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784 lines
20 KiB
ArmAsm
784 lines
20 KiB
ArmAsm
/* GRLIB AMBA Plug&Play information scanning implemented without
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* using memory (stack) and one register window. The code scan
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* the PnP info and inserts the AHB bridges/buses into register
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* i0-i5.
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* The code support
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* - up to 6 AHB buses
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* - multiple APB buses
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* - support for AHB2AHB & L2CACHE bridges
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*
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* (C) Copyright 2010, 2015
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* Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <ambapp.h>
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.seg "text"
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.globl _nomem_amba_init
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.globl _nomem_ambapp_find_buses
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.globl _nomem_find_apb
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.globl _nomem_find_ahb
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/* Overview
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* ========
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*
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* _nomem_amba_init - Init AMBA bus and calls _nomem_ambapp_find_buses
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* _nomem_ambapp_find_buses - Scan AMBA PnP info for AHB buses/bridges and
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* place them in i0-i5, see below
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* _nomem_find_apb - Find one APB device identified by VENDOR:DEVICE
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* ID and an index.
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* _nomem_find_ahb - Find one AHB Master or Slave device identified
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* by VENDOR:DEVICE ID and an index.
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* init_ahb_bridges - Local function. Clears i0-i5
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* insert_ahb_bridge - Local function. Insert a new AHB bus into first
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* free register in i0-i5. It also checks that the
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* bus has not already been added.
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* get_ahb_bridge - Local function. Get AHB bus from registers,
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* return register iN, where N is defined by o0.
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*
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* The _nomem_find_apb and _nomem_find_ahb function requires that i0-i5
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* are populated with the AHB buses of the system. The registers are
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* initialized by _nomem_ambapp_find_buses.
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*
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* AHB Bus result and requirements of i0-i5
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* ========================================
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*
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* i0: AHB BUS0 IOAREA, no parent bus
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* i1: AHB BUS1 IOAREA, parent bus is always i0 (AHB BUS0) and bridge address
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* i2: AHB BUS2 IOAREA, 3-bit parent bus number and bridge address
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* i3: AHB BUS3 IOAREA, 3-bit parent bus number and bridge address
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* i4: AHB BUS4 IOAREA, 3-bit parent bus number and bridge address
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* i5: AHB BUS5 IOAREA, 3-bit parent bus number and bridge address
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*
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* AHB BUS
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* -------
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* Bits 31-20 (0xfff00000) contain the found bus I/O Area (AHB PnP area).
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*
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* 3-bit Parent bus
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* ----------------
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* Bits 2-0 (0x00000007) contain parent bus number. Zero if no parent
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* bus, 1 = parent is AHB BUS 0 (i0), 2 = parent is AHB BUS 1 (i1)..
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*
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* Bridge Address
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* --------------
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* Bits 10-5 (0x000007e0) contain the index of the Bridge's PnP
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* information on the parent. Since all bridges are found in the
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* PnP information they all have a PnP entry. Together with the
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* parent bus number the PnP entry can be found:
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* PnPEntry = (BRIDGE_ADDRESS + (iN & 0xfff00000)) | 0x000ff800
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* where N is the parent bus minus one.
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*
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*/
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/* Function initializes the AHB Bridge I/O AREA storage. (Clears i0-i5)
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*
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* Arguments
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* none
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*
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* Results
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* none
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*
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* Clobbered
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* none
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*/
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init_ahb_bridges:
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mov %g0, %i0
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mov %g0, %i1
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mov %g0, %i2
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mov %g0, %i3
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mov %g0, %i4
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retl
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mov %g0, %i5
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/* Function returns AHB Bridge I/O AREA for specified bus.
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*
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* Arguments
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* - o0 = bus number
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*
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* Results
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* - o0 = I/O AREA
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*
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* Clobbered
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* none
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*/
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get_ahb_bridge:
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cmp %o0, 1
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be,a L1
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mov %i0, %o0
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cmp %o0, 2
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be,a L1
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mov %i1, %o0
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cmp %o0, 3
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be,a L1
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mov %i2, %o0
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cmp %o0, 4
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be,a L1
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mov %i3, %o0
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cmp %o0, 5
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be,a L1
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mov %i4, %o0
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cmp %o0, 6
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be,a L1
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mov %i5, %o0
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/* o0 > 6: only 6 buses supported */
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mov %g0, %o0
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L1:
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retl
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nop
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/* Function adds a AHB Bridge I/O AREA to the i0-i5 registers if
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* not already added. It stores the bus PnP start information.
