_dai_drv changes

 sound/soc/fsl/fsl_ssi.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index f29f3b0..7ce055c 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -217,6 +217,7 @@ struct fsl_ssi_soc_data {
  * @dai_fmt: DAI configuration this device is currently used with
  * @streams: Mask of current active streams: BIT(TX) and BIT(RX)
  * @i2s_net: I2S and Network mode configurations of SCR register
+ * @synchronous: Use synchronous mode - both of TX and RX use STCK and SFCK
  * @use_dma: DMA is used or FIQ with stream filter
  * @use_dual_fifo: DMA with support for dual FIFO mode
  * @has_ipg_clk_name: If "ipg" is in the clock name list of device tree
@@ -262,6 +263,7 @@ struct fsl_ssi {
 	unsigned int dai_fmt;
 	u8 streams;
 	u8 i2s_net;
+	bool synchronous;
 	bool use_dma;
 	bool use_dual_fifo;
 	bool has_ipg_clk_name;
@@ -673,7 +675,6 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
 	bool tx2, tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
 	struct regmap *regs = ssi->regs;
-	int synchronous = ssi->cpu_dai_drv.symmetric_rates, ret;
 	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
 	unsigned long clkrate, baudrate, tmprate;
 	unsigned int slots = params_channels(hw_params);
@@ -681,6 +682,7 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
 	u64 sub, savesub = 100000;
 	unsigned int freq;
 	bool baudclk_is_used;
+	int ret;
 
 	/* Override slots and slot_width if being specifically set... */
 	if (ssi->slots)
@@ -759,7 +761,7 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
 	mask = SSI_SxCCR_PM_MASK | SSI_SxCCR_DIV2 | SSI_SxCCR_PSR;
 
 	/* STCCR is used for RX in synchronous mode */
-	tx2 = tx || synchronous;
+	tx2 = tx || ssi->synchronous;
 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), mask, stccr);
 
 	if (!baudclk_is_used) {
@@ -807,7 +809,7 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
 	 * that should set separate configurations for STCCR and SRCCR
 	 * despite running in the synchronous mode.
 	 */
-	if (enabled && ssi->cpu_dai_drv.symmetric_rates)
+	if (enabled && ssi->synchronous)
 		return 0;
 
 	if (fsl_ssi_is_i2s_master(ssi)) {
@@ -839,7 +841,7 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	/* In synchronous mode, the SSI uses STCCR for capture */
-	tx2 = tx || ssi->cpu_dai_drv.symmetric_rates;
+	tx2 = tx || ssi->synchronous;
 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), SSI_SxCCR_WL_MASK, wl);
 
 	return 0;
@@ -968,7 +970,7 @@ static int _fsl_ssi_set_dai_fmt(struct fsl_ssi *ssi, unsigned int fmt)
 	srcr = strcr;
 
 	/* Set SYN mode and clear RXDIR bit when using SYN or AC97 mode */
-	if (ssi->cpu_dai_drv.symmetric_rates || fsl_ssi_is_ac97(ssi)) {
+	if (ssi->synchronous || fsl_ssi_is_ac97(ssi)) {
 		srcr &= ~SSI_SRCR_RXDIR;
 		scr |= SSI_SCR_SYN;
 	}
@@ -1456,6 +1458,7 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 		if (!fsl_ssi_is_ac97(ssi)) {
 			ssi->cpu_dai_drv.symmetric_rates = 1;
 			ssi->cpu_dai_drv.symmetric_samplebits = 1;
+			ssi->synchronous = true;
 		}
 
 		ssi->cpu_dai_drv.symmetric_channels = 1;
-- 
2.7.4

[PATCH v5 16/17] ASoC: fsl_ssi: Move DT related code to a separate probe()

[Nicolin Chen]

This patch cleans up probe() function by moving all Device Tree
related code into a separate function. It allows the probe() to
be Device Tree independent. This will be very useful for future
integration of imx-ssi driver which has similar functionalities
while exists only because it supports non-DT cases.

This patch also moves symmetric_channels of AC97 from the probe
to the structure snd_soc_dai_driver for simplification.

Additionally, since PowerPC and AC97 use the same pdev pointer
to register a platform device, this patch also unifies related
code.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
Changelog
v5
 * Uses NULL as the parent device as CODEC platform device with
   comments for the reason
 * Updated comments of three pointers for the platform_device
v4
 * Made bool synchronous exclusive with AC97 mode in PATCH-16

 sound/soc/fsl/fsl_ssi.c | 219 +++++++++++++++++++++++++++---------------------
 1 file changed, 124 insertions(+), 95 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 7ce055c..a8a040d 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -239,8 +239,12 @@ struct fsl_ssi_soc_data {
  *
  * @fiq_params: FIQ stream filtering parameters
  *
- * @pdev: Pointer to pdev when using fsl-ssi as sound card (ppc only)
- *        TODO: Should be replaced with simple-sound-card
+ * @card_pdev: Platform_device pointer to register a sound card for PowerPC or
+ *             to register a CODEC platform device for AC97
+ * @card_name: Platform_device name to register a sound card for PowerPC or
+ *             to register a CODEC platform device for AC97
+ * @card_idx: The index of SSI to register a sound card for PowerPC or
+ *            to register a CODEC platform device for AC97
  *
  * @dbg_stats: Debugging statistics
  *
@@ -285,7 +289,9 @@ struct fsl_ssi {
 
 	struct imx_pcm_fiq_params fiq_params;
 
