[U-Boot] [PATCH 3/3][v2] sf: parse Serial Flash Discoverable Parameters (SFDP) tables
Prabhakar Kushwaha
prabhakar.kushwaha at nxp.com
Thu Dec 21 12:12:57 UTC 2017
This patch adds support to the JESD216 rev B standard and parses the
SFDP tables to dynamically initialize the
'struct spi_nor_flash_parameter'.
It has been ported from Linux commit "mtd: spi-nor: parse Serial Flash
Discoverable Parameters (SFDP) tables". It Also ports all modifications
done on top of the mentioned commit.
This feature is enabled by defining FLASH_SFDP in spi_flash_info's
flag field.
Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>
CC: Cyrille Pitchen <cyrille.pitchen at wedev4u.fr>
CC: Marek Vasut <marek.vasut at gmail.com>
---
Changes for v2: Incorporated 'Cyrille Pitchen's comments
- Fix typos in comments
- corrected flash->dummy_byte value in spi_flash_read_sfdp
- updated flash->dummy_byte calculation logic for READ commands
- Used SPI_TX_QUAD, SPI_TX_DUAL condition check for x-4-4 and x-2-2
- Added fallback mechanism if SFDP read fails
drivers/mtd/spi/sf_internal.h | 204 ++++++++++++++++++++
drivers/mtd/spi/spi_flash.c | 429 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 633 insertions(+)
diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index 15cad3d..eb606fa 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include <linux/compiler.h>
+#include <linux/sizes.h>
/* Dual SPI flash memories - see SPI_COMM_DUAL_... */
enum spi_dual_flash {
@@ -83,6 +84,7 @@ enum spi_nor_option_flags {
#define CMD_FLAG_STATUS 0x70
#define CMD_EN4B 0xB7
#define CMD_EX4B 0xE9
+#define CMD_READ_SFDP 0x5a
/* Bank addr access commands */
#ifdef CONFIG_SPI_FLASH_BAR
@@ -156,9 +158,211 @@ struct spi_flash_info {
* Use dedicated 4byte address op codes
* to support memory size above 128Mib.
*/
+#define FLASH_SFDP BIT(9) /* Parse SFDP tables */
#define RD_FULL (RD_QUAD | RD_DUAL | RD_QUADIO | RD_DUALIO)
};
+struct sfdp_parameter_header {
+ u8 id_lsb;
+ u8 minor;
+ u8 major;
+ u8 length; /* in double words */
+ u8 parameter_table_pointer[3]; /* byte address */
+ u8 id_msb;
+};
+
+#define SFDP_PARAM_HEADER_ID(p) (((p)->id_msb << 8) | (p)->id_lsb)
+#define SFDP_PARAM_HEADER_PTP(p) \
+ (((p)->parameter_table_pointer[2] << 16) | \
+ ((p)->parameter_table_pointer[1] << 8) | \
+ ((p)->parameter_table_pointer[0] << 0))
+
+#define SFDP_BFPT_ID 0xff00 /* Basic Flash Parameter Table */
+#define SFDP_SECTOR_MAP_ID 0xff81 /* Sector Map Table */
+
+#define SFDP_SIGNATURE 0x50444653U
+#define SFDP_JESD216_MAJOR 1
+#define SFDP_JESD216_MINOR 0
+#define SFDP_JESD216A_MINOR 5
+#define SFDP_JESD216B_MINOR 6
+
+struct sfdp_header {
+ u32 signature; /* Ox50444653U <=> "SFDP" */
+ u8 minor;
+ u8 major;
+ u8 nph; /* 0-base number of parameter headers */
+ u8 unused;
+
+ /* Basic Flash Parameter Table. */
+ struct sfdp_parameter_header bfpt_header;
+};
+
+/* Basic Flash Parameter Table */
+
+/*
+ * JESD216 rev B defines a Basic Flash Parameter Table of 16 DWORDs.
+ * They are indexed from 1 but C arrays are indexed from 0.
