int (*is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
};
+/**
+ * struct spi_nor_otp_organization - Structure to describe the SPI NOR OTP regions
+ * @len: size of one OTP region in bytes.
+ * @base: start address of the OTP area.
+ * @offset: offset between consecutive OTP regions if there are more
+ * than one.
+ * @n_regions: number of individual OTP regions.
+ */
+struct spi_nor_otp_organization {
+ size_t len;
+ loff_t base;
+ loff_t offset;
+ unsigned int n_regions;
+};
+
+/**
+ * struct spi_nor_otp_ops - SPI NOR OTP methods
+ * @read: read from the SPI NOR OTP area.
+ * @write: write to the SPI NOR OTP area.
+ * @lock: lock an OTP region.
+ * @is_locked: check if an OTP region of the SPI NOR is locked.
+ */
+struct spi_nor_otp_ops {
+ int (*read)(struct spi_nor *nor, loff_t addr, size_t len, u8 *buf);
+ int (*write)(struct spi_nor *nor, loff_t addr, size_t len, u8 *buf);
+ int (*lock)(struct spi_nor *nor, unsigned int region);
+ int (*is_locked)(struct spi_nor *nor, unsigned int region);
+};
+
+/**
+ * struct spi_nor_otp - SPI NOR OTP grouping structure
+ * @org: OTP region organization
+ * @ops: OTP access ops
+ */
+struct spi_nor_otp {
+ const struct spi_nor_otp_organization *org;
+ const struct spi_nor_otp_ops *ops;
+};
+
/**
* struct spi_nor_flash_parameter - SPI NOR flash parameters and settings.
* Includes legacy flash parameters and settings that can be overwritten
* higher index in the array, the higher priority.
* @erase_map: the erase map parsed from the SFDP Sector Map Parameter
* Table.
+ * @otp_info: describes the OTP regions.
* @octal_dtr_enable: enables SPI NOR octal DTR mode.
* @quad_enable: enables SPI NOR quad mode.
* @set_4byte_addr_mode: puts the SPI NOR in 4 byte addressing mode.
* e.g. different opcodes, specific address calculation,
* page size, etc.
* @locking_ops: SPI NOR locking methods.
+ * @otp: SPI NOR OTP methods.
*/
struct spi_nor_flash_parameter {
u64 size;
struct spi_nor_pp_command page_programs[SNOR_CMD_PP_MAX];
struct spi_nor_erase_map erase_map;
+ struct spi_nor_otp otp;
int (*octal_dtr_enable)(struct spi_nor *nor, bool enable);
int (*quad_enable)(struct spi_nor *nor);
* power-up in a write-protected state.
*/
+ const struct spi_nor_otp_organization otp_org;
+
/* Part specific fixup hooks. */
const struct spi_nor_fixups *fixups;
};
.addr_width = 3, \
.flags = SPI_NOR_NO_FR | SPI_NOR_XSR_RDY,
+#define OTP_INFO(_len, _n_regions, _base, _offset) \
+ .otp_org = { \
+ .len = (_len), \
+ .base = (_base), \
+ .offset = (_offset), \
+ .n_regions = (_n_regions), \
+ },
+
/**
* struct spi_nor_manufacturer - SPI NOR manufacturer object
* @name: manufacturer name
void spi_nor_init_default_locking_ops(struct spi_nor *nor);
void spi_nor_try_unlock_all(struct spi_nor *nor);
void spi_nor_register_locking_ops(struct spi_nor *nor);
+void spi_nor_otp_init(struct spi_nor *nor);
static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd)
{
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OTP support for SPI NOR flashes
+ *
+ * Copyright (C) 2021 Michael Walle <michael@walle.cc>
+ */
+
+#include <linux/log2.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/spi-nor.h>
+
+#include "core.h"
+
+#define spi_nor_otp_region_len(nor) ((nor)->params->otp.org->len)
+#define spi_nor_otp_n_regions(nor) ((nor)->params->otp.org->n_regions)
+
+static loff_t spi_nor_otp_region_start(const struct spi_nor *nor, unsigned int region)
+{
+ const struct spi_nor_otp_organization *org = nor->params->otp.org;
+
+ return org->base + region * org->offset;
+}
+
+static size_t spi_nor_otp_size(struct spi_nor *nor)
+{
+ return spi_nor_otp_n_regions(nor) * spi_nor_otp_region_len(nor);
+}
+
+/* Translate the file offsets from and to OTP regions. */
+static loff_t spi_nor_otp_region_to_offset(struct spi_nor *nor, unsigned int region)
+{
+ return region * spi_nor_otp_region_len(nor);
+}
+
+static unsigned int spi_nor_otp_offset_to_region(struct spi_nor *nor, loff_t ofs)
+{
+ return div64_u64(ofs, spi_nor_otp_region_len(nor));
+}
+
+static int spi_nor_mtd_otp_info(struct mtd_info *mtd, size_t len,
