From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v5 02/13] mfd: add simple regmap based I2C driver Date: Fri, 17 Jul 2020 10:04:44 +0100 Message-ID: <20200717090444.GE3165313@dell> References: <20200706175353.16404-1-michael@walle.cc> <20200706175353.16404-3-michael@walle.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20200706175353.16404-3-michael-QKn5cuLxLXY@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michael Walle Cc: linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-hwmon-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pwm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Linus Walleij , Bartosz Golaszewski , Rob Herring , Jean Delvare , Guenter Roeck , Thierry Reding , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Wim Van Sebroeck , Shawn Guo , Li Yang , Thomas Gleixner , Jason Cooper , Marc Zyngier , Mark Brown List-Id: linux-pwm@vger.kernel.org On Mon, 06 Jul 2020, Michael Walle wrote: > There are I2C devices which contain several different functions but > doesn't require any special access functions. For these kind of drivers > an I2C regmap should be enough. > > Create an I2C driver which creates an I2C regmap and enumerates its > children. If a device wants to use this as its MFD core driver, it has > to add an individual compatible string. It may provide its own regmap > configuration. > > Subdevices can use dev_get_regmap() on the parent to get their regmap > instance. > > Signed-off-by: Michael Walle > --- > Changes since v4: > - new patch. Lee, please bear with me. I didn't want to delay the > new version (where a lot of remarks on the other patches were > addressed) even more, just because we haven't figured out how > to deal with the MFD part. So for now, I've included this one. > > drivers/mfd/Kconfig | 9 +++++++ > drivers/mfd/Makefile | 1 + > drivers/mfd/simple-mfd-i2c.c | 50 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 60 insertions(+) > create mode 100644 drivers/mfd/simple-mfd-i2c.c > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 33df0837ab41..f1536a710aca 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -1162,6 +1162,15 @@ config MFD_SI476X_CORE > To compile this driver as a module, choose M here: the > module will be called si476x-core. > > +config MFD_SIMPLE_MFD_I2C > + tristate "Simple regmap based I2C devices" > + depends on I2C > + select MFD_CORE > + select REGMAP_I2C > + help > + This is a consolidated driver for all MFD devices which are > + basically just a regmap bus driver. > + > config MFD_SM501 > tristate "Silicon Motion SM501" > depends on HAS_DMA > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index a60e5f835283..78d24a3e7c9e 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -264,3 +264,4 @@ obj-$(CONFIG_MFD_STMFX) += stmfx.o > obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o > > obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o > +obj-$(CONFIG_MFD_SIMPLE_MFD_I2C) += simple-mfd-i2c.o > diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c > new file mode 100644 > index 000000000000..1fdca89964b1 > --- /dev/null > +++ b/drivers/mfd/simple-mfd-i2c.c > @@ -0,0 +1,49 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include I'm pretty sure you do not require all of these headers. > +struct simple_mfd_i2c_config { > + const struct regmap_config *regmap_config; > +}; No need for this yet I feel. Let's keep it as simple as possible. > +static const struct regmap_config simple_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > +}; > + > +static int simple_mfd_i2c_probe(struct i2c_client *i2c) > +{ > + const struct regmap_config *regmap_config = &simple_regmap_config; > + const struct simple_mfd_i2c_config *config; > + struct regmap *regmap; > + > + config = device_get_match_data(&i2c->dev); Have this return regmap_config. > + if (config && config->regmap_config) > + regmap_config = config->regmap_config; > + > + regmap = devm_regmap_init_i2c(i2c, regmap_config); > + if (IS_ERR(regmap)) > + return PTR_ERR(regmap); > + > + return devm_of_platform_populate(&i2c->dev); > +} > + > +static const struct of_device_id simple_mfd_i2c_of_match[] = { > + {} > +}; > + > +static struct i2c_driver simple_mfd_i2c_driver = { > + .probe_new = simple_mfd_i2c_probe, > + .driver = { > + .name = "simple-mfd-i2c", > + .of_match_table = simple_mfd_i2c_of_match, > + }, > +}; > +builtin_i2c_driver(simple_mfd_i2c_driver); -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog