Implement support for RPMh reads, these allow reading out the
current votes for RPMh controlled resources such as regulators and
interconnects.

Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-4-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

Several bugs were discovered in the rpmh-rsc driver which collectively
meant we were never actually waiting for the TCS to flush, these were
likely missed because U-Boot runs single threaded and the RPMh had
typically processed the single command we sent by the time we went
to send the next one. However a future patch will implement rpmh read
support which requires us to properly wait for the RPMh command response
so we can return the value.

Fix these issues so we correctly ensure the TCS is done before
returning.

Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-3-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

Add some comments explaining a few of the RSC registers

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-2-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

If we don't reclaim and clear the IRQ bits, we might get a spurious
interrupt from this TCS in Linux:
WARNING: CPU: 0 PID: 0 at drivers/soc/qcom/rpmh-rsc.c:451 tcs_tx_done+0x98/0x270
...
 Call trace:
  tcs_tx_done+0x98/0x270 (P)
  __handle_irq_event_percpu+0x60/0x220
  handle_irq_event+0x54/0xc0
  handle_fasteoi_irq+0xa8/0x1c0
  handle_irq_desc+0x3c/0x68
  generic_handle_domain_irq+0x24/0x40
  gic_handle_irq+0x5c/0xd0
  ...

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-1-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

Partially reverted commit "soc: qcom: cmd-db: drop unused
functions" by restoring only the cmd_db_read_slave_id() and
cmd_db_read_aux_data() functions, which were removed in that
commit. These functions are required for the RPMH Power Domain
Driver.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
Signed-off-by: Aswin Murugan <aswin.murugan@oss.qualcomm.com>
Reviewed-by: Casey Connolly <casey.connolly@linaro.org>> ---
Link: https://patch.msgid.link/20251113113427.2218045-2-aswin.murugan@oss.qualcomm.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

The Qualcomm Snapdragon "SoC" driver cannot build without access to some
ARM64 specific functionality. Express that requirements in Kconfig as
well.

Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Signed-off-by: Tom Rini <trini@konsulko.com>

The TCS writes has no effect after the removal of the __tcs_set_trigger()
call, obviously it seems the RSC version 3 requires it to complete the transactions.

Fixes: 80c5be164ad ("soc: qcom: rpmh-rsc: drop unused multi-threading and non-active TCS support")
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Tested-by: Caleb Connolly <caleb.connolly@linaro.org> # sm8250 rb5
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>

On at least SM8650 this region might not be included in the memory map.
Use the new mmu_map_region() helper to map it during bind().

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

memcmp() can cause aborts on some platforms and generally seems to be
the wrong approach here. Use strncmp() instead which is more correct.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

Add Kconfig / Makefiles to build rpmh and cmd-db drivers.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>