-	struct platform_device *pdev;
+	struct platform_device *card_pdev;
+	char card_name[32];
+	u32 card_idx;
 
 	struct fsl_ssi_dbg dbg_stats;
 
@@ -1134,6 +1140,7 @@ static const struct snd_soc_component_driver fsl_ssi_component = {
 
 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
 	.bus_control = true,
+	.symmetric_channels = 1,
 	.probe = fsl_ssi_dai_probe,
 	.playback = {
 		.stream_name = "AC97 Playback",
@@ -1291,9 +1298,7 @@ static void make_lowercase(char *s)
 static int fsl_ssi_imx_probe(struct platform_device *pdev,
 			     struct fsl_ssi *ssi, void __iomem *iomem)
 {
-	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
-	u32 dmas[4];
 	int ret;
 
 	/* Backward compatible for a DT without ipg clock name assigned */
@@ -1327,14 +1332,8 @@ static int fsl_ssi_imx_probe(struct platform_device *pdev,
 	ssi->dma_params_tx.addr = ssi->ssi_phys + REG_SSI_STX0;
 	ssi->dma_params_rx.addr = ssi->ssi_phys + REG_SSI_SRX0;
 
-	/* Set to dual FIFO mode according to the SDMA sciprt */
-	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
-	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL) {
-		ssi->use_dual_fifo = true;
-		/*
-		 * Use even numbers to avoid channel swap due to SDMA
-		 * script design
-		 */
+	/* Use even numbers to avoid channel swap due to SDMA script design */
+	if (ssi->use_dual_fifo) {
 		ssi->dma_params_tx.maxburst &= ~0x1;
 		ssi->dma_params_rx.maxburst &= ~0x1;
 	}
@@ -1375,41 +1374,109 @@ static void fsl_ssi_imx_clean(struct platform_device *pdev, struct fsl_ssi *ssi)
 		clk_disable_unprepare(ssi->clk);
 }
 
-static int fsl_ssi_probe(struct platform_device *pdev)
+static int fsl_ssi_probe_from_dt(struct fsl_ssi *ssi)
 {
-	struct fsl_ssi *ssi;
-	int ret = 0;
-	struct device_node *np = pdev->dev.of_node;
-	struct device *dev = &pdev->dev;
+	struct device *dev = ssi->dev;
+	struct device_node *np = dev->of_node;
 	const struct of_device_id *of_id;
 	const char *p, *sprop;
 	const uint32_t *iprop;
-	struct resource *res;
-	void __iomem *iomem;
-	char name[64];
-	struct regmap_config regconfig = fsl_ssi_regconfig;
+	u32 dmas[4];
+	int ret;
 
 	of_id = of_match_device(fsl_ssi_ids, dev);
 	if (!of_id || !of_id->data)
 		return -EINVAL;
 
-	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
-	if (!ssi)
-		return -ENOMEM;
-
 	ssi->soc = of_id->data;
-	ssi->dev = dev;
+
+	ret = of_property_match_string(np, "clock-names", "ipg");
+	/* Get error code if not found */
+	ssi->has_ipg_clk_name = ret >= 0;
 
 	/* Check if being used in AC97 mode */
 	sprop = of_get_property(np, "fsl,mode", NULL);
-	if (sprop) {
-		if (!strcmp(sprop, "ac97-slave"))
-			ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
+	if (sprop && !strcmp(sprop, "ac97-slave")) {
+		ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
+
+		ret = of_property_read_u32(np, "cell-index", &ssi->card_idx);
+		if (ret) {
+			dev_err(dev, "failed to get SSI index property\n");
+			return -EINVAL;
+		}
+		strcpy(ssi->card_name, "ac97-codec");
+	} else if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
+		/*
+		 * In synchronous mode, STCK and STFS ports are used by RX
+		 * as well. So the software should limit the sample rates,
+		 * sample bits and channels to be symmetric.
+		 *
+		 * This is exclusive with FSLSSI_AC97_FORMATS as AC97 runs
+		 * in the SSI synchronous mode however it does not have to
+		 * limit symmetric sample rates and sample bits.
+		 */
+		ssi->synchronous = true;
 	}
 
 	/* Select DMA or FIQ */
 	ssi->use_dma = !of_property_read_bool(np, "fsl,fiq-stream-filter");
 
