[linux-sunxi] [PATCH 2/6] mfd: axp20x: Split the driver into core and i2c bits

On Thu, Oct 15, 2015 at 6:37 AM, Julian Calaby [off-list ref] wrote:

Hi Chen-Yu,

On Thu, Oct 15, 2015 at 3:32 AM, Chen-Yu Tsai [off-list ref] wrote:

quoted

The axp20x driver assumes the device is i2c based. This is not the
case with later models, which use a proprietary 2 wire serial bus
called "Reduced Serial Bus".

This patch follows the example of mfd/wm831x and splits it into
an interface independet core, and an i2c specific glue layer.

The old MFD_AXP20X Kconfig symbol is kept until sub-device drivers
and defconfigs have migrated to the new MFD_AXP20X_CORE symbol.

Included but unused header files are removed as well.

Signed-off-by: Chen-Yu Tsai <redacted>
---
 drivers/mfd/Kconfig                     |  18 ++++-
 drivers/mfd/Makefile                    |   3 +-
 drivers/mfd/{axp20x.c => axp20x-core.c} | 105 +++-----------------------
 drivers/mfd/axp20x-i2c.c                | 127 ++++++++++++++++++++++++++++++++
 include/linux/mfd/axp20x.h              |  33 ++++++++-
 5 files changed, 186 insertions(+), 100 deletions(-)
 rename drivers/mfd/{axp20x.c => axp20x-core.c} (87%)
 create mode 100644 drivers/mfd/axp20x-i2c.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 99d63675f073..9ba3feb3f2fc 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig

@@ -79,15 +79,25 @@ config MFD_BCM590XX
        help
          Support for the BCM590xx PMUs from Broadcom

+# Keep the old symbol until subdevice driver dependencies and defconfigs
+# have been updated.
 config MFD_AXP20X
-       bool "X-Powers AXP20X"
+       bool "X-Powers AXP series PMICs"
+       select MFD_AXP20X_I2C

Unless something has changed in KConfig, (and my knowledge on this is
likely to be outdated) I don't believe this will work as I don't think
selects don't get propagated like you expect. Have you checked that
all possible configuration options survive make oldconfig and build
without warnings?

Yeah this totally did not work out like I expected.

Also, unless there's some compelling reason not to, it's probably a
good idea to update the dependent drivers and defconfigs now. (or make
this change in a gentler manner.)

What I wanted was to keep the original symbol for a release cycle or
more, giving me time to update the related entries across the kernel.
After the changes are in, we could remove the old one.

The other way would be to change MFD_AXP20X to a hidden symbol, and
let the 2 new ones select that. Then we'd just update all the
defconfigs.

I'll rework this and add defconfig updates.

Thanks
ChenYu

quoted

+
+config MFD_AXP20X_CORE
+       bool
        select MFD_CORE
-       select REGMAP_I2C
        select REGMAP_IRQ
+
+config MFD_AXP20X_I2C
+       bool "X-Powers AXP series I2C PMICs"
+       select MFD_AXP20X_CORE
+       select REGMAP_I2C
        depends on I2C=y
        help
-         If you say Y here you get support for the X-Powers AXP202, AXP209 and
-         AXP288 power management IC (PMIC).
+         If you say Y here you get support for the X-Powers AXP series I2C
+         based power management ICs (PMICs).
          This driver include only the core APIs. You have to select individual
          components like regulators or the PEK (Power Enable Key) under the
          corresponding menus.

Thanks,

--
Julian Calaby

Email: julian.calaby at gmail.com
Profile: http://www.google.com/profiles/julian.calaby/