[v8,2/2] rtc: sophgo: add rtc support for Sophgo CV1800 SoC

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

Hi Alexandre,

Gentle ping!

On Sun, Feb 4, 2024 at 12:41 PM Jingbao Qiu <qiujingbao.dlmu@gmail.com> 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-$(CONFIG_RTC_DRV_CADENCE) += rtc-cadence.o
>  obj-$(CONFIG_RTC_DRV_CMOS)     += rtc-cmos.o
>  obj-$(CONFIG_RTC_DRV_CPCAP)    += rtc-cpcap.o
>  obj-$(CONFIG_RTC_DRV_CROS_EC)  += rtc-cros-ec.o
> +obj-$(CONFIG_RTC_DRV_CV1800)   += rtc-cv1800.o
>  obj-$(CONFIG_RTC_DRV_DA9052)   += rtc-da9052.o
>  obj-$(CONFIG_RTC_DRV_DA9055)   += rtc-da9055.o
>  obj-$(CONFIG_RTC_DRV_DA9063)   += 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 = {
> +       .reg_bits = 32,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +};
> +
> +static int cv1800_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> +       struct cv1800_rtc_priv *info = 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 = dev_get_drvdata(dev);
> +       unsigned long alarm_time;
> +
> +       alarm_time = 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 = dev_get_drvdata(dev);
> +       u32 enabled;
> +       u32 time;
> +
> +       regmap_read(info->rtc_map, ALARM_ENABLE, &enabled);
> +
> +       alarm->enabled = 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 = 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 = 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 *tm)
> +{
> +       struct cv1800_rtc_priv *info = 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 = dev_get_drvdata(dev);
> +       unsigned long sec;
> +
> +       sec = 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 = dev_id;
> +
> +       rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static const struct rtc_class_ops cv1800_rtc_ops = {
> +       .read_time = cv1800_rtc_read_time,
> +       .set_time = cv1800_rtc_set_time,
> +       .read_alarm = cv1800_rtc_read_alarm,
> +       .set_alarm = cv1800_rtc_set_alarm,
> +       .alarm_irq_enable = 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 = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
> +       if (!rtc)
> +               return -ENOMEM;
> +
> +       base = devm_platform_ioremap_resource(pdev, 0);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       rtc->rtc_map = 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 = platform_get_irq(pdev, 0);
> +       if (rtc->irq < 0)
> +               return rtc->irq;
> +
> +       ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
> +                              IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);
> +       if (ret)
> +               return dev_err_probe(&pdev->dev, ret,
> +                                    "cannot register interrupt handler\n");
> +
> +       rtc->clk = 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 = 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 = &cv1800_rtc_ops;
> +       rtc->rtc_dev->range_max = U32_MAX;
> +
> +       regmap_read(rtc->rtc_map, CTRL, &ctrl_val);
> +       ctrl_val &= CTRL_MODE_MASK;
> +
> +       if (ctrl_val == CTRL_MODE_OSC32K)
> +               rtc_enable_sec_counter(rtc);
> +
> +       return devm_rtc_register_device(rtc->rtc_dev);
> +}
> +
> +static const struct of_device_id cv1800_dt_ids[] = {
> +       { .compatible = "sophgo,cv1800-rtc" },
> +       { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, cv1800_dt_ids);
> +
> +static struct platform_driver cv1800_rtc_driver = {
> +       .driver = {
> +               .name = "sophgo-cv1800-rtc",
> +               .of_match_table = cv1800_dt_ids,
> +       },
> +       .probe = 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
>

Hello,

On 04/02/2024 12:41:43+0800, Jingbao Qiu wrote:
> +#define REG_ENABLE_FUN         BIT(0)
> +#define REG_DISABLE_FUN        0x00UL

I don't feel like these two macros make your code clearer, you should
probably simply use 0 and 1 in the proper locations.

> +static irqreturn_t cv1800_rtc_irq_handler(int irq, void *dev_id)
> +{
> +	struct rtc_device *rtc = dev_id;
> +
> +	rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);

I'm pretty sure this would result in a crash...

> +
> +	return IRQ_HANDLED;
> +}
> +
> +	ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
> +			       IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);

... you probably want to use rtc->rtc_dev here to fix this.

This also means that you have to request the irq late, else you are open
t a race condition anyway.

> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret,
> +				     "cannot register interrupt handler\n");
> +

Hi, Alexandre

I'm glad to receive your reply.

> I don't feel like these two macros make your code clearer, you should
> probably simply use 0 and 1 in the proper locations.
>

I will use 0/1 replace this macros.

> > +static irqreturn_t cv1800_rtc_irq_handler(int irq, void *dev_id)
> > +{
> > +     struct rtc_device *rtc = dev_id;
> > +
> > +     rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
>
> I'm pretty sure this would result in a crash...

Yes, it did happen. Because I inserted an incorrect pointer.

>
> > +
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +     ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
> > +                            IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);
>
> ... you probably want to use rtc->rtc_dev here to fix this.
>
> This also means that you have to request the irq late, else you are open
> t a race condition anyway.

I am very sorry about this bug.
I will use rtc->rtc_dev to fix it and request irq after
devm_rtc_allocate_device.

Best regards
Jingbao Qiu