diff mbox

[2/3] ARM: AT91: IIO: add sleep mode support

Message ID 1355942232-26251-2-git-send-email-plagnioj@jcrosoft.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jean-Christophe PLAGNIOL-VILLARD Dec. 19, 2012, 6:37 p.m. UTC
The sleep mode will allow to put the add in sleep between conversion.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: linux-iio@vger.kernel.org
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
---
 Documentation/devicetree/bindings/arm/atmel-adc.txt |    1 +
 drivers/iio/adc/at91_adc.c                          |   19 ++++++++++---------
 2 files changed, 11 insertions(+), 9 deletions(-)

Comments

Maxime Ripard Dec. 20, 2012, 10:46 a.m. UTC | #1
Hi,

Le 19/12/2012 19:37, Jean-Christophe PLAGNIOL-VILLARD a écrit :
> The sleep mode will allow to put the add in sleep between conversion.
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: linux-iio@vger.kernel.org
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
> ---
>  Documentation/devicetree/bindings/arm/atmel-adc.txt |    1 +
>  drivers/iio/adc/at91_adc.c                          |   19 ++++++++++---------
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> index fd2d69e..efb6f02 100644
> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> @@ -25,6 +25,7 @@ Optional properties:
>    - atmel,adc-use-res: String corresponding to an identifier from
>  		       atmel,adc-res-names property. If not specified, the highest
>  		       resolution will be used.
> +  - atmel,atmel,adc-sleep-mode: Boolean to enable of sleep mode when no conversion
>   
>  Optional trigger Nodes:
>    - Required properties:
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index f175a86..c563488 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -52,6 +52,7 @@ struct at91_adc_state {
>  	void __iomem		*reg_base;
>  	struct at91_adc_reg_desc *registers;
>  	u8			startup_time;
> +	bool			sleep_mode;
>  	struct iio_trigger	**trig;
>  	struct at91_adc_trigger	*trigger_list;
>  	u32			trigger_number;
> @@ -455,6 +456,8 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
>  	}
>  	st->num_channels = prop;
>  
> +	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
> +
>  	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
>  		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
>  		ret = -EINVAL;
> @@ -580,6 +583,7 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>  	struct iio_dev *idev;
>  	struct at91_adc_state *st;
>  	struct resource *res;
> +	u32 reg;
>  
>  	idev = iio_device_alloc(sizeof(struct at91_adc_state));
>  	if (idev == NULL) {
> @@ -687,16 +691,13 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>  	 */
>  	ticks = round_up((st->startup_time * adc_clk /
>  			  1000000) - 1, 8) / 8;
> -
> +	reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
> +	reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
>  	if (st->low_res)
> -		at91_adc_writel(st, AT91_ADC_MR,
> -				AT91_ADC_LOWRES |
> -				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
> -				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
> -	else
> -		at91_adc_writel(st, AT91_ADC_MR,
> -				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
> -				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
> +		reg |= AT91_ADC_LOWRES;
> +	if (st->sleep_mode)
> +		reg |= AT91_ADC_SLEEP;
> +	at91_adc_writel(st, AT91_ADC_MR, reg);

I'm fine with the code in itself, but since this also refactors what has
been added in the previous patch, maybe you can add it in the first patch.

Apart from that, you can add my Acked-by.

Maxime
Jonathan Cameron Dec. 27, 2012, 12:09 p.m. UTC | #2
On 12/20/2012 10:46 AM, Maxime Ripard wrote:
> Hi,
> 
> Le 19/12/2012 19:37, Jean-Christophe PLAGNIOL-VILLARD a écrit :
>> The sleep mode will allow to put the add in sleep between conversion.
>>
>> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
>> Cc: linux-iio@vger.kernel.org
>> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
>> Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
>> ---
>>  Documentation/devicetree/bindings/arm/atmel-adc.txt |    1 +
>>  drivers/iio/adc/at91_adc.c                          |   19 ++++++++++---------
>>  2 files changed, 11 insertions(+), 9 deletions(-)
I have no particular problem with this, but would like a brief note on what
one looses when sleep mode is enabled?  How much slower is the conversion if
we first have to come out of sleep mode?   Basically I want a justification
of why we don't always enable this.  Is this hardware specific or
should it simply be controllable from userspace?