+ */
+#define BFPT_DWORD(i) ((i) - 1)
+#define BFPT_DWORD_MAX 16
+
+/* The first version of JESB216 defined only 9 DWORDs. */
+#define BFPT_DWORD_MAX_JESD216 9
+
+/* 1st DWORD. */
+#define BFPT_DWORD1_FAST_READ_1_1_2 BIT(16)
+#define BFPT_DWORD1_ADDRESS_BYTES_MASK GENMASK(18, 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_3_ONLY (0x0UL << 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_3_OR_4 (0x1UL << 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_4_ONLY (0x2UL << 17)
+#define BFPT_DWORD1_DTR BIT(19)
+#define BFPT_DWORD1_FAST_READ_1_2_2 BIT(20)
+#define BFPT_DWORD1_FAST_READ_1_4_4 BIT(21)
+#define BFPT_DWORD1_FAST_READ_1_1_4 BIT(22)
+
+/* 5th DWORD. */
+#define BFPT_DWORD5_FAST_READ_2_2_2 BIT(0)
+#define BFPT_DWORD5_FAST_READ_4_4_4 BIT(4)
+
+/* 11th DWORD. */
+#define BFPT_DWORD11_PAGE_SIZE_SHIFT 4
+#define BFPT_DWORD11_PAGE_SIZE_MASK GENMASK(7, 4)
+
+/* 15th DWORD. */
+
+/*
+ * (from JESD216 rev B)
+ * Quad Enable Requirements (QER):
+ * - 000b: Device does not have a QE bit. Device detects 1-1-4 and 1-4-4
+ * reads based on instruction. DQ3/HOLD# functions are hold during
+ * instruction phase.
+ * - 001b: QE is bit 1 of status register 2. It is set via Write Status with
+ * two data bytes where bit 1 of the second byte is one.
+ * [...]
+ * Writing only one byte to the status register has the side-effect of
+ * clearing status register 2, including the QE bit. The 100b code is
+ * used if writing one byte to the status register does not modify
+ * status register 2.
+ * - 010b: QE is bit 6 of status register 1. It is set via Write Status with
+ * one data byte where bit 6 is one.
+ * [...]
+ * - 011b: QE is bit 7 of status register 2. It is set via Write status
+ * register 2 instruction 3Eh with one data byte where bit 7 is one.
+ * [...]
+ * The status register 2 is read using instruction 3Fh.
+ * - 100b: QE is bit 1 of status register 2. It is set via Write Status with
+ * two data bytes where bit 1 of the second byte is one.
+ * [...]
+ * In contrast to the 001b code, writing one byte to the status
+ * register does not modify status register 2.
+ * - 101b: QE is bit 1 of status register 2. Status register 1 is read using
+ * Read Status instruction 05h. Status register2 is read using
+ * instruction 35h. QE is set via Writ Status instruction 01h with
+ * two data bytes where bit 1 of the second byte is one.
+ * [...]
+ */
+#define BFPT_DWORD15_QER_MASK GENMASK(22, 20)
+#define BFPT_DWORD15_QER_NONE (0x0UL << 20) /* Micron */
+#define BFPT_DWORD15_QER_SR2_BIT1_BUGGY (0x1UL << 20)
+#define BFPT_DWORD15_QER_SR1_BIT6 (0x2UL << 20) /* Macronix */
+#define BFPT_DWORD15_QER_SR2_BIT7 (0x3UL << 20)
+#define BFPT_DWORD15_QER_SR2_BIT1_NO_RD (0x4UL << 20)
+#define BFPT_DWORD15_QER_SR2_BIT1 (0x5UL << 20) /* Spansion */
+
+struct sfdp_bfpt {
+ u32 dwords[BFPT_DWORD_MAX];
+};
+
+/* Fast Read settings. */
+
+struct sfdp_bfpt_read {
+ /*
+ * The <supported_bit> bit in <supported_dword> BFPT DWORD tells us
+ * whether the Fast Read x-y-z command is supported.
