On 1/22/21 7:22 AM, Su Yanjun wrote:
> When i debug mcp2518fd, some method to track registers is
> needed. This easy debug interface will be ok.

NACK

As the driver uses regmap, everything should be there already.

To read use:

| cat /sys/kernel/debug/regmap/spi0.0-crc/registers

Register write support for devices that are handles by proper kernel drivers is
a pure debugging tool, thus not enabled by default, not even with a Kconfig
switch. You have to enable it manually, have a look at commit:

09c6ecd39410 regmap: Add support for writing to regmap registers via debugfs

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |