FSI changes for 5.10

 - Misc code cleanups. Thanks to Colin, Xu and Rikard

 - Features for the ASPEED FSI master
  * Detect connection type and routing for Tacoma
  * Run at full speed (200MHz) by default
  * Set bus speed with a parameter
  * CFAM reset GPIO
  * 23 bit addressing

 - Core features
  * Disable unused links
  * Set LBUS ownership
fsi: aspeed: Support CFAM reset GPIO

Systems have a line for restting the remote CFAM. This is not part of
the FSI master, but is associated with it, so it makes sense to include
it in the master driver.

This exposes a sysfs interface to reset the cfam, abstracting away the
direction and polarity of the GPIO, as well as the timing of the reset
pulse. Userspace will be blocked until the reset pulse is finished.

The reset is hard coded to be in the range of (900, 1000) us. It was
observed with a scope to regularly be just over 1ms.

If the device tree property is not preset the driver will silently

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20200728025527.174503-6-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
2 files changed