[RFC PATCH 0/5] regmap: Add Parity bit Calculation to regmaps

From: linuxkernel
Date: Fri Dec 17 2021 - 17:41:26 EST


From: Christopher Tyerman <c.tyerman@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

this patch set adds parity bit calculation to regmaps

this allow support for devices that require parity bits in their
communications.

e.g. the texas instruments TPS92518-Q1 which requires a parity bit in the
7th bit of a 16 bit spi frame
or the TPS92518-Q1 which requires a parity bit in the 1st bit of a 16 bit
spi frame

parity aimed to work devices where parity in reg block
e.g. TPS65311-Q1 and TPS92518-Q1

TPS65311-Q1 frame format [PWRRRRRRDDDDDDDD]
TPS92518-Q1 frame format [WRRRRRPDDDDDDDDD]
P - parity bit, W - Read/Write bit, R - register, D -register data

TPS65311-Q1 parity mask 0x8000 (1000000000000000)
TPS92518-Q1 parity mask 0x0200 (0000001000000000)


calculates parity bit based up parity function defined by
regmap_config->parity_calc

regmap_config->parity_calc defaults to regmap_parity_calc_even()

adds alternate parity function regmap_parity_calc_odd()

calculates parity bit for writes if regmap_config->parity_write_mask is > 0
calculates parity bit for reads if regmap_config->parity_read_mask is > 0

parity is not calculated when bus implements reg_update_bits()


Altered the regmap_format_X_X_write functions to account for padding bits
allowing masks to write to either end of register address for formatted
writes

Altered formatted_write to apply write and parity masks

Added parsers for 9 bit data format which are written by formatted write

Christopher Tyerman (5):
Add Parity bit Calculation to regmaps
Altered regmap_X_X_write functions to account for padding bits
Added setting of writemap to formatted write
Add Parity Calculation to formatted write
Add parser for X_9 formats

drivers/base/regmap/internal.h | 6 +
drivers/base/regmap/regmap.c | 250 +++++++++++++++++++++++++++++++--
include/linux/regmap.h | 32 +++++
3 files changed, 280 insertions(+), 8 deletions(-)


base-commit: 02d6fdecb9c38de19065f6bed8d5214556fd061d
--
2.25.1