+ */
+ u32 supported_dword;
+ u32 supported_bit;
+
+ /*
+ * The half-word at offset <settings_dword> in <setting_dword> BFPT
+ * DWORD encodes the op code, the number of mode clocks and the number
+ * of wait states to be used by Fast Read x-y-z command.
+ */
+ u32 settings_dword;
+ u32 settings_shift;
+
+ /* The SPI Read x-y-z command. */
+ u8 read_cmd;
+
+};
+
+static const struct sfdp_bfpt_read sfdp_bfpt_reads[] = {
+ /* Fast Read 1-1-2 */
+ {
+ BFPT_DWORD(1), BIT(16), /* Supported bit */
+ BFPT_DWORD(4), 0, /* Settings */
+ CMD_READ_DUAL_OUTPUT_FAST,
+ },
+
+ /* Fast Read 1-2-2 */
+ {
+ BFPT_DWORD(1), BIT(20), /* Supported bit */
+ BFPT_DWORD(4), 16, /* Settings */
+ CMD_READ_DUAL_IO_FAST,
+ },
+
+ /* Fast Read 2-2-2 */
+ {
+ BFPT_DWORD(5), BIT(0), /* Supported bit */
+ BFPT_DWORD(6), 16, /* Settings */
+ 0xFF, /* Not supported cmd */
+ },
+
+ /* Fast Read 1-1-4 */
+ {
+ BFPT_DWORD(1), BIT(22), /* Supported bit */
+ BFPT_DWORD(3), 16, /* Settings */
+ CMD_READ_QUAD_OUTPUT_FAST,
+ },
+
+ /* Fast Read 1-4-4 */
+ {
+ BFPT_DWORD(1), BIT(21), /* Supported bit */
+ BFPT_DWORD(3), 0, /* Settings */
+ CMD_READ_QUAD_IO_FAST,
+ },
+
+ /* Fast Read 4-4-4 */
+ {
+ BFPT_DWORD(5), BIT(4), /* Supported bit */
+ BFPT_DWORD(7), 16, /* Settings */
+ 0xFF, /* Not supported cmd */
+ },
+};
+
+struct sfdp_bfpt_erase {
+ /*
+ * The half-word at offset <shift> in DWORD <dword> encodes the
+ * op code and erase sector size to be used by Sector Erase commands.
+ */
+ u32 dword;
+ u32 shift;
+};
+
+static const struct sfdp_bfpt_erase sfdp_bfpt_erases[] = {
+ /* Erase Type 1 in DWORD8 bits[15:0] */
+ {BFPT_DWORD(8), 0},
+
+ /* Erase Type 2 in DWORD8 bits[31:16] */
+ {BFPT_DWORD(8), 16},
+
+ /* Erase Type 3 in DWORD9 bits[15:0] */
+ {BFPT_DWORD(9), 0},
+
+ /* Erase Type 4 in DWORD9 bits[31:16] */
+ {BFPT_DWORD(9), 16},
+};
+
extern const struct spi_flash_info spi_flash_ids[];
/* Send a single-byte command to the device and read the response */
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index f385221..68d715f 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -1082,6 +1082,426 @@ int spi_flash_decode_fdt(struct spi_flash *flash)
}
#endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
+/*
+ * Serial Flash Discoverable Parameters (SFDP) parsing.
+ */
+
+/**
+ * spi_flash_read_sfdp() - read Serial Flash Discoverable Parameters.
