Re: [PATCH v10 08/13] drivers: memory: add DMC driver for Exynos5422

From: Lukasz Luba <l.luba@partner.samsung.com>
To: Krzysztof Kozlowski <krzk@kernel.org>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pm@vger.kernel.org,
	"linux-samsung-soc@vger.kernel.org"
	<linux-samsung-soc@vger.kernel.org>,
	linux-clk@vger.kernel.org, mturquette@baylibre.com,
	sboyd@kernel.org,
	"Bartłomiej Żołnierkiewicz" <b.zolnierkie@samsung.com>,
	kgene@kernel.org, "Chanwoo Choi" <cw00.choi@samsung.com>,
	kyungmin.park@samsung.com,
	"Marek Szyprowski" <m.szyprowski@samsung.com>,
	s.nawrocki@samsung.com, myungjoo.ham@samsung.com,
	keescook@chromium.org, tony@atomide.com, jroedel@suse.de,
	treding@nvidia.com, digetx@gmail.com, gregkh@linuxfoundation.org,
	willy.mh.wolff.ml@gmail.com
Subject: Re: [PATCH v10 08/13] drivers: memory: add DMC driver for Exynos5422
Date: Tue, 25 Jun 2019 13:26:23 +0200	[thread overview]
Message-ID: <c12891f3-2b52-a059-cd74-afe6e41271f4@partner.samsung.com> (raw)
In-Reply-To: <CAJKOXPdjXhfcNRL-XMS6K1jrUQoqoNHXGirjXoeoL4GyXzarpg@mail.gmail.com>

