# IBM_PROLOG_BEGIN_TAG
# This is an automatically generated prolog.
#
# $Source: src/occ/gpe/apss_altitude.pS $
#
# OpenPOWER OnChipController Project
#
# Contributors Listed Below - COPYRIGHT 2011,2014
# [+] Google Inc.
# [+] International Business Machines Corp.
#
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied. See the License for the specific language governing
# permissions and limitations under the License.
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# IBM_PROLOG_END_TAG

//////////////////////////////////////////////////////////////////////
// Includes
//////////////////////////////////////////////////////////////////////
.nolist
#include "pgp.h"
#include "pgas.h"
.list

//////////////////////////////////////////////////////////////////////
// Define Address Space
//////////////////////////////////////////////////////////////////////
.oci

//////////////////////////////////////////////////////////////////////
// Define Symbols
//////////////////////////////////////////////////////////////////////

#include <pss_constants.h>

#define GPE_PROG_ID 0x0002

//////////////////////////////////////////////////////////////////////
// Define Structures
//////////////////////////////////////////////////////////////////////

// Declare the offsets of the struct that will be passed to the
// GPE program via the ETR register
//
// struct G_gpe_apss_read_altitude_args =
// {
.struct     0
ERROR_RC:
    .struct ERROR_RC + 8
ERROR_FFDC:
    .struct ERROR_FFDC + 8
ALTITUDE:
// };

//////////////////////////////////////////////////////////////////////
// Begin Program
//////////////////////////////////////////////////////////////////////

.text

#include <gpe_macros.h>
#include <pss_macros.h>

//--------------------------------------------------------------------
// PORE-GPE Routine Specification:
//
// Name: GPE_apss_read_altitude
//
// Description:  Read APSS altitude
//
// Inputs:       G_gpe_apss_read_altitude_args
//     struct {
//         PoreGpeErrorStruct error;
//         uint16_t altitude;     // This is where the altitude will be stored (output)
//         uint8_t reserved[6];   // Requried since GPE only does 8 byte writes.
//     } G_gpe_apss_read_altitude_args
//     struct {
//         uint64_t rc;          // This should be read as 63:32=addr, 31:0=rc
//         uint64_t ffdc;        // Whatever GPE program puts in for FFDC data
//     } PoreGpeErrorStruct;
//
// Outputs:      Altitude (and FFDC on failure)
//
// End PORE-GPE Routine Specification
//--------------------------------------------------------------------
.global GPE_apss_read_altitude
GPE_apss_read_altitude:

    // Copy passed Structure Pointer into A1
    mr      A1, ETR

    // Wait for SPI operations to be complete (10usec timeout)
    _wait_for_spi_ops_complete 10, error_timeout

    // Setup control regs
    // frame_size=16, out_count=16, in_delay1=never, in_count2=16
    _putscom SPIPSS_P2S_CTRL_REG0, 0x410FC00004000000
    // bridge_enable, clock_divider=7, 2 frames
    _putscom SPIPSS_P2S_CTRL_REG1, 0x801C400000000000
    // inter_frame_delay=25 (2.5usec)
    _putscom SPIPSS_P2S_CTRL_REG2, 0x000C800000000000

    // APSS command to get the altitude (APSS cmd 0x9000)
    li      D0, 0x9000000000000000
    _putscom_d0 SPIPSS_P2S_WDATA_REG

    // Start SPI transaction
    _putscom SPIPSS_P2S_COMMAND_REG, 0x8000000000000000

    // wait 10usec for command to complete
    waits (10 * MICROSECONDS)

    // Wait for SPI operations to be complete (10usec timeout)
    _wait_for_spi_ops_complete 10, error_altitude_timeout

    // Read altitude and store in structure
    _getscom SPIPSS_P2S_RDATA_REG
    // The scom data for that cmd is in 2nd two bytes of the register (shift left 2 bytes)
    rols    D0, D0, 16
    std     D0, ALTITUDE, A1

    halt


error_statusreg:
    // An error/reserved bit was set when reading p2s status register...
    // D0: P2S_STATUS_REG
    _saveffdc GPE_PROG_ID, 0x0002
    halt


error_timeout:
    // p2s_ongoing bit was never cleared after several retries...
    // D0: P2S_STATUS_REG
    _saveffdc GPE_PROG_ID, 0x0001
    halt


error_altitude_timeout:
    // After sending the read altitude command, the p2s_ongoing bit was
    // never cleared after several retries...
    // D0: P2S_STATUS_REG
    _saveffdc GPE_PROG_ID, 0x0003
    halt


//////////////////////////////////////////////////////////////////////
// End of Program
//////////////////////////////////////////////////////////////////////