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*
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* Arguments
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* - o0 = AHB Bridge I/O area
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*
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* Results
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* none
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*
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* Clobbered
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* o2, o3
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*/
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insert_ahb_bridge:
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/* Check that bridge hasn't already been added */
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andn %o0, 0x7ff, %o2
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andn %i0, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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andn %i1, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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andn %i2, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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andn %i3, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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andn %i4, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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andn %i5, 0x7ff, %o3
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cmp %o3, %o2
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be L2
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/* Insert into first free posistion */
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cmp %i0, %g0
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be,a L2
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mov %o0, %i0
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cmp %i1, %g0
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be,a L2
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mov %o0, %i1
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cmp %i2, %g0
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be,a L2
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mov %o0, %i2
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cmp %i3, %g0
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be,a L2
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mov %o0, %i3
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cmp %i4, %g0
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be,a L2
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mov %o0, %i4
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cmp %i5, %g0
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be,a L2
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mov %o0, %i5
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L2:
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retl
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nop
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/* FUNCTION int _nomem_find_ahb_bus(
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* unsigned int bridge,
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* int vendor_device,
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* int index,
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* void **pconf,
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* int not_used,
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* int option
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* )
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*
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* Scans the AHB Master or Slave area for a matching VENDOR:DEVICE, the
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* index is decremented when a matching device is found but index is
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* greater than zero. When index is zero and a matching DEVICE:VENDOR
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* is found the AHB configuration address and AHB I/O area is returned.
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*
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* i0-i7,l0,l1,l2,l3,l4,g2,o6 is not available for use.
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* o1,o5 Must be left untouched
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*
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* Results
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* - o0 Number of found devices (1 or 0)
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* - o2 is decremented for each matching VENDOR:DEVICE found, zero if found
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* - o3 Address of the AHB PnP configuration entry (Only valid if o0=1)
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*
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* Clobbered
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* - o3 (Clobbered when no device was found)
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* - o4 (Number of Devices left to search)
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* - o0 (Bus ID, PnP ID, Device)
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*/
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_nomem_find_ahb_bus:
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/* Get the number of Slaves/Masters.
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* Only AHB Bus 0 has 64 AHB Masters/Slaves the
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* other AHB buses has 16 slaves and 16 masters.
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*/
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add %g0, 16, %o4 /* Defaulting to 16 */
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andcc %o0, 0x7, %g0 /* 3-bit bus id */
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be,a .L_maxloops_detected
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add %g0, 64, %o4 /* AHB Bus 0 has 64 AHB Masters/Slaves */
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.L_maxloops_detected:
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/* Get start address of AHB Slave or AHB Master area depending on what
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* we are searching for.
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*/
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andn %o0, 0x7ff, %o0 /* Remove Bus ID and 5-bit AHB/AHB
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* Bridge PnP Address to get I/O Area */
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set AMBA_CONF_AREA, %o3
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or %o3, %o0, %o3 /* Master area address */
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cmp %o5, DEV_AHB_SLV
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be,a .L_conf_area_calculated
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or %o3, AMBA_AHB_SLAVE_CONF_AREA, %o3 /* Add 0x800 to get to slave area */
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.L_conf_area_calculated:
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/* Iterate over all AHB device and try to find matching DEVICE:VENDOR
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* o1 - VENDOR|DEVICE
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* o2 - Index
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* o3 - Current AHB Device Configuration address
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* o5 - Type (leave untouched)
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*
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* o4 - Number of AHB device left to process
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* o0 - tmp
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*/
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.L_process_one_conf:
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ld [%o3], %o0
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andn %o0, 0xfff, %o0
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cmp %o0, 0 /* No device if zero */
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beq .L_next_conf
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cmp %o1, 0 /* If VENDOR:DEVICE==0, consider all matching */
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beq .L_process_ahb_dev_found
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cmp %o0, %o1 /* Does VENDOR and DEVICE Match? */
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bne .L_next_conf
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nop
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.L_process_ahb_dev_found:
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/* Found a Matching VENDOR:DEVICE, index must also match */
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cmp %o2, %g0
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bne .L_next_conf
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dec %o2
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/* Index matches also, return happy with o3 set to AHB Conf Address */
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mov %g0, %o2
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retl
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add %g0, 1, %o0
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.L_next_conf:
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subcc %o4, 1, %o4 /* One device has been processed,
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* Are there more devices to process? */
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bne .L_process_one_conf
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add %o3, AMBA_AHB_CONF_LENGH, %o3 /* Next Configuration entry */
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/* No Matching device found */
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retl
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mov %g0, %o0
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/* FUNCTION int _nomem_find_ahb(
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* int unused,
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* int vendor_device,
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* int index,
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* void **pconf,
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* int *ahb_bus_index,
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* int option,
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* )
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*
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* Find a AHB Master or AHB Slave device, it puts the address of the AHB PnP
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* configuration in o3 (pconf), the I/O Area base address in o4 (pioarea).