Hi Krzysztof,

On 6/14/19 3:47 PM, Krzysztof Kozlowski wrote:
> On Fri, 14 Jun 2019 at 11:53, Lukasz Luba <l.luba@partner.samsung.com> wrote:
>>
>> This patch adds driver for Exynos5422 Dynamic Memory Controller.
>> The driver provides support for dynamic frequency and voltage scaling for
>> DMC and DRAM. It supports changing timings of DRAM running with different
>> frequency. There is also an algorithm to calculate timigns based on
>> memory description provided in DT.
>> The patch also contains needed MAINTAINERS file update.
>>
>> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
>> ---
>>   MAINTAINERS                             |    8 +
>>   drivers/memory/samsung/Kconfig          |   17 +
>>   drivers/memory/samsung/Makefile         |    1 +
>>   drivers/memory/samsung/exynos5422-dmc.c | 1262 +++++++++++++++++++++++
>>   4 files changed, 1288 insertions(+)
>>   create mode 100644 drivers/memory/samsung/exynos5422-dmc.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 57f496cff999..6ffccfd95351 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -3470,6 +3470,14 @@ S:       Maintained
>>   F:     drivers/devfreq/exynos-bus.c
>>   F:     Documentation/devicetree/bindings/devfreq/exynos-bus.txt
>>
>> +DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5422
>> +M:     Lukasz Luba <l.luba@partner.samsung.com>
>> +L:     linux-pm@vger.kernel.org
>> +L:     linux-samsung-soc@vger.kernel.org
>> +S:     Maintained
>> +F:     drivers/memory/samsung/exynos5422-dmc.c
>> +F:     Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
>> +
>>   BUSLOGIC SCSI DRIVER
>>   M:     Khalid Aziz <khalid@gonehiking.org>
>>   L:     linux-scsi@vger.kernel.org
>> diff --git a/drivers/memory/samsung/Kconfig b/drivers/memory/samsung/Kconfig
>> index 79ce7ea58903..c93baa029654 100644
>> --- a/drivers/memory/samsung/Kconfig
>> +++ b/drivers/memory/samsung/Kconfig
>> @@ -5,6 +5,23 @@ config SAMSUNG_MC
>>            Support for the Memory Controller (MC) devices found on
>>            Samsung Exynos SoCs.
>>
>> +config ARM_EXYNOS5422_DMC
>> +       tristate "ARM EXYNOS5422 Dynamic Memory Controller driver"
>> +       depends on ARCH_EXYNOS
>> +       select DDR
>> +       select PM_DEVFREQ
>> +       select DEVFREQ_GOV_SIMPLE_ONDEMAND
>> +       select DEVFREQ_GOV_USERSPACE
>> +       select PM_DEVFREQ_EVENT
>> +       select PM_OPP
>> +       help
>> +         This adds driver for Exynos5422 DMC (Dynamic Memory Controller).
>> +         The driver provides support for Dynamic Voltage and Frequency Scaling in
>> +         DMC and DRAM. It also supports changing timings of DRAM running with
>> +         different frequency. The timings are calculated based on DT memory
>> +         information.
>> +
>> +
>>   if SAMSUNG_MC
>>
>>   config EXYNOS_SROM
>> diff --git a/drivers/memory/samsung/Makefile b/drivers/memory/samsung/Makefile
>> index 00587be66211..4f6e4383bab7 100644
>> --- a/drivers/memory/samsung/Makefile
>> +++ b/drivers/memory/samsung/Makefile
>> @@ -1,2 +1,3 @@
>>   # SPDX-License-Identifier: GPL-2.0
>> +obj-$(CONFIG_ARM_EXYNOS5422_DMC)       += exynos5422-dmc.o
>>   obj-$(CONFIG_EXYNOS_SROM)      += exynos-srom.o
>> diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
>> new file mode 100644
>> index 000000000000..b397efe0da57
>> --- /dev/null
>> +++ b/drivers/memory/samsung/exynos5422-dmc.c
>> @@ -0,0 +1,1262 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2019 Samsung Electronics Co., Ltd.
>> + * Author: Lukasz Luba <l.luba@partner.samsung.com>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/devfreq.h>
>> +#include <linux/devfreq-event.h>
>> +#include <linux/device.h>
>> +#include <linux/io.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/pm_opp.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/slab.h>
>> +#include <memory/jedec_ddr.h>
>> +#include "../of_memory.h"
>> +
>> +#define EXYNOS5_DREXI_TIMINGAREF               (0x0030)
>> +#define EXYNOS5_DREXI_TIMINGROW0               (0x0034)
>> +#define EXYNOS5_DREXI_TIMINGDATA0              (0x0038)
>> +#define EXYNOS5_DREXI_TIMINGPOWER0             (0x003C)
>> +#define EXYNOS5_DREXI_TIMINGROW1               (0x00E4)
>> +#define EXYNOS5_DREXI_TIMINGDATA1              (0x00E8)
>> +#define EXYNOS5_DREXI_TIMINGPOWER1             (0x00EC)
>> +#define CDREX_PAUSE                            (0x2091c)
>> +#define CDREX_LPDDR3PHY_CON3                   (0x20a20)
>> +#define EXYNOS5_TIMING_SET_SWI                 (1UL << 28)
>> +#define USE_MX_MSPLL_TIMINGS                   (1)
>> +#define USE_BPLL_TIMINGS                       (0)
>> +#define EXYNOS5_AREF_NORMAL                    (0x2e)
>> +
>> +/**
>> + * struct dmc_opp_table - Operating level desciption
>> + *
>> + * Covers frequency and voltage settings of the DMC operating mode.
>> + */
>> +struct dmc_opp_table {
>> +       u32 freq_hz;
>> +       u32 volt_uv;
>> +};
>> +
>> +/**
>> + * struct exynos5_dmc - main structure describing DMC device
>> + *
>> + * The main structure for the Dynamic Memory Controller which covers clocks,
>> + * memory regions, HW information, parameters and current operating mode.
>> + */
>> +struct exynos5_dmc {
>> +       struct device *dev;
>> +       struct devfreq *df;
>> +       struct devfreq_simple_ondemand_data gov_data;
>> +       void __iomem *base_drexi0;
>> +       void __iomem *base_drexi1;
>> +       struct regmap *clk_regmap;
>> +       struct mutex lock;
>> +       unsigned long curr_rate;
>> +       unsigned long curr_volt;
>> +       unsigned long bypass_rate;
>> +       struct dmc_opp_table *opp;
>> +       struct dmc_opp_table opp_bypass;
>> +       int opp_count;
>> +       u32 timings_arr_size;
>> +       u32 *timing_row;
>> +       u32 *timing_data;
>> +       u32 *timing_power;
>> +       const struct lpddr3_timings *timings;
>> +       const struct lpddr3_min_tck *min_tck;
>> +       u32 bypass_timing_row;
>> +       u32 bypass_timing_data;
>> +       u32 bypass_timing_power;
>> +       struct regulator *vdd_mif;
>> +       struct clk *fout_spll;
>> +       struct clk *fout_bpll;
>> +       struct clk *mout_spll;
>> +       struct clk *mout_bpll;
>> +       struct clk *mout_mclk_cdrex;
>> +       struct clk *mout_mx_mspll_ccore;
>> +       struct clk *mx_mspll_ccore_phy;
>> +       struct clk *mout_mx_mspll_ccore_phy;
>> +       struct devfreq_event_dev **counter;
>> +       int num_counters;
>> +};
>> +
>> +#define TIMING_FIELD(t_name, t_bit_beg, t_bit_end) \
>> +       { .name = t_name, .bit_beg = t_bit_beg, .bit_end = t_bit_end }
>> +
>> +#define TIMING_VAL(timing_array, id, t_val)                    \
>> +({                                                             \
>> +               u32 __val;                              \
>> +               __val = t_val << timing_array[id].bit_beg;      \
>> +               __val;                                          \
>> +})
>> +
>> +#define TIMING_VAL2REG(timing, t_val)                  \
>> +({                                                             \
>> +               u32 __val;                              \
>> +               __val = t_val << timing->bit_beg;       \
>> +               __val;                                          \
>> +})
>> +
>> +#define TIMING_REG2VAL(reg, timing)                    \
> 
> It seems that only some of these defines are used. Please clean them up.
Indeed, they were used in previous version which had more features and
debug options. So TIMING_REG2VAL and TIMING_VAL will be cleaned
> You have also a lot of checkpatch --strict suggestions:
>      CHECK: Macro argument 'reg' may be better as '(reg)' to avoid
> precedence issues
> which seems to be valid.
Will not be valid since it is in TIMING_REG2VAL macro which was used
for debugfs information only.
> 
> While at it please also fix few other --strict errors:
> CHECK: Please don't use multiple blank lines
> CHECK: Alignment should match open parenthesis
> CHECK: Prefer using the BIT macro
> CHECK: struct mutex definition without comment
I wouldn't call them 'errors' but will do a cleanup.

Thank you for the review.

Regards,
Lukasz
> 
> Best regards,
> Krzysztof
> 
> 