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Date:   Wed, 4 Aug 2021 10:06:20 +0100
From:   Lee Jones <lee.jones@linaro.org>
To:     Alistair Francis <alistair23@gmail.com>
Cc:     Alistair Francis <alistair@alistair23.me>,
        Rob Herring <robh+dt@kernel.org>, lgirdwood@gmail.com,
        Mark Brown <broonie@kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>,
        Sascha Hauer <kernel@pengutronix.de>,
        devicetree <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v8 02/11] mfd: sy7636a: Initial commit
Message-ID: <YQpYjEc9r8QGUhiD@google.com>
References: <20210803084456.198-1-alistair@alistair23.me>
 <20210803084456.198-2-alistair@alistair23.me>
 <YQlBtQDrVHqh3N5D@google.com>
 <CAKmqyKMZWVx3KqeysUjOc29nuxnwJfZ3wjmWjVwk9tpQ4dkh-A@mail.gmail.com>
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On Wed, 04 Aug 2021, Alistair Francis wrote:

> On Tue, Aug 3, 2021 at 11:16 PM Lee Jones <lee.jones@linaro.org> wrote:
> >
> > On Tue, 03 Aug 2021, Alistair Francis wrote:
> >
> > > Initial support for the Silergy SY7636A Power Management chip.
> > >
> > > Signed-off-by: Alistair Francis <alistair@alistair23.me>
> > > ---
> > >  drivers/mfd/Kconfig         |  9 +++++
> > >  drivers/mfd/Makefile        |  1 +
> > >  drivers/mfd/sy7636a.c       | 72 +++++++++++++++++++++++++++++++++++++
> > >  include/linux/mfd/sy7636a.h | 45 +++++++++++++++++++++++
> > >  4 files changed, 127 insertions(+)
> > >  create mode 100644 drivers/mfd/sy7636a.c
> > >  create mode 100644 include/linux/mfd/sy7636a.h
> > >
> > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > index 6a3fd2d75f96..b82208f0c79c 100644
> > > --- a/drivers/mfd/Kconfig
> > > +++ b/drivers/mfd/Kconfig
> > > @@ -1352,6 +1352,15 @@ config MFD_SYSCON
> > >         Select this option to enable accessing system control registers
> > >         via regmap.
> > >
> > > +config MFD_SY7636A
> > > +     tristate "Silergy SY7636A Power Management IC"
> > > +     select MFD_CORE
> > > +     select REGMAP_I2C
> > > +     depends on I2C
> > > +     help
> > > +       Select this option to enable support for the Silergy SY7636A
> > > +       Power Management IC.
> > > +
> > >  config MFD_DAVINCI_VOICECODEC
> > >       tristate
> > >       select MFD_CORE
> > > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > > index 8116c19d5fd4..cbe581e87fa9 100644
> > > --- a/drivers/mfd/Makefile
> > > +++ b/drivers/mfd/Makefile
> > > @@ -266,6 +266,7 @@ obj-$(CONFIG_MFD_KHADAS_MCU)      += khadas-mcu.o
> > >  obj-$(CONFIG_MFD_ACER_A500_EC)       += acer-ec-a500.o
> > >  obj-$(CONFIG_MFD_QCOM_PM8008)        += qcom-pm8008.o
> > >
> > > +obj-$(CONFIG_MFD_SY7636A)    += sy7636a.o
> > >  obj-$(CONFIG_SGI_MFD_IOC3)   += ioc3.o
> > >  obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)     += simple-mfd-i2c.o
> > >  obj-$(CONFIG_MFD_INTEL_M10_BMC)   += intel-m10-bmc.o
> > > diff --git a/drivers/mfd/sy7636a.c b/drivers/mfd/sy7636a.c
> > > new file mode 100644
> > > index 000000000000..f3ff93c7395d
> > > --- /dev/null
> > > +++ b/drivers/mfd/sy7636a.c
> > > @@ -0,0 +1,72 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * MFD parent driver for SY7636A chip
> > > + *
> > > + * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
> > > + *
> > > + * Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
> > > + *          Alistair Francis <alistair@alistair23.me>
> > > + *
> > > + * Based on the lp87565 driver by Keerthy <j-keerthy@ti.com>
> > > + */
> > > +
> > > +#include <linux/interrupt.h>
> > > +#include <linux/mfd/core.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of_device.h>
> > > +
> > > +#include <linux/mfd/sy7636a.h>
> > > +
> > > +static const struct regmap_config sy7636a_regmap_config = {
> > > +     .reg_bits = 8,
> > > +     .val_bits = 8,
> > > +};
> > > +
> > > +static const struct mfd_cell sy7636a_cells[] = {
> > > +     { .name = "sy7636a-regulator", },
> >
> > What kind of regulator is 'vcom'? LDO? DCDC?
> 
> Both I guess:
> 
> "SY7636A is a single-chip power management IC (PMIC) designed for
> electronic paper display (EPD) applications. The device supports panel
> sizes up to 9.7 inches and larger. The device integrates two
> high-efficiency DC-DC boost converters, which are boosted to 25V and
> -20V by two charge pumps to provide gate driver power for the panel.
> Two tracking LDOs create a ±15V source driver power supply that
> supports output currents up to 200mA. SY7636A also provides I2C
> interface control for specific panel requirements"

Is there a datasheet I could look at?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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