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@xxxxxxxx>
---
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
