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From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
Date: Wed, 1 May 2024 13:03:58 +0800
Message-ID: <CAJRtX8Rz0BhbtBJq+gSRTU3vsOwfyWjrqJ-Q1fqr7ZFeY2uaNQ@mail.gmail.com>
Subject: Re: [PATCH v8 2/2] rtc: sophgo: add rtc support for Sophgo CV1800 SoC
To: Inochi Amaoto <inochiama@outlook.com>
Cc: alexandre.belloni@bootlin.com, robh+dt@kernel.org, 
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, 
	paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, 
	linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, 
	linux-kernel@vger.kernel.org, dlan@gentoo.org
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Hi, Inochi

On Wed, May 1, 2024 at 10:19=E2=80=AFAM Inochi Amaoto <inochiama@outlook.co=
m> wrote:
>
> On Sun, Feb 04, 2024 at 12:41:43PM GMT, Jingbao Qiu wrote:
> > Implement the RTC driver for CV1800, which able to provide time alarm.
> >
> > Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> > ---
> >  drivers/rtc/Kconfig      |  10 ++
> >  drivers/rtc/Makefile     |   1 +
> >  drivers/rtc/rtc-cv1800.c | 244 +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 255 insertions(+)
> >  create mode 100644 drivers/rtc/rtc-cv1800.c
> >
> > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> > index e37a4341f442..3c6ed45a3b03 100644
> > --- a/drivers/rtc/Kconfig
> > +++ b/drivers/rtc/Kconfig
> > @@ -1128,6 +1128,16 @@ config RTC_DRV_DS2404
> >         This driver can also be built as a module. If so, the module
> >         will be called rtc-ds2404.
> >
> > +config RTC_DRV_CV1800
> > +     tristate "Sophgo CV1800 RTC"
> > +     depends on ARCH_SOPHGO || COMPILE_TEST
> > +     help
> > +       If you say yes here you get support the RTC driver
> > +       for Sophgo CV1800 chip.
> > +
> > +       This driver can also be built as a module.If so, the
> > +       module will be called rtc-cv1800.
> > +
> >  config RTC_DRV_DA9052
> >       tristate "Dialog DA9052/DA9053 RTC"
> >       depends on PMIC_DA9052
> > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> > index 6efff381c484..4efdd2d1e963 100644
> > --- a/drivers/rtc/Makefile
> > +++ b/drivers/rtc/Makefile
> > @@ -42,6 +42,7 @@ obj-$(CONFIG_RTC_DRV_CADENCE)       +=3D rtc-cadence.=
o
> >  obj-$(CONFIG_RTC_DRV_CMOS)   +=3D rtc-cmos.o
> >  obj-$(CONFIG_RTC_DRV_CPCAP)  +=3D rtc-cpcap.o
> >  obj-$(CONFIG_RTC_DRV_CROS_EC)        +=3D rtc-cros-ec.o
> > +obj-$(CONFIG_RTC_DRV_CV1800) +=3D rtc-cv1800.o
> >  obj-$(CONFIG_RTC_DRV_DA9052) +=3D rtc-da9052.o
> >  obj-$(CONFIG_RTC_DRV_DA9055) +=3D rtc-da9055.o
> >  obj-$(CONFIG_RTC_DRV_DA9063) +=3D rtc-da9063.o
> > diff --git a/drivers/rtc/rtc-cv1800.c b/drivers/rtc/rtc-cv1800.c
> > new file mode 100644
> > index 000000000000..60a7192659f5
> > --- /dev/null
> > +++ b/drivers/rtc/rtc-cv1800.c
> > @@ -0,0 +1,244 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * rtc-cv1800.c: RTC driver for Sophgo cv1800 RTC
> > + *
> > + * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/irq.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/rtc.h>
> > +
> > +#define CTRL                   0x08
> > +#define ANA_CALIB              0x1000
> > +#define SEC_PULSE_GEN          0x1004
> > +#define ALARM_TIME             0x1008
> > +#define ALARM_ENABLE           0x100C
> > +#define SET_SEC_CNTR_VAL       0x1010
> > +#define SET_SEC_CNTR_TRIG      0x1014
> > +#define SEC_CNTR_VAL           0x1018
> > +#define APB_RDATA_SEL          0x103C
> > +#define POR_DB_MAGIC_KEY       0x1068
> > +#define EN_PWR_WAKEUP          0x10BC
> > +
> > +/*
> > + * When in VDDBKUP domain, this MACRO register
> > + * does not power down
> > + */
> > +#define MACRO_DA_CLEAR_ALL     0x1480
> > +#define MACRO_DA_SOC_READY     0x148C
> > +#define MACRO_RO_T             0x14A8
> > +#define MACRO_RG_SET_T         0x1498
> > +
> > +#define CTRL_MODE_MASK         BIT(10)
> > +#define CTRL_MODE_OSC32K       0x00UL
> > +#define CTRL_MODE_XTAL32K      BIT(0)
> > +#define REG_ENABLE_FUN         BIT(0)
> > +#define REG_DISABLE_FUN        0x00UL
> > +#define ALARM_ENABLE_MASK      BIT(0)
> > +#define SET_SEC_CNTR_VAL_INIT  (BIT(28) || BIT(29))
> > +#define SEC_PULSE_SEL_INNER    BIT(31)
> > +#define SEC_PULSE_GEN_SEL_MASK GENMASK(30, 0)
> > +#define CALIB_SEL_FTUNE_MASK   GENMASK(30, 0)
> > +#define CALIB_SEL_FTUNE_INNER  0x00UL
> > +
> > +struct cv1800_rtc_priv {
> > +     struct rtc_device *rtc_dev;
> > +     struct regmap *rtc_map;
> > +     struct clk *clk;
> > +     int irq;
> > +};
> > +
> > +static const struct regmap_config cv1800_rtc_regmap_config =3D {
> > +     .reg_bits =3D 32,
> > +     .val_bits =3D 32,
> > +     .reg_stride =3D 4,
> > +};
> > +
> > +static int cv1800_rtc_alarm_irq_enable(struct device *dev, unsigned in=
t enabled)
> > +{
> > +     struct cv1800_rtc_priv *info =3D dev_get_drvdata(dev);
> > +
> > +     regmap_write(info->rtc_map, ALARM_ENABLE, enabled);
> > +
> > +     return 0;
> > +}
> > +
> > +static int cv1800_rtc_set_alarm(struct device *dev, struct rtc_wkalrm =
*alrm)
> > +{
> > +     struct cv1800_rtc_priv *info =3D dev_get_drvdata(dev);
> > +     unsigned long alarm_time;
> > +
> > +     alarm_time =3D rtc_tm_to_time64(&alrm->time);
> > +
> > +     cv1800_rtc_alarm_irq_enable(dev, REG_DISABLE_FUN);
> > +
> > +     regmap_write(info->rtc_map, ALARM_TIME, alarm_time);
> > +
> > +     cv1800_rtc_alarm_irq_enable(dev, alrm->enabled);
> > +
> > +     return 0;
> > +}
> > +
> > +static int cv1800_rtc_read_alarm(struct device *dev, struct rtc_wkalrm=
 *alarm)
> > +{
> > +     struct cv1800_rtc_priv *info =3D dev_get_drvdata(dev);
> > +     u32 enabled;
> > +     u32 time;
> > +
> > +     regmap_read(info->rtc_map, ALARM_ENABLE, &enabled);
> > +
> > +     alarm->enabled =3D enabled & ALARM_ENABLE_MASK;
> > +
> > +     regmap_read(info->rtc_map, ALARM_TIME, &time);
> > +
> > +     rtc_time64_to_tm(time, &alarm->time);
> > +
> > +     return 0;
> > +}
> > +
> > +static void rtc_enable_sec_counter(struct cv1800_rtc_priv *info)
> > +{
> > +     u32 sec_ro_t;
> > +     u32 sec;
> > +
> > +     /* select inner sec pulse */
> > +     regmap_update_bits(info->rtc_map, SEC_PULSE_GEN,
> > +                        (u32)(~SEC_PULSE_GEN_SEL_MASK),
> > +                        (u32)(~SEC_PULSE_SEL_INNER));
> > +
> > +     regmap_update_bits(info->rtc_map, ANA_CALIB,
> > +                        (u32)(~CALIB_SEL_FTUNE_MASK),
> > +                        CALIB_SEL_FTUNE_INNER);
> > +
> > +     sec =3D SET_SEC_CNTR_VAL_INIT;
> > +
> > +     /* load from MACRO register */
> > +     regmap_read(info->rtc_map, MACRO_RO_T, &sec_ro_t);
> > +     if (sec_ro_t > (SET_SEC_CNTR_VAL_INIT))
> > +             sec =3D sec_ro_t;
> > +
> > +     regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
> > +     regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, REG_ENABLE_FUN);
> > +}
> > +
> > +static int cv1800_rtc_read_time(struct device *dev, struct rtc_time *t=
m)
> > +{
> > +     struct cv1800_rtc_priv *info =3D dev_get_drvdata(dev);
> > +     u32 sec;
> > +
> > +     regmap_read(info->rtc_map, SEC_CNTR_VAL, &sec);
> > +
> > +     rtc_time64_to_tm(sec, tm);
> > +
> > +     return 0;
> > +}
> > +
> > +static int cv1800_rtc_set_time(struct device *dev, struct rtc_time *tm=
)
> > +{
> > +     struct cv1800_rtc_priv *info =3D dev_get_drvdata(dev);
> > +     unsigned long sec;
> > +
> > +     sec =3D rtc_tm_to_time64(tm);
> > +
> > +     regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
> > +     regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, REG_ENABLE_FUN);
> > +
> > +     regmap_write(info->rtc_map, MACRO_RG_SET_T, sec);
> > +
> > +     return 0;
> > +}
> > +
> > +static irqreturn_t cv1800_rtc_irq_handler(int irq, void *dev_id)
> > +{
> > +     struct rtc_device *rtc =3D dev_id;
> > +
> > +     rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