+ * @flash: pointer to a 'struct spi_flash'
+ * @addr: offset in the SFDP area to start reading data from
+ * @len: number of bytes to read
+ * @buf: buffer where the SFDP data are copied into (dma-safe memory)
+ *
+ * Whatever the actual numbers of bytes for address and dummy cycles are
+ * for (Fast) Read commands, the Read SFDP (5Ah) instruction is always
+ * followed by a 3-byte address and 8 dummy clock cycles.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_flash_read_sfdp(struct spi_flash *flash, u32 addr,
+ size_t len, void *buf)
+{
+ u8 addr_width, read_cmd, dummy_byte;
+ int ret;
+
+ ret = spi_claim_bus(flash->spi);
+ if (ret) {
+ debug("SF: Unable to claim SPI bus\n");
+ return ret;
+ }
+
+ read_cmd = flash->read_cmd;
+ addr_width = flash->addr_width;
+ dummy_byte = flash->dummy_byte;
+
+ flash->read_cmd = CMD_READ_SFDP;
+ flash->addr_width = 3;
+ flash->dummy_byte = 1;
+
+ ret = spi_flash_cmd_read_ops(flash, addr, len, (u8 *)buf);
+ if (ret < 0)
+ goto read_err;
+ ret = 0;
+
+read_err:
+ flash->read_cmd = read_cmd;
+ flash->addr_width = addr_width;
+ flash->dummy_byte = dummy_byte;
+
+ spi_release_bus(flash->spi);
+ return ret;
+}
+
+/**
+ * spi_flash_read_sfdp_dma_unsafe() - read Serial Flash Discoverable Parameters.
+ * @flash: pointer to a 'struct spi_flash'
+ * @addr: offset in the SFDP area to start reading data from
+ * @len: number of bytes to read
+ * @buf: buffer where the SFDP data are copied into
+ *
+ * Wrap spi_flash_read_sfdp() using a kmalloc'ed bounce buffer as @buf is now
+ * not guaranteed to be dma-safe.
+ *
+ * Return: -ENOMEM if kmalloc() fails, the return code of spi_flash_read_sfdp()
+ * otherwise.
+ */
+static int spi_flash_read_sfdp_dma_unsafe(struct spi_flash *flash, u32 addr,
+ size_t len, void *buf)
+{
+ void *dma_safe_buf;
+ int ret;
+
+ dma_safe_buf = kmalloc(len, GFP_KERNEL);
+ if (!dma_safe_buf)
+ return -ENOMEM;
+
+ ret = spi_flash_read_sfdp(flash, addr, len, dma_safe_buf);
+ memcpy(buf, dma_safe_buf, len);
+ kfree(dma_safe_buf);
+
+ return ret;
+}
+
+/**
+ * spi_flash_parse_bfpt() - read and parse the Basic Flash Parameter Table.
+ * @flash: pointer to a 'struct spi_flash'
+ * @info: pointer to a 'struct spi_flash_info'
+ * @bfpt_header: pointer to the 'struct sfdp_parameter_header' describing
+ * the Basic Flash Parameter Table length and version
+ *
+ * The Basic Flash Parameter Table is the main and only mandatory table as
+ * defined by the SFDP (JESD216) specification.
+ * It provides us with the total size (memory density) of the data array and
+ * the number of address bytes for Fast Read, Page Program and Sector Erase
+ * commands.
+ * For Fast READ commands, it also gives the number of mode clock cycles and
+ * wait states (regrouped in the number of dummy clock cycles) for each
+ * supported instruction op code.
+ * For Page Program, the page size is now available since JESD216 rev A, however
+ * the supported instruction op codes are still not provided.
+ * For Sector Erase commands, this table stores the supported instruction op
+ * codes and the associated sector sizes.
