riscv-openocd/contrib/loaders/flash/stmqspi/stmqspi_write.S

178 lines
6.8 KiB
ArmAsm

/***************************************************************************
* Copyright (C) 2016 - 2018 by Andreas Bolsch *
* andreas.bolsch@mni.thm.de *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
.text
.syntax unified
.cpu cortex-m0
.thumb
.thumb_func
/* Params:
* r0 - total count (bytes), remaining bytes (out, 0 means successful)
* r1 - flash page size
* r2 - address offset into flash
* r3 - QSPI io_base
* r8 - fifo start
* r9 - fifo end + 1
* Clobbered:
* r4 - rp
* r5 - address of QSPI_DR
* r7 - tmp
* r10 - single 0x0 / dual 0x1
*/
#include "../../../../src/flash/nor/stmqspi.h"
.macro qspi_abort
movs r5, #(1<<SPI_ABORT) /* abort bit mask */
ldr r7, [r3, #QSPI_CR] /* get QSPI_CR register */
orrs r7, r7, r5 /* set abort bit */
str r7, [r3, #QSPI_CR] /* store new CR register */
.endm
.macro wait_busy
0:
ldr r7, [r3, #QSPI_SR] /* load status */
lsrs r7, r7, #(SPI_BUSY+1) /* shift BUSY into C */
bcs 0b /* loop until BUSY cleared */
movs r7, #(1<<SPI_TCF) /* TCF bitmask */
str r7, [r3, #QSPI_FCR] /* clear TCF flag */
.endm
start:
subs r0, r0, #1 /* decrement count for DLR */
subs r1, r1, #1 /* page size mask and for DLR */
ldr r4, rp /* load rp */
ldr r7, [r3, #QSPI_CR] /* get QSPI_CR register */
lsls r7, r7, #(31-SPI_DUAL_FLASH) /* clear higher order bits */
lsrs r7, r7, #31 /* DUAL_FLASH bit into bit 0 */
mov r10, r7 /* save in r10 */
wip_loop:
qspi_abort /* start in clean state */
movs r5, #QSPI_DR /* load QSPI_DR address offset */
adds r5, r5, r3 /* address of QSPI_DR */
wait_busy
mov r7, r10 /* get dual bit */
str r7, [r3, #QSPI_DLR] /* one or two (for dual) bytes */
ldr r7, ccr_read_status /* CCR for status read */
str r7, [r3, #QSPI_CCR] /* initiate status read */
ldr r7, [r3, #QSPI_SR] /* wait for command startup */
ldrb r7, [r5] /* get first status register */
lsrs r7, r7, #(SPIFLASH_BSY+1) /* if first flash busy, */
bcs wip_loop /* then poll again */
mov r7, r10 /* get dual bit */
tst r7, r7 /* dual mode ? */
beq write_enable /* not dual, then ok */
ldrb r7, [r5] /* get second status register */
lsrs r7, r7, #(SPIFLASH_BSY+1) /* if second flash busy, */
bcs wip_loop /* then poll again */
write_enable:
tst r0, r0 /* test residual count */
bmi exit /* if negative, then finished */
wait_busy
ldr r7, ccr_write_enable /* CCR for write enable */
str r7, [r3, #QSPI_CCR] /* initiate write enable */
wait_busy
mov r7, r10 /* get dual bit */
str r7, [r3, #QSPI_DLR] /* one or two (for dual) bytes */
ldr r7, ccr_read_status /* CCR for status read */
str r7, [r3, #QSPI_CCR] /* initiate status read */
ldr r7, [r3, #QSPI_SR] /* wait for command startup */
ldrb r7, [r5] /* get first status register */
lsrs r7, r7, #(SPIFLASH_WE+1) /* if first flash not */
bcc error /* write enabled, then error */
mov r7, r10 /* get dual bit */
tst r7, r7 /* dual mode ? */
beq start_write /* not dual, then ok */
ldrb r7, [r5] /* get second status register */
lsrs r7, r7, #(SPIFLASH_WE+1) /* if second flash not */
bcc error /* write enabled, then error */
start_write:
wait_busy
mov r7, r2 /* get current start address */
orrs r7, r7, r1 /* end of current page */
subs r7, r7, r2 /* count-1 to end of page */
cmp r7, r0 /* if this count <= remaining */
bls write_dlr /* then write to end of page */
mov r7, r0 /* else write all remaining */
write_dlr:
str r7, [r3, #QSPI_DLR] /* size-1 in DLR register */
ldr r7, ccr_page_write /* CCR for page write */
str r7, [r3, #QSPI_CCR] /* initiate transfer */
str r2, [r3, #QSPI_AR] /* store SPI start address */
ldr r7, [r3, #QSPI_SR] /* wait for command startup */
write_loop:
ldr r7, wp /* get wp */
cmp r7, #0 /* if wp equals 0 */
beq exit /* then abort */
cmp r4, r7 /* check if fifo empty */
beq write_loop /* wait until not empty */
ldrb r7, [r4, #0] /* read next byte */
strb r7, [r5] /* write next byte to DR */
adds r4, r4, #1 /* increment internal rp */
cmp r4, r9 /* internal rp beyond end? */
blo upd_write /* if no, then ok */
mov r4, r8 /* else wrap around */
upd_write:
adr r7, rp /* get address of rp */
str r4, [r7] /* store updated rp */
adds r2, r2, #1 /* increment address */
subs r0, r0, #1 /* decrement (count-1) */
bmi page_end /* stop if no data left */
tst r2, r1 /* page end ? */
bne write_loop /* if not, then next byte */
page_end:
ldr r7, [r3, #QSPI_SR] /* load status */
lsrs r7, r7, #(SPI_TCF+1) /* shift TCF into C */
bcc page_end /* loop until TCF set */
bal wip_loop /* then next page */
error:
movs r0, #0 /* return 0xFFFFFFFF */
subs r0, r0, #2 /* for error */
exit:
adds r0, r0, #1 /* increment count due to the -1 */
qspi_abort /* to idle state */
.align 2 /* align to word, bkpt is 4 words */
bkpt #0 /* before code end for exit_point */
.align 2 /* align to word */
.space 4 /* not used */
ccr_read_status:
.space 4 /* QSPI_CCR value for READ_STATUS command */
.space 4 /* not used */
.space 4 /* not used */
.space 4 /* not used */
ccr_write_enable:
.space 4 /* QSPI_CCR value for WRITE_ENABLE command */
.space 4 /* not used */
.space 4 /* not used */
.space 4 /* not used */
ccr_page_write:
.space 4 /* QSPI_CCR value for PAGE_PROG command */
.space 4 /* not used */
.space 4 /* not used */
.equ wp, . /* wp, uint32_t */
.equ rp, wp + 4 /* rp, uint32_t */
.equ buffer, rp + 4 /* buffer follows right away */