Re: [Patch v3 08/11] driver/edac/fsl_ddr: Add support of little endian

[york sun]

On 08/08/2016 01:50 AM, Borislav Petkov wrote:
> On Thu, Aug 04, 2016 at 03:58:33PM -0700, York Sun wrote:
>> Get endianness from device tree. Both big endian and little endian
>> are supported. Default to big endian for backward compatibility to
>> MPC85xx.
>>
>> Signed-off-by: York Sun <york.sun@xxxxxxx>
>>
>> ---
>> Change log
>>   v3: no change
>>   v2: Separated from "Add support for ARM-based SoCs" patch
>>
>>  .../fsl/ddr.txt}                                   |  6 ++
>>  drivers/edac/fsl_ddr_edac.c                        | 83 ++++++++++++++--------
>>  2 files changed, 58 insertions(+), 31 deletions(-)
>>  rename Documentation/devicetree/bindings/{powerpc/fsl/mem-ctrlr.txt => memory-controllers/fsl/ddr.txt} (74%)
>>
>> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/mem-ctrlr.txt b/Documentation/devicetree/bindings/memory-controllers/fsl/ddr.txt
>> similarity index 74%
>> rename from Documentation/devicetree/bindings/powerpc/fsl/mem-ctrlr.txt
>> rename to Documentation/devicetree/bindings/memory-controllers/fsl/ddr.txt
>> index f87856f..62623f9 100644
>> --- a/Documentation/devicetree/bindings/powerpc/fsl/mem-ctrlr.txt
>> +++ b/Documentation/devicetree/bindings/memory-controllers/fsl/ddr.txt
>> @@ -7,6 +7,10 @@ Properties:
>>  		  "fsl,qoriq-memory-controller".
>>  - reg		: Address and size of DDR controller registers
>>  - interrupts	: Error interrupt of DDR controller
>> +- little-endian	: Specifies little-endian access to registers
>> +- big-endian	: Specifies big-endian access to registers
>> +
>> +If both little-endian and big-endian are omitted, big-endian will be used.
>>
>>  Example 1:
>>
>> @@ -14,6 +18,7 @@ Example 1:
>>  		compatible = "fsl,bsc9132-memory-controller";
>>  		reg = <0x2000 0x1000>;
>>  		interrupts = <16 2 1 8>;
>> +		big-endian;
>>  	};
>>
>>
>> @@ -24,4 +29,5 @@ Example 2:
>>  				"fsl,qoriq-memory-controller";
>>  		reg = <0x8000 0x1000>;
>>  		interrupts = <16 2 1 23>;
>> +		big-endian;
>>  	};
>
> This needs an ACK from DT maintainers. They're on CC.
>
>> diff --git a/drivers/edac/fsl_ddr_edac.c b/drivers/edac/fsl_ddr_edac.c
>> index 88ecf7d..b1b7924 100644
>> --- a/drivers/edac/fsl_ddr_edac.c
>> +++ b/drivers/edac/fsl_ddr_edac.c
>
> ...
>
>> @@ -470,6 +483,13 @@ int fsl_ddr_mc_err_probe(struct platform_device *op)
>>  	mci->ctl_name = pdata->name;
>>  	mci->dev_name = pdata->name;
>>
>> +	if (of_find_property(op->dev.of_node, "little-endian", NULL))
>> +		little_endian = true;
>> +	else if (of_find_property(op->dev.of_node, "big-endian", NULL))
>> +		little_endian = false;
>> +	else
>> +		little_endian = false;
>
> What happened here?
>
> Considering little_endian is static, this should suffice for its
> initialization:
>
> 	if (of_find_property(op->dev.of_node, "little-endian", NULL))
> 		little_endian = true;
>
>

OK.

>
>
>>  	res = of_address_to_resource(op->dev.of_node, 0, &r);
>>  	if (res) {
>>  		pr_err("%s: Unable to get resource for MC err regs\n",
>> @@ -492,7 +512,7 @@ int fsl_ddr_mc_err_probe(struct platform_device *op)
>>  		goto err;
>>  	}
>>
>> -	sdram_ctl = in_be32(pdata->mc_vbase + MC_DDR_SDRAM_CFG);
>> +	sdram_ctl = ddr_in32(pdata->mc_vbase + MC_DDR_SDRAM_CFG);
>>  	if (!(sdram_ctl & DSC_ECC_EN)) {
>>  		/* no ECC */
>>  		pr_warn("%s: No ECC DIMMs discovered\n", __func__);
>> @@ -520,11 +540,11 @@ int fsl_ddr_mc_err_probe(struct platform_device *op)
>>
>>  	/* store the original error disable bits */
>>  	orig_ddr_err_disable =
>> -	    in_be32(pdata->mc_vbase + MC_ERR_DISABLE);
>> -	out_be32(pdata->mc_vbase + MC_ERR_DISABLE, 0);
>> +	    ddr_in32(pdata->mc_vbase + MC_ERR_DISABLE);
>> +	ddr_out32(pdata->mc_vbase + MC_ERR_DISABLE, 0);
>>
>>  	/* clear all error bits */
>> -	out_be32(pdata->mc_vbase + MC_ERR_DETECT, ~0);
>> +	ddr_out32(pdata->mc_vbase + MC_ERR_DETECT, ~0);
>>
>>  	if (edac_mc_add_mc_with_groups(mci, fsl_ddr_dev_groups)) {
>>  		edac_dbg(3, "failed edac_mc_add_mc()\n");
>> @@ -532,15 +552,15 @@ int fsl_ddr_mc_err_probe(struct platform_device *op)
>>  	}
>>
>>  	if (edac_op_state == EDAC_OPSTATE_INT) {
>> -		out_be32(pdata->mc_vbase + MC_ERR_INT_EN,
>> -			 DDR_EIE_MBEE | DDR_EIE_SBEE);
>> +		ddr_out32(pdata->mc_vbase + MC_ERR_INT_EN,
>> +			  DDR_EIE_MBEE | DDR_EIE_SBEE);
>>
>>  		/* store the original error management threshold */
>> -		orig_ddr_err_sbe = in_be32(pdata->mc_vbase +
>> +		orig_ddr_err_sbe = ddr_in32(pdata->mc_vbase +
>>  					   MC_ERR_SBE) & 0xff0000;
>>
>>  		/* set threshold to 1 error per interrupt */
>> -		out_be32(pdata->mc_vbase + MC_ERR_SBE, 0x10000);
>> +		ddr_out32(pdata->mc_vbase + MC_ERR_SBE, 0x10000);
>>
>>  		/* register interrupts */
>>  		pdata->irq = irq_of_parse_and_map(op->dev.of_node, 0);
>> @@ -573,6 +593,7 @@ err:
>>  	edac_mc_free(mci);
>>  	return res;
>>  }
>> +EXPORT_SYMBOL_GPL(fsl_ddr_mc_err_probe);
>
> What's that export for?
>

I thought I need to export this symbol so it can be call from a module 
driver. Actually I don't. Will remove.

York