+ * Finally, the Quad Enable Requirements (QER) are also available since JESD216
+ * rev A. The QER bits encode the manufacturer dependent procedure to be
+ * executed to set the Quad Enable (QE) bit in some internal register of the
+ * Quad SPI memory. Indeed the QE bit, when it exists, must be set before
+ * sending any Quad SPI command to the memory. Actually, setting the QE bit
+ * tells the memory to reassign its WP# and HOLD#/RESET# pins to functions IO2
+ * and IO3 hence enabling 4 (Quad) I/O lines.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_flash_parse_bfpt(struct spi_flash *flash,
+ const struct sfdp_parameter_header *bfpt_header)
+{
+ struct spi_slave *spi = flash->spi;
+ struct sfdp_bfpt bfpt;
+ size_t len;
+ int i, err;
+ u32 addr;
+ u16 half;
+
+ /* JESD216 Basic Flash Parameter Table length is at least 9 DWORDs. */
+ if (bfpt_header->length < BFPT_DWORD_MAX_JESD216)
+ return -EINVAL;
+
+ /* Read the Basic Flash Parameter Table. */
+ len = min_t(size_t, sizeof(bfpt),
+ bfpt_header->length * sizeof(u32));
+ addr = SFDP_PARAM_HEADER_PTP(bfpt_header);
+ memset(&bfpt, 0, sizeof(bfpt));
+ err = spi_flash_read_sfdp_dma_unsafe(flash, addr, len, &bfpt);
+ if (err < 0)
+ return err;
+
+ /* Fix endianness of the BFPT DWORDs. */
+ for (i = 0; i < BFPT_DWORD_MAX; i++)
+ bfpt.dwords[i] = le32_to_cpu(bfpt.dwords[i]);
+
+ /* Number of address bytes. */
+ switch (bfpt.dwords[BFPT_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) {
+ case BFPT_DWORD1_ADDRESS_BYTES_3_ONLY:
+ flash->addr_width = 3;
+ break;
+
+ case BFPT_DWORD1_ADDRESS_BYTES_4_ONLY:
+ flash->addr_width = 4;
+ break;
+
+ case BFPT_DWORD1_ADDRESS_BYTES_3_OR_4:
+ flash->addr_width = 3;
+ break;
+
+ default: /* Reserved */
+ break;
+ }
+
+ /* Flash Memory Density (in bits). */
+ flash->size = bfpt.dwords[BFPT_DWORD(2)];
+ if (flash->size & BIT(31)) {
+ flash->size &= ~BIT(31);
+
+ /*
+ * Prevent overflows on params->size. Anyway, a NOR of 2^64
+ * bits is unlikely to exist so this error probably means
+ * the BFPT we are reading is corrupted/wrong.
+ */
+ if (flash->size > 63)
+ return -EINVAL;
+
+ flash->size = 1ULL << flash->size;
+ } else {
+ flash->size++;
+ }
+ flash->size >>= 3; /* Convert to bytes. */
+ flash->size <<= flash->shift;
+
+ flash->read_cmd = CMD_READ_ARRAY_FAST;
+
+ /* Fast Read settings. */
+ for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_reads); i++) {
+ const struct sfdp_bfpt_read *rd = &sfdp_bfpt_reads[i];
+ u32 mode_dummy_cycle;
+
+ if (!(bfpt.dwords[rd->supported_dword] & rd->supported_bit))
+ continue;
+
+ half = bfpt.dwords[rd->settings_dword] >> rd->settings_shift;
+ mode_dummy_cycle = ((half >> 5) & 0x07) + ((half >> 0) & 0x1f);
+
+ switch (rd->read_cmd) {
+ case CMD_READ_QUAD_IO_FAST:
+ /* x-4-4 */
+ if ((spi->mode & SPI_RX_QUAD) &&
+ (spi->mode & SPI_TX_QUAD)) {
+ flash->read_cmd = rd->read_cmd;
+ flash->dummy_byte = (mode_dummy_cycle * 4) / 8;
+ }
+ break;
+
+ case CMD_READ_QUAD_OUTPUT_FAST:
+ /* x-1-4 */
+ if (spi->mode & SPI_RX_QUAD) {
+ flash->read_cmd = rd->read_cmd;
+ flash->dummy_byte = mode_dummy_cycle / 8;
+ }
+ break;
+
+ case CMD_READ_DUAL_IO_FAST:
+ /* x-2-2 */
+ if (((spi->mode & SPI_RX_DUAL) &&
+ (spi->mode & SPI_TX_DUAL)) &&
+ !(spi->mode & (SPI_RX_QUAD | SPI_TX_QUAD))) {
+ flash->read_cmd = rd->read_cmd;
+ flash->dummy_byte = (mode_dummy_cycle * 2) / 8;
+ }
+ break;
+
+ case CMD_READ_DUAL_OUTPUT_FAST:
+ /* x-1-2*/
+ if ((spi->mode & SPI_RX_DUAL) &&
+ !(spi->mode & (SPI_RX_QUAD | SPI_TX_QUAD))) {