+	/* Fetch FIFO depth; Set to 8 for older DT without this property */
+	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
+	if (iprop)
+		ssi->fifo_depth = be32_to_cpup(iprop);
+	else
+		ssi->fifo_depth = 8;
+
+	/* Use dual FIFO mode depending on the support from SDMA script */
+	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
+	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL)
+		ssi->use_dual_fifo = true;
+
+	/*
+	 * Backward compatible for older bindings by manually triggering the
+	 * machine driver's probe(). Use /compatible property, including the
+	 * address of CPU DAI driver structure, as the name of machine driver
+	 *
+	 * If card_name is set by AC97 earlier, bypass here since it uses a
+	 * different name to register the device.
+	 */
+	if (!ssi->card_name[0] && of_get_property(np, "codec-handle", NULL)) {
+		sprop = of_get_property(of_find_node_by_path("/"),
+					"compatible", NULL);
+		/* Strip "fsl," in the compatible name if applicable */
+		p = strrchr(sprop, ',');
+		if (p)
+			sprop = p + 1;
+		snprintf(ssi->card_name, sizeof(ssi->card_name),
+			 "snd-soc-%s", sprop);
+		make_lowercase(ssi->card_name);
+		ssi->card_idx = 0;
+	}
+
+	return 0;
+}
+
+static int fsl_ssi_probe(struct platform_device *pdev)
+{
+	struct regmap_config regconfig = fsl_ssi_regconfig;
+	struct device *dev = &pdev->dev;
+	struct fsl_ssi *ssi;
+	struct resource *res;
+	void __iomem *iomem;
+	int ret = 0;
+
+	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
+	if (!ssi)
+		return -ENOMEM;
+
+	ssi->dev = dev;
+
+	/* Probe from DT */
+	ret = fsl_ssi_probe_from_dt(ssi);
+	if (ret)
+		return ret;
+
 	if (fsl_ssi_is_ac97(ssi)) {
 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_ac97_dai,
 		       sizeof(fsl_ssi_ac97_dai));
@@ -1433,15 +1500,11 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 			REG_SSI_SRMSK / sizeof(uint32_t) + 1;
 	}
 
-	ret = of_property_match_string(np, "clock-names", "ipg");
-	if (ret < 0) {
-		ssi->has_ipg_clk_name = false;
-		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
-	} else {
-		ssi->has_ipg_clk_name = true;
+	if (ssi->has_ipg_clk_name)
 		ssi->regs = devm_regmap_init_mmio_clk(dev, "ipg", iomem,
 						      &regconfig);
-	}
+	else
+		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
 	if (IS_ERR(ssi->regs)) {
 		dev_err(dev, "failed to init register map\n");
 		return PTR_ERR(ssi->regs);
@@ -1453,24 +1516,13 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 		return ssi->irq;
 	}
 
-	/* Set software limitations for synchronous mode */
-	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
-		if (!fsl_ssi_is_ac97(ssi)) {
-			ssi->cpu_dai_drv.symmetric_rates = 1;
-			ssi->cpu_dai_drv.symmetric_samplebits = 1;
-			ssi->synchronous = true;
-		}
-
+	/* Set software limitations for synchronous mode except AC97 */
+	if (ssi->synchronous && !fsl_ssi_is_ac97(ssi)) {
+		ssi->cpu_dai_drv.symmetric_rates = 1;
 		ssi->cpu_dai_drv.symmetric_channels = 1;
+		ssi->cpu_dai_drv.symmetric_samplebits = 1;
 	}
 
-	/* Fetch FIFO depth; Set to 8 for older DT without this property */
-	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
-	if (iprop)
-		ssi->fifo_depth = be32_to_cpup(iprop);
-	else
-		ssi->fifo_depth = 8;
-
 	/*
 	 * Configure TX and RX DMA watermarks -- when to send a DMA request
 	 *
@@ -1535,50 +1587,27 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	if (ret)
 		goto error_asoc_register;
 
-	/* Bypass it if using newer DT bindings of ASoC machine drivers */
-	if (!of_get_property(np, "codec-handle", NULL))
-		goto done;
-
-	/*
-	 * Backward compatible for older bindings by manually triggering the
-	 * machine driver's probe(). Use /compatible property, including the
-	 * address of CPU DAI driver structure, as the name of machine driver.
-	 */
-	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
-	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
-	p = strrchr(sprop, ',');
-	if (p)
-		sprop = p + 1;
-	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
-	make_lowercase(name);
-
-	ssi->pdev = platform_device_register_data(dev, name, 0, NULL, 0);
-	if (IS_ERR(ssi->pdev)) {
-		ret = PTR_ERR(ssi->pdev);
-		dev_err(dev, "failed to register platform: %d\n", ret);
-		goto error_sound_card;
-	}
-
-done:
 	/* Initially configures SSI registers */
 	fsl_ssi_hw_init(ssi);
 
-	if (fsl_ssi_is_ac97(ssi)) {
-		u32 ssi_idx;
-
-		ret = of_property_read_u32(np, "cell-index", &ssi_idx);
-		if (ret) {
-			dev_err(dev, "failed to get SSI index property\n");
-			goto error_sound_card;
-		}
-
-		ssi->pdev = platform_device_register_data(NULL, "ac97-codec",
-							  ssi_idx, NULL, 0);
-		if (IS_ERR(ssi->pdev)) {
-			ret = PTR_ERR(ssi->pdev);
-			dev_err(dev,
-				"failed to register AC97 codec platform: %d\n",
-				ret);
+	/* Register a platform device for older bindings or AC97 */
+	if (ssi->card_name[0]) {
+		struct device *parent = dev;
+		/*
+		 * Do not set SSI dev as the parent of AC97 CODEC device since
+		 * it does not have a DT node. Otherwise ASoC core will assume
+		 * CODEC has the same DT node as the SSI, so it may return a
+		 * NULL pointer of CODEC when asked for SSI via the DT node
+		 */
+		if (fsl_ssi_is_ac97(ssi))
+			parent = NULL;
+
+		ssi->card_pdev = platform_device_register_data(parent,
+				ssi->card_name, ssi->card_idx, NULL, 0);
+		if (IS_ERR(ssi->card_pdev)) {
+			ret = PTR_ERR(ssi->card_pdev);
+			dev_err(dev, "failed to register %s: %d\n",
+				ssi->card_name, ret);
 			goto error_sound_card;
 		}
 	}
@@ -1606,8 +1635,8 @@ static int fsl_ssi_remove(struct platform_device *pdev)
 