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*
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* Calls _nomem_find_ahb_bus for every AHB bus.
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*
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* i0-i7, l0, l1, o6, g1, g4-g7 is not available for use.
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*
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* Arguments
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* - o0 Unused
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*
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* Results
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* - o0 Number of found devices (1 or 0)
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* - o2 Decremented Index (Zero if found)
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* - o3 Address of the AHB PnP configuration entry
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* - o4 AHB Bus index the device was found on (if o0=1)
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* - o5 Left untouched
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*
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* Clobbered
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* - o0 (AHB Bridge and used by _nomem_find_ahb_bus)
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* - o2 (index is decremented)
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* - l2 (Current AHB Bus index)
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* - g2 (return address)
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*/
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_nomem_find_ahb:
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mov %o7, %g2 /* Save return address */
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/* Scan all AHB Buses found for the AHB Master/Slave matching VENDOR:DEVICE */
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clr %l2
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.L_search_next_ahb_bus:
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add %l2, 1, %l2
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call get_ahb_bridge /* Get bus %l0 I/O Area */
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mov %l2, %o0
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cmp %o0, %g0
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be .L_no_device_found /* If no more AHB bus is left to be scanned, proceed */
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nop
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call _nomem_find_ahb_bus /* Scan AHB bus %o0 for VENDOR:DEVICE. Index in o3 is decremented */
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nop
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cmp %o0, %g0 /* If VENDOR:DEVICE was not found scan next AHB Bus */
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be .L_search_next_ahb_bus /* Do next bus is o0=0 (not found) */
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nop
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/* The device was found, o0 is 1 */
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mov %g2, %o7 /* Restore return address */
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retl
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mov %l2, %o4 /* The AHB bus index the device was found on */
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/* No device found matching */
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.L_no_device_found:
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mov %g2, %o7 /* Restore return address */
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retl
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mov %g0, %o0
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/* FUNCTION int _nomem_find_apb_bus(
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* int apbmst,
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* int vendor_device,
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* int index,
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* void **pconf
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* )
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*
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* Find a APB Slave device, it puts the address of the APB PnP configuration
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* in o3 (pconf).
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*
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* Calls _nomem_find_ahb_bus for every AHB bus searching for AHB/APB Bridges.
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* The AHB/APB bridges are AHB Slaves with ID GAISLER_APBMST.
