linux-kernel - Re: [PATCH v12 2/7] mfd: simple-mfd-i2c: add SpacemiT P1 support

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Message-ID: <A90BFF97E4869C5B+aK0ID3oyoCtco3m5@LT-Guozexi>
Date: Tue, 26 Aug 2025 09:04:15 +0800
From: Troy Mitchell <troy.mitchell@...ux.spacemit.com>
To: Alex Elder <elder@...cstar.com>,
	Troy Mitchell <troy.mitchell@...ux.spacemit.com>, lee@...nel.org,
	lgirdwood@...il.com, broonie@...nel.org,
	alexandre.belloni@...tlin.com, robh@...nel.org, krzk+dt@...nel.org,
	conor+dt@...nel.org
Cc: mat.jonczyk@...pl, dlan@...too.org, paul.walmsley@...ive.com,
	palmer@...belt.com, aou@...s.berkeley.edu, alex@...ti.fr,
	linux.amoon@...il.com, troymitchell988@...il.com,
	guodong@...cstar.com, linux-rtc@...r.kernel.org,
	devicetree@...r.kernel.org, linux-riscv@...ts.infradead.org,
	spacemit@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v12 2/7] mfd: simple-mfd-i2c: add SpacemiT P1 support

On Mon, Aug 25, 2025 at 11:08:45AM -0500, Alex Elder wrote:
> On 8/14/25 9:28 PM, Troy Mitchell wrote:
> > Hi, Alex,
> > 
> > I did not find any accesses to the P1 shutdown or reboot registers here.
> > Does this mean that the current series does not support reboot or shutdown?
> 
> Yes, that is correct.
> 
> > If so, do you have any plans to support this functionality?
> 
> At this time I personally don't have any plans to add this, but
> it could be added later (by anyone).
> 
> I actually attempted to do this initially, but gave up.  The PMIC
> is accessed via I2C, and I needed to implement a non-blocking
> version of the I2C register write operation.  I tried that,
You tried that? so that means you have implemented a non-blocking version
of the I2C?
If so, can you give me a source tree to test it?
> but
> then found that the shutdown or reboot still did not work reliably.
ditto.

                - Troy

> As it was, this was more than I originally planned to do, so I just
> implemented the simple RTC operations instead.
> 
> 					-Alex
> 
> > If I have misunderstood, please correct me.
> > 
> > Best regards,
> > Troy
> > 
> > 
> > On Tue, Aug 12, 2025 at 09:45:03PM -0500, 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@...cstar.com>
> > > ---
> > >   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 425c5fba6cb1e..4d6a5a3a27220 100644
> > > --- a/drivers/mfd/Kconfig
> > > +++ b/drivers/mfd/Kconfig
> > > @@ -1238,6 +1238,17 @@ 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..47ffaac035cae 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,
> > > +};
> > > +
> > > +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);
> > > -- 
> > > 2.48.1
> > > 
> > > 
> > > _______________________________________________
> > > linux-riscv mailing list
> > > linux-riscv@...ts.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
> 
>

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