Re: [PATCH v10 06/13] drivers: memory: extend of_memory by LPDDR3 support

Krzysztof Kozlowski
2019-06-14T12:44:10Z

On Fri, 14 Jun 2019 at 11:53, 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/of_memory.c | 154 +++++++++++++++++++++++++++++++++++++
> drivers/memory/of_memory.h | 18 +++++
> include/memory/jedec_ddr.h | 62 +++++++++++++++
> 3 files changed, 234 insertions(+)

Previously this was going through Greg, so if I am going to take it
along with drivers/memory/samsung patches, I need some acks.

Greg, Rob,
Are you okay with this patch and with taking it through samsung-soc?

Best regards,
Krzysztof
> diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
> index 12a61f558644..30f3a3e75063 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.
> */
>
> #include <linux/device.h>
> @@ -148,3 +154,151 @@ const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
> return lpddr2_jedec_timings;
> }
> EXPORT_SYMBOL(of_get_ddr_timings);
> +
> +/**
> + * of_lpddr3_get_min_tck() - extract min timing values for lpddr3
> + * @np: pointer to ddr device tree node
> + * @device: device requesting for min timing values
> + *
> + * Populates the lpddr3_min_tck structure by extracting data
> + * from device tree node. Returns a pointer to the populated
> + * structure. If any error in populating the structure, returns NULL.
> + */
> +const struct lpddr3_min_tck *of_lpddr3_get_min_tck(struct device_node *np,
> + struct device *dev)
> +{
> + int ret = 0;
> + struct lpddr3_min_tck *min;
> +
> + min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
> + if (!min)
> + goto default_min_tck;
> +
> + ret |= of_property_read_u32(np, "tRFC-min-tck", &min->tRFC);
> + ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
> + ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
> + ret |= of_property_read_u32(np, "tRPpb-min-tck", &min->tRPpb);
> + ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
> + ret |= of_property_read_u32(np, "tRC-min-tck", &min->tRC);
> + ret |= of_property_read_u32(np, "tRAS-min-tck", &min->tRAS);
> + ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
> + ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
> + ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
> + ret |= of_property_read_u32(np, "tW2W-C2C-min-tck", &min->tW2W_C2C);
> + ret |= of_property_read_u32(np, "tR2R-C2C-min-tck", &min->tR2R_C2C);
> + ret |= of_property_read_u32(np, "tWL-min-tck", &min->tWL);
> + ret |= of_property_read_u32(np, "tDQSCK-min-tck", &min->tDQSCK);
> + ret |= of_property_read_u32(np, "tRL-min-tck", &min->tRL);
> + ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
> + ret |= of_property_read_u32(np, "tXSR-min-tck", &min->tXSR);
> + ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
> + ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE);
> + ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR);
> + ret |= of_property_read_u32(np, "tMRD-min-tck", &min->tMRD);
> +
> + if (ret) {
> + dev_warn(dev, "%s: errors while parsing min-tck values\n",
> + __func__);
> + devm_kfree(dev, min);
> + goto default_min_tck;
> + }
> +
> + return min;
> +
> +default_min_tck:
> + dev_warn(dev, "%s: using default min-tck values\n", __func__);
> + return NULL;
> +}
> +EXPORT_SYMBOL(of_lpddr3_get_min_tck);
> +
> +static int of_lpddr3_do_get_timings(struct device_node *np,
> + struct lpddr3_timings *tim)
> +{
> + int ret;
> +
> + /* The 'reg' param required since DT has changed, used as 'max-freq' */
> + ret = of_property_read_u32(np, "reg", &tim->max_freq);
> + ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
> + ret |= of_property_read_u32(np, "tRFC", &tim->tRFC);
> + ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
> + ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
> + ret |= of_property_read_u32(np, "tRPpb", &tim->tRPpb);
> + ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
> + ret |= of_property_read_u32(np, "tRC", &tim->tRC);
> + ret |= of_property_read_u32(np, "tRAS", &tim->tRAS);
> + ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