 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
 
-	if (ssi->pdev)
-		platform_device_unregister(ssi->pdev);
+	if (ssi->card_pdev)
+		platform_device_unregister(ssi->card_pdev);
 
 	/* Clean up SSI registers */
 	fsl_ssi_hw_clean(ssi);
-- 
2.7.4

[PATCH v5 17/17] ASoC: fsl_ssi: Use ssi->streams instead of reading register

[Nicolin Chen]

Since ssi->streams is being updated along with SCR register and
its SSIEN bit, it's simpler to use it instead.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
---
 sound/soc/fsl/fsl_ssi.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index a8a040d..c6c1b07 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -803,11 +803,6 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
 	unsigned int sample_size = params_width(hw_params);
 	u32 wl = SSI_SxCCR_WL(sample_size);
 	int ret;
-	u32 scr;
-	int enabled;
-
-	regmap_read(regs, REG_SSI_SCR, &scr);
-	enabled = scr & SSI_SCR_SSIEN;
 
 	/*
 	 * SSI is properly configured if it is enabled and running in
@@ -815,7 +810,7 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
 	 * that should set separate configurations for STCCR and SRCCR
 	 * despite running in the synchronous mode.
 	 */
-	if (enabled && ssi->synchronous)
+	if (ssi->streams && ssi->synchronous)
 		return 0;
 
 	if (fsl_ssi_is_i2s_master(ssi)) {
-- 
2.7.4

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Caleb Crome]

On Tue, Jan 16, 2018 at 10:51 PM, Nicolin Chen <nicoleotsuka@gmail.com> wrote:
> [ Maciej, could you please send your Tested-by/Reviewed-by for AC97
>   once you confirm this series?
>
>   And Caleb, this version does not need a test for non-AC97 cases.
>
>   Thanks both! ]
>
> ==Change log==
> v5
>  * Reworked the series by taking suggestions from Maciej for AC97
>   + Fixed SSI lockup issue by changing cleanup sequence in PATCH-13
>   + Moved fsl_ssi_hw_clean() after unregistering the CODEC device
>     in PATCH-13
>   + Set NULL as the parent of CODEC platform device to fix a NULL
>     pointer dereference bug in PATCH-16
>  * Updated comments of three variables/pointers in struct fsl_ssi
>    to describe them more accurately in PATCH-16
> v4
>  * Reworked the series by taking suggestions from Maciej
>   + Added TXBIT0 bit back to play safe in PATCH-14
>   + Made bool synchronous exclusive with AC97 mode in PATCH-16
> v3
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to make RX and TX more clearly defined
>   + Replaced "bool dir" with "int dir" in PATCH-04
>   + Replaced "!dir" with "int adir" in PATCH-05
>   + Put CBM_CFS behind the baudclk check to keep the same
>     program flow in PATCH-14
>   + Removed all cpu_dai_drv changes in PATCH-15
> v2
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to keep all ssi->i2s_net updated
>   + Replaced bool tx with bool dir in PATCH-03 and PATCH-06
>   + Moved all initial register configurations from dai probe() to
>     platform probe() so as to let AC97 CODEC successfully probe.
>  * Added Tested-by from Caleb for TDM test cases.
>
> ==Background==
> The fsl_ssi driver was designed for PPC originally and then it has
> been updated to support different modes for i.MX Series, including
> SDMA, I2S Master mode, AC97 and older i.MXs with FIQ, by different
> contributors for different use cases in different coding styles.
>
> Additionally, in order to fix/work-around hardware bugs and design
> flaws, the driver made a lot of compromise so now its program flow
> looks very complicated and it's getting hard to maintain or update.
>
> So I am going to clean up the driver on both coding style level and
> program flow level.
>
> ==Introduction==
> This series of patches is the second set to clean up fsl_ssi driver
> in the program flow level. Any patch here may impact a fundamental
> test case like playback or record.
>
> ==Verification==
> This series of patches require fully tested. I have done such tests
> on i.MX6SoloX with WM8962 using imx_v6_v7_defconfig as:
>  - Playback via I2S Master and Slave mode
>  - Record via I2S Master and Slave mode
>  - Simultaneous playback and record via I2S Master and Slave mode
>  - Background playback with foreground record (starting at different
>    time) via I2S Master and Slave mode
>  - Background record with foreground playback (starting at different
>    time) via I2S Master and Slave mode
>  * All tests above by hacking offline_config to true in imx51.
>
> Caleb has tested v1-v4 with TDM lookback tests on i.MX6.
>
> Example of uncovered tests: AC97, PowerPC and FIQ.
>
> Nicolin Chen (17):
>   ASoC: fsl_ssi: Redefine RX and TX macros
>   ASoC: fsl_ssi: Keep ssi->i2s_net updated
>   ASoC: fsl_ssi: Clean up set_dai_tdm_slot()
>   ASoC: fsl_ssi: Maintain a mask of active streams
>   ASoC: fsl_ssi: Rename fsl_ssi_disable_val macro
>   ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()
>   ASoC: fsl_ssi: Clean up helper functions of trigger()
>   ASoC: fsl_ssi: Add DAIFMT define for AC97
>   ASoC: fsl_ssi: Clean up fsl_ssi_setup_regvals()
>   ASoC: fsl_ssi: Set xFEN0 and xFEN1 together
>   ASoC: fsl_ssi: Use snd_soc_init_dma_data instead
>   ASoC: fsl_ssi: Move one-time configurations to probe()
>   ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()
>   ASoC: fsl_ssi: Clean up _fsl_ssi_set_dai_fmt()
>   ASoC: fsl_ssi: Add bool synchronous to mark synchronous mode
>   ASoC: fsl_ssi: Move DT related code to a separate probe()
>   ASoC: fsl_ssi: Use ssi->streams instead of reading register
>
>  sound/soc/fsl/fsl_ssi.c | 756 +++++++++++++++++++++++++-----------------------
>  sound/soc/fsl/fsl_ssi.h |   3 -
>  2 files changed, 395 insertions(+), 364 deletions(-)
>
> --
> 2.7.4
>
tested v5.

