remoteproc: pru: Add pru_rproc_set_ctable() function

Some firmwares expect the OS drivers to configure the CTABLE
entries publishing dynamically allocated memory regions. For
example, the PRU Ethernet firmwares use the C28 and C30 entries
for retrieving the Shared RAM and System SRAM (OCMC) areas
allocated by the PRU Ethernet client driver.

Provide a way for users to do that through a new API,
pru_rproc_set_ctable(). The API returns 0 on success and
a negative value on error.

NOTE:
The programmable CTABLE entries are typically re-programmed by
the PRU firmwares when dealing with a certain block of memory
during block processing. This API provides an interface to the
PRU client drivers to publish a dynamically allocated memory
block with the PRU firmware using a CTABLE entry instead of a
negotiated address in shared memory. Additional synchronization
may be needed between the PRU client drivers and firmwares if
different addresses needs to be published at run-time reusing
the same CTABLE entry.

CTABLE for stands for "constant table".
Each CTable entry just holds the upper address bits so PRU can
reference to external memory with larger address bits.

For use case please see
prueth_sw_emac_config() in "drivers/net/ethernet/ti/prueth_switch.c"

/* Set in constant table C28 of PRUn to ICSS Shared memory */
pru_rproc_set_ctable(prueth->pru0, PRU_C28, sharedramaddr);
pru_rproc_set_ctable(prueth->pru1, PRU_C28, sharedramaddr);

/* Set in constant table C30 of PRUn to OCMC memory */
pru_rproc_set_ctable(prueth->pru0, PRU_C30, ocmcaddr);
pru_rproc_set_ctable(prueth->pru1, PRU_C30, ocmcaddr);

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Link: https://lore.kernel.org/r/20230106121046.886863-6-danishanwar@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

remoteproc: pru: Add APIs to get and put the PRU cores

Add two new APIs, pru_rproc_get() and pru_rproc_put(), to the PRU
driver to allow client drivers to acquire and release the remoteproc
device associated with a PRU core. The PRU cores are treated as
resources with only one client owning it at a time.

The pru_rproc_get() function returns the rproc handle corresponding
to a PRU core identified by the device tree "ti,prus" property under
the client node. The pru_rproc_put() is the complementary function
to pru_rproc_get().

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230106121046.886863-4-danishanwar@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

remoteproc: pru: Add enum for PRU Core Identifiers.

Introducing enum pruss_pru_id for PRU Core Identifiers.
PRUSS_PRU0 indicates PRU Core 0.
PRUSS_PRU1 indicates PRU Core 1.
PRUSS_NUM_PRUS indicates the total number of PRU Cores.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230106121046.886863-3-danishanwar@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>