> > +
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +static const struct rtc_class_ops cv1800_rtc_ops =3D {
> > +     .read_time =3D cv1800_rtc_read_time,
> > +     .set_time =3D cv1800_rtc_set_time,
> > +     .read_alarm =3D cv1800_rtc_read_alarm,
> > +     .set_alarm =3D cv1800_rtc_set_alarm,
> > +     .alarm_irq_enable =3D cv1800_rtc_alarm_irq_enable,
> > +};
> > +
> > +static int cv1800_rtc_probe(struct platform_device *pdev)
> > +{
> > +     struct cv1800_rtc_priv *rtc;
> > +     u32 ctrl_val;
> > +     void __iomem *base;
> > +     int ret;
> > +
> > +     rtc =3D devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
> > +     if (!rtc)
> > +             return -ENOMEM;
> > +
> > +     base =3D devm_platform_ioremap_resource(pdev, 0);
> > +     if (IS_ERR(base))
> > +             return PTR_ERR(base);
> > +
> > +     rtc->rtc_map =3D devm_regmap_init_mmio(&pdev->dev, base,
> > +                                          &cv1800_rtc_regmap_config);
> > +     if (IS_ERR(rtc->rtc_map))
> > +             return PTR_ERR(rtc->rtc_map);
> > +
> > +     rtc->irq =3D platform_get_irq(pdev, 0);
> > +     if (rtc->irq < 0)
> > +             return rtc->irq;
> > +
> > +     ret =3D devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_han=
dler,
> > +                            IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);
> > +     if (ret)
> > +             return dev_err_probe(&pdev->dev, ret,
> > +                                  "cannot register interrupt handler\n=
");
> > +
> > +     rtc->clk =3D devm_clk_get_enabled(&pdev->dev, NULL);
> > +     if (IS_ERR(rtc->clk))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),
> > +                                  "clk not found\n");
> > +
> > +     rtc->rtc_dev =3D devm_rtc_allocate_device(&pdev->dev);
> > +     if (IS_ERR(rtc->rtc_dev))
> > +             return PTR_ERR(rtc->rtc_dev);
> > +
> > +     platform_set_drvdata(pdev, rtc);
> > +
> > +     rtc->rtc_dev->ops =3D &cv1800_rtc_ops;
> > +     rtc->rtc_dev->range_max =3D U32_MAX;
> > +
>
> > +     regmap_read(rtc->rtc_map, CTRL, &ctrl_val);
> > +     ctrl_val &=3D CTRL_MODE_MASK;
> > +
> > +     if (ctrl_val =3D=3D CTRL_MODE_OSC32K)
> > +             rtc_enable_sec_counter(rtc);
> > +
>
> use (ctrl_val & CTRL_MODE_OSC32K).
>
> Another thing is that I do not think is a good way to let the
> rtc driver access RTC_CTRL area directly. You have already
> know there is a 8051 device in the 0x05025000. It is necessary
> to make some room for this device. Maybe you want to implement
> them all in the rtc driver? If so, I do think it is a bad idea.


Do you mean that RTC drivers should not directly access the 0x05025000 addr=
ess?
Because there is an 8051 subsystem on this address.
Firstly, I do not intend to implement 8051 in the RTC driver,
but the 8051 subsystem is located within a module independently
powered by the RTC.
So if we want to implement the 8051 subsystem in the future, it can be
used as a node in RTC? I'm not sure.
Then, Alexandre told me that there are operations related to PM in
RTC, such as the following files.
This matches the description of address 0x05025000.

drivers/rtc/rtc jz4740. c

>
> > +     return devm_rtc_register_device(rtc->rtc_dev);
> > +}
> > +
> > +static const struct of_device_id cv1800_dt_ids[] =3D {
> > +     { .compatible =3D "sophgo,cv1800-rtc" },
> > +     { /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, cv1800_dt_ids);
> > +
> > +static struct platform_driver cv1800_rtc_driver =3D {
> > +     .driver =3D {
> > +             .name =3D "sophgo-cv1800-rtc",
> > +             .of_match_table =3D cv1800_dt_ids,
> > +     },
> > +     .probe =3D cv1800_rtc_probe,
> > +};
> > +
> > +module_platform_driver(cv1800_rtc_driver);
> > +MODULE_AUTHOR("Jingbao Qiu");
> > +MODULE_DESCRIPTION("Sophgo cv1800 RTC Driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1
> >