[3/5] mfd: ti_am335x_tscadc: Remove unwanted reg_se_cache save
diff mbox

Message ID 1415339350-17679-4-git-send-email-vigneshr@ti.com
State New, archived
Headers show

Commit Message

Vignesh Raghavendra Nov. 7, 2014, 5:49 a.m. UTC
In one shot mode, sequencer automatically disables all enabled steps at
the end of each cycle. (both ADC steps and TSC steps) Hence these steps
need not be saved in reg_se_cache for clearing these steps at a later
stage.
Also, when ADC wakes up Sequencer should not be busy executing any of the
config steps except for the charge step. Previously charge step was 1 ADC
clock cycle and hence it was ignored.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/mfd/ti_am335x_tscadc.c       | 7 +++++--
 include/linux/mfd/ti_am335x_tscadc.h | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

Comments

Lee Jones Nov. 10, 2014, 9:15 a.m. UTC | #1
On Fri, 07 Nov 2014, Vignesh R wrote:

> In one shot mode, sequencer automatically disables all enabled steps at
> the end of each cycle. (both ADC steps and TSC steps) Hence these steps
> need not be saved in reg_se_cache for clearing these steps at a later
> stage.
> Also, when ADC wakes up Sequencer should not be busy executing any of the
> config steps except for the charge step. Previously charge step was 1 ADC
> clock cycle and hence it was ignored.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
>  drivers/mfd/ti_am335x_tscadc.c       | 7 +++++--
>  include/linux/mfd/ti_am335x_tscadc.h | 1 +
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> index d877e777cce6..94ef8992f46b 100644
> --- a/drivers/mfd/ti_am335x_tscadc.c
> +++ b/drivers/mfd/ti_am335x_tscadc.c
> @@ -86,8 +86,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
>  		spin_lock_irq(&tsadc->reg_lock);
>  		finish_wait(&tsadc->reg_se_wait, &wait);
>  
> +		/*
> +		 * Sequencer should either be idle or
> +		 * busy applying the charge step.
> +		 */
>  		reg = tscadc_readl(tsadc, REG_ADCFSM);
> -		WARN_ON(reg & SEQ_STATUS);
> +		WARN_ON(reg & SEQ_STATUS & (!CHARGE_STEP));

This is almost certainly not correct.

Please take another look at the logic.

I'm _assuming_ you mean (reg & SEQ_STATUS && !CHARGE_STEP).

>  		tsadc->adc_waiting = false;
>  	}
>  	tsadc->adc_in_use = true;
> @@ -96,7 +100,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
>  void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
>  {
>  	spin_lock_irq(&tsadc->reg_lock);
> -	tsadc->reg_se_cache |= val;
>  	am335x_tscadc_need_adc(tsadc);
>  
>  	tscadc_writel(tsadc, REG_SE, val);
> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> index c99be5dc0f5c..fcce182e4a35 100644
> --- a/include/linux/mfd/ti_am335x_tscadc.h
> +++ b/include/linux/mfd/ti_am335x_tscadc.h
> @@ -128,6 +128,7 @@
>  
>  /* Sequencer Status */
>  #define SEQ_STATUS BIT(5)
> +#define CHARGE_STEP		0x11
>  
>  #define ADC_CLK			3000000
>  #define TOTAL_STEPS		16
Lee Jones Nov. 10, 2014, 9:26 a.m. UTC | #2
On Mon, 10 Nov 2014, Lee Jones wrote:

