[PATCH v4 09/20] mtd: spi-nor-core: Add support for DTR protocol
Pratyush Yadav
p.yadav at ti.com
Fri May 22 14:44:58 CEST 2020
Double Transfer Rate (DTR) is SPI protocol in which data is transferred
on each clock edge as opposed to on each clock cycle. Make
framework-level changes to allow supporting flashes in DTR mode.
Right now, mixed DTR modes are not supported. So, for example a mode
like 4S-4D-4D will not work. All phases need to be either DTR or STR.
Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
---
drivers/mtd/spi/sf_internal.h | 1 +
drivers/mtd/spi/spi-nor-core.c | 126 +++++++++++++++++++++++++++++----
include/linux/mtd/spi-nor.h | 50 +++++++++----
3 files changed, 150 insertions(+), 27 deletions(-)
diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index aa42524345..e77e335b26 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -68,6 +68,7 @@ struct flash_info {
#define USE_CLSR BIT(14) /* use CLSR command */
#define SPI_NOR_HAS_SST26LOCK BIT(15) /* Flash supports lock/unlock via BPR */
#define SPI_NOR_OCTAL_READ BIT(16) /* Flash supports Octal Read */
+#define SPI_NOR_OCTAL_DTR_READ BIT(17) /* Flash supports Octal DTR Read */
/* Part specific fixup hooks. */
const struct spi_nor_fixups *fixups;
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 9db5bffa0a..3e8393b352 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -175,6 +175,76 @@ struct spi_nor_fixups {
struct spi_nor_flash_parameter *params);
};
+/**
+ * spi_nor_get_cmd_ext() - Get the command opcode extension based on the
+ * extension type.
+ * @nor: pointer to a 'struct spi_nor'
+ * @op: pointer to the 'struct spi_mem_op' whose properties
+ * need to be initialized.
+ *
+ * Right now, only "repeat" and "invert" are supported.
+ *
+ * Return: The opcode extension.
+ */
+static u8 spi_nor_get_cmd_ext(const struct spi_nor *nor,
+ const struct spi_mem_op *op)
+{
+ switch (nor->cmd_ext_type) {
+ case SPI_NOR_EXT_INVERT:
+ return ~op->cmd.opcode;
+
+ case SPI_NOR_EXT_REPEAT:
+ return op->cmd.opcode;
+
+ default:
+ dev_err(nor->dev, "Unknown command extension type\n");
+ return 0;
+ }
+}
+
+/**
+ * spi_nor_setup_op() - Set up common properties of a spi-mem op.
+ * @nor: pointer to a 'struct spi_nor'
+ * @op: pointer to the 'struct spi_mem_op' whose properties
+ * need to be initialized.
+ * @proto: the protocol from which the properties need to be set.
+ */
+static void spi_nor_setup_op(const struct spi_nor *nor,
+ struct spi_mem_op *op,
+ const enum spi_nor_protocol proto)
+{
+ u8 ext;
+
+ op->cmd.buswidth = spi_nor_get_protocol_inst_nbits(proto);
+
+ if (op->addr.nbytes)
+ op->addr.buswidth = spi_nor_get_protocol_addr_nbits(proto);
+
+ if (op->dummy.nbytes)
+ op->dummy.buswidth = spi_nor_get_protocol_addr_nbits(proto);
+
+ if (op->data.nbytes)
+ op->data.buswidth = spi_nor_get_protocol_data_nbits(proto);
+
+ if (spi_nor_protocol_is_dtr(proto)) {
+ /*
+ * spi-mem supports mixed DTR modes, but right now we can only
+ * have all phases either DTR or STR. IOW, spi-mem can have
+ * something like 4S-4D-4D, but spi-nor can't. So, set all 4
+ * phases to either DTR or STR.