No problems,
 -Caleb

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Caleb Crome]

On Tue, Jan 16, 2018 at 10:51 PM, Nicolin Chen <nicoleotsuka@gmail.com> wrote:
> [ Maciej, could you please send your Tested-by/Reviewed-by for AC97
>   once you confirm this series?
>
>   And Caleb, this version does not need a test for non-AC97 cases.
>
>   Thanks both! ]
>
> ==Change log==
> v5
>  * Reworked the series by taking suggestions from Maciej for AC97
>   + Fixed SSI lockup issue by changing cleanup sequence in PATCH-13
>   + Moved fsl_ssi_hw_clean() after unregistering the CODEC device
>     in PATCH-13
>   + Set NULL as the parent of CODEC platform device to fix a NULL
>     pointer dereference bug in PATCH-16
>  * Updated comments of three variables/pointers in struct fsl_ssi
>    to describe them more accurately in PATCH-16
> v4
>  * Reworked the series by taking suggestions from Maciej
>   + Added TXBIT0 bit back to play safe in PATCH-14
>   + Made bool synchronous exclusive with AC97 mode in PATCH-16
> v3
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to make RX and TX more clearly defined
>   + Replaced "bool dir" with "int dir" in PATCH-04
>   + Replaced "!dir" with "int adir" in PATCH-05
>   + Put CBM_CFS behind the baudclk check to keep the same
>     program flow in PATCH-14
>   + Removed all cpu_dai_drv changes in PATCH-15
> v2
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to keep all ssi->i2s_net updated
>   + Replaced bool tx with bool dir in PATCH-03 and PATCH-06
>   + Moved all initial register configurations from dai probe() to
>     platform probe() so as to let AC97 CODEC successfully probe.
>  * Added Tested-by from Caleb for TDM test cases.
>
> ==Background==
> The fsl_ssi driver was designed for PPC originally and then it has
> been updated to support different modes for i.MX Series, including
> SDMA, I2S Master mode, AC97 and older i.MXs with FIQ, by different
> contributors for different use cases in different coding styles.
>
> Additionally, in order to fix/work-around hardware bugs and design
> flaws, the driver made a lot of compromise so now its program flow
> looks very complicated and it's getting hard to maintain or update.
>
> So I am going to clean up the driver on both coding style level and
> program flow level.
>
> ==Introduction==
> This series of patches is the second set to clean up fsl_ssi driver
> in the program flow level. Any patch here may impact a fundamental
> test case like playback or record.
>
> ==Verification==
> This series of patches require fully tested. I have done such tests
> on i.MX6SoloX with WM8962 using imx_v6_v7_defconfig as:
>  - Playback via I2S Master and Slave mode
>  - Record via I2S Master and Slave mode
>  - Simultaneous playback and record via I2S Master and Slave mode
>  - Background playback with foreground record (starting at different
>    time) via I2S Master and Slave mode
>  - Background record with foreground playback (starting at different
>    time) via I2S Master and Slave mode
>  * All tests above by hacking offline_config to true in imx51.
>
> Caleb has tested v1-v4 with TDM lookback tests on i.MX6.
>
> Example of uncovered tests: AC97, PowerPC and FIQ.
>
> Nicolin Chen (17):
>   ASoC: fsl_ssi: Redefine RX and TX macros
>   ASoC: fsl_ssi: Keep ssi->i2s_net updated
>   ASoC: fsl_ssi: Clean up set_dai_tdm_slot()
>   ASoC: fsl_ssi: Maintain a mask of active streams
>   ASoC: fsl_ssi: Rename fsl_ssi_disable_val macro
>   ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()
>   ASoC: fsl_ssi: Clean up helper functions of trigger()
>   ASoC: fsl_ssi: Add DAIFMT define for AC97
>   ASoC: fsl_ssi: Clean up fsl_ssi_setup_regvals()
>   ASoC: fsl_ssi: Set xFEN0 and xFEN1 together
>   ASoC: fsl_ssi: Use snd_soc_init_dma_data instead
>   ASoC: fsl_ssi: Move one-time configurations to probe()
>   ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()
>   ASoC: fsl_ssi: Clean up _fsl_ssi_set_dai_fmt()
>   ASoC: fsl_ssi: Add bool synchronous to mark synchronous mode
>   ASoC: fsl_ssi: Move DT related code to a separate probe()
>   ASoC: fsl_ssi: Use ssi->streams instead of reading register
>
>  sound/soc/fsl/fsl_ssi.c | 756 +++++++++++++++++++++++++-----------------------
>  sound/soc/fsl/fsl_ssi.h |   3 -
>  2 files changed, 395 insertions(+), 364 deletions(-)
>
> --
> 2.7.4
>
tested v5.

