; wrflsh.inc
;
; SPDX-FileCopyrightText: Copyright (C) 2019, 2021 Antonio Villena
;
; SPDX-License-Identifier: GPL-3.0-only

; Compatible compilers:
;   SJAsmPlus, <https://github.com/sjasmplus/sjasmplus/>

                include zxuno.def

; ------------------------
; Write to SPI flash
; Parameters:
;    A: number of pages (256 bytes) to write
;   DE: target address without last byte
;  BC': zxuno_port+$100 (constant)
;  HL': source address from memory
; ------------------------
wrflsh          ex      af, af'
                xor     a
wrfls1          wreg    flash_cs, 0     ; activamos spi, enviando un 0
                wreg    flash_spi, 6    ; envío write enable
                wreg    flash_cs, 1     ; desactivamos spi, enviando un 1
                wreg    flash_cs, 0     ; activamos spi, enviando un 0
                wreg    flash_spi, $20  ; envío sector erase
                out     (c), d
                out     (c), e
                out     (c), a
                wreg    flash_cs, 1     ; desactivamos spi, enviando un 1
wrfls2          call    waits5
                wreg    flash_cs, 0     ; activamos spi, enviando un 0
                wreg    flash_spi, 6    ; envío write enable
                wreg    flash_cs, 1     ; desactivamos spi, enviando un 1
                wreg    flash_cs, 0     ; activamos spi, enviando un 0
                wreg    flash_spi, 2    ; page program
                out     (c), d
                out     (c), e
                out     (c), a
                ld      a, $20
                exx
                ld      bc, zxuno_port+$100
wrfls3          inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                inc     b
                outi
                dec     a
                jr      nz, wrfls3
                exx
                wreg    flash_cs, 1     ; desactivamos spi, enviando un 1
                ex      af, af'
                dec     a
                jr      z, waits5
                ex      af, af'
                inc     e
                ld      a, e
                and     $0f
                jr      nz, wrfls2
                ld      hl, wrfls1
                push    hl
waits5          wreg    flash_cs, 0     ; activamos spi, enviando un 0
                wreg    flash_spi, 5    ; envío read status
                in      a, (c)
waits6          in      a, (c)
                and     1
                jr      nz, waits6
                wreg    flash_cs, 1     ; desactivamos spi, enviando un 1
                ret