Re: [RFC PATCH 3/9] of: mtd: add NAND timings retrieval support

[boris brezillon <b.brezillon@overkiz.com>]

On 08/01/2014 17:30, Rob Herring wrote:
> On Wed, Jan 8, 2014 at 8:21 AM, Boris BREZILLON <b.brezillon@overkiz.com> wrote:
>> Add a function to retrieve NAND timings from a given DT node.
>>
>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
>> ---
>>   drivers/of/of_mtd.c    |   47 +++++++++++++++++++++++++++++++++++++++++++++++
>>   include/linux/of_mtd.h |    9 +++++++++
>>   2 files changed, 56 insertions(+)
>>
>> diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
>> index a27ec94..52e07fd 100644
>> --- a/drivers/of/of_mtd.c
>> +++ b/drivers/of/of_mtd.c
>> @@ -83,3 +83,50 @@ bool of_get_nand_on_flash_bbt(struct device_node *np)
>>          return of_property_read_bool(np, "nand-on-flash-bbt");
>>   }
>>   EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);
>> +
>> +/**
>> + * of_get_nand_timings - Get nand timings for the given device_node
>> + * @np:        Pointer to the given device_node
>> + *
>> + * return 0 on success errno other wise
>> + */
>> +int of_get_nand_timings(struct device_node *np, struct nand_timings *timings)
>> +{
>> +       memset(timings, 0, sizeof(*timings));
>> +
>> +       of_property_read_u32(np, "tCLS-min", &timings->tCLS_min);
>> +       of_property_read_u32(np, "tCLH-min", &timings->tCLH_min);
>> +       of_property_read_u32(np, "tCS-min", &timings->tCS_min);
>> +       of_property_read_u32(np, "tCH-min", &timings->tCH_min);
>> +       of_property_read_u32(np, "tWP-min", &timings->tWP_min);
>> +       of_property_read_u32(np, "tALS-min", &timings->tALS_min);
>> +       of_property_read_u32(np, "tALH-min", &timings->tALH_min);
>> +       of_property_read_u32(np, "tDS-min", &timings->tDS_min);
>> +       of_property_read_u32(np, "tDH-min", &timings->tDH_min);
>> +       of_property_read_u32(np, "tWC-min", &timings->tWC_min);
>> +       of_property_read_u32(np, "tWH-min", &timings->tWH_min);
>> +       of_property_read_u32(np, "tR-max", &timings->tR_max);
>> +       of_property_read_u32(np, "tAR-min", &timings->tAR_min);
>> +       of_property_read_u32(np, "tCLR-min", &timings->tCLR_min);
>> +       of_property_read_u32(np, "tRR-min", &timings->tRR_min);
>> +       of_property_read_u32(np, "tRP-min", &timings->tRP_min);
>> +       of_property_read_u32(np, "tWB-max", &timings->tWB_max);
>> +       of_property_read_u32(np, "tRC-min", &timings->tRC_min);
>> +       of_property_read_u32(np, "tREA-max", &timings->tREA_max);
>> +       of_property_read_u32(np, "tRHZ-max", &timings->tRHZ_max);
>> +       of_property_read_u32(np, "tCHZ-max", &timings->tCHZ_max);
>> +       of_property_read_u32(np, "tRHOH-min", &timings->tRHOH_min);
>> +       of_property_read_u32(np, "tRLOH-min", &timings->tRLOH_min);
>> +       of_property_read_u32(np, "tCOH-min", &timings->tCOH_min);
>> +       of_property_read_u32(np, "tREH-min", &timings->tREH_min);
>> +       of_property_read_u32(np, "tWHR-min", &timings->tWHR_min);
>> +       of_property_read_u32(np, "tRHW-min", &timings->tRHW_min);
>> +       of_property_read_u32(np, "tIR-min", &timings->tIR_min);
>> +       of_property_read_u32(np, "tCR-min", &timings->tCR_min);
>> +       of_property_read_u32(np, "tADL-min", &timings->tADL_min);
>> +       of_property_read_u32(np, "tRST-max", &timings->tRST_max);
>> +       of_property_read_u32(np, "tWW-min", &timings->tWW_min);
> These all need to be documented.
They're document in PATCH 4/9 (but the description might be a bit
light).
> These apply to which compatible
> strings?
Actually this could apply to any nand chips.
The NAND Flash Controller driver is then responsible for converting
these values to use it.
> They should also be suffixed with the unit the property is in
> (i.e. -ms, -us, -ns).

Sure, I'll add the unit (which is -ns BTW).

Thanks.

Best Regards,

Boris
>
> Rob