+ flash->read_cmd = rd->read_cmd;
+ flash->dummy_byte = mode_dummy_cycle / 8;
+ }
+ break;
+
+ default:
+ debug("read_cmd=0x%x is not supported\n", rd->read_cmd);
+ break;
+ }
+ }
+
+ if (flash->read_cmd == CMD_READ_ARRAY_FAST && spi->mode & SPI_RX_SLOW)
+ flash->read_cmd = CMD_READ_ARRAY_SLOW;
+
+ /* Sector Erase settings. */
+ for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_erases); i++) {
+ const struct sfdp_bfpt_erase *er = &sfdp_bfpt_erases[i];
+ u32 erasesize;
+ u8 opcode;
+
+ half = bfpt.dwords[er->dword] >> er->shift;
+ erasesize = half & 0xff;
+
+ /* erasesize == 0 means this Erase Type is not supported. */
+ if (!erasesize)
+ continue;
+
+ erasesize = 1U << erasesize;
+ opcode = (half >> 8) & 0xff;
+#ifdef CONFIG_SPI_FLASH_USE_4K_SECTORS
+ if (erasesize == SZ_4K) {
+ flash->erase_cmd = opcode;
+ flash->erase_size = erasesize;
+ break;
+ }
+#endif
+ if (!flash->erase_size || flash->erase_size < erasesize) {
+ flash->erase_cmd = opcode;
+ flash->erase_size = erasesize;
+ }
+ }
+
+ flash->erase_size <<= flash->shift;
+
+ flash->sector_size = flash->erase_size;
+
+ /* Stop here if not JESD216 rev A or later. */
+ if (bfpt_header->length < BFPT_DWORD_MAX)
+ return 0;
+
+ /* Page size: this field specifies 'N' so the page size = 2^N bytes. */
+ flash->page_size = bfpt.dwords[BFPT_DWORD(11)];
+ flash->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
+ flash->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
+ flash->page_size = 1U << flash->page_size;
+ flash->page_size <<= flash->shift;
+
+ if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) ||
+ (flash->read_cmd == CMD_READ_QUAD_IO_FAST) ||
+ (flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
+ /* Quad Enable Requirements. */
+ switch (bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK) {
+ case BFPT_DWORD15_QER_NONE:
+ break;
+
+ case BFPT_DWORD15_QER_SR2_BIT1_BUGGY:
+ case BFPT_DWORD15_QER_SR2_BIT1_NO_RD:
+ break;
+
+ case BFPT_DWORD15_QER_SR1_BIT6:
+#ifdef CONFIG_SPI_FLASH_MACRONIX
+ macronix_quad_enable(flash);
+#endif
+ break;
+
+ case BFPT_DWORD15_QER_SR2_BIT7:
+
+ break;
+
+ case BFPT_DWORD15_QER_SR2_BIT1:
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+ spansion_quad_enable(flash);
+#endif
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * spi_flash_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
+ * @flash: pointer to a 'struct spi_flash'
+ *
+ * The Serial Flash Discoverable Parameters are described by the JEDEC JESD216
+ * specification. This is a standard which tends to supported by almost all
+ * (Q)SPI memory manufacturers. Those hard-coded tables allow us to learn at
+ * runtime the main parameters needed to perform basic SPI flash operations such
+ * as Fast Read, Page Program or Sector Erase commands.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_flash_parse_sfdp(struct spi_flash *flash)
+{
+ const struct sfdp_parameter_header *param_header, *bfpt_header;
+ struct sfdp_parameter_header *param_headers = NULL;
+ struct sfdp_header header;
+ size_t psize;
+ int i, err;
+
+ /* Get the SFDP header. */
+ err = spi_flash_read_sfdp_dma_unsafe(flash, 0, sizeof(header), &header);
+ if (err < 0)
+ return err;
+
+ /* Check the SFDP header version. */
+ if (le32_to_cpu(header.signature) != SFDP_SIGNATURE ||
+ header.major != SFDP_JESD216_MAJOR ||
+ header.minor < SFDP_JESD216_MINOR)
+ return -EINVAL;
+
+ /*
+ * Verify that the first and only mandatory parameter header is a
+ * Basic Flash Parameter Table header as specified in JESD216.
