Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-08 Thread Jagan Teki 
On 8 September 2015 at 06:47, Chin Liang See  wrote:
> Ensuring spi_calibration is run when there is a change of sclk
> frequency. This will ensure the qspi flash access works for high
> sclk frequency
>
> Signed-off-by: Chin Liang See 
> Cc: Dinh Nguyen 
> Cc: Dinh Nguyen 
> Cc: Marek Vasut 
> Cc: Stefan Roese 
> Cc: Vikas Manocha 
> Cc: Jagannadh Teki 
> Cc: Pavel Machek 
> ---
> Changes for v2
> - remove frequency set before calibration
> - introducing previous_hz to store requested frequency
> - prevent calibration run when request same frequency
> ---

Reviewed-by: Jagan Teki 

thanks!
-- 
Jagan | openedev.
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Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-08 Thread Marek Vasut 
On Tuesday, September 08, 2015 at 02:25:54 PM, Jagan Teki wrote:
> On 8 September 2015 at 16:38, Marek Vasut  wrote:
> > On Tuesday, September 08, 2015 at 03:17:49 AM, Chin Liang See wrote:
> >> Ensuring spi_calibration is run when there is a change of sclk
> >> frequency. This will ensure the qspi flash access works for high
> >> sclk frequency
> >> 
> >> Signed-off-by: Chin Liang See 
> >> Cc: Dinh Nguyen 
> >> Cc: Dinh Nguyen 
> >> Cc: Marek Vasut 
> >> Cc: Stefan Roese 
> >> Cc: Vikas Manocha 
> >> Cc: Jagannadh Teki 
> >> Cc: Pavel Machek 
> > 
> > Acked-by: Marek Vasut 
> > 
> > Jagan, please apply for -next or I'll pick it up. Which do you prefer ?
> 
> You can pick, no issues. once 2/4, 3/4 ready.

OK, will do.

Best regards,
Marek Vasut
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Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-08 Thread Marek Vasut 
On Tuesday, September 08, 2015 at 03:17:49 AM, Chin Liang See wrote:
> Ensuring spi_calibration is run when there is a change of sclk
> frequency. This will ensure the qspi flash access works for high
> sclk frequency
> 
> Signed-off-by: Chin Liang See 
> Cc: Dinh Nguyen 
> Cc: Dinh Nguyen 
> Cc: Marek Vasut 
> Cc: Stefan Roese 
> Cc: Vikas Manocha 
> Cc: Jagannadh Teki 
> Cc: Pavel Machek 

Acked-by: Marek Vasut 

Jagan, please apply for -next or I'll pick it up. Which do you prefer ?

[...]

> diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h
> index 98e57aa..2912e36 100644
> --- a/drivers/spi/cadence_qspi.h
> +++ b/drivers/spi/cadence_qspi.h
> @@ -38,6 +38,7 @@ struct cadence_spi_priv {
>   int qspi_is_init;
>   unsigned intqspi_calibrated_hz;
>   unsigned intqspi_calibrated_cs;

Idea for future patch: we should get rid of these qspi_ prefixes, they are
really useless.

> + unsigned intprevious_hz;
>  };
> 
>  /* Functions call declaration */

Best regards,
Marek Vasut
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Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-08 Thread Jagan Teki 
On 8 September 2015 at 16:38, Marek Vasut  wrote:
> On Tuesday, September 08, 2015 at 03:17:49 AM, Chin Liang See wrote:
>> Ensuring spi_calibration is run when there is a change of sclk
>> frequency. This will ensure the qspi flash access works for high
>> sclk frequency
>>
>> Signed-off-by: Chin Liang See 
>> Cc: Dinh Nguyen 
>> Cc: Dinh Nguyen 
>> Cc: Marek Vasut 
>> Cc: Stefan Roese 
>> Cc: Vikas Manocha 
>> Cc: Jagannadh Teki 
>> Cc: Pavel Machek 
>
> Acked-by: Marek Vasut 
>
> Jagan, please apply for -next or I'll pick it up. Which do you prefer ?

You can pick, no issues. once 2/4, 3/4 ready.