No problems,
 -Caleb

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Maciej S. Szmigiero]

On 17.01.2018 07:51, Nicolin Chen wrote:
> [ Maciej, could you please send your Tested-by/Reviewed-by for AC97
>   once you confirm this series?
>   
>   And Caleb, this version does not need a test for non-AC97 cases.
> 
>   Thanks both! ]
> 
> ==Change log==
> v5
>  * Reworked the series by taking suggestions from Maciej for AC97
>   + Fixed SSI lockup issue by changing cleanup sequence in PATCH-13
>   + Moved fsl_ssi_hw_clean() after unregistering the CODEC device
>     in PATCH-13
>   + Set NULL as the parent of CODEC platform device to fix a NULL
>     pointer dereference bug in PATCH-16
>  * Updated comments of three variables/pointers in struct fsl_ssi
>    to describe them more accurately in PATCH-16
> v4
>  * Reworked the series by taking suggestions from Maciej
>   + Added TXBIT0 bit back to play safe in PATCH-14
>   + Made bool synchronous exclusive with AC97 mode in PATCH-16
> v3
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to make RX and TX more clearly defined
>   + Replaced "bool dir" with "int dir" in PATCH-04
>   + Replaced "!dir" with "int adir" in PATCH-05
>   + Put CBM_CFS behind the baudclk check to keep the same
>     program flow in PATCH-14
>   + Removed all cpu_dai_drv changes in PATCH-15
> v2
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to keep all ssi->i2s_net updated
>   + Replaced bool tx with bool dir in PATCH-03 and PATCH-06
>   + Moved all initial register configurations from dai probe() to
>     platform probe() so as to let AC97 CODEC successfully probe.
>  * Added Tested-by from Caleb for TDM test cases.
> 
> ==Background==
> The fsl_ssi driver was designed for PPC originally and then it has
> been updated to support different modes for i.MX Series, including
> SDMA, I2S Master mode, AC97 and older i.MXs with FIQ, by different
> contributors for different use cases in different coding styles.
> 
> Additionally, in order to fix/work-around hardware bugs and design
> flaws, the driver made a lot of compromise so now its program flow
> looks very complicated and it's getting hard to maintain or update.
> 
> So I am going to clean up the driver on both coding style level and
> program flow level.
> 
> ==Introduction==
> This series of patches is the second set to clean up fsl_ssi driver
> in the program flow level. Any patch here may impact a fundamental
> test case like playback or record.
> 
> ==Verification==
> This series of patches require fully tested. I have done such tests
> on i.MX6SoloX with WM8962 using imx_v6_v7_defconfig as:
>  - Playback via I2S Master and Slave mode
>  - Record via I2S Master and Slave mode
>  - Simultaneous playback and record via I2S Master and Slave mode
>  - Background playback with foreground record (starting at different
>    time) via I2S Master and Slave mode
>  - Background record with foreground playback (starting at different
>    time) via I2S Master and Slave mode
>  * All tests above by hacking offline_config to true in imx51.
> 
> Caleb has tested v1-v4 with TDM lookback tests on i.MX6.
> 
> Example of uncovered tests: AC97, PowerPC and FIQ.

For the whole series:
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>

However, I have a small nitpick regarding a comment newly added in
this version of patch 16:
+		/*
+		 * Do not set SSI dev as the parent of AC97 CODEC device since
+		 * it does not have a DT node. Otherwise ASoC core will assume
+		 * CODEC has the same DT node as the SSI, so it may return a
+		 * NULL pointer of CODEC when asked for SSI via the DT node

The second part of the last sentence isn't really true, the ASoC core
will return a (valid, non-NULL) CODEC object pointer when asked for
the SSI one if we set the SSI as the parent device of a AC'97 CODEC
platform device.

The NULL pointer dereference when starting a playback that I wrote
about in my previous message happens because in this situation the SSI
DAI probe callback won't ever get called and so won't setup DMA data
pointers (they will remain NULL).
And this in turn will cause the ASoC DMA code to dereference these
NULL pointers when starting a playback (the same will probably happen
also when starting a capture).

Sorry if I wasn't 100% clear about these details in my previous
message describing this issue.