+ size_t *retlen, struct otp_info *buf)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+ unsigned int n_regions = spi_nor_otp_n_regions(nor);
+ unsigned int i;
+ int ret, locked;
+
+ if (len < n_regions * sizeof(*buf))
+ return -ENOSPC;
+
+ ret = spi_nor_lock_and_prep(nor);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < n_regions; i++) {
+ buf->start = spi_nor_otp_region_to_offset(nor, i);
+ buf->length = spi_nor_otp_region_len(nor);
+
+ locked = ops->is_locked(nor, i);
+ if (locked < 0) {
+ ret = locked;
+ goto out;
+ }
+
+ buf->locked = !!locked;
+ buf++;
+ }
+
+ *retlen = n_regions * sizeof(*buf);
+
+out:
+ spi_nor_unlock_and_unprep(nor);
+
+ return ret;
+}
+
+static int spi_nor_mtd_otp_read_write(struct mtd_info *mtd, loff_t ofs,
+ size_t total_len, size_t *retlen,
+ u8 *buf, bool is_write)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+ const size_t rlen = spi_nor_otp_region_len(nor);
+ loff_t rstart, rofs;
+ unsigned int region;
+ size_t len;
+ int ret;
+
+ if (ofs < 0 || ofs >= spi_nor_otp_size(nor))
+ return 0;
+
+ ret = spi_nor_lock_and_prep(nor);
+ if (ret)
+ return ret;
+
+ /* don't access beyond the end */
+ total_len = min_t(size_t, total_len, spi_nor_otp_size(nor) - ofs);
+
+ *retlen = 0;
+ while (total_len) {
+ /*
+ * The OTP regions are mapped into a contiguous area starting
+ * at 0 as expected by the MTD layer. This will map the MTD
+ * file offsets to the address of an OTP region as used in the
+ * actual SPI commands.
+ */
+ region = spi_nor_otp_offset_to_region(nor, ofs);
+ rstart = spi_nor_otp_region_start(nor, region);
+
+ /*
+ * The size of a OTP region is expected to be a power of two,
+ * thus we can just mask the lower bits and get the offset into
+ * a region.
+ */
+ rofs = ofs & (rlen - 1);
+
+ /* don't access beyond one OTP region */
+ len = min_t(size_t, total_len, rlen - rofs);
+
+ if (is_write)
+ ret = ops->write(nor, rstart + rofs, len, buf);
+ else
+ ret = ops->read(nor, rstart + rofs, len, buf);
+ if (ret == 0)
+ ret = -EIO;
+ if (ret < 0)
+ goto out;
+
+ *retlen += ret;
+ ofs += ret;
+ buf += ret;
+ total_len -= ret;
+ }
+ ret = 0;
+
+out:
+ spi_nor_unlock_and_unprep(nor);
+ return ret;
+}
+
+static int spi_nor_mtd_otp_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u8 *buf)
+{
+ return spi_nor_mtd_otp_read_write(mtd, from, len, retlen, buf, false);
+}
+
+static int spi_nor_mtd_otp_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, u8 *buf)
+{
+ return spi_nor_mtd_otp_read_write(mtd, to, len, retlen, buf, true);
+}
+
+static int spi_nor_mtd_otp_lock(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+ const size_t rlen = spi_nor_otp_region_len(nor);
+ unsigned int region;
+ int ret;
+
+ if (from < 0 || (from + len) > spi_nor_otp_size(nor))
+ return -EINVAL;
+
+ /* the user has to explicitly ask for whole regions */
+ if (!IS_ALIGNED(len, rlen) || !IS_ALIGNED(from, rlen))
+ return -EINVAL;
+
+ ret = spi_nor_lock_and_prep(nor);
+ if (ret)
+ return ret;
+
+ while (len) {
+ region = spi_nor_otp_offset_to_region(nor, from);
+ ret = ops->lock(nor, region);
+ if (ret)
+ goto out;
+
+ len -= rlen;
+ from += rlen;
+ }
+
+out:
+ spi_nor_unlock_and_unprep(nor);
+
+ return ret;
+}
+
+void spi_nor_otp_init(struct spi_nor *nor)
+{
+ struct mtd_info *mtd = &nor->mtd;
+
+ if (!nor->params->otp.ops)
+ return;
+
+ if (WARN_ON(!is_power_of_2(spi_nor_otp_region_len(nor))))
+ return;
+
+ /*
+ * We only support user_prot callbacks (yet).
+ *
+ * Some SPI NOR flashes like Macronix ones can be ordered in two
+ * different variants. One with a factory locked OTP area and one where
+ * it is left to the user to write to it. The factory locked OTP is
+ * usually preprogrammed with an "electrical serial number". We don't
+ * support these for now.
+ */
+ mtd->_get_user_prot_info = spi_nor_mtd_otp_info;
+ mtd->_read_user_prot_reg = spi_nor_mtd_otp_read;
+ mtd->_write_user_prot_reg = spi_nor_mtd_otp_write;
+ mtd->_lock_user_prot_reg = spi_nor_mtd_otp_lock;
+}
projects / linux-2.6-microblaze.git / commitdiff