> + ret |= of_property_read_u32(np, "tWR", &tim->tWR);
> + ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
> + ret |= of_property_read_u32(np, "tW2W-C2C", &tim->tW2W_C2C);
> + ret |= of_property_read_u32(np, "tR2R-C2C", &tim->tR2R_C2C);
> + ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
> + ret |= of_property_read_u32(np, "tXSR", &tim->tXSR);
> + ret |= of_property_read_u32(np, "tXP", &tim->tXP);
> + ret |= of_property_read_u32(np, "tCKE", &tim->tCKE);
> + ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
> + ret |= of_property_read_u32(np, "tMRD", &tim->tMRD);
> +
> + return ret;
> +}
> +
> +/**
> + * of_lpddr3_get_ddr_timings() - extracts the lpddr3 timings and updates no of
> + * frequencies available.
> + * @np_ddr: Pointer to ddr device tree node
> + * @dev: Device requesting for ddr timings
> + * @device_type: Type of ddr
> + * @nr_frequencies: No of frequencies available for ddr
> + * (updated by this function)
> + *
> + * Populates lpddr3_timings structure by extracting data from device
> + * tree node. Returns pointer to populated structure. If any error
> + * while populating, returns NULL.
> + */
> +const struct lpddr3_timings
> +*of_lpddr3_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
> + u32 device_type, u32 *nr_frequencies)
> +{
> + struct lpddr3_timings *timings = NULL;
> + u32 arr_sz = 0, i = 0;
> + struct device_node *np_tim;
> + char *tim_compat = NULL;
> +
> + switch (device_type) {
> + case DDR_TYPE_LPDDR3:
> + tim_compat = "jedec,lpddr3-timings";
> + break;
> + default:
> + dev_warn(dev, "%s: un-supported memory type\n", __func__);
> + }
> +
> + for_each_child_of_node(np_ddr, np_tim)
> + if (of_device_is_compatible(np_tim, tim_compat))
> + arr_sz++;
> +
> + if (arr_sz)
> + timings = devm_kcalloc(dev, arr_sz, sizeof(*timings),
> + GFP_KERNEL);
> +
> + if (!timings)
> + goto default_timings;
> +
> + for_each_child_of_node(np_ddr, np_tim) {
> + if (of_device_is_compatible(np_tim, tim_compat)) {
> + if (of_lpddr3_do_get_timings(np_tim, &timings[i])) {
> + devm_kfree(dev, timings);
> + goto default_timings;
> + }
> + i++;
> + }
> + }
> +
> + *nr_frequencies = arr_sz;
> +
> + return timings;
> +
> +default_timings:
> + dev_warn(dev, "%s: using default timings\n", __func__);
> + *nr_frequencies = 0;
> + return NULL;
> +}
> +EXPORT_SYMBOL(of_lpddr3_get_ddr_timings);
> diff --git a/drivers/memory/of_memory.h b/drivers/memory/of_memory.h
> index b077cc836b0b..e39ecc4c733d 100644
> --- a/drivers/memory/of_memory.h
> +++ b/drivers/memory/of_memory.h
> @@ -14,6 +14,11 @@ extern const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
> extern const struct lpddr2_timings
> *of_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
> u32 device_type, u32 *nr_frequencies);
> +extern const struct lpddr3_min_tck
> + *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev);
> +extern const struct lpddr3_timings
> + *of_lpddr3_get_ddr_timings(struct device_node *np_ddr,
> + struct device *dev, u32 device_type, u32 *nr_frequencies);
> #else
> static inline const struct lpddr2_min_tck
> *of_get_min_tck(struct device_node *np, struct device *dev)
> @@ -27,6 +32,19 @@ static inline const struct lpddr2_timings
> {
> return NULL;
> }
> +
> +static inline const struct lpddr3_min_tck
> + *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev)
> +{
> + return NULL;
> +}
> +
> +static inline const struct lpddr3_timings
> + *of_lpddr3_get_ddr_timings(struct device_node *np_ddr,
> + struct device *dev, u32 device_type, u32 *nr_frequencies)
> +{
> + return NULL;
> +}
> #endif /* CONFIG_OF && CONFIG_DDR */
>
> #endif /* __LINUX_MEMORY_OF_REG_ */
> diff --git a/include/memory/jedec_ddr.h b/include/memory/jedec_ddr.h
> index ddad0f870e5d..3601825f807d 100644
> --- a/include/memory/jedec_ddr.h
> +++ b/include/memory/jedec_ddr.h
> @@ -32,6 +32,7 @@
> #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
> @@ -172,4 +173,65 @@ 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 /* __LINUX_JEDEC_DDR_H */
> --
> 2.17.1
>