Re: [PATCH v12 3/9] drivers: memory: extend of_memory by LPDDR3 support

[Lukasz Luba <l.luba@partner.samsung.com>]

Hi Krzysztof,

On 7/24/19 1:39 PM, Krzysztof Kozlowski wrote:
> On Mon, 22 Jul 2019 at 11:47, Lukasz Luba <l.luba@partner.samsung.com> wrote:
>>
>> The patch adds AC timings information needed to support LPDDR3 and memory
>> controllers. The structure is used in of_memory and currently in Exynos
>> 5422 DMC. Add parsing data needed for LPDDR3 support.
>> It is currently used in Exynos5422 Dynamic Memory Controller.
>>
>> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
>> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
>> ---
>>   drivers/memory/jedec_ddr.h |  61 +++++++++++++++
>>   drivers/memory/of_memory.c | 154 +++++++++++++++++++++++++++++++++++++
>>   drivers/memory/of_memory.h |  18 +++++
>>   3 files changed, 233 insertions(+)
>>
>> diff --git a/drivers/memory/jedec_ddr.h b/drivers/memory/jedec_ddr.h
>> index 4a21b5044ff8..38e26d461bdb 100644
>> --- a/drivers/memory/jedec_ddr.h
>> +++ b/drivers/memory/jedec_ddr.h
>> @@ -29,6 +29,7 @@
>>   #define DDR_TYPE_LPDDR2_S4     3
>>   #define DDR_TYPE_LPDDR2_S2     4
>>   #define DDR_TYPE_LPDDR2_NVM    5
>> +#define DDR_TYPE_LPDDR3                6
>>
>>   /* DDR IO width */
>>   #define DDR_IO_WIDTH_4         1
>> @@ -169,4 +170,64 @@ extern const struct lpddr2_timings
>>          lpddr2_jedec_timings[NUM_DDR_TIMING_TABLE_ENTRIES];
>>   extern const struct lpddr2_min_tck lpddr2_jedec_min_tck;
>>
>> +/*
>> + * Structure for timings for LPDDR3 based on LPDDR2 plus additional fields.
>> + * All parameters are in pico seconds(ps) unless explicitly indicated
>> + * with a suffix like tRAS_max_ns below
>> + */
>> +struct lpddr3_timings {
>> +       u32 max_freq;
>> +       u32 min_freq;
>> +       u32 tRFC;
>> +       u32 tRRD;
>> +       u32 tRPab;
>> +       u32 tRPpb;
>> +       u32 tRCD;
>> +       u32 tRC;
>> +       u32 tRAS;
>> +       u32 tWTR;
>> +       u32 tWR;
>> +       u32 tRTP;
>> +       u32 tW2W_C2C;
>> +       u32 tR2R_C2C;
>> +       u32 tWL;
>> +       u32 tDQSCK;
>> +       u32 tRL;
>> +       u32 tFAW;
>> +       u32 tXSR;
>> +       u32 tXP;
>> +       u32 tCKE;
>> +       u32 tCKESR;
>> +       u32 tMRD;
>> +};
>> +
>> +/*
>> + * Min value for some parameters in terms of number of tCK cycles(nCK)
>> + * Please set to zero parameters that are not valid for a given memory
>> + * type
>> + */
>> +struct lpddr3_min_tck {
>> +       u32 tRFC;
>> +       u32 tRRD;
>> +       u32 tRPab;
>> +       u32 tRPpb;
>> +       u32 tRCD;
>> +       u32 tRC;
>> +       u32 tRAS;
>> +       u32 tWTR;
>> +       u32 tWR;
>> +       u32 tRTP;
>> +       u32 tW2W_C2C;
>> +       u32 tR2R_C2C;
>> +       u32 tWL;
>> +       u32 tDQSCK;
>> +       u32 tRL;
>> +       u32 tFAW;
>> +       u32 tXSR;
>> +       u32 tXP;
>> +       u32 tCKE;
>> +       u32 tCKESR;
>> +       u32 tMRD;
>> +};
>> +
>>   #endif /* __JEDEC_DDR_H */
>> diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
>> index 46539b27a3fb..4f5b8c81669f 100644
>> --- a/drivers/memory/of_memory.c
>> +++ b/drivers/memory/of_memory.c
>> @@ -3,6 +3,12 @@
>>    * OpenFirmware helpers for memory drivers
>>    *
>>    * Copyright (C) 2012 Texas Instruments, Inc.
>> + * Copyright (C) 2019 Samsung Electronics Co., Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
> 
> What's this?
My bad, in the meantime Thomas Gleixner has replaced the license header.
The old part has been automatically taken again during my re-base.
I will just remove the old license comment.

Regards,
Lukasz
> 
> Please, get a independent review or ack for this patch.
> 
> Best regards,
> Krzysztof
> 
>