Re: [PATCH] spi: dw-mmio: add MSCC Jaguar2 support

[Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>]

Hi Alexandre,
 
 On mer., août 29 2018, Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote:

> Unfortunately, the Jaguar2 CPU_SYSTEM_CTRL register set has a different
> layout than the Ocelot one. Handle that while keeping most of the code
> common.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

Reviewed-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>

Gregory

> ---
>
> Hi,
>
> This is really unfortunate and I hope it will not be necessary to do the same
> for every SoC in the line.
>
> I didn't use a regmap_field because it is only accessed once at probe time.
>
>  drivers/spi/spi-dw-mmio.c | 28 ++++++++++++++++++++++------
>  1 file changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
> index e80f60ed6fdf..351f49976161 100644
> --- a/drivers/spi/spi-dw-mmio.c
> +++ b/drivers/spi/spi-dw-mmio.c
> @@ -34,8 +34,8 @@ struct dw_spi_mmio {
>  };
>  
>  #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL	0x24
> -#define OCELOT_IF_SI_OWNER_MASK			GENMASK(5, 4)
>  #define OCELOT_IF_SI_OWNER_OFFSET		4
> +#define JAGUAR2_IF_SI_OWNER_OFFSET		6
>  #define MSCC_IF_SI_OWNER_SISL			0
>  #define MSCC_IF_SI_OWNER_SIBM			1
>  #define MSCC_IF_SI_OWNER_SIMC			2
> @@ -76,7 +76,8 @@ static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
>  }
>  
>  static int dw_spi_mscc_init(struct platform_device *pdev,
> -			    struct dw_spi_mmio *dwsmmio)
> +			    struct dw_spi_mmio *dwsmmio,
> +			    const char *cpu_syscon, u32 if_si_owner_offset)
>  {
>  	struct dw_spi_mscc *dwsmscc;
>  	struct resource *res;
> @@ -92,7 +93,7 @@ static int dw_spi_mscc_init(struct platform_device *pdev,
>  		return PTR_ERR(dwsmscc->spi_mst);
>  	}
>  
> -	dwsmscc->syscon = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon");
> +	dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon);
>  	if (IS_ERR(dwsmscc->syscon))
>  		return PTR_ERR(dwsmscc->syscon);
>  
> @@ -101,8 +102,8 @@ static int dw_spi_mscc_init(struct platform_device *pdev,
>  
>  	/* Select the owner of the SI interface */
>  	regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
> -			   OCELOT_IF_SI_OWNER_MASK,
> -			   MSCC_IF_SI_OWNER_SIMC << OCELOT_IF_SI_OWNER_OFFSET);
> +			   0x3 << if_si_owner_offset,
> +			   MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
>  
>  	dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
>  	dwsmmio->priv = dwsmscc;
> @@ -110,6 +111,20 @@ static int dw_spi_mscc_init(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
> +				   struct dw_spi_mmio *dwsmmio)
> +{
> +	return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
> +				OCELOT_IF_SI_OWNER_OFFSET);
> +}
> +
> +static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
> +				    struct dw_spi_mmio *dwsmmio)
> +{
> +	return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
> +				JAGUAR2_IF_SI_OWNER_OFFSET);
> +}
> +
>  static int dw_spi_mmio_probe(struct platform_device *pdev)
>  {
>  	int (*init_func)(struct platform_device *pdev,
> @@ -212,7 +227,8 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
>  
>  static const struct of_device_id dw_spi_mmio_of_match[] = {
>  	{ .compatible = "snps,dw-apb-ssi", },
> -	{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_init},
> +	{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
> +	{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
>  	{ /* end of table */}
>  };
>  MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
> -- 
> 2.18.0
>

-- 
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com