Re: [RFC PATCH v2 2/2] rtc: add driver for Marvell 88PM886 PMIC RTC

From: Alexandre Belloni
Date: Mon Nov 11 2024 - 17:30:30 EST


Lee,

I'm happy taking this patch, I guess you are going to take 1/2 ?

On 12/10/2024 21:31:39+0200, Karel Balej wrote:
> RTC lives on the chip's base register page. Add the relevant register
> definitions and implement a basic set/read time functionality. Tested
> with the samsung,coreprimevelte smartphone which contains this PMIC and
> whose vendor kernel tree has also served as the sole reference for this.
>
> Signed-off-by: Karel Balej <balejk@xxxxxxxxx>
> ---
>
> Notes:
> RFC v2:
> - Move in the register definitions from the preceding patch and reword
> the commit message accordingly.
> - Rebase to v6.12-rc2.
>
> MAINTAINERS | 1 +
> drivers/rtc/Kconfig | 10 ++++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-88pm886.c | 97 +++++++++++++++++++++++++++++++++++++
> include/linux/mfd/88pm886.h | 9 ++++
> 5 files changed, 118 insertions(+)
> create mode 100644 drivers/rtc/rtc-88pm886.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a097afd76ded..3a15b8711041 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13710,6 +13710,7 @@ F: Documentation/devicetree/bindings/mfd/marvell,88pm886-a1.yaml
> F: drivers/input/misc/88pm886-onkey.c
> F: drivers/mfd/88pm886.c
> F: drivers/regulator/88pm886-regulator.c
> +F: drivers/rtc/rtc-88pm886.c
> F: include/linux/mfd/88pm886.h
>
> MARVELL ARMADA 3700 PHY DRIVERS
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 66eb1122248b..2718ea194dd4 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -182,6 +182,16 @@ config RTC_DRV_88PM80X
> This driver can also be built as a module. If so, the module
> will be called rtc-88pm80x.
>
> +config RTC_DRV_88PM886
> + tristate "Marvell 88PM886 RTC driver"
> + depends on MFD_88PM886_PMIC
> + help
> + If you say yes here you will get support for the RTC function in the
> + Marvell 88PM886 chip.
> +
> + This driver can also be built as a module. If so, the module
> + will be called rtc-88pm886.
> +
> config RTC_DRV_ABB5ZES3
> select REGMAP_I2C
> tristate "Abracon AB-RTCMC-32.768kHz-B5ZE-S3"
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index f62340ecc534..70bbce968a43 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_RTC_LIB_KUNIT_TEST) += lib_test.o
>
> obj-$(CONFIG_RTC_DRV_88PM80X) += rtc-88pm80x.o
> obj-$(CONFIG_RTC_DRV_88PM860X) += rtc-88pm860x.o
> +obj-$(CONFIG_RTC_DRV_88PM886) += rtc-88pm886.o
> obj-$(CONFIG_RTC_DRV_AB8500) += rtc-ab8500.o
> obj-$(CONFIG_RTC_DRV_ABB5ZES3) += rtc-ab-b5ze-s3.o
> obj-$(CONFIG_RTC_DRV_ABEOZ9) += rtc-ab-eoz9.o
> diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c
> new file mode 100644
> index 000000000000..57e9b0a66eed
> --- /dev/null
> +++ b/drivers/rtc/rtc-88pm886.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <linux/limits.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/rtc.h>
> +
> +#include <linux/mfd/88pm886.h>
> +
> +/*
> + * Time is calculated as the sum of a 32-bit read-only advancing counter and a
> + * writeable constant offset stored in the chip's spare registers.
> + */
> +
> +static int pm886_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct regmap *regmap = dev_get_drvdata(dev);
> + u32 time;
> + u32 buf;
> + int ret;
> +
> + ret = regmap_bulk_read(regmap, PM886_REG_RTC_SPARE1, &buf, 4);
> + if (ret)
> + return ret;
> + time = buf;
> +
> + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4);
> + if (ret)
> + return ret;
> + time += buf;
> +
> + rtc_time64_to_tm(time, tm);
> +
> + return 0;
> +}
> +
> +static int pm886_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct regmap *regmap = dev_get_drvdata(dev);
> + u32 buf;
> + int ret;
> +
> + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4);
> + if (ret)
> + return ret;
> +
> + buf = rtc_tm_to_time64(tm) - buf;
> +
> + return regmap_bulk_write(regmap, PM886_REG_RTC_SPARE1, &buf, 4);
> +}
> +
> +static const struct rtc_class_ops pm886_rtc_ops = {
> + .read_time = pm886_rtc_read_time,
> + .set_time = pm886_rtc_set_time,
> +};
> +
> +static int pm886_rtc_probe(struct platform_device *pdev)
> +{
> + struct pm886_chip *chip = dev_get_drvdata(pdev->dev.parent);
> + struct device *dev = &pdev->dev;
> + struct rtc_device *rtc;
> + int ret;
> +
> + platform_set_drvdata(pdev, chip->regmap);
> +
> + rtc = devm_rtc_allocate_device(dev);
> + if (IS_ERR(rtc))
> + return dev_err_probe(dev, PTR_ERR(rtc),
> + "Failed to allocate RTC device\n");
> +
> + rtc->ops = &pm886_rtc_ops;
> + rtc->range_max = U32_MAX;
> +
> + ret = devm_rtc_register_device(rtc);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to register RTC device\n");
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id pm886_rtc_id_table[] = {
> + { "88pm886-rtc", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table);
> +
> +static struct platform_driver pm886_rtc_driver = {
> + .driver = {
> + .name = "88pm886-rtc",
> + },
> + .probe = pm886_rtc_probe,
> + .id_table = pm886_rtc_id_table,
> +};
> +module_platform_driver(pm886_rtc_driver);
> +
> +MODULE_DESCRIPTION("Marvell 88PM886 RTC driver");
> +MODULE_AUTHOR("Karel Balej <balejk@xxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/88pm886.h b/include/linux/mfd/88pm886.h
> index 133aa302e492..85eca44f39ab 100644
> --- a/include/linux/mfd/88pm886.h
> +++ b/include/linux/mfd/88pm886.h
> @@ -31,6 +31,15 @@
> #define PM886_INT_WC BIT(1)
> #define PM886_INT_MASK_MODE BIT(2)
>
> +#define PM886_REG_RTC_CNT1 0xd1
> +#define PM886_REG_RTC_CNT2 0xd2
> +#define PM886_REG_RTC_CNT3 0xd3
> +#define PM886_REG_RTC_CNT4 0xd4
> +#define PM886_REG_RTC_SPARE1 0xea
> +#define PM886_REG_RTC_SPARE2 0xeb
> +#define PM886_REG_RTC_SPARE3 0xec
> +#define PM886_REG_RTC_SPARE4 0xed
> +#define PM886_REG_RTC_SPARE5 0xee
> #define PM886_REG_RTC_SPARE6 0xef
>
> #define PM886_REG_BUCK_EN 0x08
> --
> 2.47.0
>

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com