> On Fri, 07 Nov 2014, Vignesh R wrote:
> 
> > In one shot mode, sequencer automatically disables all enabled steps at
> > the end of each cycle. (both ADC steps and TSC steps) Hence these steps
> > need not be saved in reg_se_cache for clearing these steps at a later
> > stage.
> > Also, when ADC wakes up Sequencer should not be busy executing any of the
> > config steps except for the charge step. Previously charge step was 1 ADC
> > clock cycle and hence it was ignored.
> > 
> > Signed-off-by: Vignesh R <vigneshr@ti.com>
> > ---
> >  drivers/mfd/ti_am335x_tscadc.c       | 7 +++++--
> >  include/linux/mfd/ti_am335x_tscadc.h | 1 +
> >  2 files changed, 6 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> > index d877e777cce6..94ef8992f46b 100644
> > --- a/drivers/mfd/ti_am335x_tscadc.c
> > +++ b/drivers/mfd/ti_am335x_tscadc.c
> > @@ -86,8 +86,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
> >  		spin_lock_irq(&tsadc->reg_lock);
> >  		finish_wait(&tsadc->reg_se_wait, &wait);
> >  
> > +		/*
> > +		 * Sequencer should either be idle or
> > +		 * busy applying the charge step.
> > +		 */
> >  		reg = tscadc_readl(tsadc, REG_ADCFSM);
> > -		WARN_ON(reg & SEQ_STATUS);
> > +		WARN_ON(reg & SEQ_STATUS & (!CHARGE_STEP));
> 
> This is almost certainly not correct.
> 
> Please take another look at the logic.
> 
> I'm _assuming_ you mean (reg & SEQ_STATUS && !CHARGE_STEP).

So I just saw that CHARGE_STEP is actually the new macro below.

So you're currently ANDing these together.

xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx  reg
00000000 00000000 00000000 00100000  #define SEQ_STATUS   BIT(5)
00000000 00000000 00000000 00010001  #define CHARGE_STEP  0x11

... which will always equate to 0.

> >  		tsadc->adc_waiting = false;
> >  	}
> >  	tsadc->adc_in_use = true;
> > @@ -96,7 +100,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
> >  void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
> >  {
> >  	spin_lock_irq(&tsadc->reg_lock);
> > -	tsadc->reg_se_cache |= val;

Didn't you add this line a little over 1 month ago?

Why the change of heart?

> >  	am335x_tscadc_need_adc(tsadc);
> >  
> >  	tscadc_writel(tsadc, REG_SE, val);
> > diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> > index c99be5dc0f5c..fcce182e4a35 100644
> > --- a/include/linux/mfd/ti_am335x_tscadc.h
> > +++ b/include/linux/mfd/ti_am335x_tscadc.h
> > @@ -128,6 +128,7 @@
> >  
> >  /* Sequencer Status */
> >  #define SEQ_STATUS BIT(5)
> > +#define CHARGE_STEP		0x11
> >  
> >  #define ADC_CLK			3000000
> >  #define TOTAL_STEPS		16
>
Vignesh Raghavendra Nov. 10, 2014, 10:44 a.m. UTC | #3
On Monday 10 November 2014 02:56 PM, Lee Jones wrote:
> On Mon, 10 Nov 2014, Lee Jones wrote:
> 
>> On Fri, 07 Nov 2014, Vignesh R wrote:
>>
>>> In one shot mode, sequencer automatically disables all enabled steps at
>>> the end of each cycle. (both ADC steps and TSC steps) Hence these steps
>>> need not be saved in reg_se_cache for clearing these steps at a later
>>> stage.
>>> Also, when ADC wakes up Sequencer should not be busy executing any of the
>>> config steps except for the charge step. Previously charge step was 1 ADC
>>> clock cycle and hence it was ignored.
>>>
>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>> ---
>>>  drivers/mfd/ti_am335x_tscadc.c       | 7 +++++--
>>>  include/linux/mfd/ti_am335x_tscadc.h | 1 +
>>>  2 files changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
>>> index d877e777cce6..94ef8992f46b 100644
>>> --- a/drivers/mfd/ti_am335x_tscadc.c
>>> +++ b/drivers/mfd/ti_am335x_tscadc.c
>>> @@ -86,8 +86,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
>>>  		spin_lock_irq(&tsadc->reg_lock);
>>>  		finish_wait(&tsadc->reg_se_wait, &wait);
>>>  
>>> +		/*
>>> +		 * Sequencer should either be idle or
>>> +		 * busy applying the charge step.
>>> +		 */
>>>  		reg = tscadc_readl(tsadc, REG_ADCFSM);
>>> -		WARN_ON(reg & SEQ_STATUS);
>>> +		WARN_ON(reg & SEQ_STATUS & (!CHARGE_STEP));
>>
>> This is almost certainly not correct.
>>
>> Please take another look at the logic.
>>
>> I'm _assuming_ you mean (reg & SEQ_STATUS && !CHARGE_STEP).
> 
> So I just saw that CHARGE_STEP is actually the new macro below.
> 
> So you're currently ANDing these together.
> 
> xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx  reg
> 00000000 00000000 00000000 00100000  #define SEQ_STATUS   BIT(5)
> 00000000 00000000 00000000 00010001  #define CHARGE_STEP  0x11
> 
> ... which will always equate to 0.
> 

