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

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

On 6/14/19 2:43 PM, Krzysztof Kozlowski wrote:
> 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?

Greg, Rob: gentle ping.

Currently there is a v13, with only minor changes to this patch:
https://lkml.org/lkml/2019/8/21/289
(you are on cc list of the patch set)

Could you please have a look. Thank you.

Regards,
Lukasz

> 
> 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
>>
> 
>