>
> [...]
>
>> diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h
>> index 98e57aa..2912e36 100644
>> --- a/drivers/spi/cadence_qspi.h
>> +++ b/drivers/spi/cadence_qspi.h
>> @@ -38,6 +38,7 @@ struct cadence_spi_priv {
>>   int qspi_is_init;
>>   unsigned intqspi_calibrated_hz;
>>   unsigned intqspi_calibrated_cs;
>
> Idea for future patch: we should get rid of these qspi_ prefixes, they are
> really useless.
>
>> + unsigned intprevious_hz;
>>  };
>>
>>  /* Functions call declaration */
>

thanks!
-- 
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Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-07 Thread Chin Liang See 
Hi,

On Thu, 2015-09-03 at 16:17 +0200, ma...@denx.de wrote:
> On Thursday, September 03, 2015 at 03:41:59 PM, Chin Liang See wrote:
> > Ensuring spi_calibration is run when there is a change of sclk
> > frequency. This will ensure the qspi flash access works for high
> > sclk frequency
> > 
> > Signed-off-by: Chin Liang See 
> > Cc: Dinh Nguyen 
> > Cc: Dinh Nguyen 
> > Cc: Marek Vasut 
> > Cc: Stefan Roese 
> > Cc: Vikas Manocha 
> > Cc: Jagannadh Teki 
> > Cc: Pavel Machek 
> > ---
> >  drivers/spi/cadence_qspi.c |8 
> >  1 files changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
> > index 34a0f46..300934e 100644
> > --- a/drivers/spi/cadence_qspi.c
> > +++ b/drivers/spi/cadence_qspi.c
> > @@ -37,7 +37,7 @@ static int cadence_spi_write_speed(struct udevice *bus,
> > uint hz) }
> > 
> >  /* Calibration sequence to determine the read data capture delay register
> > */ -static int spi_calibration(struct udevice *bus)
> > +static int spi_calibration(struct udevice *bus, uint hz)
> >  {
> > struct cadence_spi_platdata *plat = bus->platdata;
> > struct cadence_spi_priv *priv = dev_get_priv(bus);
> > @@ -64,7 +64,7 @@ static int spi_calibration(struct udevice *bus)
> > }
> > 
> > /* use back the intended clock and find low range */
> > -   cadence_spi_write_speed(bus, plat->max_hz);
> > +   cadence_spi_write_speed(bus, hz);
> > for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
> > /* Disable QSPI */
> > cadence_qspi_apb_controller_disable(base);
> > @@ -111,7 +111,7 @@ static int spi_calibration(struct udevice *bus)
> >   (range_hi + range_lo) / 2, range_lo, range_hi);
> > 
> > /* just to ensure we do once only when speed or chip select change */
> > -   priv->qspi_calibrated_hz = plat->max_hz;
> > +   priv->qspi_calibrated_hz = hz;
> > priv->qspi_calibrated_cs = spi_chip_select(bus);
> > 
> > return 0;
> > @@ -131,7 +131,7 @@ static int cadence_spi_set_speed(struct udevice *bus,
> 
> Hi,
> 
> My impression is that the logic here should be like this:
> 
> if (hz > plat->max_hz) {
> printf("error, freq. too high");
> return -EINVAL;
> }
> if (priv->previous_hz != hz) /* Bus frequency changed, re-calibrate */
> spi_calibrate(bus, hz)
> cadence_spi_write_speed(bus, priv->qspi_calibrated_hz);
> priv->previous_hz = hz;
> 
> Note that you need a new private variable, previous_hz, to hold the previous
> value of "hz". This is needed since the calibrated frequency might not be
> equal to requested frequency.
> 

I know where you coming from. 
Yah, calibration can be skipped when requested frequency same as
previous or calibrated one.
Let me add that.

> > uint hz) /* Calibration required for different SCLK speed or chip select
> > */ if (priv->qspi_calibrated_hz != plat->max_hz ||
> > priv->qspi_calibrated_cs != spi_chip_select(bus)) {
> > -   err = spi_calibration(bus);
> > +   err = spi_calibration(bus, hz);
> 
> This is called after the frequency is configured in this function, this looks
> really backwards.

Yah, let me remove the old code.

Thanks
Chin Liang

> 
> > if (err)
> > return err;
> > }
> 
> Best regards,
> Marek Vasut


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[U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-07 Thread Chin Liang See 
Ensuring spi_calibration is run when there is a change of sclk
frequency. This will ensure the qspi flash access works for high
sclk frequency

Signed-off-by: Chin Liang See 
Cc: Dinh Nguyen 
Cc: Dinh Nguyen 
Cc: Marek Vasut 
Cc: Stefan Roese 
Cc: Vikas Manocha 
Cc: Jagannadh Teki 
Cc: Pavel Machek 
---
Changes for v2
- remove frequency set before calibration
- introducing previous_hz to store requested frequency
- prevent calibration run when request same frequency
---
 drivers/spi/cadence_qspi.c |   19 ---
 drivers/spi/cadence_qspi.h |1 +
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
index 34a0f46..23c88d5 100644
--- a/drivers/spi/cadence_qspi.c
+++ b/drivers/spi/cadence_qspi.c
@@ -37,7 +37,7 @@ static int cadence_spi_write_speed(struct udevice *bus, uint 
hz)
 }
 
 /* Calibration sequence to determine the read data capture delay register */
-static int spi_calibration(struct udevice *bus)
+static int spi_calibration(struct udevice *bus, uint hz)
 {
struct cadence_spi_platdata *plat = bus->platdata;
struct cadence_spi_priv *priv = dev_get_priv(bus);
@@ -46,6 +46,10 @@ static int spi_calibration(struct udevice *bus)
unsigned int idcode = 0, temp = 0;
int err = 0, i, range_lo = -1, range_hi = -1;
 
+   /* if calibrated frequency same as reqeusted, skip it */
+   if (priv->qspi_calibrated_hz == hz)
+   return 0;
+
/* start with slowest clock (1 MHz) */
cadence_spi_write_speed(bus, 100);
 
@@ -64,7 +68,7 @@ static int spi_calibration(struct udevice *bus)
}
 
/* use back the intended clock and find low range */
-   cadence_spi_write_speed(bus, plat->max_hz);
+   cadence_spi_write_speed(bus, hz);
for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
/* Disable QSPI */
cadence_qspi_apb_controller_disable(base);
@@ -111,7 +115,7 @@ static int spi_calibration(struct udevice *bus)
  (range_hi + range_lo) / 2, range_lo, range_hi);
 
/* just to ensure we do once only when speed or chip select change */
-   priv->qspi_calibrated_hz = plat->max_hz;
+   priv->qspi_calibrated_hz = hz;
priv->qspi_calibrated_cs = spi_chip_select(bus);
 
return 0;
@@ -126,14 +130,15 @@ static int cadence_spi_set_speed(struct udevice *bus, 
uint hz)
/* Disable QSPI */
cadence_qspi_apb_controller_disable(priv->regbase);
 
-   cadence_spi_write_speed(bus, hz);
-
/* Calibration required for different SCLK speed or chip select */
-   if (priv->qspi_calibrated_hz != plat->max_hz ||
+   if (priv->previous_hz != hz ||
priv->qspi_calibrated_cs != spi_chip_select(bus)) {
-   err = spi_calibration(bus);
+   err = spi_calibration(bus, hz);
if (err)
return err;
+
+   /* prevent calibration run when same as previous request */
+   priv->previous_hz = hz;
}
 
/* Enable QSPI */
diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h
index 98e57aa..2912e36 100644
--- a/drivers/spi/cadence_qspi.h
+++ b/drivers/spi/cadence_qspi.h
@@ -38,6 +38,7 @@ struct cadence_spi_priv {
int qspi_is_init;
unsigned intqspi_calibrated_hz;
unsigned intqspi_calibrated_cs;
+   unsigned intprevious_hz;
 };
 
 /* Functions call declaration */
-- 
1.7.7.4

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[U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-03 Thread Chin Liang See 
Ensuring spi_calibration is run when there is a change of sclk
frequency. This will ensure the qspi flash access works for high
sclk frequency

Signed-off-by: Chin Liang See 
Cc: Dinh Nguyen 
Cc: Dinh Nguyen 
Cc: Marek Vasut 
Cc: Stefan Roese 
Cc: Vikas Manocha 
Cc: Jagannadh Teki 
Cc: Pavel Machek 
---
 drivers/spi/cadence_qspi.c |8 
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
index 34a0f46..300934e 100644
--- a/drivers/spi/cadence_qspi.c
+++ b/drivers/spi/cadence_qspi.c
@@ -37,7 +37,7 @@ static int cadence_spi_write_speed(struct udevice *bus, uint 
hz)
 }
 
 /* Calibration sequence to determine the read data capture delay register */
-static int spi_calibration(struct udevice *bus)
+static int spi_calibration(struct udevice *bus, uint hz)
 {
struct cadence_spi_platdata *plat = bus->platdata;
struct cadence_spi_priv *priv = dev_get_priv(bus);
@@ -64,7 +64,7 @@ static int spi_calibration(struct udevice *bus)
}
 
