Messages in this thread |  | | Date | Tue, 28 Jul 2020 09:42:26 +0200 | From | Michael Walle <> | Subject | Re: [PATCH v6 01/13] mfd: add simple regmap based I2C driver |
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Am 2020-07-28 09:19, schrieb Lee Jones: > On Sun, 26 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 <michael@walle.cc> >> --- >> Changes since v5: >> - removed "select MFD_CORE" in Kconfig >> - removed help text in Kconfig, we assume that the users of this > > That's the opposite of what I asked for.
What is the use to describe the symbol, if it is not user selectable? I'm not aware this is done anywhere in the kernel, am I missing something?
>> driver will have a "select MFD_SIMPLE_MFD_I2C". Instead added >> a small description to the driver itself. >> - removed "struct simple_mfd_i2c_config" and use regmap_config >> directly >> - changed builtin_i2c_driver() to module_i2c_driver(), added >> MODULE_ boilerplate >> - cleaned up the included files >> >> 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 | 5 ++++ >> drivers/mfd/Makefile | 1 + >> drivers/mfd/simple-mfd-i2c.c | 55 >> ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 61 insertions(+) >> create mode 100644 drivers/mfd/simple-mfd-i2c.c >> >> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig >> index 33df0837ab41..c08539c7a166 100644 >> --- a/drivers/mfd/Kconfig >> +++ b/drivers/mfd/Kconfig >> @@ -1162,6 +1162,11 @@ 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 >> + depends on I2C >> + select REGMAP_I2C > > Please provide a full help.
See above.
> >> 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..45090ddad104 >> --- /dev/null >> +++ b/drivers/mfd/simple-mfd-i2c.c >> @@ -0,0 +1,55 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * A very simple I2C MFD driver > > Simple MFD - I2C
ok.
>> + * The driver enumerates its children and registers a common regmap. >> Use >> + * dev_get_regmap(pdev->dev.parent, NULL) in the child nodes to fetch >> that >> + * regmap instance. > > This driver creates a single register map with the intention for it to > be shared by all sub-devices. Children can use their parent's device > structure (dev.parent) in order reference it.
Should this be appended or should it replace my paragraph? If its the latter, the "enumeration of the children" is missing.
>> + * In the future this driver might be extended to support also other >> interfaces >> + * like SPI etc. > > Remove this please.
Why would you remove information about the intention of this driver? If someone looks for a place to implement its SPI/I3C/Slimbus MFD driver this might come in handy.
-michael
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