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*
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* Results
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* - o0 Number of found devices (1 or 0)
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* - o2 Decremented Index
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* - o3 Address of the found APB device PnP configuration entry
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*
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* Clobbered
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* - o5 PnP VENDOR:DEVICE ID
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*/
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_nomem_find_apb_bus:
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set AMBA_CONF_AREA, %o3
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or %o0, %o3, %o3 /* Calc start of APB device PnP info */
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add %g0, 16, %o0 /* o0, number of APB Slaves left to scan */
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.L_process_one_apb_conf:
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ld [%o3], %o5
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andn %o5, 0xfff, %o5
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cmp %o5, 0 /* No device if zero */
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beq .L_process_apb_dev_not_found
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cmp %o1, 0 /* If VENDOR:DEVICE == -1, consider all matching */
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beq .L_process_apb_dev_found
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cmp %o1, %o5 /* Found VENDOR:DEVICE */
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bne .L_process_apb_dev_not_found
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nop
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.L_process_apb_dev_found:
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/* Found matching device, compare index */
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cmp %o2, %g0
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bne .L_process_apb_dev_not_found
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dec %o2
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/* Matching index and VENDOR:DEVICE */
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retl
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add %g0, 1, %o0
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.L_process_apb_dev_not_found:
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subcc %o0, 1, %o0
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bne .L_process_one_apb_conf
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add %o3, 8, %o3
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retl
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mov %g0, %o0
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/* FUNCTION int _nomem_find_apb(
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* int unused,
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* int vendor_device,
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* int index,
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* void **pconf,
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* int *ahb_bus_index
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* )
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*
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* Find a APB Slave device, it puts the address of the APB PnP configuration
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* in o3 (pconf), the APB Master I/O Area base address in o4 (papbarea).
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*
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* Calls _nomem_find_ahb_bus for every AHB bus searching for AHB/APB Bridges.
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* The AHB/APB bridges are AHB Slaves with ID GAISLER_APBMST.
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*
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* i0-i7, l0, l1, o6 is not available for use.
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*
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* Arguments
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* - o0 Unused
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*
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* Results
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* - o0 Number of found devices (1 or 0)
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* - o2 Decremented Index if not found
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* - o3 Address of the APB PnP configuration entry
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* - o4 AHB Bus index of APB Bridge/APB Device
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*
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* Clobbered
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* - o0 (AHB Bridge)
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* - o2 (index is decremented)
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* - l2 (APB DEV Index [7..4] : APBMST AHB Index [3..0])
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* - l3 (Current AHB Bus index)
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* - l4 (temporary storage for APB VENDOR:DEVICE)
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* - o5 (AHB Slave ID)
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* - o0 (clobbered by _nomem_find_ahb_bus)
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* - g2 (Return address)
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*/
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_nomem_find_apb:
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/* Scan all AHB Buses found for AHB/APB Bridges */
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mov %o7, %g2 /* Save return address */
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mov %o1, %l4 /* Save APB VENDOR:DEVICE */
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sll %o2, 4, %l2 /* APB MST index = 0 */
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add %g0, 1, %l3 /* AHB Bus index = 0 */
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.L2_search_next_ahb_bus:
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call get_ahb_bridge /* Get bus %l3 I/O Area */
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mov %l3, %o0
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cmp %o0, %g0
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be .L2_no_device_found /* If no more AHB bus is left to be scanned, proceed */
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add %g0, DEV_AHB_SLV, %o5 /* Search for AHB Slave */
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sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER, GAISLER_APBMST)), %o1
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call _nomem_find_ahb_bus /* Scan AHB bus %o0 for VENDOR:DEVICE. Index in o3 is decremented */
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and %l2, 0xf, %o2 /* Set APBMST index */
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cmp %o0, %g0 /* If no AHB/APB Bridge was not found, scan next AHB Bus */
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be .L_no_apb_bridge_found /* Do next bus */
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nop
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/* The AHB/APB Bridge was found.
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* Search for the requested APB Device on the APB bus using
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* find_apb_bus, it will decrement the index.
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*/
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ld [%o3 + AMBA_AHB_MBAR0_OFS], %o3
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sll %o3, 16, %o0
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and %o0, %o3, %o0 /* Address AND Address Mask */
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sethi %hi(0xfff00000), %o3
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and %o0, %o3, %o0 /* AHB/APB Bridge address */
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srl %l2, 4, %o2 /* APB DEV Index */
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call _nomem_find_apb_bus
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mov %l4, %o1 /* APB VENDOR:DEVICE */
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cmp %o0, %g0
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be .L_apb_dev_not_found
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mov %g2, %o7 /* Restore return address */
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/* APB Device found
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|
* o0 1
|
|
* o2 Index is decremented to zero
|
|
* o3 APB configuration address,
|
|
* o4 APB Bridge Configuration address.
