From eceae583930666a69ab805eee8e81f9699bf6930 Mon Sep 17 00:00:00 2001 From: Jonathan Neuschäfer Date: Sun, 24 Jan 2021 22:41:23 +0100 Subject: mfd: Add base driver for Netronix embedded controller MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Netronix embedded controller is a microcontroller found in some e-book readers designed by the original design manufacturer Netronix, Inc. It contains RTC, battery monitoring, system power management, and PWM functionality. This driver implements register access and version detection. Third-party hardware documentation is available at: https://github.com/neuschaefer/linux/wiki/Netronix-MSP430-embedded-controller The EC supports interrupts, but the driver doesn't make use of them so far. Signed-off-by: Jonathan Neuschäfer Signed-off-by: Lee Jones --- include/linux/mfd/ntxec.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 include/linux/mfd/ntxec.h (limited to 'include') diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h new file mode 100644 index 000000000000..361204d125f1 --- /dev/null +++ b/include/linux/mfd/ntxec.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2020 Jonathan Neuschäfer + * + * Register access and version information for the Netronix embedded + * controller. + */ + +#ifndef NTXEC_H +#define NTXEC_H + +#include + +struct device; +struct regmap; + +struct ntxec { + struct device *dev; + struct regmap *regmap; +}; + +/* + * Some registers, such as the battery status register (0x41), are in + * big-endian, but others only have eight significant bits, which are in the + * first byte transmitted over I2C (the MSB of the big-endian value). + * This convenience function converts an 8-bit value to 16-bit for use in the + * second kind of register. + */ +static inline __be16 ntxec_reg8(u8 value) +{ + return value << 8; +} + +/* Known firmware versions */ +#define NTXEC_VERSION_KOBO_AURA 0xd726 /* found in Kobo Aura */ + +#endif -- cgit v1.2.3-71-gd317