mfd: intel-m10-bmc: Manage access to MAX 10 fw handshake registers

On some MAX 10 cards, the BMC firmware is not available to service
handshake registers during secure update erase and write phases at
normal speeds. This problem affects at least hwmon driver. When the MAX
10 hwmon driver tries to read the sensor values during a secure update,
the reads are slowed down (e.g., reading all D5005 sensors takes ~24s
which is magnitudes worse than the normal <0.02s).

Manage access to the handshake registers using a rw semaphore and a FW
state variable to prevent accesses during those secure update phases
and return -EBUSY instead.

If handshake_sys_reg_nranges == 0, don't update bwcfw_state as it is not
used. This avoids the locking cost.

Co-developed-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Co-developed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230417092653.16487-5-ilpo.jarvinen@linux.intel.com

mfd: intel-m10-bmc: Move core symbols to own namespace

Create INTEL_M10_BMC_CORE namespace for symbols exported by
intel-m10-bmc-core.

Reviewed-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230417092653.16487-2-ilpo.jarvinen@linux.intel.com

mfd: intel-m10-bmc: Prefix register defines with M10BMC_N3000

Prefix the M10BMC defines register defines with M10BMC_N3000 to make it
more obvious these are related to some board type. All current
non-N3000 board types have the same layout so they'll be reused. The
less generic makes it more obvious they're not meant for the
generic/interface agnostic code.

Reviewed-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230116100845.6153-8-ilpo.jarvinen@linux.intel.com

mfd: intel-m10-bmc: Support multiple CSR register layouts

There are different addresses for the MAX10 CSR registers. Introducing
a new data structure m10bmc_csr_map for the register definition of
MAX10 CSR.

Provide the csr_map for SPI.

Co-developed-by: Tianfei zhang <tianfei.zhang@intel.com>
Signed-off-by: Tianfei zhang <tianfei.zhang@intel.com>
Reviewed-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230116100845.6153-6-ilpo.jarvinen@linux.intel.com

mfd: intel-m10-bmc: Split into core and spi specific parts

Split the common code from intel-m10-bmc driver into intel-m10-bmc-core
and move the SPI bus parts into an interface specific file.

intel-m10-bmc-core becomes the core MFD functions which can support
multiple bus interface like SPI bus.

Co-developed-by: Tianfei zhang <tianfei.zhang@intel.com>
Signed-off-by: Tianfei zhang <tianfei.zhang@intel.com>
Reviewed-by: Russ Weight <russell.h.weight@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net> # hwmon
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230116100845.6153-5-ilpo.jarvinen@linux.intel.com