Oops.. Sorry.. I meant ((reg & SEQ_STATUS) && !(reg & CHARGE_STEP)).
I will fix this.


>>>  		tsadc->adc_waiting = false;
>>>  	}
>>>  	tsadc->adc_in_use = true;
>>> @@ -96,7 +100,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
>>>  void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
>>>  {
>>>  	spin_lock_irq(&tsadc->reg_lock);
>>> -	tsadc->reg_se_cache |= val;
> 
> Didn't you add this line a little over 1 month ago?
> 
> Why the change of heart?
> 

Previously, TSC did not reliably re-enable its steps as the TSC irq
handler received false pen up events. Hence, in order to use TSC after
ADC operation, it was necessary to save and re-enable TSC steps
(basically, to keep TSC steps enabled always).
The change was more of a workaround to overcome limitation of TSC irq
handler. With this series of patches, TSC irq handler is very reliable
and the workaround is no longer required.

>>>  	am335x_tscadc_need_adc(tsadc);
>>>  
>>>  	tscadc_writel(tsadc, REG_SE, val);
>>> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
>>> index c99be5dc0f5c..fcce182e4a35 100644
>>> --- a/include/linux/mfd/ti_am335x_tscadc.h
>>> +++ b/include/linux/mfd/ti_am335x_tscadc.h
>>> @@ -128,6 +128,7 @@
>>>  
>>>  /* Sequencer Status */
>>>  #define SEQ_STATUS BIT(5)
>>> +#define CHARGE_STEP		0x11
>>>  
>>>  #define ADC_CLK			3000000
>>>  #define TOTAL_STEPS		16
>>
> 
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Patch
diff mbox

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index d877e777cce6..94ef8992f46b 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -86,8 +86,12 @@  static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 		spin_lock_irq(&tsadc->reg_lock);
 		finish_wait(&tsadc->reg_se_wait, &wait);
 
+		/*
+		 * Sequencer should either be idle or
+		 * busy applying the charge step.
+		 */
 		reg = tscadc_readl(tsadc, REG_ADCFSM);
-		WARN_ON(reg & SEQ_STATUS);
+		WARN_ON(reg & SEQ_STATUS & (!CHARGE_STEP));
 		tsadc->adc_waiting = false;
 	}
 	tsadc->adc_in_use = true;
@@ -96,7 +100,6 @@  static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
 {
 	spin_lock_irq(&tsadc->reg_lock);
-	tsadc->reg_se_cache |= val;
 	am335x_tscadc_need_adc(tsadc);
 
 	tscadc_writel(tsadc, REG_SE, val);
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index c99be5dc0f5c..fcce182e4a35 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -128,6 +128,7 @@ 
 
 /* Sequencer Status */
 #define SEQ_STATUS BIT(5)
+#define CHARGE_STEP		0x11
 
 #define ADC_CLK			3000000
 #define TOTAL_STEPS		16