[PATCH] spi: fsl-dspi: Set max_speed_hz for master

[PATCH] spi: fsl-dspi: Set max_speed_hz for master

[Bhuvanchandra DV]

Calculate and update max speed from bus clock for SoC's
using DSPI IP.

The bus clock factor's are taken from the data sheet's
of respective SoC's.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
---
 drivers/spi/spi-fsl-dspi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 59a1143..8753276 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -121,18 +121,22 @@ enum dspi_trans_mode {
 
 struct fsl_dspi_devtype_data {
 	enum dspi_trans_mode trans_mode;
+	u8 max_clock_factor;
 };
 
 static const struct fsl_dspi_devtype_data vf610_data = {
 	.trans_mode = DSPI_EOQ_MODE,
+	.max_clock_factor = 2,
 };
 
 static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
 	.trans_mode = DSPI_TCFQ_MODE,
+	.max_clock_factor = 8,
 };
 
 static const struct fsl_dspi_devtype_data ls2085a_data = {
 	.trans_mode = DSPI_TCFQ_MODE,
+	.max_clock_factor = 8,
 };
 
 struct fsl_dspi {
@@ -726,6 +730,9 @@ static int dspi_probe(struct platform_device *pdev)
 	}
 	clk_prepare_enable(dspi->clk);
 
+	master->max_speed_hz =
+		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;
+
 	init_waitqueue_head(&dspi->waitq);
 	platform_set_drvdata(pdev, master);
 
-- 
2.7.3

Re: [PATCH] spi: fsl-dspi: Set max_speed_hz for master

[Stefan Agner]

On 2016-03-21 13:11, Bhuvanchandra DV wrote:
> Calculate and update max speed from bus clock for SoC's
> using DSPI IP.
> 
> The bus clock factor's are taken from the data sheet's
> of respective SoC's.

Plurals are without apostrophe...

I wonder if GCC optimizes this to a bit shift...

Acked-by: Stefan Agner <stefan@agner.ch>

> 
> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
> ---
>  drivers/spi/spi-fsl-dspi.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
> index 59a1143..8753276 100644
> --- a/drivers/spi/spi-fsl-dspi.c
> +++ b/drivers/spi/spi-fsl-dspi.c
> @@ -121,18 +121,22 @@ enum dspi_trans_mode {
>  
>  struct fsl_dspi_devtype_data {
>  	enum dspi_trans_mode trans_mode;
> +	u8 max_clock_factor;
>  };
>  
>  static const struct fsl_dspi_devtype_data vf610_data = {
>  	.trans_mode = DSPI_EOQ_MODE,
> +	.max_clock_factor = 2,
>  };
>  
>  static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
>  	.trans_mode = DSPI_TCFQ_MODE,
> +	.max_clock_factor = 8,
>  };
>  
>  static const struct fsl_dspi_devtype_data ls2085a_data = {
>  	.trans_mode = DSPI_TCFQ_MODE,
> +	.max_clock_factor = 8,
>  };
>  
>  struct fsl_dspi {
> @@ -726,6 +730,9 @@ static int dspi_probe(struct platform_device *pdev)
>  	}
>  	clk_prepare_enable(dspi->clk);
>  
> +	master->max_speed_hz =
> +		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;
> +
>  	init_waitqueue_head(&dspi->waitq);
>  	platform_set_drvdata(pdev, master);