Messages in this thread | | | From | "Alex A. Mihaylov" <> | Subject | [RFC 0/2] Again w1-regman and power_supply MAX1721x | Date | Mon, 8 May 2017 09:13:26 +0300 |
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Hi! I wrote driver for Maxim MAX17211/MAX17215 standalone fuel gauge IC.
Earlier I post preliminary versions of this driver and got recommendations to translate it into the infrastructure of regmap. Accordingly, it was necessary to implement at least basic support of regmap for the OneWire bus. Which was done. There was a criticism about the use of an intermediate platform_device. In this edition, this is also fixed.
I would like to hear not only criticism, but also constructive proposals for the implementation or correction of this code.
Known issuie/troubles: ~~~~~~~~~~~~~~~~~~~~~~ 1. Endian for W1-regmap Code writen for use nativ endian for host (master) device. But waiting for little-endian slave divice. I don't know W1 slave device with big-endian addrees or data format. May be regmap_bus or regmap_config will be checked for host/device endian requirements?
2. W1 Family/device infrastructure All present power_supply class drivers in vanilla kernel use w1-slave devices. All of them create platform_device with name "chip-battery.X.auto", and power_supply class driver use this platform device. Why used this way? I write code, allocated power_supply at W1 slave (family) device register. This work as expected.
3. Device names All W1 device have unical 64 bit ID (8-bit family, 48-bit serial number, 8 bit CRC). W1 infrastructure show 56 bits (family-serial_nimber) as w1 slave device name. I use this (unical) device name as power_supply battery name. This work. But in /sys/class/power_supply is placed machine readabe subdir "26-HexDigString", instead of human-readable "chip-battery.X.auto". But in /sys/class/power_supply/26-HexDigString/type file still content human-readable type "Battery". Thermal zone working, but in /sys/class/thermal/thermal_zoneX/type also placed "26-HexDigString", instead of "chip-battery.X.auto". I can rename "26-HexDigString" to "battery-26-HexDigString" or "26-HexDigString-battery", but this exceeded 20 chars thermal zone device name. So, thermal zone will have to be disabled.
Alex A. Mihaylov (2): Basic support for regmap ifrastucture over Maxim/Dalas OneWire Bus MAX1721x Standalone Fuel Gauge IC power_supply class driver
drivers/base/regmap/Kconfig | 6 +- drivers/base/regmap/Makefile | 1 + drivers/base/regmap/regmap-w1.c | 241 +++++++++++++++++++++ drivers/power/supply/Kconfig | 14 ++ drivers/power/supply/Makefile | 1 + drivers/power/supply/max1721x_battery.c | 361 ++++++++++++++++++++++++++++++++ include/linux/power/max172xx-battery.h | 100 +++++++++ include/linux/regmap.h | 34 +++ 8 files changed, 757 insertions(+), 1 deletion(-) create mode 100644 drivers/base/regmap/regmap-w1.c create mode 100644 drivers/power/supply/max1721x_battery.c create mode 100644 include/linux/power/max172xx-battery.h
-- 2.8.4 (Apple Git-73)
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