|
|
*/
|
|
mov %g0, %o2
|
|
retl
|
|
mov %l3, %o4
|
|
|
|
.L_apb_dev_not_found:
|
|
/* Update APB DEV Index by saving output from find_apb_bus
|
|
* (index parameter) into bits [31..4] in L2.
|
|
*/
|
|
sll %o2, 4, %o2
|
|
and %l2, 0xf, %l2
|
|
or %o2, %l2, %l2
|
|
/* Try finding the next AHB/APB Bridge on the same AHB bus
|
|
* to find more APB devices
|
|
*/
|
|
ba .L2_search_next_ahb_bus /* Find next AHB/APB bridge */
|
|
inc %l2
|
|
|
|
.L_no_apb_bridge_found:
|
|
inc %l3 /* Next AHB Bus */
|
|
ba .L2_search_next_ahb_bus /* Process next AHB bus */
|
|
andn %l2, 0xf, %l2 /* Start at APB Bridge index 0 at every AHB Bus */
|
|
/* No device found matching */
|
|
.L2_no_device_found:
|
|
mov %g2, %o7 /* Restore return address */
|
|
srl %l2, 4, %o2 /* APB DEV Index */
|
|
retl
|
|
mov %g0, %o0
|
|
|
|
|
|
|
|
/* FUNCTION _nomem_amba_scan_gaisler_ahb2ahb_bridge(unsigned int bridge, int bus)
|
|
*
|
|
* Constraints:
|
|
* - o1 may not be used
|
|
* - o0, o2, o3 may be used.
|
|
*
|
|
* Arguments
|
|
* - o0 PnP Address of Bridge AHB device
|
|
* - o2 PnP ID of AHB device
|
|
*
|
|
* Results
|
|
* - o0 Address of new bus PnP area or a 1 if AHB device is no bridge
|
|
*
|
|
* Clobbered
|
|
* - o0, o2
|
|
*
|
|
*/
|
|
_nomem_amba_scan_gaisler_ahb2ahb_bridge:
|
|
andn %o2, 0xfff, %o2
|
|
sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER,GAISLER_AHB2AHB)), %o3
|
|
cmp %o2, %o3
|
|
beq .L_is_ahb2ahb_bridge
|
|
nop
|
|
|
|
retl
|
|
add %g0, 1, %o0
|
|
|
|
.L_is_ahb2ahb_bridge:
|
|
/* Found a GAISLER AHB2AHB bridge */
|
|
retl
|
|
ld [%o0 + AMBA_AHB_CUSTOM1_OFS], %o0 /* Get address of bridge PnP area */
|
|
|
|
|
|
/* FUNCTION _nomem_amba_scan_gaisler_l2cache_bridge(unsigned int bridge, int bus)
|
|
*
|
|
* Constraints:
|
|
* - o1 may not be used
|
|
* - o0, o2, o3 may be used.
|
|
*
|
|
* Arguments
|
|
* - o0 PnP Address of Bridge AHB device
|
|
* - o2 PnP ID of AHB device
|
|
*
|
|
* Results
|
|
* - o0 Address of new bus PnP area or a 1 if AHB device is no bridge
|
|
*
|
|
* Clobbered
|
|
* - o0, o2
|
|
*
|
|
*/
|
|
_nomem_amba_scan_gaisler_l2cache_bridge:
|
|
andn %o2, 0xfff, %o2
|
|
sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER,GAISLER_L2CACHE)), %o3
|
|
cmp %o2, %o3
|
|
beq .L_is_l2cache_bridge
|
|
nop
|
|
|
|
retl
|
|
add %g0, 1, %o0
|
|
|
|
.L_is_l2cache_bridge:
|
|
/* Found a GAISLER l2cache bridge */
|
|
retl
|
|
ld [%o0 + AMBA_AHB_CUSTOM1_OFS], %o0 /* Get address of bridge PnP area */
|
|
|
|
|
|
/* FUNCTION _nomem_amba_scan(unsigned int bridge, int bus)
|
|
*
|
|
* Constraints:
|
|
* i0-i7, l0 is used by caller
|
|
* o5-o7 may not be used.
