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

From: Krzysztof Kozlowski
Date: Wed Jul 24 2019 - 07:40:05 EST


On Mon, 22 Jul 2019 at 11:47, Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxx>
> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
> ---
> 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?

Please, get a independent review or ack for this patch.

Best regards,
Krzysztof