+ */
+ op->cmd.dtr = op->addr.dtr = op->dummy.dtr =
+ op->data.dtr = true;
+
+ /* 2 bytes per clock cycle in DTR mode. */
+ op->dummy.nbytes *= 2;
+
+ ext = spi_nor_get_cmd_ext(nor, op);
+ op->cmd.opcode = (op->cmd.opcode << 8) | ext;
+ op->cmd.nbytes = 2;
+ }
+}
+
static int spi_nor_read_write_reg(struct spi_nor *nor, struct spi_mem_op
*op, void *buf)
{
@@ -193,6 +263,8 @@ static int spi_nor_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
SPI_MEM_OP_DATA_IN(len, NULL, 1));
int ret;
+ spi_nor_setup_op(nor, &op, nor->reg_proto);
+
ret = spi_nor_read_write_reg(nor, &op, val);
if (ret < 0)
dev_dbg(nor->dev, "error %d reading %x\n", ret, code);
@@ -207,6 +279,8 @@ static int spi_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_DATA_OUT(len, NULL, 1));
+ spi_nor_setup_op(nor, &op, nor->reg_proto);
+
return spi_nor_read_write_reg(nor, &op, buf);
}
@@ -221,14 +295,12 @@ static ssize_t spi_nor_read_data(struct spi_nor *nor, loff_t from, size_t len,
size_t remaining = len;
int ret;
- /* get transfer protocols. */
- op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
- op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
- op.dummy.buswidth = op.addr.buswidth;
- op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
+ spi_nor_setup_op(nor, &op, nor->read_proto);
/* convert the dummy cycles to the number of bytes */
op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
+ if (spi_nor_protocol_is_dtr(nor->read_proto))
+ op.dummy.nbytes *= 2;
while (remaining) {
op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
@@ -258,14 +330,11 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
SPI_MEM_OP_DATA_OUT(len, buf, 1));
int ret;
- /* get transfer protocols. */
- op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
- op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
- op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
-
if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
op.addr.nbytes = 0;
+ spi_nor_setup_op(nor, &op, nor->write_proto);
+
ret = spi_mem_adjust_op_size(nor->spi, &op);
if (ret)
return ret;
@@ -668,6 +737,8 @@ static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_NO_DATA);
+ spi_nor_setup_op(nor, &op, nor->write_proto);
+
if (nor->erase)
return nor->erase(nor, addr);
@@ -2182,11 +2253,25 @@ static int spi_nor_init_params(struct spi_nor *nor,
SNOR_PROTO_1_1_8);
}
+ if (info->flags & SPI_NOR_OCTAL_DTR_READ) {
+ params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+ spi_nor_set_read_settings(¶ms->reads[SNOR_CMD_READ_8_8_8_DTR],
+ 0, 20, SPINOR_OP_READ_FAST,
+ SNOR_PROTO_8_8_8_DTR);
+ }
+
/* Page Program settings. */
params->hwcaps.mask |= SNOR_HWCAPS_PP;
spi_nor_set_pp_settings(¶ms->page_programs[SNOR_CMD_PP],
SPINOR_OP_PP, SNOR_PROTO_1_1_1);
+ /*
+ * Since xSPI Page Program opcode is backward compatible with
+ * Legacy SPI, use Legacy SPI opcode there as well.
+ */
+ spi_nor_set_pp_settings(¶ms->page_programs[SNOR_CMD_PP_8_8_8_DTR],
+ SPINOR_OP_PP, SNOR_PROTO_8_8_8_DTR);
+
if (info->flags & SPI_NOR_QUAD_READ) {
params->hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4;
spi_nor_set_pp_settings(¶ms->page_programs[SNOR_CMD_PP_1_1_4],
@@ -2220,7 +2305,8 @@ static int spi_nor_init_params(struct spi_nor *nor,
/* Override the parameters with data read from SFDP tables. */
nor->addr_width = 0;
nor->mtd.erasesize = 0;
- if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
+ if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
+ SPI_NOR_OCTAL_DTR_READ)) &&
!(info->flags & SPI_NOR_SKIP_SFDP)) {
struct spi_nor_flash_parameter sfdp_params;
@@ -2267,6 +2353,7 @@ static int spi_nor_hwcaps_read2cmd(u32 hwcaps)
{ SNOR_HWCAPS_READ_1_8_8, SNOR_CMD_READ_1_8_8 },
{ SNOR_HWCAPS_READ_8_8_8, SNOR_CMD_READ_8_8_8 },
{ SNOR_HWCAPS_READ_1_8_8_DTR, SNOR_CMD_READ_1_8_8_DTR },
+ { SNOR_HWCAPS_READ_8_8_8_DTR, SNOR_CMD_READ_8_8_8_DTR },
};
return spi_nor_hwcaps2cmd(hwcaps, hwcaps_read2cmd,
@@ -2283,6 +2370,7 @@ static int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
{ SNOR_HWCAPS_PP_1_1_8, SNOR_CMD_PP_1_1_8 },
{ SNOR_HWCAPS_PP_1_8_8, SNOR_CMD_PP_1_8_8 },
{ SNOR_HWCAPS_PP_8_8_8, SNOR_CMD_PP_8_8_8 },
+ { SNOR_HWCAPS_PP_8_8_8_DTR, SNOR_CMD_PP_8_8_8_DTR },
};
return spi_nor_hwcaps2cmd(hwcaps, hwcaps_pp2cmd,
@@ -2381,12 +2469,16 @@ spi_nor_adjust_hwcaps(struct spi_nor *nor,
{
unsigned int cap;
- /* DTR modes are not supported yet, mask them all. */
- *hwcaps &= ~SNOR_HWCAPS_DTR;
-
- /* X-X-X modes are not supported yet, mask them all. */
+ /* Some modes are not supported yet. Mask them. */
*hwcaps &= ~SNOR_HWCAPS_X_X_X;
+ /*
+ * If the reset line is broken, we do not want to enter a stateful
+ * mode.