|
|
*
|
|
* Arguments
|
|
* - o0 Bridge Information: I/O AREA and parent bus
|
|
* - o1 Bus
|
|
*
|
|
* Results
|
|
* - o0 Number of AHB bridges found
|
|
*
|
|
* Clobbered
|
|
* - o0 (Current AHB slave conf address)
|
|
* - o2 (Used by insert_bridge)
|
|
* - o3 (Used by insert_bridge)
|
|
* - l1 (Number of AHB Slaves left to process)
|
|
* - l2 (Current AHB slave conf address)
|
|
* - g2 (Return address)
|
|
*/
|
|
_nomem_amba_scan:
|
|
mov %o7, %g2 /* Save return address */
|
|
set 16, %l1
|
|
cmp %o1, 1
|
|
be,a .L2_maxloops_detected
|
|
add %g0, 64, %l1
|
|
.L2_maxloops_detected:
|
|
|
|
/* Clear 3-bit parent bus from bridge to get I/O AREA, then or
|
|
* (AMBA_CONF_AREA | AMBA_AHB_SLAVE_CONF_AREA) to get first AHB slave
|
|
* conf address.
|
|
*/
|
|
andn %o0, 0x7ff, %o0
|
|
set (AMBA_CONF_AREA | AMBA_AHB_SLAVE_CONF_AREA), %l2
|
|
or %o0, %l2, %l2
|
|
|
|
/* Scan AHB Slave area for AHB<->AHB bridges. For each AHB device
|
|
* all "bridge drivers" are called, the driver function interface:
|
|
*
|
|
* Input:
|
|
* - o0 PnP Address of Bridge AHB device
|
|
* - o2 PnP ID of AHB device
|
|
* Return values:
|
|
* - o0 Address of new bus PnP area, returning a 1 in o2 means not found
|
|
*
|
|
* Constraints:
|
|
* - o1 may not be used
|
|
* - o0, o2, o3 may be used.
|
|
*
|
|
*/
|
|
.L_scan_one_ahb_slave:
|
|
ld [%l2], %o2
|
|
|
|
cmp %o2, %g0
|
|
beq .L_scan_next_ahb_slave
|
|
nop
|
|
|
|
/* Call the GAISLER AHB2AHB bridge driver */
|
|
call _nomem_amba_scan_gaisler_ahb2ahb_bridge
|
|
mov %l2, %o0
|
|
cmp %o0, 1
|
|
bne .L_found_bridge
|
|
ld [%l2], %o2
|
|
|
|
/* Call the GAISLER L2CACHE bridge driver */
|
|
call _nomem_amba_scan_gaisler_l2cache_bridge
|
|
mov %l2, %o0
|
|
cmp %o0, 1
|
|
bne .L_found_bridge
|
|
ld [%l2], %o2
|
|
|
|
/* Insert next bridge "driver" function here */
|
|
|
|
|
|
/* The PnP ID did not match a bridge - a new bus was not found ==>
|
|
* step to next AHB device */
|
|
ba .L_scan_next_ahb_slave
|
|
nop
|
|
|
|
/* Add Found bus */
|
|
.L_found_bridge:
|
|
and %l2, 0x7e0, %o2
|
|
or %o2, %o0, %o0 /* Add AHB/AHB Bridge PnP address */
|
|
call insert_ahb_bridge /* Insert Bridge into found buses storage */
|
|
or %o1, %o0, %o0 /* Add parent bus LSB 3-bits */
|
|
|
|
.L_scan_next_ahb_slave:
|
|
/* More Slaves to process? */
|
|
subcc %l1, 1, %l1
|
|
bne .L_scan_one_ahb_slave
|
|
add %l2, AMBA_AHB_CONF_LENGH, %l2
|
|
|
|
/* No more AHB devices to process */
|
|
mov %g2, %o7 /* Restore return address */
|
|
retl
|
|
nop
|
|
|
|
/* FUNCTION _nomem_ambapp_find_buses(unsigned int ioarea)
|
|
*
|
|
* Find AMBA AHB buses.
