diff mbox series

[13/40] mfd: ti_am335x_tscadc: Reword the comment explaining the dividers

Message ID 20210825152518.379386-14-miquel.raynal@bootlin.com
State Superseded
Headers show
Series TI AM437X ADC1 | expand

Commit Message

Miquel Raynal Aug. 25, 2021, 3:24 p.m. UTC
The comment misses the main information which is that we assume that a
sample takes 15 ADC clock cycles to be generated. Let's take the
occasion to rework a little bit this comment.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/mfd/ti_am335x_tscadc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Jonathan Cameron Aug. 30, 2021, 1:43 p.m. UTC | #1
On Wed, 25 Aug 2021 17:24:51 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> The comment misses the main information which is that we assume that a

> sample takes 15 ADC clock cycles to be generated. Let's take the

> occasion to rework a little bit this comment.

> 

> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Fair enough. It does seem a little clearer to me after your rewording.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>


> ---

>  drivers/mfd/ti_am335x_tscadc.c | 12 ++++++------

>  1 file changed, 6 insertions(+), 6 deletions(-)

> 

> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c

> index 0fef35e1e64b..3afe22680973 100644

> --- a/drivers/mfd/ti_am335x_tscadc.c

> +++ b/drivers/mfd/ti_am335x_tscadc.c

> @@ -195,12 +195,12 @@ static	int ti_tscadc_probe(struct platform_device *pdev)

>  	pm_runtime_get_sync(&pdev->dev);

>  

>  	/*

> -	 * The TSC_ADC_Subsystem has 2 clock domains

> -	 * OCP_CLK and ADC_CLK.

> -	 * The ADC clock is expected to run at target of 3MHz,

> -	 * and expected to capture 12-bit data at a rate of 200 KSPS.

> -	 * The TSC_ADC_SS controller design assumes the OCP clock is

> -	 * at least 6x faster than the ADC clock.

> +	 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.

> +	 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles.

> +	 * am33xx ADCs expect to capture 200ksps.

> +	 * We need the ADC clocks to run at 3MHz.

> +	 * This frequency is valid since TSC_ADC_SS controller design

> +	 * assumes the OCP clock is at least 6x faster than the ADC clock.

>  	 */

>  	clk = devm_clk_get(&pdev->dev, "adc_tsc_fck");

>  	if (IS_ERR(clk)) {
diff mbox series

Patch

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 0fef35e1e64b..3afe22680973 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -195,12 +195,12 @@  static	int ti_tscadc_probe(struct platform_device *pdev)
 	pm_runtime_get_sync(&pdev->dev);
 
 	/*
-	 * The TSC_ADC_Subsystem has 2 clock domains
-	 * OCP_CLK and ADC_CLK.
-	 * The ADC clock is expected to run at target of 3MHz,
-	 * and expected to capture 12-bit data at a rate of 200 KSPS.
-	 * The TSC_ADC_SS controller design assumes the OCP clock is
-	 * at least 6x faster than the ADC clock.
+	 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.
+	 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles.
+	 * am33xx ADCs expect to capture 200ksps.
+	 * We need the ADC clocks to run at 3MHz.
+	 * This frequency is valid since TSC_ADC_SS controller design
+	 * assumes the OCP clock is at least 6x faster than the ADC clock.
 	 */
 	clk = devm_clk_get(&pdev->dev, "adc_tsc_fck");
 	if (IS_ERR(clk)) {