8e8caca2e2
Avoid bug where a bad status read is copied back to flash and can set lock bits.
72 lines
2.2 KiB
C
72 lines
2.2 KiB
C
// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "rom/spi_flash.h"
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#include "soc/spi_reg.h"
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static const uint32_t STATUS_QIE_BIT = (1 << 9); /* Quad Enable */
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#define SPI_IDX 1
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#define OTH_IDX 0
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extern SpiFlashChip SPI_flashchip_data;
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static void IRAM_ATTR Wait_SPI_Idle(void)
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{
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/* Wait for SPI state machine to be idle */
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while((REG_READ(SPI_EXT2_REG(SPI_IDX)) & SPI_ST)) {
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}
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while(REG_READ(SPI_EXT2_REG(OTH_IDX)) & SPI_ST) {
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}
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}
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/* Modified version of SPIUnlock() that replaces version in ROM.
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This works around a bug where SPIUnlock sometimes reads the wrong
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high status byte (RDSR2 result) and then copies it back to the
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flash status, which can cause the CMP bit or Status Register
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Protect bit to become set.
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Like other ROM SPI functions, this function is not designed to be
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called directly from an RTOS environment without taking precautions
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about interrupts, CPU coordination, flash mapping. However some of
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the functions in esp_spi_flash.c call it.
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*/
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SpiFlashOpResult IRAM_ATTR SPIUnlock(void)
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{
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uint32_t status;
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Wait_SPI_Idle();
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if (SPI_read_status_high(&status) != SPI_FLASH_RESULT_OK) {
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return SPI_FLASH_RESULT_ERR;
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}
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/* Clear all bits except QIE, if it is set.
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(This is different from ROM SPIUnlock, which keeps all bits as-is.)
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*/
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status &= STATUS_QIE_BIT;
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Wait_SPI_Idle();
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REG_WRITE(SPI_CMD_REG(SPI_IDX), SPI_FLASH_WREN);
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while(REG_READ(SPI_CMD_REG(SPI_IDX)) != 0) {
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}
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Wait_SPI_Idle();
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SET_PERI_REG_MASK(SPI_CTRL_REG(SPI_IDX), SPI_WRSR_2B);
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if (SPI_write_status(&SPI_flashchip_data, status) != SPI_FLASH_RESULT_OK) {
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return SPI_FLASH_RESULT_ERR;
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}
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return SPI_FLASH_RESULT_OK;
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}
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