|
|
*
|
|
* Constraints:
|
|
* i6-i7, l7 is used by caller
|
|
*
|
|
* Arguments
|
|
* - o0 Bridge Information: I/O AREA and parent bus
|
|
*
|
|
* Results
|
|
* - o0 Number of AHB bridges found
|
|
* - i0-i5 initialized
|
|
*
|
|
* Clobbered
|
|
* - o0 (Current AHB slave conf address)
|
|
* - o2 (Used by insert_bridge)
|
|
* - o3 (Used by insert_bridge)
|
|
* - l0 (Current AHB Bus)
|
|
* - l1 (Used by nomem_amba_scan)
|
|
* - l2 (Used by nomem_amba_scan)
|
|
* - l3 (Used by nomem_amba_scan)
|
|
* - l4 (Used by nomem_amba_scan)
|
|
*
|
|
* - g1 (level 1 return address)
|
|
* - g2 (Used by nomem_amba_scan)
|
|
*/
|
|
_nomem_ambapp_find_buses:
|
|
mov %o7, %g1 /* Save return address */
|
|
|
|
/* Initialize AHB Bus storage */
|
|
call init_ahb_bridges
|
|
nop
|
|
|
|
/* Insert AHB Bus 0 */
|
|
call insert_ahb_bridge
|
|
nop /* Argument already prepared by caller */
|
|
|
|
/* Scan AHB Bus 0 for AHB Bridges */
|
|
call _nomem_amba_scan
|
|
add %g0, 1, %o1
|
|
|
|
/* Scan all AHB Buses found for more AHB Bridges */
|
|
add %g0, 2, %l0
|
|
.L100_search_next_ahb_bus:
|
|
call get_ahb_bridge /* Get bus %l0 I/O Area */
|
|
mov %l0, %o0
|
|
cmp %o0, %g0
|
|
be .L100_return /* If no more AHB bus is left to be scanned, proceed */
|
|
nop
|
|
call _nomem_amba_scan /* Scan bus %l0 for AHB Bridges. i0-i7,l0 is used */
|
|
mov %l0, %o1 /* I/O AREA untouched in o0 */
|
|
ba .L100_search_next_ahb_bus /* Do next bus */
|
|
add %l0, 1, %l0
|
|
|
|
.L100_return:
|
|
mov %g1, %o7
|
|
retl
|
|
nop
|
|
|
|
|
|
/* FUNCTION _nomem_amba_init(unsigned int ioarea)
|
|
*
|
|
* Find all AHB buses
|
|
*
|
|
* Constraints:
|
|
* i6, i7, o6, o7, l7, l6, g3, g4, g5, g6, g7 is used by caller
|
|
*
|
|
* Arguments
|
|
* - o0 Bridge Information: I/O AREA and parent bus
|
|
*
|
|
* Results
|
|
* - o0 Number of AHB bridges found
|
|
*
|
|
* Clobbered
|
|
* - l0, l1, l2, l3, l4, g1, g2 (used by _nomem_ambapp_find_buses)
|
|
* - o0, o1, o2, o3 (Used as arguments)
|
|
* - o5 (return address)
|
|
* - g1 (level 1 return address)
|
|
* - g2 (level 2 return address)
|
|
*/
|
|
_nomem_amba_init:
|
|
mov %o7, %o5 /* Save return address, o5 not used */
|
|
|
|
/* Scan for buses, it will init i0-i5 */
|
|
call _nomem_ambapp_find_buses
|
|
nop
|
|
|
|
mov %o5, %o7
|
|
retl
|
|
nop
|
|
|
|
/* Call tree and their return address register
|
|
*
|
|
*_nomem_amba_scan (g1)
|
|
* -> init_ahb_bridges (o7)
|
|
* -> insert_ahb_bridge (o7)
|
|
* -> _nomem_amba_scan (g2)
|
|
* -> insert_ahb_bridge (o7)
|
|
* -> get_ahb_bridge (o7)
|
|
*
|
|
*
|
|
* -> _nomem_find_apb (g2)
|
|
* -> get_ahb_bridge (o7)
|
|
* -> _nomem_find_ahb_bus (o7)
|
|
* -> _nomem_find_apb_bus (o7)
|
|
* -> _nomem_find_ahb (g2)
|
|
* -> get_ahb_bridge (o7)
|
|
* -> _nomem_find_ahb_bus (o7)
|
|
* -> mem_handler.func() (o7)
|
|
*
|
|
*/
|