Maciej

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Maciej S. Szmigiero]

On 17.01.2018 07:51, Nicolin Chen wrote:
> [ Maciej, could you please send your Tested-by/Reviewed-by for AC97
>   once you confirm this series?
>   
>   And Caleb, this version does not need a test for non-AC97 cases.
> 
>   Thanks both! ]
> 
> ==Change log==
> v5
>  * Reworked the series by taking suggestions from Maciej for AC97
>   + Fixed SSI lockup issue by changing cleanup sequence in PATCH-13
>   + Moved fsl_ssi_hw_clean() after unregistering the CODEC device
>     in PATCH-13
>   + Set NULL as the parent of CODEC platform device to fix a NULL
>     pointer dereference bug in PATCH-16
>  * Updated comments of three variables/pointers in struct fsl_ssi
>    to describe them more accurately in PATCH-16
> v4
>  * Reworked the series by taking suggestions from Maciej
>   + Added TXBIT0 bit back to play safe in PATCH-14
>   + Made bool synchronous exclusive with AC97 mode in PATCH-16
> v3
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to make RX and TX more clearly defined
>   + Replaced "bool dir" with "int dir" in PATCH-04
>   + Replaced "!dir" with "int adir" in PATCH-05
>   + Put CBM_CFS behind the baudclk check to keep the same
>     program flow in PATCH-14
>   + Removed all cpu_dai_drv changes in PATCH-15
> v2
>  * Reworked the series by taking suggestions from Maciej
>   + Added PATCH-01 to keep all ssi->i2s_net updated
>   + Replaced bool tx with bool dir in PATCH-03 and PATCH-06
>   + Moved all initial register configurations from dai probe() to
>     platform probe() so as to let AC97 CODEC successfully probe.
>  * Added Tested-by from Caleb for TDM test cases.
> 
> ==Background==
> The fsl_ssi driver was designed for PPC originally and then it has
> been updated to support different modes for i.MX Series, including
> SDMA, I2S Master mode, AC97 and older i.MXs with FIQ, by different
> contributors for different use cases in different coding styles.
> 
> Additionally, in order to fix/work-around hardware bugs and design
> flaws, the driver made a lot of compromise so now its program flow
> looks very complicated and it's getting hard to maintain or update.
> 
> So I am going to clean up the driver on both coding style level and
> program flow level.
> 
> ==Introduction==
> This series of patches is the second set to clean up fsl_ssi driver
> in the program flow level. Any patch here may impact a fundamental
> test case like playback or record.
> 
> ==Verification==
> This series of patches require fully tested. I have done such tests
> on i.MX6SoloX with WM8962 using imx_v6_v7_defconfig as:
>  - Playback via I2S Master and Slave mode
>  - Record via I2S Master and Slave mode
>  - Simultaneous playback and record via I2S Master and Slave mode
>  - Background playback with foreground record (starting at different
>    time) via I2S Master and Slave mode
>  - Background record with foreground playback (starting at different
>    time) via I2S Master and Slave mode
>  * All tests above by hacking offline_config to true in imx51.
> 
> Caleb has tested v1-v4 with TDM lookback tests on i.MX6.
> 
> Example of uncovered tests: AC97, PowerPC and FIQ.

For the whole series:
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>

However, I have a small nitpick regarding a comment newly added in
this version of patch 16:
+		/*
+		 * Do not set SSI dev as the parent of AC97 CODEC device since
+		 * it does not have a DT node. Otherwise ASoC core will assume
+		 * CODEC has the same DT node as the SSI, so it may return a
+		 * NULL pointer of CODEC when asked for SSI via the DT node

The second part of the last sentence isn't really true, the ASoC core
will return a (valid, non-NULL) CODEC object pointer when asked for
the SSI one if we set the SSI as the parent device of a AC'97 CODEC
platform device.

The NULL pointer dereference when starting a playback that I wrote
about in my previous message happens because in this situation the SSI
DAI probe callback won't ever get called and so won't setup DMA data
pointers (they will remain NULL).
And this in turn will cause the ASoC DMA code to dereference these
NULL pointers when starting a playback (the same will probably happen
also when starting a capture).

Sorry if I wasn't 100% clear about these details in my previous
message describing this issue.

Maciej

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Nicolin Chen]

On Wed, Jan 17, 2018 at 08:38:48PM +0100, Maciej S. Szmigiero wrote:

> However, I have a small nitpick regarding a comment newly added in
> this version of patch 16:
> +		/*
> +		 * Do not set SSI dev as the parent of AC97 CODEC device since
> +		 * it does not have a DT node. Otherwise ASoC core will assume
> +		 * CODEC has the same DT node as the SSI, so it may return a
> +		 * NULL pointer of CODEC when asked for SSI via the DT node
> 
> The second part of the last sentence isn't really true, the ASoC core
> will return a (valid, non-NULL) CODEC object pointer when asked for
> the SSI one if we set the SSI as the parent device of a AC'97 CODEC
> platform device.
> 
> The NULL pointer dereference when starting a playback that I wrote
> about in my previous message happens because in this situation the SSI
> DAI probe callback won't ever get called and so won't setup DMA data
> pointers (they will remain NULL).

Well, somehow the DMA data pointer of CODEC could be described
as "a NULL pointer of CODEC" reluctantly...it confuses people
though.

> And this in turn will cause the ASoC DMA code to dereference these
> NULL pointers when starting a playback (the same will probably happen
> also when starting a capture).
> 
> Sorry if I wasn't 100% clear about these details in my previous
> message describing this issue.

I would prefer to send an incremental patch later to update it,
if there are no new comments against this version; Otherwise, I
will update it in a next version once there is a need to send a
v6 anyway.