+ */
+ if (nor->flags & SNOR_F_BROKEN_RESET)
+ *hwcaps &= ~(SNOR_HWCAPS_X_X_X | SNOR_HWCAPS_X_X_X_DTR);
+
for (cap = 0; cap < sizeof(*hwcaps) * BITS_PER_BYTE; cap++) {
int rdidx, ppidx;
@@ -2578,6 +2670,7 @@ static int spi_nor_init(struct spi_nor *nor)
}
if (nor->addr_width == 4 &&
+ !(nor->info->flags & SPI_NOR_OCTAL_DTR_READ) &&
(JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
!(nor->info->flags & SPI_NOR_4B_OPCODES)) {
/*
@@ -2700,6 +2793,9 @@ int spi_nor_scan(struct spi_nor *nor)
if (nor->addr_width) {
/* already configured from SFDP */
+ } else if (spi_nor_protocol_is_dtr(nor->read_proto)) {
+ /* Always use 4-byte addresses in DTR mode. */
+ nor->addr_width = 4;
} else if (info->addr_width) {
nor->addr_width = info->addr_width;
} else if (mtd->size > SZ_16M) {
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 327491fb17..9184534e82 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -200,6 +200,7 @@ enum spi_nor_protocol {
SNOR_PROTO_1_2_2_DTR = SNOR_PROTO_DTR(1, 2, 2),
SNOR_PROTO_1_4_4_DTR = SNOR_PROTO_DTR(1, 4, 4),
SNOR_PROTO_1_8_8_DTR = SNOR_PROTO_DTR(1, 8, 8),
+ SNOR_PROTO_8_8_8_DTR = SNOR_PROTO_DTR(8, 8, 8),
};
static inline bool spi_nor_protocol_is_dtr(enum spi_nor_protocol proto)
@@ -267,7 +268,7 @@ struct spi_nor_hwcaps {
* then Quad SPI protocols before Dual SPI protocols, Fast Read and lastly
* (Slow) Read.
*/
-#define SNOR_HWCAPS_READ_MASK GENMASK(14, 0)
+#define SNOR_HWCAPS_READ_MASK GENMASK(15, 0)
#define SNOR_HWCAPS_READ BIT(0)
#define SNOR_HWCAPS_READ_FAST BIT(1)
#define SNOR_HWCAPS_READ_1_1_1_DTR BIT(2)
@@ -284,11 +285,12 @@ struct spi_nor_hwcaps {
#define SNOR_HWCAPS_READ_4_4_4 BIT(9)
#define SNOR_HWCAPS_READ_1_4_4_DTR BIT(10)
-#define SNOR_HWCPAS_READ_OCTO GENMASK(14, 11)
+#define SNOR_HWCPAS_READ_OCTO GENMASK(15, 11)
#define SNOR_HWCAPS_READ_1_1_8 BIT(11)
#define SNOR_HWCAPS_READ_1_8_8 BIT(12)
#define SNOR_HWCAPS_READ_8_8_8 BIT(13)
#define SNOR_HWCAPS_READ_1_8_8_DTR BIT(14)
+#define SNOR_HWCAPS_READ_8_8_8_DTR BIT(15)
/*
* Page Program capabilities.
@@ -299,18 +301,19 @@ struct spi_nor_hwcaps {
* JEDEC/SFDP standard to define them. Also at this moment no SPI flash memory
* implements such commands.
