tree a7db5cff2eaf325e95a27ef114978a7f3548051b
parent fc4f17be6d6c49ff55e93e460e4474bdb2e74919
author Mirela Simonovic <mirela.simonovic@aggios.com> 1537187116 +0200
committer Jolly Shah <jolly.shah@xilinx.com> 1578438184 -0800

zynqmp: pm: Fix clock models and IDs of GEM-related clocks

GEM-related clock models were incorrect and are fixed as follows
(documented below for GEM0, but the same holds for any GEM ID):

- CLK_GEM0_REF_UNGATED represents clock that has DIV0/1 divisors and
 the multiplexer controllable in GEM0_REF_CTRL (CRL_APB). The ID of this
 clock is newly introduced in this patch.

- CLK_GEM0_REF models the clock mux that selects the reference clock
 for Tx, i.e. selects CLK_GEM0_REF_UNGATED or external Tx clock. This
 mux is controllable via GEM_CLK_CTRL (IOU_SLCR), bit GEM0_REF_SRC_SEL.
 Note that the routing of external clock to the mux is not modelled
 and is assumed to be configured by the FSBL if required, and not
 changeable at runtime. The ID of this clock is introduced in this patch.

- CLK_GEM0_TX models clock with only a gate that is controlled via
 bit 25 in GEM0_REF_CTRL (CRL_APB). The parent of this clock is
 CLK_GEM0_REF. The clock ID of CLK_GEM0_TX matches the previous ID
 value of CLK_GEM0_REF. This is done in order to fix the clock models
 and incorrect binding without requiring to change device-tree (binding
 of clock IDs to GEM interface).

- CLK_GEM0_RX models clock that has only gate controlled via RX_CLKACT
 bit (26) in GEM0_REF_CTRL (CRL_APB). Parent of this clock is sourced
 from external RGMII PHY (via MIO or EMIO). We do not model the whole
 clock path to the Rx gate, since this is configured by the FSBL and
 never changed at runtime (and there is no mechanism to change the
 path at runtime). The clock ID of CLK_GEM0_RX clock is equal to the
 previous ID value of CLK_GEM0_TX clock. This is done because the TX/RX
 were swapped in device tree, so by fixing the IDs this way there is no
 need for device tree fix.

Rates of the external RX/TX clocks can be specified in device tree if
needed. Right now, that's not necessary because Tx clock is sourced
from an on-chip PLL (via CLK_GEM0_REF_UNGATED/CLK_GEM0_REF), whereas
the Rx clock is sourced from external reference and the driver never
attempts to get/get clock rate (only to enable it). If this changes in
future, ATF clock model doesn't need to be changed. Instead, the clock
rates for gem0_tx_ext and gem0_rx_ext have to be specified in device
tree.

Signed-off-by: Mirela Simonovic <mirela.simonovic@aggios.com>
Acked-by: Will Wong <will.wong@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: I6497d4309e92205c527bd81b3aa932f4474f5b79