+ */
+ bfpt_header = &header.bfpt_header;
+ if (SFDP_PARAM_HEADER_ID(bfpt_header) != SFDP_BFPT_ID ||
+ bfpt_header->major != SFDP_JESD216_MAJOR)
+ return -EINVAL;
+
+ /*
+ * Allocate memory then read all parameter headers with a single
+ * Read SFDP command. These parameter headers will actually be parsed
+ * twice: a first time to get the latest revision of the basic flash
+ * parameter table, then a second time to handle the supported optional
+ * tables.
+ * Hence we read the parameter headers once for all to reduce the
+ * processing time. Also we use kmalloc() instead of devm_kmalloc()
+ * because we don't need to keep these parameter headers: the allocated
+ * memory is always released with kfree() before exiting this function.
+ */
+ if (header.nph) {
+ psize = header.nph * sizeof(*param_headers);
+
+ param_headers = kmalloc(psize, GFP_KERNEL);
+ if (!param_headers)
+ return -ENOMEM;
+
+ err = spi_flash_read_sfdp(flash, sizeof(header),
+ psize, param_headers);
+ if (err < 0) {
+ debug("SF: failed to read SFDP parameter headers\n");
+ goto exit;
+ }
+ }
+
+ /*
+ * Check other parameter headers to get the latest revision of
+ * the basic flash parameter table.
+ */
+ for (i = 0; i < header.nph; i++) {
+ param_header = ¶m_headers[i];
+
+ if (SFDP_PARAM_HEADER_ID(param_header) == SFDP_BFPT_ID &&
+ param_header->major == SFDP_JESD216_MAJOR &&
+ (param_header->minor > bfpt_header->minor ||
+ (param_header->minor == bfpt_header->minor &&
+ param_header->length > bfpt_header->length)))
+ bfpt_header = param_header;
+ }
+
+ err = spi_flash_parse_bfpt(flash, bfpt_header);
+ if (err)
+ goto exit;
+
+ /* Parse other parameter headers. */
+ for (i = 0; i < header.nph; i++) {
+ param_header = ¶m_headers[i];
+
+ switch (SFDP_PARAM_HEADER_ID(param_header)) {
+ case SFDP_SECTOR_MAP_ID:
+ debug("non-uniform erase sector maps not supported\n");
+ break;
+
+ default:
+ break;
+ }
+
+ if (err)
+ goto exit;
+ }
+
+exit:
+ kfree(param_headers);
+ return err;
+}
+
int spi_flash_scan(struct spi_flash *flash)
{
struct spi_slave *spi = flash->spi;
@@ -1272,6 +1692,15 @@ int spi_flash_scan(struct spi_flash *flash)
flash->addr_width = SPI_FLASH_3B_ADDR_LEN;
+ /* Override the parameters with data read from SFDP tables. */
+ if ((info->flags & RD_FULL) && (info->flags & FLASH_SFDP)) {
+ struct spi_flash sfdp_flash;
+
+ memcpy(&sfdp_flash, flash, sizeof(struct spi_flash));
+ if (spi_flash_parse_sfdp(flash))
+ memcpy(flash, &sfdp_flash, sizeof(struct spi_flash));
+ }
+
if (flash->size > SPI_FLASH_16MB_BOUN) {
/* enable 4-byte addressing if the device exceeds 16MiB */
flash->addr_width = SPI_FLASH_4B_ADDR_LEN;
--
2.7.4
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