On Fri, Apr 07, 2017 at 12:26:36PM -0700, matthew.gerlach@linux.intel.com wrote:
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> 
> The value in the version register of the altera freeze bridge
> controller changed from the beta value of 2 to the
> value of 0xad000003 in the official release of the IP.
> This patch supports the old and new version numbers, and the
> driver's probe function will fail if neither of the supported
> versions is found.
> 
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
> ---
> v2: change warning to fail as per Moritz Fischer <mdf@kernel.org>
> ---
>  drivers/fpga/altera-freeze-bridge.c | 30 +++++++++++++++++++-----------
>  1 file changed, 19 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
> index 8dcd9fb..114d3cb 100644
> --- a/drivers/fpga/altera-freeze-bridge.c
> +++ b/drivers/fpga/altera-freeze-bridge.c
> @@ -28,6 +28,7 @@
>  #define FREEZE_CSR_REG_VERSION			12
>  
>  #define FREEZE_CSR_SUPPORTED_VERSION		2
> +#define FREEZE_CSR_OFFICIAL_VERSION		0xad000003
>  
>  #define FREEZE_CSR_STATUS_FREEZE_REQ_DONE	BIT(0)
>  #define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE	BIT(1)
> @@ -218,6 +219,7 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct device_node *np = pdev->dev.of_node;
> +	void __iomem *base_addr;
>  	struct altera_freeze_br_data *priv;
>  	struct resource *res;
>  	u32 status, revision;
> @@ -225,26 +227,32 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>  	if (!np)
>  		return -ENODEV;
>  
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	base_addr = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(base_addr))
> +		return PTR_ERR(base_addr);
> +
> +	revision = readl(base_addr + FREEZE_CSR_REG_VERSION);
> +	if ((revision != FREEZE_CSR_SUPPORTED_VERSION) &&
> +	    (revision != FREEZE_CSR_OFFICIAL_VERSION)) {
> +		dev_err(dev,
> +			"%s unexpected revision 0x%x != 0x%x != 0x%x\n",
> +			__func__, revision, FREEZE_CSR_SUPPORTED_VERSION,
> +			FREEZE_CSR_OFFICIAL_VERSION);
> +		return -EINVAL;
> +	}
> +
>  	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>  	if (!priv)
>  		return -ENOMEM;
>  
>  	priv->dev = dev;
>  
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	priv->base_addr = devm_ioremap_resource(dev, res);
> -	if (IS_ERR(priv->base_addr))
> -		return PTR_ERR(priv->base_addr);
> -
> -	status = readl(priv->base_addr + FREEZE_CSR_STATUS_OFFSET);
> +	status = readl(base_addr + FREEZE_CSR_STATUS_OFFSET);
>  	if (status & FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE)
>  		priv->enable = 1;
>  
> -	revision = readl(priv->base_addr + FREEZE_CSR_REG_VERSION);
> -	if (revision != FREEZE_CSR_SUPPORTED_VERSION)
> -		dev_warn(dev,
> -			 "%s Freeze Controller unexpected revision %d != %d\n",
> -			 __func__, revision, FREEZE_CSR_SUPPORTED_VERSION);
> +	priv->base_addr = base_addr;
>  
>  	return fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>  				    &altera_freeze_br_br_ops, priv);
> -- 
> 2.7.4
> 

Thanks,
Moritz