Thanks

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Nicolin Chen]

On Wed, Jan 17, 2018 at 08:38:48PM +0100, Maciej S. Szmigiero wrote:

> However, I have a small nitpick regarding a comment newly added in
> this version of patch 16:
> +		/*
> +		 * Do not set SSI dev as the parent of AC97 CODEC device since
> +		 * it does not have a DT node. Otherwise ASoC core will assume
> +		 * CODEC has the same DT node as the SSI, so it may return a
> +		 * NULL pointer of CODEC when asked for SSI via the DT node
> 
> The second part of the last sentence isn't really true, the ASoC core
> will return a (valid, non-NULL) CODEC object pointer when asked for
> the SSI one if we set the SSI as the parent device of a AC'97 CODEC
> platform device.
> 
> The NULL pointer dereference when starting a playback that I wrote
> about in my previous message happens because in this situation the SSI
> DAI probe callback won't ever get called and so won't setup DMA data
> pointers (they will remain NULL).

Well, somehow the DMA data pointer of CODEC could be described
as "a NULL pointer of CODEC" reluctantly...it confuses people
though.

> And this in turn will cause the ASoC DMA code to dereference these
> NULL pointers when starting a playback (the same will probably happen
> also when starting a capture).
> 
> Sorry if I wasn't 100% clear about these details in my previous
> message describing this issue.

I would prefer to send an incremental patch later to update it,
if there are no new comments against this version; Otherwise, I
will update it in a next version once there is a need to send a
v6 anyway.

Thanks

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Maciej S. Szmigiero]

On 17.01.2018 21:02, Nicolin Chen wrote:
> On Wed, Jan 17, 2018 at 08:38:48PM +0100, Maciej S. Szmigiero wrote:
> 
>> However, I have a small nitpick regarding a comment newly added in
>> this version of patch 16:
>> +		/*
>> +		 * Do not set SSI dev as the parent of AC97 CODEC device since
>> +		 * it does not have a DT node. Otherwise ASoC core will assume
>> +		 * CODEC has the same DT node as the SSI, so it may return a
>> +		 * NULL pointer of CODEC when asked for SSI via the DT node
>>
>> The second part of the last sentence isn't really true, the ASoC core
>> will return a (valid, non-NULL) CODEC object pointer when asked for
>> the SSI one if we set the SSI as the parent device of a AC'97 CODEC
>> platform device.
>>
>> The NULL pointer dereference when starting a playback that I wrote
>> about in my previous message happens because in this situation the SSI
>> DAI probe callback won't ever get called and so won't setup DMA data
>> pointers (they will remain NULL).
> 
> Well, somehow the DMA data pointer of CODEC could be described
> as "a NULL pointer of CODEC" reluctantly...it confuses people
> though.
> 
>> And this in turn will cause the ASoC DMA code to dereference these
>> NULL pointers when starting a playback (the same will probably happen
>> also when starting a capture).
>>
>> Sorry if I wasn't 100% clear about these details in my previous
>> message describing this issue.
> 
> I would prefer to send an incremental patch later to update it,
> if there are no new comments against this version; Otherwise, I
> will update it in a next version once there is a need to send a
> v6 anyway.

IMHO it is such a tiny thing that it isn't worth respinning 17
patch series just for it, it can be easily improved later via
a separate patch.

> Thanks
> 

Thanks,
Maciej

Re: [PATCH v5 00/17] ASoC: fsl_ssi: Clean up - program flow level

[Maciej S. Szmigiero]

On 17.01.2018 21:02, Nicolin Chen wrote:
> On Wed, Jan 17, 2018 at 08:38:48PM +0100, Maciej S. Szmigiero wrote:
> 
>> However, I have a small nitpick regarding a comment newly added in
>> this version of patch 16:
>> +		/*
>> +		 * Do not set SSI dev as the parent of AC97 CODEC device since
>> +		 * it does not have a DT node. Otherwise ASoC core will assume
>> +		 * CODEC has the same DT node as the SSI, so it may return a
>> +		 * NULL pointer of CODEC when asked for SSI via the DT node
>>
>> The second part of the last sentence isn't really true, the ASoC core
>> will return a (valid, non-NULL) CODEC object pointer when asked for
>> the SSI one if we set the SSI as the parent device of a AC'97 CODEC
>> platform device.
>>
>> The NULL pointer dereference when starting a playback that I wrote
>> about in my previous message happens because in this situation the SSI
>> DAI probe callback won't ever get called and so won't setup DMA data
>> pointers (they will remain NULL).
> 
> Well, somehow the DMA data pointer of CODEC could be described
> as "a NULL pointer of CODEC" reluctantly...it confuses people
> though.
> 
>> And this in turn will cause the ASoC DMA code to dereference these
>> NULL pointers when starting a playback (the same will probably happen
>> also when starting a capture).
>>
>> Sorry if I wasn't 100% clear about these details in my previous
>> message describing this issue.
> 
> I would prefer to send an incremental patch later to update it,
> if there are no new comments against this version; Otherwise, I
> will update it in a next version once there is a need to send a
> v6 anyway.

IMHO it is such a tiny thing that it isn't worth respinning 17
patch series just for it, it can be easily improved later via
a separate patch.

> Thanks
> 

Thanks,
Maciej