>>
>> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> index fd2d69e..efb6f02 100644
>> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> @@ -25,6 +25,7 @@ Optional properties:
>>    - atmel,adc-use-res: String corresponding to an identifier from
>>  		       atmel,adc-res-names property. If not specified, the highest
>>  		       resolution will be used.
>> +  - atmel,atmel,adc-sleep-mode: Boolean to enable of sleep mode when no conversion
>>   
>>  Optional trigger Nodes:
>>    - Required properties:
>> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
>> index f175a86..c563488 100644
>> --- a/drivers/iio/adc/at91_adc.c
>> +++ b/drivers/iio/adc/at91_adc.c
>> @@ -52,6 +52,7 @@ struct at91_adc_state {
>>  	void __iomem		*reg_base;
>>  	struct at91_adc_reg_desc *registers;
>>  	u8			startup_time;
>> +	bool			sleep_mode;
>>  	struct iio_trigger	**trig;
>>  	struct at91_adc_trigger	*trigger_list;
>>  	u32			trigger_number;
>> @@ -455,6 +456,8 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
>>  	}
>>  	st->num_channels = prop;
>>  
>> +	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
>> +
>>  	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
>>  		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
>>  		ret = -EINVAL;
>> @@ -580,6 +583,7 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>>  	struct iio_dev *idev;
>>  	struct at91_adc_state *st;
>>  	struct resource *res;
>> +	u32 reg;
>>  
>>  	idev = iio_device_alloc(sizeof(struct at91_adc_state));
>>  	if (idev == NULL) {
>> @@ -687,16 +691,13 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
>>  	 */
>>  	ticks = round_up((st->startup_time * adc_clk /
>>  			  1000000) - 1, 8) / 8;
>> -
>> +	reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
>> +	reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
>>  	if (st->low_res)
>> -		at91_adc_writel(st, AT91_ADC_MR,
>> -				AT91_ADC_LOWRES |
>> -				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
>> -				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
>> -	else
>> -		at91_adc_writel(st, AT91_ADC_MR,
>> -				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
>> -				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
>> +		reg |= AT91_ADC_LOWRES;
>> +	if (st->sleep_mode)
>> +		reg |= AT91_ADC_SLEEP;
>> +	at91_adc_writel(st, AT91_ADC_MR, reg);
> 
> I'm fine with the code in itself, but since this also refactors what has
> been added in the previous patch, maybe you can add it in the first patch.
> 
> Apart from that, you can add my Acked-by.
> 
> Maxime
>
Maxime Ripard Dec. 27, 2012, 5:54 p.m. UTC | #3
Hi,

Le 19/12/2012 19:37, Jean-Christophe PLAGNIOL-VILLARD a écrit :
> The sleep mode will allow to put the add in sleep between conversion.
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: linux-iio@vger.kernel.org
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
> ---
>  Documentation/devicetree/bindings/arm/atmel-adc.txt |    1 +
>  drivers/iio/adc/at91_adc.c                          |   19 ++++++++++---------
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> index fd2d69e..efb6f02 100644
> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> @@ -25,6 +25,7 @@ Optional properties:
>    - atmel,adc-use-res: String corresponding to an identifier from
>  		       atmel,adc-res-names property. If not specified, the highest
>  		       resolution will be used.
> +  - atmel,atmel,adc-sleep-mode: Boolean to enable of sleep mode when no conversion

I forgot it in my first review, but there's a typo in the name of the
property here (one extra "atmel,")

Maxime
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
index fd2d69e..efb6f02 100644
--- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
@@ -25,6 +25,7 @@  Optional properties:
   - atmel,adc-use-res: String corresponding to an identifier from
 		       atmel,adc-res-names property. If not specified, the highest
 		       resolution will be used.
+  - atmel,atmel,adc-sleep-mode: Boolean to enable of sleep mode when no conversion
  
 Optional trigger Nodes:
   - Required properties:
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index f175a86..c563488 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -52,6 +52,7 @@  struct at91_adc_state {
 	void __iomem		*reg_base;
 	struct at91_adc_reg_desc *registers;
 	u8			startup_time;
+	bool			sleep_mode;
 	struct iio_trigger	**trig;
 	struct at91_adc_trigger	*trigger_list;
 	u32			trigger_number;
@@ -455,6 +456,8 @@  static int at91_adc_probe_dt(struct at91_adc_state *st,
 	}
 	st->num_channels = prop;
 
+	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
+
 	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
 		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
 		ret = -EINVAL;
@@ -580,6 +583,7 @@  static int __devinit at91_adc_probe(struct platform_device *pdev)
 	struct iio_dev *idev;
 	struct at91_adc_state *st;
 	struct resource *res;
+	u32 reg;
 
 	idev = iio_device_alloc(sizeof(struct at91_adc_state));
 	if (idev == NULL) {
@@ -687,16 +691,13 @@  static int __devinit at91_adc_probe(struct platform_device *pdev)
 	 */
 	ticks = round_up((st->startup_time * adc_clk /
 			  1000000) - 1, 8) / 8;
-
+	reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
+	reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
 	if (st->low_res)
-		at91_adc_writel(st, AT91_ADC_MR,
-				AT91_ADC_LOWRES |
-				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
-				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
-	else
-		at91_adc_writel(st, AT91_ADC_MR,
-				(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
-				(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
+		reg |= AT91_ADC_LOWRES;
+	if (st->sleep_mode)
+		reg |= AT91_ADC_SLEEP;
+	at91_adc_writel(st, AT91_ADC_MR, reg);
 
 	/* Setup the ADC channels available on the board */
 	ret = at91_adc_channel_init(idev);