Re: [PATCH v4 2/7] mfd: simple-mfd-i2c: add SpacemiT P1 support

From: Lee Jones <lee@kernel.org>
To: Alex Elder <elder@riscstar.com>
Cc: lgirdwood@gmail.com, broonie@kernel.org,
	alexandre.belloni@bootlin.com, robh@kernel.org,
	krzk+dt@kernel.org, conor+dt@kernel.org, mat.jonczyk@o2.pl,
	dlan@gentoo.org, paul.walmsley@sifive.com, palmer@dabbelt.com,
	aou@eecs.berkeley.edu, alex@ghiti.fr, troymitchell988@gmail.com,
	linux-rtc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-riscv@lists.infradead.org, spacemit@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/7] mfd: simple-mfd-i2c: add SpacemiT P1 support
Date: Fri, 27 Jun 2025 13:51:19 +0100	[thread overview]
Message-ID: <20250627125119.GF10134@google.com> (raw)
In-Reply-To: <20250625164119.1068842-3-elder@riscstar.com>

On Wed, 25 Jun 2025, Alex Elder wrote:

> Enable support for the RTC and regulators found in the SpacemiT P1
> PMIC.  Support is implemented by the simple I2C MFD driver.
> 
> The P1 PMIC is normally implemented with the SpacemiT K1 SoC.  This
> PMIC provides 6 buck converters and 12 LDO regulators.  It also
> implements a switch, watchdog timer, real-time clock, and more.
> Initially its RTC and regulators are supported.
> 
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
> v4: - Add a dependency on I2C, to avoid a CROSS_COMPILE build error
> 
>  drivers/mfd/Kconfig          | 11 +++++++++++
>  drivers/mfd/simple-mfd-i2c.c | 18 ++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 6fb3768e3d71c..01805c3eec57d 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1182,6 +1182,17 @@ config MFD_QCOM_RPM
>  	  Say M here if you want to include support for the Qualcomm RPM as a
>  	  module. This will build a module called "qcom_rpm".
>  
> +config MFD_SPACEMIT_P1
> +	tristate "SpacemiT P1 PMIC"
> +	depends on I2C
> +	select MFD_SIMPLE_MFD_I2C
> +	help
> +	  This option supports the I2C-based SpacemiT P1 PMIC, which
> +	  contains regulators, a power switch, GPIOs, an RTC, and more.
> +	  This option is selected when any of the supported sub-devices
> +	  is configured.  The basic functionality is implemented by the
> +	  simple MFD I2C driver.
> +
>  config MFD_SPMI_PMIC
>  	tristate "Qualcomm SPMI PMICs"
>  	depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
> index 22159913bea03..026cd92e20ad3 100644
> --- a/drivers/mfd/simple-mfd-i2c.c
> +++ b/drivers/mfd/simple-mfd-i2c.c
> @@ -93,12 +93,30 @@ static const struct simple_mfd_data maxim_mon_max77705 = {
>  	.mfd_cell_size = ARRAY_SIZE(max77705_sensor_cells),
>  };
>  
> +static const struct regmap_config spacemit_p1_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0xaa,
> +};

Suggest making this more widely useful by adding the 'max_register'
attribute to 'struct simple_mfd' and conditionally overriding
regmap_config_8r_8v's value during probe.

> +static const struct mfd_cell spacemit_p1_cells[] = {
> +	{ .name = "spacemit-p1-regulator", },
> +	{ .name = "spacemit-p1-rtc", },
> +};
> +
> +static const struct simple_mfd_data spacemit_p1 = {
> +	.regmap_config = &spacemit_p1_regmap_config,
> +	.mfd_cell = spacemit_p1_cells,
> +	.mfd_cell_size = ARRAY_SIZE(spacemit_p1_cells),
> +};
> +
>  static const struct of_device_id simple_mfd_i2c_of_match[] = {
>  	{ .compatible = "kontron,sl28cpld" },
>  	{ .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
>  	{ .compatible = "maxim,max5970", .data = &maxim_max5970},
>  	{ .compatible = "maxim,max5978", .data = &maxim_max5970},
>  	{ .compatible = "maxim,max77705-battery", .data = &maxim_mon_max77705},
> +	{ .compatible = "spacemit,p1", .data = &spacemit_p1, },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
> -- 
> 2.45.2
> 

-- 
Lee Jones [李琼斯]