/* use back the intended clock and find low range */
-   cadence_spi_write_speed(bus, plat->max_hz);
+   cadence_spi_write_speed(bus, hz);
for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
/* Disable QSPI */
cadence_qspi_apb_controller_disable(base);
@@ -111,7 +111,7 @@ static int spi_calibration(struct udevice *bus)
  (range_hi + range_lo) / 2, range_lo, range_hi);
 
/* just to ensure we do once only when speed or chip select change */
-   priv->qspi_calibrated_hz = plat->max_hz;
+   priv->qspi_calibrated_hz = hz;
priv->qspi_calibrated_cs = spi_chip_select(bus);
 
return 0;
@@ -131,7 +131,7 @@ static int cadence_spi_set_speed(struct udevice *bus, uint 
hz)
/* Calibration required for different SCLK speed or chip select */
if (priv->qspi_calibrated_hz != plat->max_hz ||
priv->qspi_calibrated_cs != spi_chip_select(bus)) {
-   err = spi_calibration(bus);
+   err = spi_calibration(bus, hz);
if (err)
return err;
}
-- 
1.7.7.4

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Re: [U-Boot] [PATCH 1/4] spi: cadence_qspi: Ensure spi_calibration is run when sclk change

2015-09-03 Thread Marek Vasut 
On Thursday, September 03, 2015 at 03:41:59 PM, Chin Liang See wrote:
> Ensuring spi_calibration is run when there is a change of sclk
> frequency. This will ensure the qspi flash access works for high
> sclk frequency
> 
> Signed-off-by: Chin Liang See 
> Cc: Dinh Nguyen 
> Cc: Dinh Nguyen 
> Cc: Marek Vasut 
> Cc: Stefan Roese 
> Cc: Vikas Manocha 
> Cc: Jagannadh Teki 
> Cc: Pavel Machek 
> ---
>  drivers/spi/cadence_qspi.c |8 
>  1 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
> index 34a0f46..300934e 100644
> --- a/drivers/spi/cadence_qspi.c
> +++ b/drivers/spi/cadence_qspi.c
> @@ -37,7 +37,7 @@ static int cadence_spi_write_speed(struct udevice *bus,
> uint hz) }
> 
>  /* Calibration sequence to determine the read data capture delay register
> */ -static int spi_calibration(struct udevice *bus)
> +static int spi_calibration(struct udevice *bus, uint hz)
>  {
>   struct cadence_spi_platdata *plat = bus->platdata;
>   struct cadence_spi_priv *priv = dev_get_priv(bus);
> @@ -64,7 +64,7 @@ static int spi_calibration(struct udevice *bus)
>   }
> 
>   /* use back the intended clock and find low range */
> - cadence_spi_write_speed(bus, plat->max_hz);
> + cadence_spi_write_speed(bus, hz);
>   for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
>   /* Disable QSPI */
>   cadence_qspi_apb_controller_disable(base);
> @@ -111,7 +111,7 @@ static int spi_calibration(struct udevice *bus)
> (range_hi + range_lo) / 2, range_lo, range_hi);
> 
>   /* just to ensure we do once only when speed or chip select change */
> - priv->qspi_calibrated_hz = plat->max_hz;
> + priv->qspi_calibrated_hz = hz;
>   priv->qspi_calibrated_cs = spi_chip_select(bus);
> 
>   return 0;
> @@ -131,7 +131,7 @@ static int cadence_spi_set_speed(struct udevice *bus,

Hi,

My impression is that the logic here should be like this:

if (hz > plat->max_hz) {
printf("error, freq. too high");
return -EINVAL;
}
if (priv->previous_hz != hz) /* Bus frequency changed, re-calibrate */
spi_calibrate(bus, hz)
cadence_spi_write_speed(bus, priv->qspi_calibrated_hz);
priv->previous_hz = hz;

Note that you need a new private variable, previous_hz, to hold the previous
value of "hz". This is needed since the calibrated frequency might not be
equal to requested frequency.

> uint hz) /* Calibration required for different SCLK speed or chip select
> */ if (priv->qspi_calibrated_hz != plat->max_hz ||
>   priv->qspi_calibrated_cs != spi_chip_select(bus)) {
> - err = spi_calibration(bus);
> + err = spi_calibration(bus, hz);

This is called after the frequency is configured in this function, this looks
really backwards.

>   if (err)
>   return err;
>   }

Best regards,
Marek Vasut
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