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![Simon Glass](/assets/img/avatar_default.png)
This feature was dropped from U-Boot some time ago:
f12f96cfaf
(sf: Drop spl_flash_get_sw_write_prot")
However, we do need a way to see if a flash device is write-protected,
since if it is, it may not be possible to write to do (i.e. failing to
write is expected).
I am not sure of the correct layer to implement this, so this patch is a
stab at it. If spi-flash makes sense then I will add to the 'sf' also.
Re the points mentioned in the removal commit:
1) This kind of requirement can be achieved using existing
flash operations and flash locking API calls instead of
making a separate flash API.
Which uclass is this?
2) Technically there is no real hardware user for this API to
use in the source tree.
I do want coral (at least) to support this.
3) Having a flash operations API for simple register read bits
also make difficult to extend the flash operations.
This new patch only mentions write-protect being on or off, rather than
the actual mechanism.
4) Instead of touching generic code, it is possible to have
this functionality inside spinor operations in the form of
flash hooks or fixups for associated flash chips.
That sounds to me like what drivers are for. But we still need some sort
of API for it to be accessible.
Signed-off-by: Simon Glass <sjg@chromium.org>
184 lines
4.0 KiB
C
184 lines
4.0 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* SPI flash probing
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*
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* Copyright (C) 2008 Atmel Corporation
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* Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
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* Copyright (C) 2013 Jagannadha Sutradharudu Teki, Xilinx Inc.
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <log.h>
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#include <malloc.h>
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#include <spi.h>
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#include <spi_flash.h>
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#include "sf_internal.h"
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/**
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* spi_flash_probe_slave() - Probe for a SPI flash device on a bus
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*
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* @flashp: Pointer to place to put flash info, which may be NULL if the
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* space should be allocated
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*/
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static int spi_flash_probe_slave(struct spi_flash *flash)
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{
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struct spi_slave *spi = flash->spi;
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int ret;
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/* Setup spi_slave */
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if (!spi) {
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printf("SF: Failed to set up slave\n");
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return -ENODEV;
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}
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/* Claim spi bus */
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ret = spi_claim_bus(spi);
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if (ret) {
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debug("SF: Failed to claim SPI bus: %d\n", ret);
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return ret;
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}
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ret = spi_nor_scan(flash);
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if (ret)
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goto err_read_id;
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if (CONFIG_IS_ENABLED(SPI_FLASH_MTD))
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ret = spi_flash_mtd_register(flash);
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err_read_id:
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spi_release_bus(spi);
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return ret;
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}
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#if !CONFIG_IS_ENABLED(DM_SPI_FLASH)
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struct spi_flash *spi_flash_probe(unsigned int busnum, unsigned int cs,
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unsigned int max_hz, unsigned int spi_mode)
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{
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struct spi_slave *bus;
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struct spi_flash *flash;
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bus = spi_setup_slave(busnum, cs, max_hz, spi_mode);
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if (!bus)
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return NULL;
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/* Allocate space if needed (not used by sf-uclass */
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flash = calloc(1, sizeof(*flash));
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if (!flash) {
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debug("SF: Failed to allocate spi_flash\n");
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return NULL;
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}
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flash->spi = bus;
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if (spi_flash_probe_slave(flash)) {
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spi_free_slave(bus);
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free(flash);
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return NULL;
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}
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return flash;
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}
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void spi_flash_free(struct spi_flash *flash)
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{
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if (CONFIG_IS_ENABLED(SPI_FLASH_MTD))
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spi_flash_mtd_unregister();
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spi_free_slave(flash->spi);
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free(flash);
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}
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#else /* defined CONFIG_DM_SPI_FLASH */
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static int spi_flash_std_read(struct udevice *dev, u32 offset, size_t len,
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void *buf)
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{
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struct spi_flash *flash = dev_get_uclass_priv(dev);
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struct mtd_info *mtd = &flash->mtd;
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size_t retlen;
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return log_ret(mtd->_read(mtd, offset, len, &retlen, buf));
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}
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static int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
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const void *buf)
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{
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struct spi_flash *flash = dev_get_uclass_priv(dev);
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struct mtd_info *mtd = &flash->mtd;
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size_t retlen;
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return mtd->_write(mtd, offset, len, &retlen, buf);
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}
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static int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
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{
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struct spi_flash *flash = dev_get_uclass_priv(dev);
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struct mtd_info *mtd = &flash->mtd;
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struct erase_info instr;
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if (offset % mtd->erasesize || len % mtd->erasesize) {
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debug("SF: Erase offset/length not multiple of erase size\n");
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return -EINVAL;
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}
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memset(&instr, 0, sizeof(instr));
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instr.addr = offset;
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instr.len = len;
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return mtd->_erase(mtd, &instr);
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}
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static int spi_flash_std_get_sw_write_prot(struct udevice *dev)
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{
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struct spi_flash *flash = dev_get_uclass_priv(dev);
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return spi_flash_cmd_get_sw_write_prot(flash);
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}
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int spi_flash_std_probe(struct udevice *dev)
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{
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struct spi_slave *slave = dev_get_parent_priv(dev);
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struct spi_flash *flash;
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flash = dev_get_uclass_priv(dev);
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flash->dev = dev;
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flash->spi = slave;
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return spi_flash_probe_slave(flash);
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}
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static int spi_flash_std_remove(struct udevice *dev)
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{
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if (CONFIG_IS_ENABLED(SPI_FLASH_MTD))
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spi_flash_mtd_unregister();
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return 0;
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}
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static const struct dm_spi_flash_ops spi_flash_std_ops = {
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.read = spi_flash_std_read,
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.write = spi_flash_std_write,
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.erase = spi_flash_std_erase,
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.get_sw_write_prot = spi_flash_std_get_sw_write_prot,
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};
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static const struct udevice_id spi_flash_std_ids[] = {
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{ .compatible = "jedec,spi-nor" },
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{ }
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};
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U_BOOT_DRIVER(jedec_spi_nor) = {
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.name = "jedec_spi_nor",
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.id = UCLASS_SPI_FLASH,
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.of_match = spi_flash_std_ids,
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.probe = spi_flash_std_probe,
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.remove = spi_flash_std_remove,
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.priv_auto = sizeof(struct spi_nor),
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.ops = &spi_flash_std_ops,
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};
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DM_DRIVER_ALIAS(jedec_spi_nor, spansion_m25p16)
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#endif /* CONFIG_DM_SPI_FLASH */
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