*/
-#define SNOR_HWCAPS_PP_MASK GENMASK(22, 16)
-#define SNOR_HWCAPS_PP BIT(16)
+#define SNOR_HWCAPS_PP_MASK GENMASK(23, 16)
+#define SNOR_HWCAPS_PP BIT(16)
-#define SNOR_HWCAPS_PP_QUAD GENMASK(19, 17)
-#define SNOR_HWCAPS_PP_1_1_4 BIT(17)
-#define SNOR_HWCAPS_PP_1_4_4 BIT(18)
-#define SNOR_HWCAPS_PP_4_4_4 BIT(19)
+#define SNOR_HWCAPS_PP_QUAD GENMASK(19, 17)
+#define SNOR_HWCAPS_PP_1_1_4 BIT(17)
+#define SNOR_HWCAPS_PP_1_4_4 BIT(18)
+#define SNOR_HWCAPS_PP_4_4_4 BIT(19)
-#define SNOR_HWCAPS_PP_OCTO GENMASK(22, 20)
-#define SNOR_HWCAPS_PP_1_1_8 BIT(20)
-#define SNOR_HWCAPS_PP_1_8_8 BIT(21)
-#define SNOR_HWCAPS_PP_8_8_8 BIT(22)
+#define SNOR_HWCAPS_PP_OCTO GENMASK(23, 20)
+#define SNOR_HWCAPS_PP_1_1_8 BIT(20)
+#define SNOR_HWCAPS_PP_1_8_8 BIT(21)
+#define SNOR_HWCAPS_PP_8_8_8 BIT(22)
+#define SNOR_HWCAPS_PP_8_8_8_DTR BIT(23)
#define SNOR_HWCAPS_X_X_X (SNOR_HWCAPS_READ_2_2_2 | \
SNOR_HWCAPS_READ_4_4_4 | \
@@ -318,6 +321,9 @@ struct spi_nor_hwcaps {
SNOR_HWCAPS_PP_4_4_4 | \
SNOR_HWCAPS_PP_8_8_8)
+#define SNOR_HWCAPS_X_X_X_DTR (SNOR_HWCAPS_READ_8_8_8_DTR | \
+ SNOR_HWCAPS_PP_8_8_8_DTR)
+
#define SNOR_HWCAPS_DTR (SNOR_HWCAPS_READ_1_1_1_DTR | \
SNOR_HWCAPS_READ_1_2_2_DTR | \
SNOR_HWCAPS_READ_1_4_4_DTR | \
@@ -360,6 +366,7 @@ enum spi_nor_read_command_index {
SNOR_CMD_READ_1_8_8,
SNOR_CMD_READ_8_8_8,
SNOR_CMD_READ_1_8_8_DTR,
+ SNOR_CMD_READ_8_8_8_DTR,
SNOR_CMD_READ_MAX
};
@@ -376,6 +383,7 @@ enum spi_nor_pp_command_index {
SNOR_CMD_PP_1_1_8,
SNOR_CMD_PP_1_8_8,
SNOR_CMD_PP_8_8_8,
+ SNOR_CMD_PP_8_8_8_DTR,
SNOR_CMD_PP_MAX
};
@@ -391,6 +399,22 @@ struct spi_nor_flash_parameter {
int (*quad_enable)(struct spi_nor *nor);
};
+/**
+ * enum spi_nor_cmd_ext - describes the command opcode extension in DTR mode
+ * @SPI_MEM_NOR_NONE: no extension. This is the default, and is used in Legacy
+ * SPI mode
+ * @SPI_MEM_NOR_REPEAT: the extension is same as the opcode
+ * @SPI_MEM_NOR_INVERT: the extension is the bitwise inverse of the opcode
+ * @SPI_MEM_NOR_HEX: the extension is any hex value. The command and opcode
+ * combine to form a 16-bit opcode.
+ */
+enum spi_nor_cmd_ext {
+ SPI_NOR_EXT_NONE = 0,
+ SPI_NOR_EXT_REPEAT,
+ SPI_NOR_EXT_INVERT,
+ SPI_NOR_EXT_HEX,
+};
+
/**
* struct flash_info - Forward declaration of a structure used internally by
* spi_nor_scan()
@@ -428,6 +452,7 @@ struct flash_info;
* @write_proto: the SPI protocol for write operations
* @reg_proto the SPI protocol for read_reg/write_reg/erase operations
* @cmd_buf: used by the write_reg
+ * @cmd_ext_type: the command opcode extension for DTR mode.
* @prepare: [OPTIONAL] do some preparations for the
* read/write/erase/lock/unlock operations
* @unprepare: [OPTIONAL] do some post work after the
@@ -469,6 +494,7 @@ struct spi_nor {
bool sst_write_second;
u32 flags;
u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];
+ enum spi_nor_cmd_ext cmd_ext_type;
int (*setup)(struct spi_nor *nor, const struct flash_info *info,
const struct spi_nor_flash_parameter *params,
--
2.26.2
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